Science.gov

Sample records for 10-100 nm range

  1. TCSPC FLIM in the wavelength range from 800 nm to 1700 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Shcheslavsky, Vladislav

    2016-03-01

    Excitation and detection in the wavelength range above 800nm is a convenient and relatively inexpensive way to increase the penetration depth in optical microscopy. Moreover, detection at long wavelength avoids the problem that tissue autofluorescence contaminates the signals from endogenous fluorescence probes. FLIM at NIR wavelength may therefore be complementary to multiphoton microscopy, especially if the lifetimes of NIR fluorophores report biological parameters of the tissue structures they are bound to. Unfortunately, neither the excitation sources nor the detectors of standard confocal and multiphoton laser scanning systems are directly suitable for excitation and detection of NIR fluorescence. Most of these problems can be solved, however, by using ps diode lasers or Ti:Sapphire lasers at their fundamental wavelength, and NIR-sensitive detectors. With NIR-sensitive PMTs the detection wavelength range can be extended up to 900 nm, with InGaAs SPAD detectors up to 1700 nm. Here, we demonstrate the use of a combination of laser scanning, multi-dimensional TCSPC, and advanced excitation sources and detectors for FLIM at up to 1700 nm. The performance was tested at tissue samples incubated with NIR dyes. The fluorescence lifetimes generally get shorter with increasing absorption and emission wavelengths of the dyes. For the cyanine dye IR1061, absorbing around 1060 nm, the lifetime was found to be as short as 70 ps. Nevertheless the fluorescence decay could still be clearly detected. Almost all dyes showed clear lifetime changes depending on the binding to different tissue constituents.

  2. Optical constants determination of neodymium and gadolinium in the 3-nm to 100-nm wavelength range

    NASA Astrophysics Data System (ADS)

    Kjornrattanawanich, B.; Windt, D. L.; Uspenskii, Y. A.; Seely, J. F.

    2006-08-01

    The optical constants (n, k) of the wavelength-dependent index of refraction N = n+ik = 1-δ+ik of Nd (Neodymium) and Gd (Gadolinium) are determined in the wavelength range of 3 nm to 100 nm by the transmittance method using synchrotron radiation. Nd and Gd films with thicknesses ranging from 5 nm to 180 nm were fabricated on Si photodiodes (which served as the coating substrates as well as the detectors) and capped with Si layers to protect these reactive rare earth elements from oxidation. The imaginary part (k) obtained directly from the transmittance measurement is used in the derivation of the real part (δ) of the complex index of refraction N through the Kramers- Kronig integral. The measured optical constants are used in the design of currently developed Nd- and Gd-based multilayers for solar imaging applications. Our results on Nd and Gd optical constants and the reflectance of some Nd- and Gd-based multilayers are presented.

  3. 21 CFR 10.100 - Public calendar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Public calendar. 10.100 Section 10.100 Food and... PRACTICES AND PROCEDURES General Administrative Procedures § 10.100 Public calendar. (a) Public calendar. A public calendar will be prepared and made publicly available by FDA each week showing, to the...

  4. 21 CFR 10.100 - Public calendar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Public calendar. 10.100 Section 10.100 Food and... PRACTICES AND PROCEDURES General Administrative Procedures § 10.100 Public calendar. (a) Public calendar. A public calendar will be prepared and made publicly available by FDA each week showing, to the...

  5. 21 CFR 10.100 - Public calendar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Public calendar. 10.100 Section 10.100 Food and... PRACTICES AND PROCEDURES General Administrative Procedures § 10.100 Public calendar. (a) Public calendar. A public calendar will be prepared and made publicly available by FDA each week showing, to the...

  6. 21 CFR 10.100 - Public calendar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Public calendar. 10.100 Section 10.100 Food and... PRACTICES AND PROCEDURES General Administrative Procedures § 10.100 Public calendar. (a) Public calendar. A public calendar will be prepared and made publicly available by FDA each week showing, to the...

  7. 21 CFR 10.100 - Public calendar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Public calendar. 10.100 Section 10.100 Food and... PRACTICES AND PROCEDURES General Administrative Procedures § 10.100 Public calendar. (a) Public calendar. A public calendar will be prepared and made publicly available by FDA each week showing, to the...

  8. 750 nm 1.5 W frequency-doubled semiconductor disk laser with a 44 nm tuning range.

    PubMed

    Saarinen, Esa J; Lyytikäinen, Jari; Ranta, Sanna; Rantamäki, Antti; Sirbu, Alexei; Iakovlev, Vladimir; Kapon, Eli; Okhotnikov, Oleg G

    2015-10-01

    We demonstrate 1.5 W of output power at the wavelength of 750 nm by intracavity frequency doubling a wafer-fused semiconductor disk laser diode-pumped at 980 nm. An optical-to-optical efficiency of 8.3% was achieved using a bismuth borate crystal. The wavelength of the doubled emission could be tuned from 720 to 764 nm with an intracavity birefringent plate. The beam quality parameter M2 of the laser output was measured to be below 1.5 at all pump powers. The laser is a promising tool for biomedical applications that can take advantage of the large penetration depth of light in tissue in the 700-800 nm spectral range.

  9. Predictive value of [-2]propsa (p2psa) and its derivatives for the prostate cancer detection in the 2.0 to 10.0ng/mL PSA range

    PubMed Central

    Vukovic, I.; Djordjevic, D.; Bojanic, N.; Babic, U.; Soldatovic, I.

    2017-01-01

    ABSTRACT Introduction To assess predictive value of new tumor markers, precursor of prostate specific antigen (p2PSA) and its derivates-%p2PSA and prostate health index (PHI) in detection of patients with indolent and aggressive prostate cancer (PC) in a subcohort of man whose total PSA ranged from 2 to 10ng/mL. Materials and Methods This cross-sectional study included 129 consecutive male patients aged over 50 years, with no previous history of PC and with normal digital rectal examination findings, but with serum PSA in interval between 2 and 10ng/mL. All patients underwent standard transrectal ultrasonography guided prostate biopsy for the first time. For all patients, serum PSA, free PSA (fPSA) and p2PSA were measured and PHI and %p2PSA were calculated. Results PHI and %p2PSA levels were significanlty higher in patients with PC compared to those without this malignancy. The same findings have been observed in group of patients with Gleason score ≥7 compared to those with Gleason score <7. ROC analysis reveled the highest area under the curve with these two markers. Multivariate logistic regression showed significant improvement in PC detection and its agressive form (assumed as Gleason score ≥7). Conclusions New markers, derivates of p2PSA (especially %p2PSA and PHI), represente potentially very important clinical tool for predicting presence of PC, and even more important, to discriminate patients with Gleason score <7 from those with Gleason score ≥7 with total PSA in range from 2 to 10ng/mL. PMID:28124526

  10. A Multi-Center Study of [−2]Pro-Prostate-Specific Antigen (PSA) in Combination with PSA and Free PSA for Prostate Cancer Detection in the 2.0 to 10.0 ng/mL PSA Range

    PubMed Central

    Catalona, William J.; Partin, Alan W.; Sanda, Martin G.; Wei, John T.; Klee, George G.; Bangma, Chris H.; Slawin, Kevin M.; Marks, Leonard S.; Loeb, Stacy; Broyles, Dennis L.; Shin, Sanghyuk S.; Cruz, Amabelle B.; Chan, Daniel W.; Sokoll, Lori J.; Roberts, William L.; van Schaik, Ron H.N.; Mizrahi, Isaac A.

    2011-01-01

    Purpose PSA and free PSA (fPSA) have limited specificity for detecting clinically significant, curable prostate cancer (PCa), leading to unnecessary biopsies and detection and treatment of some indolent tumors. [−2]proPSA (p2PSA) may improve specificity for detecting clinically significant PCa. Our objective was to evaluate p2PSA, fPSA, and PSA in a mathematical formula (prostate health index [phi] = [−2]proPSA / fPSA) × PSA1/2) to enhance specificity for detecting overall and high-grade PCa. Materials and Methods We enrolled 892 men in a prospective multi-institutional trial with no history of PCa, normal rectal examination, a PSA of 2–10 ng/mL, and ≥6- core prostate biopsy. We examined the relationship of serum PSA, %fPSA and phi with biopsy results. The primary endpoints were the specificity and AUC using phi to detect overall and Gleason ≥7 prostate cancer on biopsy compared with %fPSA. Results For the 2–10 ng/mL PSA range, at 80–95% sensitivity, the specificity and AUC (0.703) of phi exceeded those of PSA and %fPSA. Increasing phi was associated with a 4.7-fold increased risk of PCa and 1.61-fold increased risk of Gleason ≥7 disease on biopsy. The AUC for phi (0.724) exceeded that of %fPSA (0.670) in discriminating between PCa with Gleason ≥ 4+3 vs. lower grade disease or negative biopsies. Phi results were not associated with age and prostate volume. Conclusions Phi may be useful in PCa screening to reduce unnecessary biopsies in men age ≥50 years with PSA 2–10 ng/mL and negative DRE, with minimal loss in sensitivity. PMID:21419439

  11. Megahertz FDML laser with up to 143nm sweep range for ultrahigh resolution OCT at 1050nm

    NASA Astrophysics Data System (ADS)

    Kolb, Jan Philip; Klein, Thomas; Eibl, Matthias; Pfeiffer, Tom; Wieser, Wolfgang; Huber, Robert

    2016-03-01

    We present a new design of a Fourier Domain Mode Locked laser (FDML laser), which provides a new record in sweep range at ~1μm center wavelength: At the fundamental sweep rate of 2x417 kHz we reach 143nm bandwidth and 120nm with 4x buffering at 1.67MHz sweep rate. The latter configuration of our system is characterized: The FWHM of the point spread function (PSF) of a mirror is 5.6μm (in tissue). Human in vivo retinal imaging is performed with the MHz laser showing more details in vascular structures. Here we could measure an axial resolution of 6.0μm by determining the FWHM of specular reflex in the image. Additionally, challenges related to such a high sweep bandwidth such as water absorption are investigated.

  12. Articular Cartilage Optical Properties in the Spectral Range 300-850 nm.

    PubMed

    Ebert, D W; Roberts, C; Farrar, S K; Johnston, W M; Litsky, A S; Bertone, A L

    1998-07-01

    Measurements of absolute total reflectance were recorded from weight-bearing (n=9) and nonweight-bearing (n=9) equine articular cartilage specimens from 300 to 850 nm using a spectrophotometer with integrating sphere attachment. Following correction of measured spectra for interfacial reflections and edge losses, Kubelka-Munk theory was applied to estimate absorption and scattering coefficient, one-dimensional light intensity distribution, and light penetration depth. Kubelka-Munk absorption coefficients ranged from ∼7 cm-1 at 330 nm to ∼1 cm-1 at 850 nm. A localized absorption peak was noted at ∼340 nm. Above 510 nm, weight-bearing cartilage demonstrated significantly higher absorption coefficients than nonweight-bearing tissue (paired t-test, p<0.05). Kubelka-Munk scattering coefficients ranged from ∼40 cm-1 at 360 nm to ∼6 cm-1 at 850 nm. No statistical differences in scattering coefficient were noted between weight-bearing and nonweight-bearing tissue. Penetration depths predicted by Kubelka-Munk theory ranged from 0.6 mm at 350 nm to over 3 mm at 850 nm. Stronger absorption in weight-bearing cartilage compared to nonweight-bearing tissue resulted in lower light penetration depths in weight-bearing cartilage at all wavelengths longer than 510 nm. © 1998 Society of Photo-Optical Instrumentation Engineers.

  13. Articular cartilage optical properties in the spectral range 300--850 nm

    NASA Astrophysics Data System (ADS)

    Ebert, Daniel W.; Roberts, Cynthia J.; Farrar, Stuart K.; Johnston, William M.; Litsky, Alan S.; Bertone, Alicia L.

    1998-07-01

    Measurements of absolute total reflectance were recorded from weight-bearing (n equals 9) and nonweight-bearing (n equals 9) equine articular cartilage specimens from 300 to 850 nm using a spectrophotometer with integrating sphere attachment. Following correction of measured spectra for interfacial reflections and edge losses, Kubelka-Munk theory was applied to estimate absorption and scattering coefficient, 1D light intensity distribution, and light penetration depth. Kubelka-Munk absorption coefficients ranged from approximately 7 cm-1 at 330 nm to approximately 1 cm-1 at 850 nm. A localized absorption peak was noted at approximately 340 nm. Above 510 nm, weight-bearing cartilage demonstrated significantly higher absorption coefficients than nonweight-bearing tissue (paired t-test, p < 0.05). Kubelka-Munk scattering coefficients ranged from approximately 40 cm-1 at 360 nm to approximately 6 cm-1 at 850 nm. No statistical differences in scattering coefficient were noted between weight-bearing and nonweight-bearing tissue. Penetration depths predicted by Kubelka-Munk theory ranged from 0.6 mm at 350 nm to over 3 mm at 850 nm. Stronger absorption in weight-bearing cartilage compared to nonweight-bearing tissue resulted in lower light penetration depths in weight-bearing cartilage at all wavelengths longer than 510 nm.

  14. Semiconductor lasers with a continuous tuning range above 100 nm in the nearest IR spectral region

    SciTech Connect

    Kostin, Yu O; Lobintsov, A A; Shramenko, M V; Ladugin, M A; Marmalyuk, A A; Chamorovsky, A Yu; Yakubovich, S D

    2015-08-31

    We have developed two new types of lasers based on quantum-confined semiconductor optical amplifiers with an acousto-optic tunable filter in an external fibre ring cavity. The lasers offer continuous wavelength tuning ranges from 780 to 885 and from 880 to 1010 nm, 20 mW of cw output power, and a tuning rate up to 10{sup 4} nm s{sup -1} at an instantaneous spectral linewidth less than 0.1 nm. (lasers)

  15. Research of the Additional Losses Occurring in Optical Fiber at its Multiple Bends in the Range Waves 1310nm, 1550nm and 1625nm Long

    NASA Astrophysics Data System (ADS)

    Yurchenko, A. V.; Gorlov, N. I.; Alkina, A. D.; Mekhtiev, A. D.; Kovtun, A. A.

    2016-01-01

    Article is devoted to research of the additional losses occurring in the optical fiber at its multiple bends in the range waves of 1310 nanometers, 1550 nanometers and 1625 nanometers long. Article is directed on creation of the external factors methods which allow to estimate and eliminate negative influence. The automated way of calculation of losses at a bend is developed. Results of scientific researches are used by engineers of “Kazaktelekom” AS for practical definition of losses service conditions. For modeling the Wolfram|Alpha environment — the knowledge base and a set of computing algorithms was chosen. The greatest losses are noted on wavelength 1310nm and 1625nm. All dependences are nonlinear. Losses with each following excess are multiplicative.

  16. Carbon Nanotube Mode-Locked Thulium Fiber Laser With 200 nm Tuning Range.

    PubMed

    Meng, Yafei; Li, Yao; Xu, Yongbing; Wang, Fengqiu

    2017-03-21

    We demonstrated a mode-locked thulium/holmium (Tm/Ho) fiber laser continuously tunable across 200 nm (from 1860 nm to 2060 nm), which to the best of our knowledge represents the widest tuning range ever achieved for a passively mode-locked fiber laser oscillator. The combined use of a broadband carbon nanotube (CNT) saturable absorber and a diffraction grating mirror ensures ultra-broad tuning range, superb stability and repeatability, and makes the demonstrated laser a highly practical source for spectroscopy, imaging and optical communications. The laser emits <5 ps pulses with an optical spectral bandwidth of ∼3 nm across the full tuning range. Our results indicate that carbon nanotubes can be an excellent saturable absorber for achieving gain-bandwidth-limited tunable operation for 2 μm thulium fiber lasers.

  17. Carbon Nanotube Mode-Locked Thulium Fiber Laser With 200 nm Tuning Range

    NASA Astrophysics Data System (ADS)

    Meng, Yafei; Li, Yao; Xu, Yongbing; Wang, Fengqiu

    2017-03-01

    We demonstrated a mode-locked thulium/holmium (Tm/Ho) fiber laser continuously tunable across 200 nm (from 1860 nm to 2060 nm), which to the best of our knowledge represents the widest tuning range ever achieved for a passively mode-locked fiber laser oscillator. The combined use of a broadband carbon nanotube (CNT) saturable absorber and a diffraction grating mirror ensures ultra-broad tuning range, superb stability and repeatability, and makes the demonstrated laser a highly practical source for spectroscopy, imaging and optical communications. The laser emits <5 ps pulses with an optical spectral bandwidth of ∼3 nm across the full tuning range. Our results indicate that carbon nanotubes can be an excellent saturable absorber for achieving gain-bandwidth-limited tunable operation for 2 μm thulium fiber lasers.

  18. Carbon Nanotube Mode-Locked Thulium Fiber Laser With 200 nm Tuning Range

    PubMed Central

    Meng, Yafei; Li, Yao; Xu, Yongbing; Wang, Fengqiu

    2017-01-01

    We demonstrated a mode-locked thulium/holmium (Tm/Ho) fiber laser continuously tunable across 200 nm (from 1860 nm to 2060 nm), which to the best of our knowledge represents the widest tuning range ever achieved for a passively mode-locked fiber laser oscillator. The combined use of a broadband carbon nanotube (CNT) saturable absorber and a diffraction grating mirror ensures ultra-broad tuning range, superb stability and repeatability, and makes the demonstrated laser a highly practical source for spectroscopy, imaging and optical communications. The laser emits <5 ps pulses with an optical spectral bandwidth of ∼3 nm across the full tuning range. Our results indicate that carbon nanotubes can be an excellent saturable absorber for achieving gain-bandwidth-limited tunable operation for 2 μm thulium fiber lasers. PMID:28322327

  19. A Sounding Rocket Mission Concept to Acquire High-Resolution Radiometric Spectra Spanning the 9 nm - 31 nm Wavelength Range

    NASA Technical Reports Server (NTRS)

    Krause, L. Habash; Cirtain, Jonathan; McGuirck, Michael; Pavelitz, Steven; Weber, Ed.; Winebarger, Amy

    2012-01-01

    When studying Solar Extreme Ultraviolet (EUV) emissions, both single-wavelength, two- dimensional (2D) spectroheliograms and multi-wavelength, one-dimensional (1D) line spectra are important, especially for a thorough understanding of the complex processes in the solar magnetized plasma from the base of the chromosphere through the corona. 2D image data are required for a detailed study of spatial structures, whereas radiometric (i.e., spectral) data provide information on relevant atomic excitation/ionization state densities (and thus temperature). Using both imaging and radiometric techniques, several satellite missions presently study solar dynamics in the EUV, including the Solar Dynamics Observatory (SDO), Hinode, and the Solar-Terrestrial Relations Observatory (STEREO). The EUV wavelengths of interest typically span 9 nm to 31 nm, with the shorter wavelengths being associated with the hottest features (e.g., intense flares and bright points) and the longer wavelengths associated with cooler features (e.g., coronal holes and filaments). Because the optical components of satellite instruments degrade over time, it is not uncommon to conduct sounding rocket underflights for calibration purposes. The authors have designed a radiometric sounding rocket payload that could serve as both a calibration underflight for and a complementary scientific mission to the upcoming Solar Ultraviolet Imager (SUVI) mission aboard the GOES-R satellite (scheduled for a 2015 launch). The challenge to provide quality radiometric line spectra over the 9-31 nm range covered by SUVI was driven by the multilayer coatings required to make the optical components, including mirrors and gratings, reflective over the entire range. Typically, these multilayers provide useful EUV reflectances over bandwidths of a few nm. Our solution to this problem was to employ a three-telescope system in which the optical components were coated with multilayers that spanned three wavelength ranges to cover

  20. Double Brillouin frequency spaced multiwavelength Brillouin-erbium fiber laser with 50 nm tuning range

    NASA Astrophysics Data System (ADS)

    Zhao, J. F.; Liao, T. Q.; Zhang, C.; Zhang, R. X.; Miao, C. Y.; Tong, Z. R.

    2012-09-01

    A 50 nm tuning range multiwavelength Brillouin-erbium fiber laser (MWBEFL) with double Brillouin frequency spacing is presented. Two separated gain blocks with symmetrical architecture, consisted by erbium-doped fiber amplifiers (EDFAs) and Brillouin gain media, are used to generate double Brillouin frequency spacing. The wider tuning range is realized by eliminating the self-lasing cavity modes existing in conventional MWBEFLs because of the absence of the physical mirrors at the ends of the linear cavity. The Brillouin pump (BP) is preamplified by the EDFA before entering the single-mode fiber (SMF), which leads to the reduction of threshold power and the generation enhancement of Brillouin Stokes (BS) signals. Four channels with 0.176 nm spacing are achieved at 2 mW BP power and 280 mW 980 nm pump power which can be tuned from 1525 to 1575 nm.

  1. Femtosecond stimulated Raman spectrometer in the 320-520nm range.

    PubMed

    Pontecorvo, E; Kapetanaki, S M; Badioli, M; Brida, D; Marangoni, M; Cerullo, G; Scopigno, T

    2011-01-17

    Multi-µJ narrow-bandwidth (≈ 10 cm(-1)) picosecond pulses, broadly tunable in the visible-UV range (320-520 nm), are generated by spectral compression of femtosecond pulses emitted by an amplified Ti:sapphire system. Such pulses provide the ideal Raman pump for broadband femtosecond stimulated Raman spectroscopy, as here demonstrated on a heme protein.

  2. Generation of picosecond laser pulses at 1030 nm with gigahertz range continuously tunable repetition rate.

    PubMed

    Aubourg, Adrien; Lhermite, Jérôme; Hocquet, Steve; Cormier, Eric; Santarelli, Giorgio

    2015-12-01

    We report on a watt range laser system generating picosecond pulses using electro-optical modulation of a 1030 nm single frequency low noise laser diode. Its repetition rate is continuously tunable between 11 and 18 GHz. Over this range, output spectra and pulse characteristics are measured and compared with a numerical simulation. Finally, amplitude and residual phase noise measurements of the source are also presented.

  3. Optical properties of mice skull bone in the 455- to 705-nm range

    NASA Astrophysics Data System (ADS)

    Haleh, Soleimanzad; Hirac, Gurden; Frédéric, Pain

    2017-01-01

    Rodent brain is studied to understand the basics of brain function. The activity of cell populations and networks is commonly recorded in vivo with wide-field optical imaging techniques such as intrinsic optical imaging, fluorescence imaging, or laser speckle imaging. These techniques were recently adapted to unrestrained mice carrying transcranial windows. Furthermore, optogenetics studies would benefit from optical stimulation through the skull without implanting an optical fiber, especially for longitudinal studies. In this context, the knowledge of bone optical properties is requested to improve the quantitation of the depth and volume of imaged or stimulated tissues. Here, we provide experimental measurements of absorption and reduced scattering coefficients of freshly excised mice skull for wavelengths between 455 and 705 nm. Absorption coefficients from 6 to 8 months mice skull samples range between 1.67±0.28 mm-1 at 455 nm and 0.47±0.07 mm-1 at 705 nm, whereas reduced scattering coefficients were in the range of 2.79±0.26 mm-1 at 455 nm up to 2.29±0.12 mm-1 at 705 nm. In comparison, measurements carried out on 4 to 5 weeks mice showed similar spectral profiles but smaller absorption and reduced scattering coefficients by a factor of about 2 and 1.5, respectively.

  4. 2-D mapping of skin chromophores in the spectral range 500 - 700 nm.

    PubMed

    Jakovels, Dainis; Spigulis, Janis

    2010-03-01

    The multi-spectral imaging technique has been used for distant mapping of in-vivo skin chromophores by analyzing spectral data at each reflected image pixel and constructing 2-D maps of the relative concentrations of oxy-/deoxy-haemoglobin and melanin. Instead of using a broad visible-NIR spectral range, this study focuses on narrowed spectral band 500-700 nm, speeding-up the signal processing procedure. Regression analysis confirmed that superposition of three Gaussians is optimal analytic approximation for the oxy-haemoglobin absorption tabular spectrum in this spectral band, while superposition of two Gaussians fits well for deoxy-haemoglobin absorption and exponential function - for melanin absorption. The proposed approach was clinically tested for three types of in-vivo skin provocations: ultraviolet irradiance, chemical reaction with vinegar essence and finger arterial occlusion. Spectral range 500-700 nm provided better sensitivity to oxy-haemoglobin changes and higher response stability to melanin than two reduced ranges 500-600 nm and 530-620 nm.

  5. Superconducting nanowire single photon detector at 532 nm and demonstration in satellite laser ranging.

    PubMed

    Li, Hao; Chen, Sijing; You, Lixing; Meng, Wengdong; Wu, Zhibo; Zhang, Zhongping; Tang, Kai; Zhang, Lu; Zhang, Weijun; Yang, Xiaoyan; Liu, Xiaoyu; Wang, Zhen; Xie, Xiaoming

    2016-02-22

    Superconducting nanowire single-photon detectors (SNSPDs) at a wavelength of 532 nm were designed and fabricated aiming to satellite laser ranging (SLR) applications. The NbN SNSPDs were fabricated on one-dimensional photonic crystals with a sensitive-area diameter of 42 μm. The devices were coupled with multimode fiber (ϕ = 50 μm) and exhibited a maximum system detection efficiency of 75% at an extremely low dark count rate of <0.1 Hz. An SLR experiment using an SNSPD at a wavelength of 532 nm was successfully demonstrated. The results showed a depth ranging with a precision of ~8.0 mm for the target satellite LARES, which is ~3,000 km away from the ground ranging station at the Sheshan Observatory.

  6. Narrowband multilayer coatings for the extreme ultraviolet range of 50-92 nm.

    PubMed

    Vidal-Dasilva, Manuela; Fernández-Perea, Mónica; Méndez, José A; Aznárez, José A; Larruquert, Juan I

    2009-12-07

    A new type of multilayer coatings with narrowband reflection properties and peaked in the approximately 50- 92 nm spectral range has been developed. Multilayers are based on Yb, Al, and SiO films and they have been prepared by thermal evaporation. Efficient multilayers based on Yb and Al, with an SiO protective layer were prepared, but they developed a dendrite structure, which was attributed to the reactivity between Al and Yb. Multilayers based on Yb and Al, with both SiO protective and barrier layers, resulted in efficient reflective filters, with no observable dendrite growth. The peak reflectance of aged multilayers was of the order of approximately 0.20, with bandwidths in the range of 12 to 22 nm FWHM.

  7. Optical properties of human colon tissues in the 350 – 2500 nm spectral range

    SciTech Connect

    Bashkatov, A N; Genina, E A; Kochubey, V I; Kolesnikova, E A; Tuchin, V V; Rubtsov, V S

    2014-08-31

    We present the optical characteristics of the mucosa and submucosa of human colon tissue. The experiments are performed in vitro using a LAMBDA 950 spectrophotometer in the 350 – 2500 nm spectral range. The absorption and scattering coefficients and the scattering anisotropy factor are calculated based on the measured diffuse reflectance and total and collimated transmittance spectra using the inverse Monte Carlo method. (laser biophotonics)

  8. Stable Gain-Switched Thulium Fiber Laser With 140-nm Tuning Range

    NASA Astrophysics Data System (ADS)

    Wang, Fengqiu; Meng, Yafei; Kelleher, Edmund; Guo, Guoxiang; Li, Yao; Xu, Yongbing; Zhu, Shining

    2016-06-01

    We demonstrate a gain-switched thulium fiber laser that can be continuously tuned over 140 nm, while maintaining stable nanosecond single-pulse operation. To the best of our knowledge, this system represents the broadest tuning range for a gain-switched fiber laser. The system simplicity and wideband wavelength tunability combined with the ability to control the temporal characteristics of the gain-switched pulses mean this is a versatile source highly suited to a wide range of applications in the eye-safe region of the infrared, including spectroscopy, sensing and material processing, as well as being a practical seed source for pumping nonlinear processes.

  9. Optical properties of circulating human blood in the wavelength range 400-2500 nm

    NASA Astrophysics Data System (ADS)

    Roggan, Andre; Friebel, Moritz; Doerschel, Klaus; Hahn, Andreas; Mueller, Gerhard J.

    1999-01-01

    Knowledge about the optical properties (mu) a, (mu) s, and g of human blood plays an important role for many diagnostic and therapeutic applications in laser medicine and medical diagnostics. They strongly depend on physiological parameters such as oxygen saturation, osmolarity, flow conditions, haematocrit, etc. The integrating sphere technique and inverse Monte Carlo simulations were applied to measure (mu) a, (mu) s, and g of circulating human blood. At 633 nm the optical properties of human blood with a haematocrit of 10% and an oxygen saturation of 98% were found to be 0.210 +/- 0.002 mm-1 for (mu) a, 77.3 +/- 0.5 mm-1 for (mu) s, and 0.994 +/- 0.001 for the g factor. An increase of the haematocrit up to 50% lead to a linear increase of absorption and reduced scattering. Variations in osmolarity and wall shear rate led to changes of all three parameters while variations in the oxygen saturation only led to a significant change of the absorption coefficient. A spectrum of all three parameters was measured in the wavelength range 400 - 2500 nm for oxygenated and deoxygenated blood, showing that blood absorption followed the absorption behavior of haemoglobin and water. The scattering coefficient decreased for wavelengths above 500 nm with approximately (lambda) -1.7; the g factor was higher than 0.9 over the whole wavelength range.

  10. Broadband semiconductor optical amplifiers of the spectral range 750 – 1100 nm

    SciTech Connect

    Andreeva, E V; Il'chenko, S N; Lobintsov, A A; Shramenko, M V; Ladugin, M A; Marmalyuk, A A; Yakubovich, S D

    2013-11-30

    A line of travelling-wave semiconductor optical amplifiers (SOAs) based on heterostructures used for production of broadband superluminescent diodes is developed. The pure small-signal gains of the developed SOA modules are about 25 dB, while the gain bandwidths at a level of –10 dB reach 50 – 100 nm. As a whole, the SOA modules cover the IR spectral range from 750 to 1100 nm. The SOAs demonstrate a high reliability at a single-mode fibre-coupled cw output power up to 50 mW. Examples of application of two of the developed SOA modules as active elements of broadband fast-tunable lasers are presented. (lasers)

  11. Dependent scattering in Intralipid® phantoms in the 600-1850 nm range.

    PubMed

    Aernouts, Ben; Van Beers, Robbe; Watté, Rodrigo; Lammertyn, Jeroen; Saeys, Wouter

    2014-03-10

    The effect of dependent scattering on the bulk scattering properties of intralipid phantoms in the 600-1850 nm wavelength range has been investigated. A set of 57 liquid optical phantoms, covering a wide range of intralipid concentrations (1-100% v/v), was prepared and the bulk optical properties were accurately determined. The bulk scattering coefficient as a function of the particle density could be well described with Twersky's packing factor (R(2) > 0.990). A general model was elaborated taking into account the wavelength dependency and the effect of the concentration of scattering particles (R(2) = 0.999). Additionally, an empirical approach was followed to characterize the effect of dense packing of scattering particles on the anisotropy factor (R(2) = 0.992) and the reduced scattering coefficient (R(2) = 0.999) of the phantoms. The derived equations can be consulted in future research for the calculation of the bulk scattering properties of intralipid dilutions in the 600-1850 nm range, or for the validation of theories that describe the effects of dependent scattering on the scattering properties of intralipid-like systems.

  12. A new approach to distance measurements between two spin labels in the >10 nm range.

    PubMed

    Blank, A

    2017-02-15

    ESR spectroscopy can be efficiently used to acquire the distance between two spin labels placed on a macromolecule by measuring their mutual dipolar interaction frequency, as long as the distance is not greater than ∼10 nm. Any hope to significantly increase this figure is hampered by the fact that all available spin labels have a phase memory time (Tm), restricted to the microseconds range, which provides a limited window during which the dipolar interaction frequency can be measured. Thus, due to the inverse cubic dependence of the dipolar frequency over the labels' separation distance, evaluating much larger distances, e.g. 20 nm, would require to have a Tm that is ∼200 microsecond, clearly beyond any hope. Here we propose a new approach to greatly enhancing the maximum measured distance available by relying on another type of dipole interaction-mediated mechanism called spin diffusion. This mechanism operates and can be evaluated during the spin lattice relaxation time, T1 (commonly in the milliseconds range), rather than only during Tm. Up until recently, the observation of spin diffusion in solid electron spin systems was considered experimentally impractical. However, recent developments have enabled its direct measurement by means of high sensitivity pulsed ESR that employs intense short magnetic field gradients, thus opening the door to the subsequent utilization of these capabilities. The manuscript presents the subject of spin diffusion, the ways it can be directly measured, and a theoretical discussion on how intramolecular spin-pair distance, even in the range of 20-30 nm, could be accurately extracted from spin diffusion measurements.

  13. High-power cw laser bars of the 750 - 790-nm wavelength range

    SciTech Connect

    Degtyareva, N S; Kondakov, S A; Mikayelyan, G T; Gorlachuk, P V; Ladugin, M A; Marmalyuk, Aleksandr A; Ryaboshtan, Yu L; Yarotskaya, I V

    2013-06-30

    We have developed the effective design of semiconductor heterostructures, which allow one to fabricate cw laser diodes emitting in the 750 - 790-nm spectral range. The optimal conditions for fabrication of GaAsP/AlGaInP/GaAs heterostructures by MOCVD have been determined. It is shown that the use of quantum wells with a precisely defined quantity mismatch reduces the threshold current density and increases the external differential efficiency. The results of studies of characteristics of diode laser bars fabricated from these heterostructures are presented. (lasers)

  14. Optical properties of peritoneal biological tissues in the spectral range of 350-2500 nm

    NASA Astrophysics Data System (ADS)

    Bashkatov, A. N.; Genina, E. A.; Kozintseva, M. D.; Kochubei, V. I.; Gorodkov, S. Yu.; Tuchin, V. V.

    2016-01-01

    The optical characteristics of biological tissues sampled from the anterior abdominal wall of laboratory rats are for the first time experimentally studied in a wide wavelength range (350-2500 nm). The experiments have been performed in vitro using a LAMBDA 950 (PerkinElmer, United States) spectrophotometer. Inverse Monte Carlo simulation is used to restore the spectral dependences for scattering and absorption coefficients, as well as the scattering anisotropy factor for biological tissue based on the recorded spectra of diffuse reflection and total and collimated transmissions.

  15. Spectrally tailored narrowband pulses for femtosecond stimulated Raman spectroscopy in the range 330-750 nm.

    PubMed

    Pontecorvo, E; Ferrante, C; Elles, C G; Scopigno, T

    2013-03-25

    Spectral compression of femtosecond pulses by second harmonic generation in the presence of substantial group velocity dispersion provides a convenient source of narrowband Raman pump pulses for femtosecond stimulated Raman spectroscopy (FSRS). We discuss here a simple and efficient modification that dramatically increases the versatility of the second harmonic spectral compression technique. Adding a spectral filter following second harmonic generation produces narrowband pulses with a superior temporal profile. This simple modification i) increases the Raman gain for a given pulse energy, ii) improves the spectral resolution, iii) suppresses coherent oscillations associated with slowly dephasing vibrations, and iv) extends the useful tunable range to at least 330-750 nm.

  16. Large two-photon absorptivity of hemoglobin in the infrared range of 780-880 nm.

    PubMed

    Clay, G Omar; Schaffer, Chris B; Kleinfeld, David

    2007-01-14

    Porphyrin molecules have a highly conjugated cyclic structure and are theorized to have unusually large two-photon absorptivities (sigmaTPA), i.e., sigmaTPA approximately 10(2) GM. The authors tested this claim. Ultrafast two-photon absorption (TPA) spectroscopy was performed on solutions of hemoglobin, which contains a naturally occurring metaloporphyrin. They used a pump-probe technique to directly detect the change in transmission induced by TPA over the wavelength range of lambda0=780-880 nm. As controls, they measured the TPA of the dyes rhodamine 6G and B; their measurements both verify and extend previously reported values. In new results, hemoglobin was found to have a peak two-photon absorptivity of sigmaTPA approximately 150 GM at lambda0=825 nm, near a resonance of the Soret band. This value supports theoretical expectations. They also found a significant difference in the TPA of carboxyhemoglobin versus oxyhemoglobin, e.g., sigmaTPA=61 GM versus sigmaTPA=18 GM, respectively, at lambda0=850 nm, which shows that the ligand affects the electronic states involved in TPA.

  17. Distinct Short-Range Order Is Inherent to Small Amorphous Calcium Carbonate Clusters (<2 nm)

    SciTech Connect

    Sun, Shengtong; Chevrier, Daniel M.; Zhang, Peng; Gebauer, Denis; Cölfen, Helmut

    2016-09-09

    Amorphous intermediate phases are vital precursors in the crystallization of many biogenic minerals. While inherent short-range orders have been found in amorphous calcium carbonates (ACCs) relating to different crystalline forms, it has never been clarified experimentally whether such orders already exist in very small clusters less than 2 nm in size. Here, we studied the stability and structure of 10,12-pentacosadiynoic acid (PCDA) protected ACC clusters with a core size of ca. 1.4 nm consisting of only seven CaCO3 units. Ligand concentration and structure are shown to be key factors in stabilizing the ACC clusters. More importantly, even in such small CaCO3 entities, a proto-calcite short-range order can be identified but with a relatively high degree of disorder that arises from the very small size of the CaCO3 core. Our findings support the notion of a structural link between prenucleation clusters, amorphous intermediates, and final crystalline polymorphs, which appears central to the understanding of polymorph selection.

  18. 21-nm-range wavelength-tunable L-band Er-doped fiber linear-cavity laser

    NASA Astrophysics Data System (ADS)

    Yang, Shiquan; Zhao, Chunliu; Li, Zhaohui; Ding, Lei; Yuan, Shuzhong; Dong, Xiaoyi

    2001-10-01

    A novel method, which utilizes amplified spontaneous emission (ASE) as a secondary pump source, is presented for implanting a linear cavity erbium-doped fiber laser operating in L-Band. The output wavelength tuned from 1566 nm to 1587 nm, about 21 nm tuning range, was obtained in the experiment and the stability of the laser is very good.

  19. Performance of diethylene glycol based particle counters in the sub 3 nm size range

    NASA Astrophysics Data System (ADS)

    Wimmer, D.; Lehtipalo, K.; Franchin, A.; Kangasluoma, J.; Kreissl, F.; Kürten, A.; Kupc, A.; Metzger, A.; Mikkilä, J.; Petäjä, T.; Riccobono, F.; Vanhanen, J.; Kulmala, M.; Curtius, J.

    2013-02-01

    When studying new particle formation, the uncertainty in determining the "true" nucleation rate is considerably reduced when using Condensation Particle Counters (CPCs) capable of measuring concentrations of aerosol particles at sizes close to or even at the critical cluster size (1-2 nm). Recently CPCs, able to reliably detect particles below 2 nm in size and even close to 1 nm became available. The corrections needed to calculate nucleation rates are substantially reduced compared to scaling the observed formation rate to the nucleation rate at the critical cluster size. However, this improved instrumentation requires a careful characterization of their cut-off size and the shape of the detection efficiency curve because relatively small shifts in the cut-off size can translate into larger relative errors when measuring particles close to the cut-off size. Here we describe the development of two continuous flow CPCs using diethylene glycol (DEG) as the working fluid. The design is based on two TSI 3776 counters. Several sets of measurements to characterize their performance at different temperature settings were carried out. Furthermore two mixing-type Particle Size Magnifiers (PSM) A09 from Airmodus were characterized in parallel. One PSM was operated at the highest mixing ratio (1 L min-1 saturator flow), and the other was operated in a scanning mode, where the mixing ratios are changed periodically, resulting in a range of cut-off sizes. Different test aerosols were generated using a nano-Differential Mobility Analyzer (nano-DMA) or a high resolution DMA, to obtain detection efficiency curves for all four CPCs. One calibration setup included a high resolution mass spectrometer (APi-TOF) for the determination of the chemical composition of the generated clusters. The lowest cut-off sizes were achieved with negatively charged ammonium sulphate clusters, resulting in cut-offs of 1.4 nm for the laminar flow CPCs and 1.2 and 1.1 nm for the PSMs. A comparison of one

  20. Performance of diethylene glycol-based particle counters in the sub-3 nm size range

    NASA Astrophysics Data System (ADS)

    Wimmer, D.; Lehtipalo, K.; Franchin, A.; Kangasluoma, J.; Kreissl, F.; Kürten, A.; Kupc, A.; Metzger, A.; Mikkilä, J.; Petäjä, T.; Riccobono, F.; Vanhanen, J.; Kulmala, M.; Curtius, J.

    2013-07-01

    When studying new particle formation, the uncertainty in determining the "true" nucleation rate is considerably reduced when using condensation particle counters (CPCs) capable of measuring concentrations of aerosol particles at sizes close to or even at the critical cluster size (1-2 nm). Recently, CPCs able to reliably detect particles below 2 nm in size and even close to 1 nm became available. Using these instruments, the corrections needed for calculating nucleation rates are substantially reduced compared to scaling the observed formation rate to the nucleation rate at the critical cluster size. However, this improved instrumentation requires a careful characterization of their cut-off size and the shape of the detection efficiency curve because relatively small shifts in the cut-off size can translate into larger relative errors when measuring particles close to the cut-off size. Here we describe the development of two continuous-flow CPCs using diethylene glycol (DEG) as the working fluid. The design is based on two TSI 3776 counters. Several sets of measurements to characterize their performance at different temperature settings were carried out. Furthermore, two mixing-type particle size magnifiers (PSM) A09 from Airmodus were characterized in parallel. One PSM was operated at the highest mixing ratio (1 L min-1 saturator flow), and the other was operated in a scanning mode, where the mixing ratios are changed periodically, resulting in a range of cut-off sizes. The mixing ratios are determined by varying the saturator flow, where the aerosol flow stays constant at 2.5 L min-1. Different test aerosols were generated using a nano-differential mobility analyser (nano-DMA) or a high-resolution DMA, to obtain detection efficiency curves for all four CPCs. One calibration setup included a high-resolution mass spectrometer (APi-TOF) for the determination of the chemical composition of the generated clusters. The lowest cut-off sizes were achieved with negatively

  1. Optical properties of apple skin and flesh in the wavelength range from 350 to 2200 nm

    NASA Astrophysics Data System (ADS)

    Saeys, Wouter; Velazco-Roa, Maria A.; Thennadil, Suresh N.; Ramon, Herman; Nicolaï, Bart M.

    2008-03-01

    Optical measurement of fruit quality is challenging due to the presence of a skin around the fruit flesh and the multiple scattering by the structured tissues. To gain insight in the light-tissue interaction, the optical properties of apple skin and flesh tissue are estimated in the 350-2200 nm range for three cultivars. For this purpose, single integrating sphere measurements are combined with inverse adding-doubling. The observed absorption coefficient spectra are dominated by water in the near infrared and by pigments and chlorophyll in the visible region, whose concentrations are much higher in skin tissue. The scattering coefficient spectra show the monotonic decrease with increasing wavelength typical for biological tissues with skin tissue being approximately three times more scattering than flesh tissue. Comparison to the values from time-resolved spectroscopy reported in literature showed comparable profiles for the optical properties, but overestimation of the absorption coefficient values, due to light losses.

  2. Optical properties of apple skin and flesh in the wavelength range from 350 to 2200 nm.

    PubMed

    Saeys, Wouter; Velazco-Roa, Maria A; Thennadil, Suresh N; Ramon, Herman; Nicolaï, Bart M

    2008-03-01

    Optical measurement of fruit quality is challenging due to the presence of a skin around the fruit flesh and the multiple scattering by the structured tissues. To gain insight in the light-tissue interaction, the optical properties of apple skin and flesh tissue are estimated in the 350-2200 nm range for three cultivars. For this purpose, single integrating sphere measurements are combined with inverse adding-doubling. The observed absorption coefficient spectra are dominated by water in the near infrared and by pigments and chlorophyll in the visible region, whose concentrations are much higher in skin tissue. The scattering coefficient spectra show the monotonic decrease with increasing wavelength typical for biological tissues with skin tissue being approximately three times more scattering than flesh tissue. Comparison to the values from time-resolved spectroscopy reported in literature showed comparable profiles for the optical properties, but overestimation of the absorption coefficient values, due to light losses.

  3. The optical absorption of triatomic carbon C3 for the wavelength range 260 to 560 nm

    NASA Technical Reports Server (NTRS)

    Jones, J. J.

    1978-01-01

    The spectral absorption properties of C3 have been measured in a shock tube containing a test gas mixture of acetylene diluted with argon. The absorption of a pulsed xenon light source was measured by means of eight photomultiplier channels to a spectrograph and an accompanying drum camera. The postshock test gas temperature and pressure were varied over the range 3240 to 4300 K and 37 to 229 kPa, respectively. The results showed appreciable absorption by C3 for the wavelength range 300 to 540 nm. The various reported measurements of the heat of formation of C3 which are available in the open literature were reviewed, and a value of 198 kcal/mol is recommended. This value, along with best available values for other species, was used to calculate the number density of C3 for the conditions of the present experiments in order to compute absorption cross section or electronic oscillator strength. The computed electronic oscillator strength varied from a high of 0.062 at 3300 K to a low of 0.036 at 3900 K.

  4. High power laser diodes at 14xx nm wavelength range for industrial and medical applications

    NASA Astrophysics Data System (ADS)

    Telkkälä, Jarkko; Boucart, Julien; Krejci, Martin; Crum, Trevor; Lichtenstein, Norbert

    2014-03-01

    We report on the development of the latest generation of high power laser diodes at 14xx nm wavelength range suitable for industrial applications such as plastics welding and medical applications including acne treatment, skin rejuvenation and surgery. The paper presents the newest chip generation developed at II-VI Laser Enterprise, increasing the output power and the power conversion efficiency while retaining the reliability of the initial design. At an emission wavelength around 1440 nm we applied the improved design to a variety of assemblies exhibiting maximum power values as high as 7 W for broad-area single emitters. For 1 cm wide bars on conductive coolers and for bars on active micro channel coolers we have obtained 50 W and 72 W in continuous wave (cw) operation respectively. The maximum power measured for a 1 cm bar operated with 50 μs pulse width and 0.01% duty cycle was 184 W, demonstrating the potential of the chip design for optimized cooling. Power conversion efficiency values as high as 50% for a single emitter device and over 40% for mounted bars have been demonstrated, reducing the required power budget to operate the devices. Both active and conductive bar assembly configurations show polarization purity greater than 98%. Life testing has been conducted at 95 A, 50% duty cycle and 0.5 Hz hard pulsed operation for bars which were soldered to conductive copper CS mounts using our hard solder technology. The results after 5500 h, or 10 million "on-off" cycles show stable operation.

  5. Comparison of Na lidar and meteor radar wind measurements at Starfire Optical Range, NM, USA

    NASA Astrophysics Data System (ADS)

    Liu, Alan Z.; Hocking, Wayne K.; Franke, Steven J.; Thayaparan, T.

    2002-01-01

    Simultaneous wind measurements in the mesopause region at Starfire Optical Range near Albuquerque, NM with Na wind/temperature lidar and meteor radar have been performed and compared. 20 nights of hourly data recorded with these two instruments at two layers around 86 and 93km altitude are compared for both zonal and meridional wind components. The mean values are found to have no statistically significant differences. The correlation coefficients vary between 0.63 and 0.70, indicating that the two sets of measurements are broadly consistent. When comparing the averaged variations over the night, the two measurements are highly correlated, with correlation coefficients varying from 0.84 to 0.95. It indicates that the strong tidal variation is well captured by both instruments. Differences are however significant at individual hours, which are believed to be mainly due to the fact that the meteor radar wind is an average over the entire sky while the lidar measures wind within a volume about 100m in diameter.

  6. Comparison of Na Lidar and Meteor Radar Wind Measurements at Starfire Optical Range, NM, USA

    NASA Astrophysics Data System (ADS)

    Liu, A. Z.; Hocking, W. K.; Franke, S. J.; Thayaparan, T.

    2001-05-01

    Simultaneous wind measurements in the mesopause region at Starfire Optical Range near Albuquerque, NM with Na wind/temperature lidar and meteor radar have been performed and compared. 20 nights of hourly data recorded with these two instruments at two layers around 86 and 93~km altitude are compared for both zonal and meridional wind components. The mean values are found to have no statistically significant differences. The correlation coefficients vary between 0.63 and 0.70, indicating that the two sets of measurements are broadly consistent. When comparing the averaged variations over the night, the two measurements are highly correlated, with correlation coefficients varying from 0.84 to 0.95. It indicates the strong tidal variation is well captured by both instruments. Differences are however significant at individual hours, which are believed to be mainly due to the fact that the radar wind is an average over the entire sky while the lidar measures wind within a volume about 100~m in diameter.

  7. 19 CFR 10.100 - Entry, examination, and tariff status.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. General Provisions United States Government Importations § 10.100 Entry, examination, and tariff status. Except as otherwise..., importations made by or for the account of any agency or office of the United States Government are subject...

  8. 31 CFR 10.0 - Scope of part.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Money and Finance: Treasury Office of the Secretary of the Treasury PRACTICE BEFORE THE INTERNAL REVENUE SERVICE § 10.0 Scope of part. This part contains rules governing the recognition of attorneys, certified public accountants, enrolled agents, and other persons representing clients before the Internal...

  9. Semiconductor optical amplifiers for the 1000-1100-nm spectral range

    SciTech Connect

    Lobintsov, A A; Shramenko, M V; Yakubovich, S D

    2008-07-31

    Two types of semiconductor optical amplifiers (SOAs) based on a double-layer quantum-well (InGa)As/(GaAl)As/GaAs heterostructure are investigated. The optical gain of more than 30 dB and saturation output power of more than 30 mW are achived at 1060 nm in pigtailed SOA modules. These SOAs used as active elements of a tunable laser provide rapid continuous tuning within 85 nm and 45 nm at output powers of 0.5 mW and more than 30 mW, respectively. (active media, lasers, and amplifiers)

  10. The use of hyperspectral imaging in the VNIR (400-1000nm) and SWIR range (1000-2500nm) for detecting counterfeit drugs with identical API composition.

    PubMed

    Wilczyński, Sławomir; Koprowski, Robert; Marmion, Mathieu; Duda, Piotr; Błońska-Fajfrowska, Barbara

    2016-11-01

    The risk of death from taking counterfeit drugs is now greater than the probability of dying from malaria and AIDS combined (at least half a million deaths each year). At the same time, counterfeit medicines are falsified more and more "skillfully". According to WHO about 10% of counterfeit drugs are copies of original products. The methods of hyperspectral imaging and image analysis and processing were used to detect counterfeit drugs. Original Viagra® (Pfizer) and counterfeit tablets were compared. Hyperspectral imaging was used to acquire hyperspectral data cubes from both original and counterfeit tablets in the spectral range of 400-2500nm. Spectral parameters for both the original Viagra® and counterfeit drugs were compared. Grey-Level Co-Occurrence Matrix (GLCM) analysis and Principal Component Analysis (PCA) were performed. Hyperspectral analysis of the surface of the original Viagra® and counterfeit tablets demonstrates significant differences in reflectance (maximum difference for 1619.75nm). The GLCM contrast for the falsified drug is on average higher than for the original one 16±4%. GLCM contrast analysis enables to quantify homogeneity of distribution of tablet ingredients and enables to distinguish tablets with identical chemical composition. SWIR (1000-2500nm) hyperspectral imaging has a definite advantage over imaging in VNIR (400-1000nm) - higher wavelength is less sensitive to non-uniform illumination.

  11. Report to the DOE nuclear data committee. [EV RANGE 10-100; CROSS SECTIONS; PHOTONEUTRONS; NEUTRONS; GAMMA RADIATION; COUPLED CHANNEL THEORY; DIFFERENTIAL CROSS SECTIONS; MEV RANGE 01-10; ; CAPTURE; GAMMA SPECTRA; THERMAL NEUTRONS; COMPUTER CALCULATIONS; DECAY; FISSION PRODUCTS; FISSION YIELD; SHELL MODELS; NUCLEAR DATA COLLECTIONS

    SciTech Connect

    Struble, G.L.; Haight, R.C.

    1981-03-01

    Topics covered include: studies of (n, charged particle) reactions with 14 to 15 MeV neutrons; photoneutron cross sections for /sup 15/N; neutron radiative capture; Lane-model analysis of (p,p) and (n,n) scattering on the even tin isotopes; neutron scattering cross sections for /sup 181/Ta, /sup 197/Au, /sup 209/Bi, /sup 232/Th, and /sup 238/U inferred from proton scattering and charge exchange cross sections; neutron-induced fission cross sections of /sup 245/Cm and /sup 242/Am; fission neutron multiplicities for /sup 245/Cm and /sup 242/Am; the transport of 14 MeV neutrons through heavy materials 150 < A < 208; /sup 249/Cm energy levels from measurement of thermal neutron capture gamma rays; /sup 231/Th energy levels from neutron capture gamma ray and conversion electron spectroscopy; new measurements of conversion electron binding energies in berkelium and californium; nuclear level densities; relative importance of statistical vs. valence neutron capture in the mass-90 region; determination of properties of short-lived fission products; fission yield of /sup 87/Br and /sup 137/I from 15 nuclei ranging from /sup 232/Th to /sup 249/Cf; evaluation of charged particle data for the ECPL library; evaluation of secondary charged-particle energy and angular distributions for ENDL; and evaluated nuclear structure libraries derived from the table of isotopes. (GHT)

  12. Spectral emission properties of a LPP light source in the sub-200nm range for wafer inspection applications

    NASA Astrophysics Data System (ADS)

    Gambino, Nadia; Rollinger, Bob; Hudgins, Duane; Abhari, Reza; Abreau, F.

    2015-03-01

    In this work, the spectral emission proprieties of a droplet-based laser-produced plasma are investigated in the VUV range. These studies are performed with a spectrograph operating from 30 nm to 180 nm at a spectral resolution of 0.1 nm. The emission spectra are recorded for different droplet-based metal fuels such as tin, indium and gallium in the presence of different background gas pressure levels. The experimental results are relevant for alternative light sources that would be needed for future wafer inspection tools. In addition, the experimental results help to determine the Out- Of-Band (OOB) radiation emission of the EUV source. By tuning the type of fuel, the laser energies and the background gas, the LPP light source shows good capabilities to be operated as a tunable light source that covers a spectral emission range from the EUV to the sub-200 nm range.

  13. Satellite laser ranging using superconducting nanowire single-photon detectors at 1064  nm wavelength.

    PubMed

    Xue, Li; Li, Zhulian; Zhang, Labao; Zhai, Dongsheng; Li, Yuqiang; Zhang, Sen; Li, Ming; Kang, Lin; Chen, Jian; Wu, Peiheng; Xiong, Yaoheng

    2016-08-15

    Satellite laser ranging operating at 1064 nm wavelength using superconducting nanowire single-photon detectors (SNSPDs) is successfully demonstrated. A SNSPD with an intrinsic quantum efficiency of 80% and a dark count rate of 100 cps at 1064 nm wavelength is developed and introduced to Yunnan Observatory in China. With improved closed-loop telescope systems (field of view of about 26''), satellites including Cryosat, Ajisai, and Glonass with ranges of 1600 km, 3100 km, and 19,500 km, respectively, are experimentally ranged with mean echo rates of 1200/min, 4200/min, and 320/min, respectively. To the best of our knowledge, this is the first demonstration of laser ranging for satellites using SNSPDs at 1064 nm wavelength. Theoretical analysis of the detection efficiency and the mean echo rate for typical satellites indicate that it is possible for a SNSPD to range satellites from low Earth orbit to geostationary Earth orbit.

  14. 10. 100 foot through truss north west bearing abutment ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. 100 foot through truss - north west bearing abutment of the second through truss, showing the diagonal sway bracing to its alternate pier. This bearing point is on a concrete extension of the original bearing point now covered by rock and soil. Note that the bearing point is to the backmost position on the concrete pier. - Weidemeyer Bridge, Spanning Thomes Creek at Rawson Road, Corning, Tehama County, CA

  15. Performance of a polarizer using synthetic mica crystal in the 12-25 nm wavelength range

    NASA Astrophysics Data System (ADS)

    Cui, Ming-Qi; Chen, Kai; Zhao, Jia; Sun, Li-Juan; Xi, Shi-Bo; Yan, Fen

    2011-05-01

    To develop polarizer functioning in the extreme ultraviolet (EUV) and soft X-ray region, the polarization performance of synthetic mica has been investigated theoretically with a simulation code using Fresnel equations and optical constants from the Henke database. The reflectance of synthetic mica crystal for s and p polarization was measured to investigate its polarization performance in a home-made synchrotron radiation soft X-ray polarimeter at beamline 3W1B, Beijing Synchrotron Radiation Facility (BSRF). The reflectivity of the synthetic mica crystal at an angle of grazing incidence of 48° was obtained from the experimental data, which is about 4.8×10-3 at 25 nm and 6.0×10-4 at 12 nm, and the linear polarizance of the X-ray reflected by the synthetic mica crystal that we measured using an analyzer-rotating method increases from 80% to 96.6% in this EUV region, while higher than 98.2% in the simulation. The result indicates that this synthetic mica crystal works as a practical polarizer in this EUV region of 12-25 nm, and also in an extensive wavelength region higher than 25 nm.

  16. LASERS: Highly efficient semiconductor optical amplifier for the 820-860-nm spectral range

    NASA Astrophysics Data System (ADS)

    Lobintsov, A. A.; Uspenskii, Mikhail B.; Shishkin, Viktor A.; Shramenko, M. V.; Yakubovich, S. D.

    2010-06-01

    A single-pass optical amplifier with a gain up to 32 dB at a wavelength of 840 nm is developed. Its high reliability is demonstrated at a single-mode fibre-coupled cw output power up to 50 mW. Examples of efficient application of this amplifier in MOPA systems are presented.

  17. Ytterbium-doped fibre laser tunable in the range 1017 - 1040 nm with second-harmonic generation

    SciTech Connect

    Dontsova, E I; Kablukov, S I; Babin, Sergei A

    2013-05-31

    A cladding-pumped ytterbium-doped fibre laser has been tuned to shorter emission wavelengths (from 1040 to 1017 nm). The laser output power obtained has been compared to calculation results. We have studied frequency doubling of the laser in a KTiOPO{sub 4} (KTP) crystal with type II phase matching in the XY plane and demonstrated wavelength tuning in the range 510 - 520 nm. (lasers)

  18. Optical frequency domain imaging with a rapidly swept laser in the 815-870 nm range

    NASA Astrophysics Data System (ADS)

    Lim, H.; de Boer, J. F.; Park, B. H.; Lee, E. C.; Yelin, R.; Yun, S. H.

    2006-06-01

    Optical frequency domain imaging (OFDI) in the 800-nm biological imaging window is demonstrated by using a novel wavelength-swept laser source. The laser output is tuned continuously from 815 to 870 nm at a 43.2-kHz repetition rate with 7-mW average power. Axial resolution of 10-μm in biological tissue and peak sensitivity of 96 dB are achieved. In vivo imaging of Xenopus laevis is demonstrated with an acquisition speed of 84 frames per second (512 axial lines per frame). This new imaging technique may prove useful in comprehensive retinal screening for medical diagnosis and contrast-agent-based imaging for biological investigations.

  19. Emission properties and CW laser operation of Pr:YLF in the 910 nm spectral range.

    PubMed

    Cai, Z P; Qu, B; Cheng, Y J; Luo, S Y; Xu, B; Xu, H Y; Luo, Z Q; Camy, P; Doualan, J L; Moncorgé, R

    2014-12-29

    The polarized emission spectra for the 3P01G4 emission transition of the Pr3+ ion around 910 nm in the Pr3+:LiYF4 (Pr:YLF) laser crystal were registered and calibrated in unit of cross sections for the first time. Continuous-wave (CW) laser operation is demonstrated at 915 nm in π polarization by pumping the crystal with an optically pumped semiconductor laser (OPSL) at 479.2 nm. An output power of 218 mW is thus obtained with a laser slope efficiency of about 24% for an output coupler (OC) transmission of 1.9%. CW laser operation is also demonstrated at 907 nm in σ polarization by using a thin plate oriented at Brewster angle. An output power of about 89 mW with a slope efficiency of about 10% is then obtained for an OC transmission of 0.8%.The round-trip cavity losses are estimated for different experimental cavity configurations to be about 1% and the typical beam quality M2 factors measured in the transverse x and y directions are found equal to about 1.07 and 1.04, respectively. Finally, we also report on a double laser wavelength operation by using an OC with a transmission of about 0.05%, such effect resulting from joint-etalon effects inside the cavity.

  20. Mode-locked Er:Yb-doped double-clad fiber laser with 75-nm tuning range.

    PubMed

    Meng, Yichang; Salhi, Mohamed; Niang, Alioune; Guesmi, Khmaies; Semaan, Georges; Sanchez, Francois

    2015-04-01

    We demonstrate a widely tunable Er:Yb-doped double-clad multiple-soliton fiber laser based on nonlinear polarization rotation (NPR). Based on both an artificial birefringent filtering effect of the cavity and population inversion related gain variation, the central wavelength can be continuously tuned over 75 nm range (1545-1620 nm). Wavelength tunability is achieved by controlling both the linear loss of the cavity and the polarization controllers (PCs). This is the widest tunable range yet reported in tunable passively mode-locked erbium-doped fiber lasers.

  1. Ruby Emission in the Range 400-800 nm with Excitation by Continuous-Wave CO2 Laser Pulses

    NASA Astrophysics Data System (ADS)

    Marchenko, V. M.; Kiselev, V. V.

    2017-01-01

    Thermal emission spectra of ruby single crystals in the range 400-800 nm were studied experimentally as functions of the intensity at 10.6 μm of exciting pulses ( 0.5 s) from a continuous-wave electrical-discharge CO2 laser. Spectra at excitation intensity 1-20 kW/cm2 were superpositions of the thermal emission continuum of the sapphire crystal lattice in the range 600-800 nm and selective emission spectra of Cr3+ that were observed for the first time for ruby and consisted of R-lines at 695 nm; N-lines at 715 nm; 2 T 1, 4 T 2 → 4 A 2 transition bands at 672 and 643 nm; and 4 T 1, 2 T 2 → 4 A 2 transition bands at 530 and 490 nm that were not observed in the luminescence spectrum. Time dependences of the shapes of selective emission spectra, quenching and shifts of the R 1 line, and the temperature dependence of ruby luminescence spectra were investigated.

  2. Interlaced zone plate optics for hard X-ray imaging in the 10 nm range

    NASA Astrophysics Data System (ADS)

    Mohacsi, Istvan; Vartiainen, Ismo; Rösner, Benedikt; Guizar-Sicairos, Manuel; Guzenko, Vitaliy A.; McNulty, Ian; Winarski, Robert; Holt, Martin V.; David, Christian

    2017-03-01

    Multi-keV X-ray microscopy has been particularly successful in bridging the resolution gap between optical and electron microscopy. However, resolutions below 20 nm are still considered challenging, as high throughput direct imaging methods are limited by the availability of suitable optical elements. In order to bridge this gap, we present a new type of Fresnel zone plate lenses aimed at the sub-20 and the sub-10 nm resolution range. By extending the concept of double-sided zone plate stacking, we demonstrate the doubling of the effective line density and thus the resolution and provide large aperture, singlechip optical devices with 15 and 7 nm smallest zone widths. The detailed characterization of these lenses shows excellent optical properties with focal spots down to 7.8 nm. Beyond wave front characterization, the zone plates also excel in typical imaging scenarios, verifying their resolution close to their diffraction limited optical performance.

  3. Extended femtosecond laser wavelength range to 330 nm in a high power LBO based optical parametric oscillator.

    PubMed

    Fan, Jintao; Gu, Chenglin; Wang, Chingyue; Hu, Minglie

    2016-06-13

    We experimentally demonstrate a compact tunable, high average power femtosecond laser source in the ultraviolet (UV) regime. The laser source is based on intra-cavity frequency doubling of a temperature-tuned lithium tribotate (LBO) optical parametric oscillator (OPO), synchronously pumped at 520 nm by a frequency-doubled, Yb-fiber femtosecond laser amplifier system. By adjusting crystal temperature, the OPO can provide tunable visible to near-infrared (NIR) signal pulse, which have a wide spectral tuning range from 660 to 884 nm. Using a β-barium borate (BBO) crystal for intra-cavity frequency doubling, tunable femtosecond UV pulse are generated across 330~442 nm with up to 364 mW at 402 nm.

  4. Interlaced zone plate optics for hard X-ray imaging in the 10 nm range

    PubMed Central

    Mohacsi, Istvan; Vartiainen, Ismo; Rösner, Benedikt; Guizar-Sicairos, Manuel; Guzenko, Vitaliy A.; McNulty, Ian; Winarski, Robert; Holt, Martin V.; David, Christian

    2017-01-01

    Multi-keV X-ray microscopy has been particularly successful in bridging the resolution gap between optical and electron microscopy. However, resolutions below 20 nm are still considered challenging, as high throughput direct imaging methods are limited by the availability of suitable optical elements. In order to bridge this gap, we present a new type of Fresnel zone plate lenses aimed at the sub-20 and the sub-10 nm resolution range. By extending the concept of double-sided zone plate stacking, we demonstrate the doubling of the effective line density and thus the resolution and provide large aperture, singlechip optical devices with 15 and 7 nm smallest zone widths. The detailed characterization of these lenses shows excellent optical properties with focal spots down to 7.8 nm. Beyond wave front characterization, the zone plates also excel in typical imaging scenarios, verifying their resolution close to their diffraction limited optical performance.

  5. Mobility of Chromophores Absorbing Light in the 320-420 nm Range in Transparent and Cataract Lens Tissue

    NASA Astrophysics Data System (ADS)

    Halets-Bui, I. V.; Sukhodol, A. A.; Shcharbin, D. G.

    2014-11-01

    We have analyzed the spectral and kinetic characteristics of phosphorescence at room temperature on a millisecond time scale for transparent and cataract lens tissues. We have studied the nature of the change (with age and with cataract development in the lens tissues) in the molecular mobility of the products absorbing light in the 320-420 nm range.

  6. Ion generation and CPC detection efficiency studies in sub 3-nm size range

    SciTech Connect

    Kangasluoma, J.; Junninen, H.; Sipilae, M.; Kulmala, M.; Petaejae, T.; Lehtipalo, K.; Mikkilae, J.; Vanhanen, J.; Attoui, M.; Worsnop, D.

    2013-05-24

    We studied the chemical composition of commonly used condensation particle counter calibration ions with a mass spectrometer and found that in our calibration setup the negatively charged ammonium sulphate, sodium chloride and tungsten oxide are the least contaminated whereas silver on both positive and negative and the three mentioned earlier in positive mode are contaminated with organics. We report cut-off diameters for Airmodus Particle Size Magnifier (PSM) 1.1, 1.3, 1.4, 1.6 and 1.6-1.8 nm for negative sodium chloride, ammonium sulphate, tungsten oxide, silver and positive organics, respectively. To study the effect of sample relative humidity on detection efficiency of the PSM we used different humidities in the differential mobility analyzer sheath flow and found that with increasing relative humidity also the detection efficiency of the PSM increases.

  7. A new bismuth-doped fibre laser, emitting in the range 1625 – 1775 nm

    SciTech Connect

    Dianov, E M; Firstov, S V; Alyshev, S V; Riumkin, K E; Shubin, A V; Medvedkov, O I; Mel'kumov, M A; Khopin, V F; Gur'yanov, A N

    2014-06-30

    CW lasing of a Bi-doped germanosilicate fibre in a wavelength range that covers the spectral region between the emission bands of Er and Tm fibre lasers has been demonstrated for the first time. (letters)

  8. Study of transitions in thulium atoms in the 410-420-nm range for laser cooling

    SciTech Connect

    Akimov, A V; Chebakov, K Yu; Tolstikhina, I Yu; Sokolov, A V; Rodionov, P B; Kanorsky, S I; Sorokin, V N; Kolachevsky, N N

    2008-10-31

    The possibility of laser cooling of thulium atoms is considered. The hyperfine structure of almost cyclic 4f{sup 13}6s{sup 2} (J{sub g} = 7/2) {r_reversible} 4f{sup 12}5d{sub 3/2}6s{sup 2} (J{sub e} = 9/2) and 4f{sup 13}6s{sup 2} (J{sub g} = 7/2) {r_reversible} 4f{sup 12}5d{sub 5/2}6s{sup 2} (J{sub e} = 9/2) transitions at 410.6 and 420.4 nm, respectively, is studied by the method of sub-Doppler saturation spectroscopy in counterpropagating laser beams. The hyperfine splitting of excited levels involved in these transitions is measured and the natural linewidths of these transitions are determined. The structure of the neighbouring 4f{sup 13}6s6p (J{sub e} = 5/2) and 4f{sup 12}5d{sub 5/2}6s{sup 2} (J{sub e} = 7/2) levels is studied for the first time by this method. The decay probabilities of the J{sub e} = 9/2 levels via channels removing atoms from the cooling cycle are calculated. It is found that the branching ratio for the strong transition at 410.6 nm (A = 6x10{sup 7} s{sup -1}) is smaller than 2x10{sup -5}, which makes this transition most promising for laser cooling. The laser cooling of atoms in a Zeeman cooler at this transition is simulated. The possibility of using a laser-cooled cloud of thulium atoms to study the metrological transition at 1.14 {mu}m is discussed. (laser cooling of atoms)

  9. The spectral opacity of triatomic carbon measured in a graphite tube furnace over the 280 to 600 nm wavelength range

    NASA Technical Reports Server (NTRS)

    Snow, W. L.; Wells, W. L.

    1980-01-01

    The opacity of linear triatomic carbon (C3) was measured in a graphite tube furnace from 280 to 600 nm to supplement the earlier measurements of Brewer and Engelke. The spectral cross section was estimated from the opacities using temperature profiles determined pyrometrically and a revised heat of formation delta H = 198 kcal/mole). The cross section was found to be nonnegligible over the range 300 to 500 nm and the electronic oscillator strength based on the total cross section estimate was 0.02.

  10. Supercontinuum laser based optical characterization of Intralipid® phantoms in the 500-2250 nm range.

    PubMed

    Aernouts, Ben; Zamora-Rojas, Eduardo; Van Beers, Robbe; Watté, Rodrigo; Wang, Ling; Tsuta, Mizuki; Lammertyn, Jeroen; Saeys, Wouter

    2013-12-30

    A supercontinuum laser based double integrating sphere setup in combination with an unscattered transmittance measurement setup was developed and carefully validated for optical characterization of turbid samples in the 500-2250 nm wavelength range. A set of 57 liquid optical phantoms, covering a wide range of absorption and scattering properties, were prepared and measured at two sample thicknesses. The estimated bulk optical properties matched well for both thicknesses, and with theory and literature, without significant crosstalk between absorption and scattering. Equations were derived for the bulk scattering properties μ(s), μ(s)' and g of Intralipid® 20% which can be used to calculate the bulk scattering properties of intralipid-dilutions in the 500-2250 nm range.

  11. Preparation of aqueous colloidal mesostructured and mesoporous silica nanoparticles with controlled particle size in a very wide range from 20 nm to 700 nm

    NASA Astrophysics Data System (ADS)

    Yamada, Hironori; Urata, Chihiro; Ujiie, Hiroto; Yamauchi, Yusuke; Kuroda, Kazuyuki

    2013-06-01

    Particle size control of colloidal mesoporous silica nanoparticles (CMPS) in a very wide range is quite significant for the design of CMPS toward various applications, such as catalysis and drug delivery. Various types of CMPS and their precursors (colloidal mesostructured silica nanoparticles (CMSS)) with different particle sizes (ca. 20-700 nm) were newly prepared from tetraalkoxysilanes with different alkoxy groups (Si(OR)4, R = Me, Et, Pr, and Bu) in the presence of alcohols (R'OH, R' = Me, Et, Pr, and Bu) as additives. CMSS with larger particle size were obtained by using tetrabutoxysilane (TBOS) and by increasing the amount of BuOH, which is explained by both the difference in the hydrolysis rates of tetraalkoxysilanes themselves and the effect of added alcohols on the hydrolysis rates of tetraalkoxysilanes. Larger amounts of alcohols with longer alkyl chains decrease the hydrolysis rates of tetraalkoxysilanes and the subsequent formation rates of silica species. Thus, the preferential particle growth of CMSS to nucleation occurs, and larger CMSS are formed. Highly dispersed CMPS were prepared by the removal of surfactants of CMSS by dialysis which can lead to the preparation of CMPS without aggregation. Therefore, the particle size control through the tuning of the hydrolysis rate of tetraalkoxysilanes can be conducted by a one-pot and easy approach. Even larger CMPS (ca. 700 nm in size) show relatively high dispersibility. This dispersibility will surely contribute to the design of materials both retaining nanoscale characteristics and avoiding various nanorisks.Particle size control of colloidal mesoporous silica nanoparticles (CMPS) in a very wide range is quite significant for the design of CMPS toward various applications, such as catalysis and drug delivery. Various types of CMPS and their precursors (colloidal mesostructured silica nanoparticles (CMSS)) with different particle sizes (ca. 20-700 nm) were newly prepared from tetraalkoxysilanes with

  12. Investigation of the lithium 670.7 nm wavelength range in the solar spectrum

    NASA Astrophysics Data System (ADS)

    Caffau, Elisabetta; Mott, Alessandro; Harutyunyan, Gohar; Malherbe, Jean-Marie; Steffen, Matthias

    2016-07-01

    Lithium is a key chemical element, with a chemical evolution that is different from that of most other elements. It is also very fragile, as it is destroyed by nuclear reactions with protons at temperatures higher than about 2.5 million K. According to standard Big Bang nucleosynthesis, only the isotope 7Li is produced in significant amounts, while the primordial abundance of the lighter isotope 6Li is negligible. Lithium is not produced by nucleosynthesis in normal stars, except in peculiar phases of stellar evolution (e.g. in AGB stars and Novae). Lithium may also be formed as a result of flares in the atmospheres of young, active stars. To investigate the history of Li production and depletion in the Galaxy, it is necessary to analyse stars of all ages, including those at solar metallicity. In this case, the spectroscopic determination of the Li abundance is complicated by the presence of other spectral lines overlapping with the Li doublet at 670.7 nm. The correct identification and knowledge of the atomic parameters of these blend lines is critical, especially if the 6LI/7Li isotopic ratio is to be derived. In this investigation, we consider several line lists of the blending components available in the literature and use them to compute synthetic spectra, performing the line formation computations both for the classical 1D Holweger-Mueller model and a CO5BOLD 3D hydrodynamical simulation of the solar atmosphere. The synthetic spectra are then compared to the solar spectrum observed at different limb angles. This allows us to check the quality of existing line lists, to find potentially misidentified blend lines, and to construct an optimized line list for solar-type stars.

  13. Multispectral measurement of contrast in tissue-mimicking phantoms in near-infrared spectral range of 650 to 1600 nm

    NASA Astrophysics Data System (ADS)

    Salo, Daniel; Zhang, Hairong; Kim, David M.; Berezin, Mikhail Y.

    2014-08-01

    In order to identify the optimal imaging conditions for the highest spatial contrast in biological tissue, we explored the properties of a tissue-mimicking phantom as a function of the wavelengths in a broad range of near-infrared spectra (650 to 1600 nm). Our customized multispectral hardware, which featured a scanning transmission microscope and imaging spectrographs equipped with silicon and InGaAs charge-coupled diode array detectors, allowed for direct comparison of the Michelson contrast obtained from a phantom composed of a honeycomb grid, Intralipid, and India ink. The measured contrast depended on the size of the grid, luminance, and the wavelength of measurements. We demonstrated that at low thickness of the phantom, a reasonable contrast of the objects can be achieved at any wavelength between 700 and 1400 nm and between 1500 and 1600 nm. At larger thicknesses, such contrast can be achieved mostly between 1200 and 1350 nm. These results suggest that distinguishing biological features in deep tissue and developing contrast agents for in vivo may benefit from imaging in this spectral range.

  14. Photoluminescence quantum yields of PbSe and PbS QDs in the range of 1000 nm to 2000 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Beard, Matthew C.; Semonin, Octavi E.; Johnson, Justin C.; Marshall, Ashley; Zhang, Jianbing; Chernomordik, Boris D.

    2016-03-01

    PbS and PbSe quantum dots (QDs) are promising strong infrared emitters. We have developed several synthetic routes to producing PbS and PbSe QDs with a variety of sizes such that the bandgap can be continuously tuned from 2000 to 1000 nm. We provide a simple and accurate synthetic route to reproducibly produce PbS QDs with a narrow size-distribution and high chemical yield. The different synthetic routes lead to differences in their surface chemistry and to differences in their air stability and photoluminescence quantum yields (PLQY). To characterize the PLQY we directly measured the PLQY IR-26 (a standard IR emitting organic dye) at a range of concentrations as well as the PLQY of PbS and PbSe QDs for a range of sizes. We find that the PLQY of IR-26 has a weak concentration dependence due to reabsorption, with a PLQY of 0:048_0:002% for low concentrations, lower than previous reports by a full order of magnitude. We also find a dramatic size dependence for both PbS and PbSe QDs, with the smallest dots exhibiting a PLQY in excess of 60% while larger dots fall below 3%. A model, including nonradiative transition between electronic states and energy transfer to ligand vibrations, appears to explain this size dependence. These findings provide both a better characterization of photoluminescence for near infrared emitters. Halogen surface passivation provides both a larger PLQY (~ 30% improvement) as well as increased air stability.

  15. Terminal Area Simulation System User's Guide - Version 10.0

    NASA Technical Reports Server (NTRS)

    Switzer, George F.; Proctor, Fred H.

    2014-01-01

    The Terminal Area Simulation System (TASS) is a three-dimensional, time-dependent, large eddy simulation model that has been developed for studies of wake vortex and weather hazards to aviation, along with other atmospheric turbulence, and cloud-scale weather phenomenology. This document describes the source code for TASS version 10.0 and provides users with needed documentation to run the model. The source code is programed in Fortran language and is formulated to take advantage of vector and efficient multi-processor scaling for execution on massively-parallel supercomputer clusters. The code contains different initialization modules allowing the study of aircraft wake vortex interaction with the atmosphere and ground, atmospheric turbulence, atmospheric boundary layers, precipitating convective clouds, hail storms, gust fronts, microburst windshear, supercell and mesoscale convective systems, tornadic storms, and ring vortices. The model is able to operate in either two- or three-dimensions with equations numerically formulated on a Cartesian grid. The primary output from the TASS is time-dependent domain fields generated by the prognostic equations and diagnosed variables. This document will enable a user to understand the general logic of TASS, and will show how to configure and initialize the model domain. Also described are the formats of the input and output files, as well as the parameters that control the input and output.

  16. New Measurements of the Absolute Spectral Energy Distribution of Solar Radiation in the Range Double Lambda 650-1070 NM

    NASA Astrophysics Data System (ADS)

    Burlov-Vasilev, K. A.; Vasileva, I. E.; Matveev, Yu. B.

    1996-01-01

    Spectral measurements of the solar disk centre intensity for the near-IR region have been made at he Terskol High-Altitude Station in 1992. These measurements are the continuation of the program for the solar absolute spectral energy distribution investigation. Data published earlier are extended to the longwave spectral region up to 1070 nm. The special-purpose solar telescope SEF-1 was used. We compared the disk centre brightness with brightness of the calibrated region of the standard ribbon tungsten lamp. The atmospheric extinction was taken into account by the Bouguer method with simultaneous control of the atmosphere stability. The 1-nm integrals of the disk centre intensity in the range double lamda 650-1070 nm based on 5-day measurements in March-October 1992 are given. The uncertainty of these values is 2%. In regions with strong telluric absorption by oxygen and water-vapour bands, the reductions are made, using synthetic atmospheric absorption spectra computed on the basis of molecular parameter atlas HITRAN and the standard model atmosphere. By the use of the solar limb darkening coefficients the values of the solar flux at 1 A.U. were derived. Our measurements show the best agreement with the data of Makarova, Kharitonov, and Kazachevskaya as well as with the common data from Shaw and Frohlich. For lambda greater than 850 nm our data are systematically lower than the data by Neckel and Labs.

  17. Spectroscopic photoacoustic imaging of lipid-rich plaques in the human aorta in the 740 to 1400 nm wavelength range

    NASA Astrophysics Data System (ADS)

    Allen, Thomas J.; Hall, Andrew; Dhillon, Amar P.; Owen, James S.; Beard, Paul C.

    2012-06-01

    Spectroscopic photoacoustic imaging has the potential to discriminate between normal and lipid-rich atheromatous areas of arterial tissue by exploiting the differences in the absorption spectra of lipids and normal arterial tissue in the 740 to 1400 nm wavelength range. Identification of regions of high lipid concentration would be useful to identify plaques that are likely to rupture (vulnerable plaques). To demonstrate the feasibility of visualizing lipid-rich plaques, samples of human aortas were imaged in forward mode, at wavelengths of 970 and 1210 nm. It was shown that the structure of the arterial wall and the boundaries of lipid-rich plaques obtained from the photoacoustic images were in good agreement with histology. The presence of lipids was also confirmed by comparing the photoacoustic spectra (740 to 1400 nm) obtained in a region within the plaque to the spectral signature of lipids. Furthermore, a lipid-rich plaque was successfully imaged while illuminating the sample through 2.8 mm of blood demonstrating the possibility of implementing the photoacoustic technique in vivo.

  18. Design concepts of monolithic metamorphic vertical-cavity surface-emitting lasers for the 1300–1550 nm spectral range

    SciTech Connect

    Egorov, A. Yu. Karachinsky, L. Ya.; Novikov, I. I.; Babichev, A. V.; Nevedomskiy, V. N.; Bugrov, V. E.

    2015-11-15

    Possible design concepts for long-wavelength vertical-cavity surface-emitting lasers for the 1300–1550 nm spectral range on GaAs substrates are suggested. It is shown that a metamorphic GaAs–InGaAs heterostructure with a thin buffer layer providing rapid transition from the lattice constant of GaAs to that of In{sub x}Ga{sub 1–x}As with an indium fraction of x < 0.3 can be formed by molecular-beam epitaxy. Analysis by transmission electron microscopy demonstrated the effective localization of mismatch dislocations in the thin buffer layer and full suppression of their penetration into the overlying InGaAs metamorphic layer.

  19. Absolutely Calibrated Vacuum Ultraviolet Spectra in the 150 nm to 250 nm Range from Plasmas Generated by the NIKE KrF Laser

    DTIC Science & Technology

    2005-03-25

    BN, Al, Si, S, Ti, Pd, and Au. Titanium-doped silica aerogels in pyrex cylinders were also irradiated. Spectra of the target elements were observed...silica aerogel targets at 248 nm was typically 6x10-6 the incident NIKE laser energy, and the spectral broadening corresponded to the 1 THz bandwidth of...targets consisted of planar foils of CH, BN, Al, Si, S, Ti, Pd, and Au. Titanium-doped silica aerogels in pyrex cylinders were also irradiated. Spectra of

  20. On the elastic, elastic-plastic properties of Au nanowires in the range of diameter 1-200 nm

    NASA Astrophysics Data System (ADS)

    Deb Nath, S. K.; Kim, Sung-Gaun

    2012-12-01

    In the present study, we obtain Young's modulus and yield strength of <100> Au nanowire in the range of diameters 1-30 nm by tension and bending tests using molecular dynamics simulations. Double clamped Au nanowire is bended applying a point load at its middle span using cylindrical indenter by the atomistic approach. The superiority of the present bending technique is highlighted by analyzing the distribution of Von Misses stress of the present bending Au nanowire by 3D finite element modeling. First, Young's modulus and yield strength of Au nanowires are determined using classical theory of continuum mechanics. Then the obtained Young's modulus and yield strength of Au nanowires are corrected using 3D finite element modeling based on inverse technique [Deb Nath et al. Appl. Phys. A 103(2), 493 (2011) and Tohmyoh et al. Appl. Phys. A 103(2), 285 (2011)]. Effects of anisotropy on the tension and bending stiffness, tension and bending strength of Au nanowires are also discussed with graphs. Effects of temperature on the tension and bending stiffness, tension and bending strength of Au nanowires are discussed. Effects of vertical displacement of the indenter on the mid span of double clamped Au nanowires on the bending stiffness and strength during molecular dynamics simulation are discussed. Besides, the obtained Young's modulus and yield strength of Au nanowires by Wu et al. [Nature Mater. 4, 525 (2005)] in the range of diameters 40 to 200 nm using the theory of classical continuum mechanics are corrected using the 3D finite element modeling based on inverse technique [Deb Nath et al. Appl. Phys. A 103(2), 493 (2011) and Tohmyoh et al. Appl. Phys. A 103(2), 285 (2011)].

  1. Assessing the link between chlorophyll concentration and absorption line height at 676 nm over a broad range of water types.

    PubMed

    Nardelli, Schuyler C; Twardowski, Michael S

    2016-10-31

    The relationship between absorption at 676 nm normalized to chlorophyll-a, i.e., specific absorption aph*(676), and various optical and environmental properties is examined in extensive data sets from Case I and Case II waters found globally to assess drivers of variability such as pigment packaging. A better understanding of this variability could lead to more accurate estimates of chlorophyll concentrations from in situ optical measurements that may be made autonomously. Values of aph*(676) ranged from 0.00006 to 0.0944 m2/mg Chl a across all sites studied, but converged on median and mean values (n = 563) of 0.0108 and 0.0139 m2/mg Chl a respectively, with no apparent relationship with various optical properties, latitude, coastal or open ocean environment, depth, temperature, salinity, photoadaptation, ecosystem health, or albedo. Relative consistency in aph* across such diverse water types and the full range in chlorophyll concentration suggests a single aph* may be used to estimate chlorophyll concentration from absorption measurements with better accuracy than currently thought.

  2. Radiance Temperatures (in the Wavelength Range 530 to 1500 nm) of Nickel at Its Melting Point by a Pulse-Heating Technique

    NASA Astrophysics Data System (ADS)

    Kaschnitz, E.; McClure, J. L.; Cezairliyan, A.

    1998-11-01

    The radiance temperatures (at seven wavelengths in the range 530 to 1500 nm) of nickel at its melting point were measured by a pulse-heating technique. The method is based on rapid resistive self-heating of the specimen from room temperature to its melting point in less than 1 s and on simultaneously measuring specimen radiance temperatures every 0.5 ms. Melting of the specimen was manifested by a plateau in the radiance temperature-versus-time function for each wavelength. The melting-point radiance temperatures for a given specimen were determined by averaging the measured temperatures along the plateau at each wavelength. The melting-point radiance temperatures for nickel, as determined by averaging the results at each wavelength for 25 specimens, are: 1641 K at 530 nm, 1615 K at 627 nm, 1606 K at 657 nm, 1589 K at 722 nm, 1564 K at 812 nm, 1538 K at 908 nm, and 1381 K at 1500 nm. Based on uncertainties arising from pyrometry and specimen conditions, the combined uncertainty (two standard-deviation level) is about ± 6 K for the reported values in the range 530 to 900 nm and is about ± 8 K for the reported value at 1500 nm.

  3. Optical properties of dental restorative materials in the wavelength range 400 to 700 nm for the simulation of color perception

    NASA Astrophysics Data System (ADS)

    Friebel, Moritz; Povel, Kirsten; Cappius, Hans-Joachim; Helfmann, Jürgen; Meinke, Martina

    2009-09-01

    Aesthetic restorations require dental restorative materials to have optical properties very similar to those of the teeth. A method is developed to this end to determine the optical parameters absorption coefficient μa, scattering coefficient μs, anisotropy factor g, and effective scattering coefficient μs' of dental restorative materials. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer followed by inverse Monte Carlo simulations. Using this method the intrinsic optical parameters are determined for shade B2 of the light-activated composites TPH® Spectrum®, Esthet-X®, and the Ormocer® Definite® in the wavelength range 400 to 700 nm. By using the determined parameters μa, μs, and g together with an appropriate phase function, the reflectance of samples with 1-mm layer thickness and shade B2 could be predicted with a very high degree of accuracy using a forward Monte Carlo simulation. The color perception was calculated from the simulated reflectance according to the CIELAB system. We initiate the compilation of a data pool of optical parameters that in the future will enable calculation models to be used as a basis for optimization of the optical approximation of the natural tooth, and the composition of new materials and their production process.

  4. Optical properties of dental restorative materials in the wavelength range 400 to 700 nm for the simulation of color perception.

    PubMed

    Friebel, Moritz; Povel, Kirsten; Cappius, Hans-Joachim; Helfmann, Jürgen; Meinke, Martina

    2009-01-01

    Aesthetic restorations require dental restorative materials to have optical properties very similar to those of the teeth. A method is developed to this end to determine the optical parameters absorption coefficient mu(a), scattering coefficient mu(s), anisotropy factor g, and effective scattering coefficient mu(s) (') of dental restorative materials. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer followed by inverse Monte Carlo simulations. Using this method the intrinsic optical parameters are determined for shade B2 of the light-activated composites TPH((R)) Spectrum, Esthet-X, and the Ormocer Definite in the wavelength range 400 to 700 nm. By using the determined parameters mu(a), mu(s), and g together with an appropriate phase function, the reflectance of samples with 1-mm layer thickness and shade B2 could be predicted with a very high degree of accuracy using a forward Monte Carlo simulation. The color perception was calculated from the simulated reflectance according to the CIELAB system. We initiate the compilation of a data pool of optical parameters that in the future will enable calculation models to be used as a basis for optimization of the optical approximation of the natural tooth, and the composition of new materials and their production process.

  5. Optical absorption and scattering properties of bulk porcine muscle phantoms from interstitial radiance measurements in 650-900 nm range

    NASA Astrophysics Data System (ADS)

    Grabtchak, Serge; Montgomery, Logan G.; Whelan, William M.

    2014-05-01

    We demonstrated the application of relative radiance-based continuous wave (cw) measurements for recovering absorption and scattering properties (the effective attenuation coefficient, the diffusion coefficient, the absorption coefficient and the reduced scattering coefficient) of bulk porcine muscle phantoms in the 650-900 nm spectral range. Both the side-firing fiber (the detector) and the fiber with a spherical diffuser at the end (the source) were inserted interstitially at predetermined locations in the phantom. The porcine phantoms were prostate-shaped with ˜4 cm in diameter and ˜3 cm thickness and made from porcine loin or tenderloin muscles. The described method was previously validated using the diffusion approximation on simulated and experimental radiance data obtained for homogenous Intralipid-1% liquid phantom. The approach required performing measurements in two locations in the tissue with different distances to the source. Measurements were performed on 21 porcine phantoms. Spectral dependences of the effective attenuation and absorption coefficients for the loin phantom deviated from corresponding dependences for the tenderloin phantom for wavelengths <750 nm. The diffusion constant and the reduced scattering coefficient were very close for both phantom types. To quantify chromophore presence, the plot for the absorption coefficient was matched with a synthetic absorption spectrum constructed from deoxyhemoglobin, oxyhemoglobin and water. The closest match for the porcine loin spectrum was obtained with the following concentrations: 15.5 µM (±30% s.d.) Hb, 21 µM (±30% s.d.) HbO2 and 0.3 (±30% s.d.) fractional volume of water. The tenderloin absorption spectrum was best described by 30 µM Hb (±30% s.d), 19 µM (±30% s.d.) HbO2 and 0.3 (±30% s.d.) fractional volume of water. The higher concentration of Hb in tenderloin was consistent with a dark-red appearance of the tenderloin phantom. The method can be applied to a number of biological

  6. Study of coercive fields and Kβ/Kα X-ray intensity ratios of nickel films in the thickness range of 5-2000 nm

    NASA Astrophysics Data System (ADS)

    Prajapat, C. L.; Singh, M. R.; Ravikumar, G.; Gupta, S. K.; Joseph, D.; Nayak, B. K.; Saxena, A.

    2012-06-01

    Coercive fields and X-Ray intensity ratios of the K-series lines of Ni films in the thickness range of 5-2000 nm deposited onto Si (111) substrate have been studied. The Coercive field is observed to increase with thickness and follows power law for the thickness range ≥ 50 nm. For lower thickness, there is a deviation from power law. A correlated change is also observed in the Kβ/Kα X-ray intensity ratios.

  7. Influence of oxygen saturation on the optical scattering properties of human red blood cells in the spectral range 250 to 2,000 nm.

    PubMed

    Friebel, Moritz; Helfmann, Jürgen; Netz, Uwe; Meinke, Martina

    2009-01-01

    The intrinsic optical parameters absorption coefficient mu(a), scattering coefficient micros, anisotropy factor g, and effective scattering coefficient micros were determined for human red blood cell (RBC) suspensions of hematocrit 33.2% dependent on the oxygen saturation (SAT O(2)) in the wavelength range 250 to 2,000 nm, including the range above 1,100 nm, about which there are no data available in the literature. Integrating sphere measurements of light transmittance and reflectance in combination with inverse Monte Carlo simulation were carried out for SAT O(2) levels of 100 and 0%. In the wavelength range up to 1,200 nm, the absorption behavior is determined by the hemoglobin absorption. The spectral range above the cells' absorption shows no dependence on SAT O(2) and approximates the absorption of water with values 20 to 30% below the respective values for water. Parameters micros and g are significantly influenced by the SAT O(2)-induced absorption changes. Above 600 nm, micros decreases continuously from values of 85 mm(-1) to values of 30 mm(-1) at 2,000 nm. The anisotropy factor shows a slight decrease with wavelengths above 600 nm. In the spectral regions of 1,450 and 1,900 nm where water has local absorption maxima, g shows a significant decrease down to 0.85, whereas micros increases.

  8. Calculations of neutron shielding data for 10-100 MeV proton accelerators.

    PubMed

    Chen, C C; Sheu, R J; Jian, S H

    2005-01-01

    The characteristics of neutron sources and their attenuation in concrete were investigated in detail for protons with energies ranging from 10 to 100 MeV striking on target materials of C, N, Al, Fe, Cu and W. A two-step approach was adopted: thick-target double-differential neutron yields were first calculated from the (p, xn) cross sections recommended in the ICRU Report 63; further, transport simulations of those neutrons in concrete were performed by using the FLUKA Monte Carlo code. The purpose of this study is to provide reasonably accurate parameters for shielding design for 10-100 MeV proton accelerators. Source terms and the corresponding attenuation lengths in concrete for several target materials are given as a function of proton energies and neutron emission angles.

  9. 20 CFR 10.100 - How and when is a notice of traumatic injury filed?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false How and when is a notice of traumatic injury filed? 10.100 Section 10.100 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... filed? (a) To claim benefits under the FECA, an employee who sustains a work-related traumatic...

  10. Kinetic study on the photoabsorption process of gaseous O 2 dimol at 630 nm in a wide pressure range

    NASA Astrophysics Data System (ADS)

    Ida, Akira; Furui, Eiji; Akai, Nobuyuki; Kawai, Akio; Shibuya, Kazuhiko

    2010-03-01

    The visible light absorption of gaseous O 2 dimol at 630 nm was measured in the pressure region of 0.04-90 atm. The intensities measured at high pressures did not agree with the values extrapolated from the data obtained at low pressures. A kinetic analysis assuming the equilibrium between the dimol and free O 2 monomers was performed. All the data are well reproduced by the model using the 630 nm absorption cross-section of (5.6 ± 3.3) × 10 -24 cm 2 molecule -1 and the dissociation equilibrium constant of (6.8 ± 4.2) × 10 21 molecules cm -3. The critical distance between the O 2 molecules in the dimol is discussed on the basis of the equilibrium constant determined.

  11. Polarizers for a spectral range centered at 121.6 nm operating by reflectance or by transmittance

    NASA Astrophysics Data System (ADS)

    Larruquert, Juan I.; Malvezzi, A. Marco; Giglia, Angelo; Aznárez, José A.; Rodríguez-de Marcos, Luis; Méndez, José A.; Miotti, Paolo; Frassetto, Fabio; Massone, Giuseppe; Capobianco, Gerardo; Fineschi, Silvano; Nannarone, Stefano

    2015-05-01

    Polarimetry is a powerful tool to interpret how the coronal plasma is involved in the energy transfer processes from the Sun's inner parts to the outer space. Space polarimetry in the far ultraviolet (FUV) provides essential information of processes governed by the Doppler and Hanle resonant electron scattering effects. Among the key FUV spectral lines to observe these processes, H I Lyman α (121.6 nm) is the most intense. Some developing or proposed solar physics missions, such as CLASP, SolmeX, and COMPASS, plan to perform polarimetry at 121.6 nm. Classical solutions, such as a parallel plate of a transparent material, either MgF2 or LiF, result in a modest efficiency of the passing polarization component. The development of more efficient linear polarizers at this wavelength will benefit future space instruments. A research has been conducted to develop polarizers based on (Al/MgF2)n multilayer coatings in a band containing 121.6 nm, to obtain a significant efficiency increase over plates. Coatings operating by reflectance resulted in a high efficiency after approximately one year of storage under nitrogen. In parallel, coating polarizers operating by transmittance have been prepared for the first time. Transmissive polarizers have the advantage that they involve no deviation of the beam. As a further benefit, the developed transmittance polarizers additionally incorporate filtering properties to help reject wavelengths both shortwards and longwards of a band containing 121.6 nm. Hence a polarizer combined with a filter is obtained with a single device. The combined polarizer-filter could enable a higher performance polarimeter for solar physics if the use of a separate filter to isolate Lyman α turns unnecessary.

  12. Coumarins in the gaseous phase. II. Investigation of stimulated emission from coumarin vapors in the range 470--540 nm

    SciTech Connect

    Logunov, O.A.; Startsev, A.V.; Stoilov, Y.Y.

    1981-06-01

    An investigation was made of the spectral and time characteristics of lasers utilizing coumarin 7 (C7, C153, C30, 7-diethylamino-3(2'-benzoxazolyl)-coumarin, and C6 vapors mixed with buffer gases (approx.35 atm) and kept at 200 /sup 0/C. The lasing efficiency in the region of 500 nm exceeded 6% and the threshold pump intensities were below 0.3 MW/cm/sup 2/, so that it should be possible to construct efficient cw and pulsed tunable gas lasers emitting in the blue-green part of the spectrum.

  13. Diode pumped Yb:CN laser at 1082 nm and intracavity doubling to the green spectral range

    NASA Astrophysics Data System (ADS)

    Liu, B.; Li, Y. L.; Jiang, H. L.

    2011-08-01

    A diode pumped Yb:CaNb2O6 (Yb:CN) laser at 1082 nm with a maximum output of 1.35 W at 13.3 W pump power has been demonstrated. The slope efficiency was 12.4%. Moreover, intracavity second-harmonic generation (SHG) has also been achieved with a maximum green power of 374 mW by using a LiB3O5 (LBO) nonlinear crystal. To the best of our knowledge, this is the first report on continuous wave (CW) green generation by intracavity frequency doubling Yb:CN laser.

  14. Transillumination of subcutaneous adipose tissues using near-infrared hyperspectral imaging in the 1100-1800 nm wavelength range

    NASA Astrophysics Data System (ADS)

    Ishii, K.; Kitayabu, A.; Kobayashi, Y.; Honda, N.; Awazu, K.

    2011-02-01

    Hyperspectral imaging (HSI) is a chemical imaging modality with spectroscopic information. This technique was often used in agricultural or pharmaceutical industries. But there have been a few reports for clinical medical applications. In near-infrared (NIR) wavelength region, the significant absorption peaks are often observed by the overtone of midinfrared molecular vibration. In addition, NIR light has a high penetration because of low scattering and less absorption by water or protein. In this study, we constructed the NIR-HSI system and the high-contrast subcutaneous adipose tissue imaging was conducted in-vitro. In the absorption spectra which are obtained by our NIR-HSI system, the characteristic absorption bands were observed around 1200 nm and 1700 nm. In the processed images using these wavelength bands, subcutaneous adipose tissue was observed through a skin. In a hyperspectral image by another processing using all wavelengths, a high-contrast image of subcutaneous adipose tissue is also obtained. NIR-HSI system is a powerful diagnostic technique for adipose tissues distribution and their morphological change on/inside a tissue.

  15. Spectral studies of SiCl4 + N2O + Ar and SiH4 + Ar mixtures in a shock tube in 160-550 nm range

    NASA Technical Reports Server (NTRS)

    Park, C.; Fujiwara, T.

    1978-01-01

    Gases containing SiO, SiO2, SiH, and Si2 were produced in the reflected-shock region of a shock tube by heating SiCl4 + N2O + Ar and SiH4 + Ar mixtures with shock waves. Spectral absorption characteristics were measured in the 160-550 nm wavelength range and in the 2800-3600 K temperature range and compared to calculated values. The sums of the squares of electronic transition moments at equilibrium separation were derived. It was found that absorption by SiO2 and other known bands of SiO, SiH, and Si2 were too weak to be measured. The cross section of absorption by a continuum, believed due to SiH, varied from 2.5 x 10 to the -17th sq cm at 280 nm to 1.6 x 10 to the -18th sq cm at 440 nm.

  16. Metamorphic distributed Bragg reflectors for the 1440–1600 nm spectral range: Epitaxy, formation, and regrowth of mesa structures

    SciTech Connect

    Egorov, A. Yu. Karachinsky, L. Ya.; Novikov, I. I.; Babichev, A. V.; Berezovskaya, T. N.; Nevedomskiy, V. N.

    2015-10-15

    It is shown that metamorphic In{sub 0.3}Ga{sub 0.7}As/In{sub 0.3}Al{sub 0.7}As distributed Bragg reflectors (DBRs) with a reflection band at 1440–1600 nm and a reflectance of no less than 0.999 can be fabricated by molecular beam epitaxy (MBE) on a GaAs substrate. It is demonstrated that mesa structures formed from metamorphic DBRs on a GaAs substrate can be regrown by MBE and microcavities can be locally formed in two separate epitaxial processes. The results obtained can find wide application in the fabrication of vertical-cavity surface-emitting lasers (VCSELs) with a buried tunnel junction.

  17. A new method to calculate the threshold temperature of a perfect blackbody to protect cornea and lens in the range of 780-3,000 nm.

    PubMed

    Madjidi, Faramarz; Mohammadi, Jamshid

    2015-01-01

    Exposure to IR-A and IR-B radiation, in the wavelength region of 780 nm to 3,000 nm, may lead to the development of cataractogenesis. Estimation of the exposure levels is the first step in controlling adverse health effects. In the present study, the irradiance of a hot blackbody emitter is replaced by its temperature in the exposure limit values for cornea and lens in the range of 780-3,000 nm. This paper explains the development and implementation of a computer code to predict a temperature, defined as Threshold Temperature, which satisfies the exposure limits already proposed by the ICNIRP. To this end, first an infinite series was created for the calculation of spectral radiance by integration with Planck's law. For calculation of irradiance, the initial terms of this infinite series were selected, and integration was performed in the wavelength region of 780 nm to 3,000 nm. Finally, using a computer code, an unknown source temperature that can emit the same irradiance was found. Exposure duration, source area, and observer distance from the hot source were entered as input data in this proposed code. Consequently, it is possible only by measurement of a Planckian emitter temperature and taking into account the distance from source and exposure time for an observer to decide whether the exposure to IR radiation in the range of 780 to 3,000 nm is permissible or not. It seems that the substitution of irradiance by the source temperature is an easier and more convenient way for hygienists to evaluate IR exposures.

  18. Tuning range and output power optimization of an external-cavity GaN diode laser at 455  nm.

    PubMed

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2016-03-20

    In this paper we discuss how different feedback gratings affect the tuning range and the output power of external feedback diode laser systems. A tunable high-power narrow-spectrum external-cavity diode laser system around 455 nm is investigated. The laser system is based on a high-power GaN diode laser in a Littrow external-cavity. Both a holographic diffraction grating and a ruled diffraction grating are used as feedback elements in the external cavity. The output power, spectral bandwidth, and tunable range of the external cavity diode laser system are measured and compared with the two gratings at different injected currents. When the holographic grating is used, the laser system can be tuned over a range of 1.4 nm with an output power around 530 mW. When the ruled grating is used, the laser system can be tuned over a range of 6.0 nm with an output power around 80 mW. The results can be used as a guide for selecting gratings for external-cavity diode lasers for different requirements.

  19. Wide tuning range wavelength-swept laser with a single SOA at 1020 nm for ultrahigh resolution Fourier-domain optical coherence tomography.

    PubMed

    Lee, Sang-Won; Song, Hyun-Woo; Jung, Moon-Youn; Kim, Seung-Hwan

    2011-10-24

    In this study, we demonstrated a wide tuning range wavelength-swept laser with a single semiconductor optical amplifier (SOA) at 1020 nm for ultrahigh resolution, Fourier-domain optical coherence tomography (UHR, FD-OCT). The wavelength-swept laser was constructed with an external line-cavity based on a Littman configuration. An optical wavelength selection filter consisted of a grating, a telescope, and a polygon scanner. Before constructing the optical wavelength selection filter, we observed that the optical power, the spectrum bandwidth, and the center wavelength of the SOA were affected by the temperature of the thermoelectric (TE) cooler in the SOA mount as well as the applied current. Therefore, to obtain a wide wavelength tuning range, we adjusted the temperature of the TE cooler in the SOA mount. When the temperature in the TE cooler was 9 °C, our swept source had a tuning range of 142 nm and a full-width at half-maximum (FWHM) of 121.5 nm at 18 kHz. The measured instantaneous spectral bandwidth (δλ) is 0.085 nm, which was measured by an optical spectrum analyzer with a resolution bandwidth of 0.06 nm. This value corresponds to an imaging depth of 3.1 mm in air. Additionally, the averaged optical power of our swept source was 8.2 mW. In UHR, FD/SS-OCT using our swept laser, the measured axial resolution was 4.0 μm in air corresponding to 2.9 μm in tissue (n = 1.35). The sensitivity was measured to be 93.1 dB at a depth of 100 μm. Finally, we obtained retinal images (macular and optic disk) and a corneal image.

  20. Chemical analyses of soil samples collected from the Sandia National Laboratories/NM, Tonopah Test Range environs, 1994-2005.

    SciTech Connect

    Deola, Regina Anne; Oldewage, Hans D.; Herrera, Heidi M.; Miller, Mark Laverne

    2006-05-01

    From 1994 through 2005, the Environmental Management Department of Sandia National Laboratories (SNL) at the Tonopah Test Range (TTR), NV, has collected soil samples at numerous locations on-site, on the perimeter, and off-site for the purpose of determining potential impacts to the environs from operations at TTR. These samples were submitted to an analytical laboratory of metal-in-soil analyses. Intercomparisons of these results were then made to determine if there was any statistical difference between on-site, perimeter, and off-site samples, or if there were increasing or decreasing trends which indicated that further investigation may be warranted. This work provided the SNL Environmental Management Department with a sound baseline data reference against which to compare future operational impacts. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data is presented in graphical format with narrative commentaries on particular items of interest.

  1. Spectral emission properties of a laser-produced plasma light source in the sub-200 nm range for wafer inspection applications

    NASA Astrophysics Data System (ADS)

    Gambino, Nadia; Rollinger, Bob; Hudgins, Duane; Abhari, Reza S.

    2015-07-01

    The spectral emission properties of a droplet-based laser-produced plasma are investigated in the vacuum ultraviolet (VUV) range. Measurements are performed with a spectrograph that operates from 30 to 180 nm with a spectral resolution of 0.1 nm. The emission spectra are recorded for different metal droplet targets, namely tin, indium, and gallium. Measurements were performed at different pressure levels of the background gas. Several characteristic emission lines are observed. The spectra are also calibrated in intensity in terms of spectral radiance to allow absolute emission power estimations from the light source in the VUV region. The presented experimental results are relevant for alternative light sources that would be needed for future wafer inspection tools. In addition, the experimental results help to determine the out-of-band radiation emission of a tin-based extreme ultraviolet (EUV) source. By tuning the type of fuel, the laser energies, and the background gas, the laser-produced plasma light source shows good capabilities to be operated as a light source that covers a spectral emission range from the EUV to the sub-200 nm range.

  2. Influence of four-wave mixing in short- and medium-range 1310  nm dense wavelength division multiplexing systems.

    PubMed

    Markowski, Konrad; Chorchos, Łukasz; Turkiewicz, Jarosław Piotr

    2016-04-10

    In this paper, we demonstrate a comprehensive analysis of the impact of four-wave mixing (FWM) on the quality of transmission in short- and medium-range dense wavelength division multiplexing (DWDM) systems in the 1310 nm wavelength domain. The presented analysis proves that, for the system with uniform power per channel assignment, setting proper input channel power can substantially reduce the influence of the FWM effect on bit error rate in low channel spaced short-range systems, despite the position of the DWDM grid around the zero-dispersion wavelength. Simulations and experimental analysis of the possibility of FWM suppression have been provided. The power penalty measurements show that the influence of FWM on system performance may be as low as 0.3 dB with reasonable input power (i.e., -11  dBm per channel), making possible the transmission of data by fiber over distances of 25 km. Finally, we demonstrate that, for channel spacing as low as 120 GHz, error-free transmission in the 1310 nm wavelength domain is possible, despite high efficiency of FWM generation. The results prove that utilization of the 1310 nm wavelength domain in a system with low channel spacing, i.e., with better bandwidth allocation, is an interesting solution for data storage and processing center applications.

  3. A wide range ultra-low power Phase-Locked Loop with automatic frequency setting in 130 nm CMOS technology for data serialisation

    NASA Astrophysics Data System (ADS)

    Firlej, M.; Fiutowski, T.; Idzik, M.; Moroń, J.; Świentek, K.

    2015-12-01

    The design and measurements results of a wide frequency range ultra-low power Phase-Locked Loop (PLL) for applications in readout systems of particle physics detectors are presented. The PLL was fabricated in a 130 nm CMOS technology. To allow the implementation of different data serialisation schemes multiple division factors (6, 8, 10, 16) were implemented in the PLL feedback loop. The main PLL block—VCO works in 16 frequency ranges/modes, switched either manually or automatically. A dedicated automatic frequency mode switching circuit was developed to allow simple frequency tuning. Although the PLL was designed and simulated for a frequency range of 30 MHz-3 GHz, due to the SLVS interface limits, the measurements were done only up to 1.3 GHz. The full PLL functionality was experimentally verified, confirming a very low and frequency scalable power consumption (0.7 mW at 1 GHz).

  4. 6.7-nm Emission from Gd and Tb Plasmas over a Broad Range of Irradiation Parameters Using a Single Laser

    NASA Astrophysics Data System (ADS)

    Yin, Liang; Wang, Hanchen; Reagan, Brendan A.; Baumgarten, Cory; Gullikson, Eric; Berrill, Mark; Shlyaptsev, Vyacheslav N.; Rocca, Jorge J.

    2016-09-01

    We report a comprehensive study of the emission from Gd and Tb laser-produced plasmas in the 6.5-6.7-nm wavelength region for a broad range of laser-irradiation parameters using a single λ =1030 nm laser with tunable pulse duration in the 120-ps-to-4-ns range. The results are of interest for beyond-extreme-ultraviolet (BEUV) lithography of integrated circuits. BEUV emission spectra are measured as a function of laser-pulse duration, emission angle, and spatial location within the plasma. Images of the BEUV-emitting plasma region at the BEUV wavelength are obtained as a function of irradiation parameters. The emission spectrum is observed to broaden and to shift to a longer wavelength as the duration of the driver laser pulses is shortened from nanoseconds to hundreds of picoseconds. Transient self-consistent hydrodynamic and atomic physics simulations show that the picosecond irradiation creates significantly hotter plasmas in which the dominant emission originates from more highly ionized species. Gd-plasma emission driven by nanosecond laser pulses spectrally best matches the responsivity of the energy monitors used, centered near λ =6.74 nm . Spatially resolved spectra of the Gd plasma are acquired for different laser-pulse durations. The conversion efficiency (CE) of Gd /Tb plasma into a 0.6% bandwidth in a 2 π solid angle is determined by integrating angularly resolved measurements obtained using an array of calibrated energy monitors. Similar maximum CEs of about 0.47% for both the Gd and Tb plasmas are obtained. The source size is measured to approximately match the spot size of the laser on target, in agreement with simulations.

  5. Simulation of laser propagation through a three-layer human skin model in the spectral range from 1000 to 1900 nm

    NASA Astrophysics Data System (ADS)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-07-01

    For understanding the mechanisms of low-level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. We present a three-dimensional, multilayer reduced-variance Monte Carlo simulation tool for studying light penetration and absorption in human skin. Local profiles of light penetration and volumetric absorption were calculated for uniform as well as Gaussian profile beams with different spreads over the spectral range from 1000 to 1900 nm. The results showed that lasers within this wavelength range could be used to effectively and safely deliver energy to specific skin layers as well as achieve large penetration depths for treating deep tissues, without causing skin damage. In addition, by changing the beam profile from uniform to Gaussian, the local volumetric dosage could increase as much as three times for otherwise similar lasers. We expect that this tool along with the results presented will aid researchers in selecting wavelength and laser power in LLLT.

  6. Comparative study of tunable room-temperature laser operation in the 900-1100-nm range: LiF:F2+ and Ti3+:sapphire.

    PubMed

    Rawle, C B; McKinnie, I T; Ter-Mikirtychev, V V; Sandle, W J

    2000-08-20

    We report on a comparative evaluation of efficient room-temperature solid-state lasers based on Ti:sapphire and LiF:F(2)(+) operating in the 900-1100-nm range. LiF:F(2)(+) lasers are shown to operate with substantially lower threshold, broader tuning, and higher output pulse energies. The shorter fluorescence lifetime in LiF:F(2)(+) leads to higher peak output powers and a considerable reduction in buildup-time fluctuations. The main limitations on LiF:F(2)(+) laser operation are identified as amplified spontaneous emission (ASE) and long-term thermal degradation of the color centers. ASE restricts the tuning range, slope efficiency, and bandwidth of the LiF:F(2)(+) laser for high pump intensity, but broader tuning is achieved with longer pump pulses. The beam quality of the LiF:F(2)(+) laser is comparable with that of the Ti:sapphire laser.

  7. Simulation of laser propagation through a three-layer human skin model in the spectral range from 1000 to 1900 nm.

    PubMed

    Nasouri, Babak; Murphy, Thomas E; Berberoglu, Halil

    2014-01-01

    For understanding the mechanisms of low-level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. We present a three-dimensional, multilayer reduced-variance Monte Carlo simulation tool for studying light penetration and absorption in human skin. Local profiles of light penetration and volumetric absorption were calculated for uniform as well as Gaussian profile beams with different spreads over the spectral range from 1000 to 1900 nm. The results showed that lasers within this wavelength range could be used to effectively and safely deliver energy to specific skin layers as well as achieve large penetration depths for treating deep tissues, without causing skin damage. In addition, by changing the beam profile from uniform to Gaussian, the local volumetric dosage could increase as much as three times for otherwise similar lasers. We expect that this tool along with the results presented will aid researchers in selecting wavelength and laser power in LLLT.

  8. Planetary Boundary Layer (PBL) Structures and Evolution analysis by Combination of Fractal Dimension of 3 Wavelength Lidar Signal and Range Correct Signal of 1064nm

    NASA Astrophysics Data System (ADS)

    Lei, L.; McCormick, M. P.; Su, J.

    2015-12-01

    Detection of the PBL heights and the PBL structure is very important for understanding the dynamic of the PBL since heat, water vapor and pollutions which come from the surface must transport through the PBL before they can affect the upper atmosphere. Fractal dimension (FD) retrieved from the three wavelengths lidar signals and the range- corrected signal (RCS) of 1064nm were used to analyses the PBL height and structure in Hampton University (HU, 37.02° N, 76.33° W). And the result shows that the new method has the potential to determine the top of different layer at same time. Combination of the FD and RCS signal also can be used to derive the structure of the PBL. Also the PBL evolution and the long time variety of the PBL in Hampton were analyzed. Wavelet covariance transform (WCT) was used to objectively determine the top and structure of the PBL from the FD signal and RCS signal.

  9. Ab initio study of semiconductor atoms impurities in zigzag edge (10,0) carbon nanotubes

    SciTech Connect

    Muttaqien, Fahdzi Suprijadi

    2015-04-16

    The substitutional impurities in zigzag edge (10,0) carbon nanotubes have been studied by using first principles calculations. Silicon (Si), gallium (Ga), and arsenic (As) atom have been chosen as semiconductor based-atom for replacing carbon atoms in CNT’s surface. The silicon atom changes the energy gap of pristine zigzag (10,0) CNT, it is 0.19 eV more narrow than that of pristine CNT. Geometrically, the silicon atom creates sp{sup 3} bond with three adjacent carbon atoms, where the tetrahedral form of its sp{sup 3} bond is consisted of free unoccupied state. The silicon atom does not induce magnetism to zigzag CNT. Due to gallium (Ga) and arsenic (As) atom substitution, the zigzag CNT becomes metallic and has magnetic moment of 1 µ{sub B}. The valance and conduction band are crossed each other, then the energy gap is vanished. The electronic properties of GaAs-doped CNT are dominantly affected by gallium atom and its magnetic properties are dominantly affected by arsenic atom. These results prove that the CNT with desired properties can be obtained with substitutional impurities without any giving structural defect.

  10. UV spectroscopy of Titan's atmosphere, planetary organic chemistry and prebiological synthesis. II. Interpretation of new IUE observations in the 220-335 nm range.

    PubMed

    Courtin, R; Wagener, R; McKay, C P; Caldwell, J; Fricke K-H; Raulin, F; Bruston, P

    1991-01-01

    We report on new observations of Titan with the International Ultraviolet Explorer in the mid-UV range (lambda approximately 220-335 nm). We use these data to determine upper limits for the abundances of simple organic compounds in the gas phase and to further constrain the properties of the high altitude haze on Titan. As a baseline, we adopted the parametrized microphysical model of McKay et al. (1989) which is successful at reproducing Titan's thermal structure while satisfying several other observational constraints in the visible and IR regions. However, we find that such a model--in which all particles at a given altitude are assumed to have the same size--cannot match simultaneously the IUE observations and the visible/IR data, even when allowance is made for a wide range of values in the adjustable parameters. On the other hand, a good overall agreement is obtained when considering a biomodal size distribution, with small haze particles or "polymers" (r < 0.02 micrometer) acting as strong Rayleigh absorbers below 300 nm and larger haze particles (r approximately 0.1-0.5 micrometer) being responsible for the characteristics of the albedo spectrum in the near-UV, visible, and IR regions. This approach is consistent with the results of several previous investigations of the properties of Titan's haze, although our preferred vertical structure for the haze + polymer material somewhat differs from earlier solutions. On the basis of simple dynamical considerations, we adopted a uniformly mixed layer between 150 and 600 km. The IUE data allow us to place fairly stringent constraints on the abundance of the Rayleigh absorbers, if we assume that their optical properties are similar to those of laboratory-synthesized "tholins": The column-mass density of this material--the essential observable that can be determined from our study--is of the order of 5 micrograms cm-2. This would correspond to number-densities between 10(3) and 10(7) cm-3 in the 150-600 km altitude

  11. Influence of polymer packaging films on hyperspectral imaging data in the visible-near-infrared (450-950 nm) wavelength range.

    PubMed

    Gowen, A A; O'Donnell, C P; Esquerre, C; Downey, G

    2010-03-01

    Hyperspectral imaging (HSI) has recently emerged as a useful tool for quality analysis of consumer goods (e.g., food and pharmaceutical products). These products are typically packaged in polymeric film prior to distribution; however, HSI experiments are typically carried out on such samples ex-packaging (either prior to or after removal from packaging). This research examines the effects of polymer packaging films (polyvinyl chloride (PVC) and polyethylene terephthalate (PET)) on spectral and spatial features of HSI data in order to investigate the potential of HSI for quality evaluation of packaged goods. The effects of packaging film were studied for hyperspectral images of samples obtained in the visible-near-infrared (Vis-NIR, i.e., 450-950 nm) wavelength range, which is relevant to many food, agricultural, and pharmaceutical products. The dominant influence of the films tested in this wavelength range could be attributed to light scattering. Relative position of the light source, film, and detector were shown to be highly influential on the scattering effects observed. Detection of features on samples imaged through film was shown to be possible after some data preprocessing. This suggests that quality analysis of products packaged in polymer film is feasible using HSI. These findings would be useful in the development of quality monitoring tools for consumer products post-packaging using HSI.

  12. Optical absorption of carbon and hydrocarbon species from shock heated acetylene and methane in the 135-220 nm wavelength range

    NASA Technical Reports Server (NTRS)

    Shinn, J. L.

    1981-01-01

    Absorption spectroscopy of carbon and hydrocarbon species has been performed in a shock tube at an incident shock condition for a wavelength range of 135-220 nm, in order to obtain information needed for calculating radiation blockage ahead of a planetary probe. Instrumentation consisted of high frequency response pressure transducers, thin-film heat transfer gages, or photomultipliers coupled by light pipes. Two test-gas mixtures, one with acetylene and the other with methane, both diluted with argon, were used to provide a reliable variation of C3 and C2H concentration ratio. Comparison of tests results of the two mixtures, in the temperature range of 3750 + or - 100 K, showed the main absorbing species to be C3. The wavelength for maximum absorption agrees well with the theoretical values of 7.68 eV and 8.03 eV for the vertical excitation energy, and a value of 0.90 for the electronic oscillator strength, obtained from the measured absorption band, is also in good agreement with the predicted value of 0.92.

  13. Optical properties measurement of laser coagulated tissues with double integrating sphere and inverse Monte Carlo technique in the wavelength range from 350 to 2100 nm

    NASA Astrophysics Data System (ADS)

    Honda, Norihiro; Nanjo, Takuya; Ishii, Katsunori; Awazu, Kunio

    2012-03-01

    In laser medicine, the accurate knowledge about the optical properties (absorption coefficient; μa, scattering coefficient; μs, anisotropy factor; g) of laser irradiated tissues is important for the prediction of light propagation in tissues, since the efficacy of laser treatment depends on the photon propagation within the irradiated tissues. Thus, it is likely that the optical properties of tissues at near-ultraviolet, visible and near-infrared wavelengths will be more important due to more biomedical applications of lasers will be developed. For improvement of the laser induced thermotherapy, the optical property change during laser treatment should be considered in the wide wavelength range. For estimation of the optical properties of the biological tissues, the optical properties measurement system with a double integrating sphere setup and an inverse Monte Carlo technique was developed. The optical properties of chicken muscle tissue were measured in the native state and after laser coagulation using the optical properties measurement system in the wavelength range from 350 to 2100 nm. A CO2 laser was used for laser coagulation. After laser coagulation, the reduced scattering coefficient of the tissue increased. And, the optical penetration depth decreased. For improvement of the treatment depth during laser coagulation, a quantitative procedure using the treated tissue optical properties for determination of the irradiation power density following light penetration decrease might be important in clinic.

  14. Rocket spectrogram of a solar flare in the 10-100 A region

    NASA Technical Reports Server (NTRS)

    Acton, L. W.; Bruner, M. E.; Brown, W. A.; Fawcett, B. C.; Schweizer, W.; Speer, R. J.

    1985-01-01

    The soft (10-100 A) X-ray spectrum of an M-class solar flare was observed with a high-resolution (0.02 A) rocket-borne spectrograph on 1982 July 13. The spectrum samples an area of 600/sq arcsec on the sun, centered on or near the brightest X-ray feature of the flare. Several hundred emission lines characteristic of temperatures from about 0.5 to 7 x 10 to the 6th K have been photographically recorded. All but three of the stronger lines have been identified. It is argued that previous identification of the line at 17.62 A as iron Ly-alpha is incorrect. Spectral lines from nickel, iron, chromium, calcium, sulphur, silicon, aluminium, magnesium, neon, oxygen, nitrogen, and carbon are tabulated and discussed with extensive reference to earlier work. Absolute line intensities are given and the calibration of the telescope-spectrograph is discussed.

  15. Ultrahigh wavelength range (300nm-2μm) polarization-independent 500gs/s single-shot pulse, all-optical real time oscilloscope

    NASA Astrophysics Data System (ADS)

    Gleyze, Jean-François; Hocquet, Steve; Monnier Bourdin, Dominique; Le Boudec, Patrice; Arnaud, Romain; Chassagne, Bruno; Jolly, Alain; Penninckx, Denis

    2014-03-01

    The development of ultra-broadband oscilloscopes is mainly governed by the needs of future telecom networks. But other applications are requesting the availability of true real-time acquisition oscilloscopes. Systems able to be used in single-shot operation are of prime interest for Inertial Confinement Fusion (ICF) and for the related R&D for plasma physics. We previously demonstrate a single-shot, 100GHz design of an all-optical sampling oscilloscope at 1μm (MULO). This laboratory system has been improved in stability and compactness to make an all-in-one box prototype. More, by the addition of an opto-electro-optics (OEO) sub-system at the input, we developed the ability to use this oscilloscope to analyze an electrical input signal up to 60GHz. This new integrated subset also increases the range of wavelength for optical input signal, from 300nm up to 2μm. Furthermore, it allows the use of inexpensive opto-electronic components at telecom wavelength for this system regardless of the signal to be analysed. In parallel with these improvements, by optimizing the heart of the system, we get a very high sampling rate, up to 500Gs/s and more; this allows considering much higher bandwidths in the future. In this talk, we will present latest developments and integration of this system. It will also allow us to give more details on the innovative OEO sub-system.

  16. Determination of optical properties of human blood in the spectral range 250 to 1100 nm using Monte Carlo simulations with hematocrit-dependent effective scattering phase functions.

    PubMed

    Friebel, Moritz; Roggan, André; Müller, Gerhard; Meinke, Martina

    2006-01-01

    The absorption coefficient mu(a), scattering coefficient mu(s), and anisotropy factor g of diluted and undiluted human blood (hematocrit 0.84 and 42.1%) are determined under flow conditions in the wavelength range 250 to 1100 nm, covering the absorption bands of hemoglobin. These values are obtained by high precision integrating sphere measurements in combination with an optimized inverse Monte Carlo simulation (IMCS). With a new algorithm, appropriate effective phase functions could be evaluated for both blood concentrations using the IMCS. The best results are obtained using the Reynolds-McCormick phase function with the variation factor alpha = 1.2 for hematocrit 0.84%, and alpha = 1.7 for hematocrit 42.1%. The obtained data are compared with the parameters given by the Mie theory. The use of IMCS in combination with selected appropriate effective phase functions make it possible to take into account the nonspherical shape of erythrocytes, the phenomenon of coupled absorption and scattering, and multiple scattering and interference phenomena. It is therefore possible for the first time to obtain reasonable results for the optical behavior of human blood, even at high hematocrit and in high hemoglobin absorption areas. Moreover, the limitations of the Mie theory describing the optical properties of blood can be shown.

  17. A laboratory study of the performance of the handheld diffusion size classifier (DiSCmini) for various aerosols in the 15-400 nm range.

    PubMed

    Bau, S; Zimmermann, B; Payet, R; Witschger, O

    2015-02-01

    In addition to chemical composition, particle concentration and size are among the main parameters used to characterize exposure to airborne ultrafine or nanoparticles. To assess occupational inhalation exposure, real-time instruments are recommended in recent strategies published. Among portable devices for personal exposure assessment in the workplace, DiSCmini (Matter Aerosol AG, Switzerland) has been identified as a potential candidate with its capacity to measure the airborne nanoparticle concentration and average particle size with good time-resolution. Monodisperse and polydisperse test nanoaerosols of varying compositions and morphologies were produced in the laboratory using the CAIMAN facility. These aerosols covered a range of particle sizes between 15 and 400 nm and number concentrations from 700 to 840,000 cm(-3). The aerosols were used to investigate the behavior of DiSCmini, comparing experimental data to reference data. In spite of a slight tendency to underestimate particle size, all particle diameters, number concentrations and surface area concentrations measured were in the same order of magnitude as reference data. Furthermore, no significant effect due to particle composition or morphology was noted.

  18. Electrospray synthesis of monodisperse polymer particles in a broad (60 nm-2 μm) diameter range: guiding principles and formulation recipes.

    PubMed

    Almería, Begoña; Gomez, Alessandro

    2014-03-01

    This study reports on a methodology to control the size of polymer particles generated by the electrospray (ES) drying route, with emphasis on the generation of biodegradable polymer nanoparticles that are well suited for biomedical applications. The ability to produce spherical poly(lactic-co-glycolic) acid (PLGA) particles with and without encapsulated active agent, with relative standard deviation not exceeding 15%, was demonstrated over a remarkably broad (60 nm-2 μm) diameter range. By judiciously choosing ES parameters and solution properties, we can control the monodispersity and the size of the obtained particles, tailoring it to a specific application. The main parameters affecting particle size include solution electrical conductivity, flow rate and initial polymer volume fraction. Quasi-monodispersity at both the micro- and the more challenging nano-scale was achieved by avoiding Coulomb fission in the spray droplets, via entanglement of the polymer chains within the droplets rather than by charge neutralization. Guiding principles in the formulation of the solutions to satisfy a multiplicity of constraints are provided along with an extensive database of "recipes".

  19. Ultrafast laser with an average power of 120 W at 515 nm and a highly dynamic repetition rate in the MHz range for novel applications in micromachining

    NASA Astrophysics Data System (ADS)

    Harth, F.; Piontek, M. C.; Herrmann, T.; L'huillier, J. A.

    2016-03-01

    A new generation of resonant scanners in the kHz-range shows ultra-high deflection speeds of more than 1000m/s but suffer from an inherent nonlinear mirror oscillation. If this oscillation is not compensated, a typical bitmap, written point by point, would be strongly distorted because of the decreasing spot distance at the turning point of the scanning mirror. However, this can be avoided by a dynamic adaption of the repetition rate (RR) of the ultrafast laser. Since resonant scanners are operated in the 10 kHz-range, this means that the RR has to be continuously swept up to several 10 000 times per second between e.g. 5MHz and 10 MHz. High-speed continuous adaption of the RR could also optimize laser micromachining of narrow curved geometries, where nowadays a time consuming approximation with numerous vectors is required. We present a laser system, which is capable of sweeping the RR more than 32 000 times per second between 5MHz and 10MHz at an average output power of more than 120W at 515nm with a pulse duration of about 40 ps. The laser consists of a semiconductor oscillator, a 3-stage fiber pre-amplifier, a solid state InnoSlab power amplifier and a SHG stage. We systematically analyzed the dynamic of the laser system as well as the spectral and temporal behavior of the optical pulses. Switching the repetition rate typically causes a varying pulse energy, which could affect the machining quality over one scanning line. This effect will be analyzed and discussed. Possible techniques to compensate or avoid this effect will be considered.

  20. Optical absorption and scattering properties of bulk porcine muscle phantoms from interstitial radiance measurements in 650-900 nm range.

    PubMed

    Grabtchak, Serge; Montgomery, Logan G; Whelan, William M

    2014-05-21

    We demonstrated the application of relative radiance-based continuous wave (cw) measurements for recovering absorption and scattering properties (the effective attenuation coefficient, the diffusion coefficient, the absorption coefficient and the reduced scattering coefficient) of bulk porcine muscle phantoms in the 650-900 nm spectral range. Both the side-firing fiber (the detector) and the fiber with a spherical diffuser at the end (the source) were inserted interstitially at predetermined locations in the phantom. The porcine phantoms were prostate-shaped with ∼4 cm in diameter and ∼3 cm thickness and made from porcine loin or tenderloin muscles. The described method was previously validated using the diffusion approximation on simulated and experimental radiance data obtained for homogenous Intralipid-1% liquid phantom. The approach required performing measurements in two locations in the tissue with different distances to the source. Measurements were performed on 21 porcine phantoms. Spectral dependences of the effective attenuation and absorption coefficients for the loin phantom deviated from corresponding dependences for the tenderloin phantom for wavelengths <750 nm. The diffusion constant and the reduced scattering coefficient were very close for both phantom types. To quantify chromophore presence, the plot for the absorption coefficient was matched with a synthetic absorption spectrum constructed from deoxyhemoglobin, oxyhemoglobin and water. The closest match for the porcine loin spectrum was obtained with the following concentrations: 15.5 µM (±30% s.d.) Hb, 21 µM (±30% s.d.) HbO2 and 0.3 (±30% s.d.) fractional volume of water. The tenderloin absorption spectrum was best described by 30 µM Hb (±30% s.d), 19 µM (±30% s.d.) HbO2 and 0.3 (±30% s.d.) fractional volume of water. The higher concentration of Hb in tenderloin was consistent with a dark-red appearance of the tenderloin phantom. The method can be applied to a number of

  1. Review of ultraresolution (10-100 megapixel) visualization systems built by tiling commercial display components

    NASA Astrophysics Data System (ADS)

    Hopper, Darrel G.; Haralson, David G.; Simpson, Matthew A.; Longo, Sam J.

    2002-08-01

    Ultra-resolution visualization systems are achieved by the technique of tiling many direct or project-view displays. During the past fews years, several such systems have been built from commercial electronics components (displays, computers, image generators, networks, communication links, and software). Civil applications driving this development have independently determined that they require images at 10-100 megapixel (Mpx) resolution to enable state-of-the-art research, engineering, design, stock exchanges, flight simulators, business information and enterprise control centers, education, art and entertainment. Military applications also press the art of the possible to improve the productivity of warfighters and lower the cost of providing for the national defense. The environment in some 80% of defense applications can be addressed by ruggedization of commercial components. This paper reviews the status of ultra-resolution systems based on commercial components and describes a vision for their integration into advanced yet affordable military command centers, simulator/trainers, and, eventually, crew stations in air, land, sea and space systems.

  2. COMPARATIVE STUDY OF MICROANASTOMOSIS WITH DISTINCT 10-0 NYLON SUTURES IN RATS

    PubMed Central

    Silva, Ricardo Teixeira e; Barros, Thiago Felipe Santos; de Carvalho, José Thomé; Ribeiro, André Araújo; Pires, André Fernandes; Wei, Teng Hsiang

    2016-01-01

    ABSTRACT Objective: The aim of this study is to compare micro-sutures commonly used in our midst. Methods: In this double-blind study, 30 Wistar rats were operated randomly divided into three groups matched according to the suture used (Nylon 10-0, 75micron, brands Microsuture(r), Polysuture(r) and Ethicon(r)). We analyzed the number of surgical nodes required, bleeding, surgical time and histological evaluation. Results: There was no significant difference between the amount of stitches of arterial suture per anastomosis. Surgical time was longer in Microsuture(r) group as compared to Polysuture(r) (p ≤ 0.05). Bleeding in Microsuture(r) group was higher when compared to the others (p <0.01). In the histological analysis, the Microsuture(r) group showed a greater tendency to develop fibrosis and aneurysm in surgical site than the others (p <0.01 and p≤0,05, respectively). Similarly, the Ethicon(r) group showed less tendency to myointimal proliferation than the rest. (p = 0.025). Conclusion: The results confirm the relevance of the choice of surgical thread as an independent determining factor for the success of the procedure, besides serving as a rational subsidy for a better cost-benefit analysis. Level of Evidence I, Experimental Study, Controlled Animal Study. PMID:26997912

  3. White light tunable emissions from ZnS: Eu3+ nanophosphors over 330-465 nm excitation range for white LED applications

    NASA Astrophysics Data System (ADS)

    Ahemen, I.; De, D. K.; Dejene, F. B.; Viana, B.

    2016-04-01

    (ZnS: Eu3+ - CMC) nanophosphors of cubic (zinc blende) structure were synthesized using a precipitation technique with doping concentrations of Eu3+ ions 1 mol% and 5 mol%. The crystal sizes were 2.56 nm and 2.91 nm respectively. Annealing at 300 °C in a sulfur-rich atmosphere altered the crystal size to 4.35 nm and 3.65 nm respectively and the band gap from 4.2 eV to 3.76 eV and 3.81 eV respectively. The as-synthesized samples gave pure orange-red emission when excited at wavelengths of 394 nm and 465 nm. After thermal annealing of the samples, a broad emission band in the blue-green region assigned to defect related states emerged or were enhanced. Also enhanced were the emission lines of Eu3+ ions in the orange-red region. A combination of these two transitions gave white light of different shades (recorded on the CIE 1931 chromaticity diagram) from cool white through day-light to warm white light, depending on Eu3+ concentration and the excitation wavelengths (UV-330 to blue 465 nm), thus showing great potential of these nano-phosphors in the generation of high quality white light.

  4. Spatially resolved in vivo measurement system for estimating the optical properties of tissue in the wavelength range 1000-1700 nm

    NASA Astrophysics Data System (ADS)

    Hjalmarsson, Pär; Thennadil, Suresh N.

    2007-07-01

    For non-invasive estimation of optical properties (i.e. determination of the absorption and the reduced scattering coefficients) of turbid media such as tissue, spatially resolved diffuse reflectance spectroscopy is one of most used technique. So far this has only been done for wavelengths covered by CCD-detectors (about 350-1050nm). The NIR region beyond 1050nm i.e. the second and first overtone regions, has absorption peaks of interest e.g. for tissue the glucose peak at around 1250nm and 1600nm. Thus for non-invasive medical diagnostics applications, a spatially resolved measurement system capable of estimating optical properties in this region will be very useful. Until now optical properties of tissue in this region have only been estimated using in vitro methods e.g. using an integrating sphere set-up. In this paper we describe a spatially resolved system that will extend the region up to 1700nm by using a TE cooled 320×256 pixel InGaAS detector, a white light source and a probe that consists of 9×200micron fibres spanning 0.3 to 2.7mm from the source. Across the 320 pixels 680nm will be dispersed giving a resolution of 2.125nm/pixel and a resolving power of about 14nm. The system is validated using tissue-like phantoms. Since tissue has a high concentration of water which leads to high absorption after 950nm, the diffusion approximation cannot be used to extract the optical properties from the spatially resolved measurements. Instead, two techniques based around Monte Carlo simulations of diffuse reflectance profiles, to build a lookup table coupled with interpolation using splines or a third order polynomial, have been used to calculate the optical properties for different wavelengths. The performances of these techniques are compared. It was found that the spline fitting produced lower error for the wavelength region considered.

  5. Generation of high-power femtosecond supercontinua in the near-IR spectral range using broadband parametric frequency conversion in LBO and DCDA crystals pumped at λ = 620 nm

    SciTech Connect

    Podshivalov, A A; Sidorov-Biryukov, D A; Potemkin, F V

    2014-09-30

    The pump wavelength of parametric amplifiers based on CLBO, DCDA and LBO crystals and pumped by the second harmonic of a femtosecond Cr : forsterite laser (620 nm) is close to optimal for broadband amplification because of the proximity of group velocities of interacting pulses. Injection of a broadband continuum into the range of the signal-wave gain in LBO and DCDA parametric amplifiers, pumped at λ = 620 nm, leads to generation of broadband femtosecond pulses with a spectrum ranging from 1050 to 1600 nm and peak powers up to 20 MW. (nonlinear optical phenomena)

  6. UV spectroscopy of Titan's atmosphere, planetary organic chemistry and prebiological synthesis. II - Interpretation of new IUE observations in the 220-335 nm range

    NASA Technical Reports Server (NTRS)

    Courtin, Regis; Wagener, Richard; Mckay, Christopher P.; Caldwell, John; Fricke, Karl-Heinrich

    1991-01-01

    The theoretical model developed by McKay et al. (1989) to characterize the size distribution, thermal structure, and chemical composition of the stratospheric haze of Titan is applied to new 220-335-nm albedo measurements obtained with the long-wavelength prime camera of the IUE during August 1987. Data and model predictions are presented in extensive graphs and discussed in detail. It is shown that a simple model with particles of one size at a given altitude does not accurately reproduce the observed features in all spectral regions, but that good general agreement is obtained using a model with a uniformly mixed layer at 150-600 km and a bimodal distribution of small 'polymer' haze particles (radius less than 20 nm) and larger haze particles (radius 100-500 nm). The number densities implied by this model require, however, a mechanism such as electrostatic charging or reaction kinetics to inhibit coagulation of the smaller particles.

  7. Broadband time-resolved diffuse optical spectrometer for clinical diagnostics: characterization and in-vivo measurements in the 600-1350 nm spectral range

    NASA Astrophysics Data System (ADS)

    Konugolu Venkata Sekar, Sanathana; Farina, Andrea; Martinenghi, Edoardo; Dalla Mora, Alberto; Taroni, Paola; Pifferi, Antonio; Durduran, Turgut; Pagliazzi, Marco; Lindner, Claus; Farzam, Parisa; Mora, Mireia; Squarcia, Mattia; Urbano-Ispizua, A.

    2015-07-01

    We report on the design, performance assessment, and first in vivo measurement of a Time-Resolved Diffuse Optical system for broadband (600-1350 nm) nm measurement of absorption and scattering spectra of biological tissues for non-invasive clinical diagnostics. Two strategies to reduce drift and enhance responsivity are adopted. The system was enrolled in a first in vivo test phase on healthy volunteers, carrying out non-invasive, in vivo quantification of key tissue constituents (oxy- and deoxy-hemoglobin, water, lipids, collagen) and tissue micro-structure (scatterer size and density).

  8. Dual-color multiple-particle tracking at 50-nm localization and over 100-µm range in 3D with temporal focusing two-photon microscopy

    PubMed Central

    Ding, Yu; Li, Chunqiang

    2016-01-01

    Nanoscale particle tracking in three dimensions is crucial to directly observe dynamics of molecules and nanoparticles in living cells. Here we present a three-dimensional particle tracking method based on temporally focused two-photon excitation. Multiple particles are imaged at 30 frames/s in volume up to 180 × 180 × 100 µm3. The spatial localization precision can reach 50 nm. We demonstrate its capability of tracking fast swimming microbes at speed of ~200 µm/s. Two-photon dual-color tracking is achieved by simultaneously exciting two kinds of fluorescent beads at 800 nm to demonstrate its potential in molecular interaction studies. Our method provides a simple wide-field fluorescence imaging approach for deep multiple-particle tracking. PMID:27867724

  9. [Two-photon excitation fluorescence spectrum of the light-harvesting complex LH2 from Chromatium minutissimum within 650-745 nm range is determined by two-photon absorption of bacteriochlorophyll rather than of carotenoids].

    PubMed

    Krikunova, M A; Leupold, D; Rini, M; Voigt, B; Moskalenko, A A; Toropygina, O A; Razzhivin, A P

    2002-01-01

    Two-photon fluorescence excitation spectra of the peripheral light-harvesting complex LH2 from the purple photosynthetic bacterium Chromatium minutissimum were examined within the expected spectral range of the optically forbidden S1 singlet state of carotenoids. LH2 preparations isolated from wild-type and carotenoid-depleted cells were used. 100-fs laser pulses in the range of 1300-1490 nm with an energy of 7-9 mW (corresponding to one-photon absorption between 650 and 745 nm) were used for two-photon fluorescence excitation. It was shown that two-photon fluorescence excitation spectra of LH2 complex from wild and carotenoid-depleted cells are very similar to each other and to the two-photon fluorescence excitation spectrum of bacteriochlorophyll a in acetone. It was concluded that direct two-photon excitation of bacteriochlorophyll a determines the fluorescence of both samples within the 650-745 nm spectral range.

  10. Time-dependent seafloor acoustic backscatter (10-100 kHz).

    PubMed

    Sternlicht, Daniel D; de Moustier, Christian P

    2003-11-01

    A time-dependent model of the acoustic intensity backscattered by the seafloor is described and compared with data from a calibrated, vertically oriented, echo-sounder operating at 33 and 93 kHz. The model incorporates the characteristics of the echo-sounder and transmitted pulse, and the water column spreading and absorption losses. Scattering from the water-sediment interface is predicted using Helmholtz-Kirchhoff theory, parametrized by the mean grain size, the coherent reflection coefficient, and the strength and exponent of a power-law roughness spectrum. The composite roughness approach of Jackson et al. [J. Acoust. Soc. Am. 79, 1410-1422 (1986)], modified for the finite duration of the transmitted signal, is used to predict backscatter from subbottom inhomogeneities. It depends on the sediment's volume scattering and attenuation coefficients, as well as the interface characteristics governing sound transmission into the sediment. Estimation of model parameters (mean grain size, roughness spectrum strength and exponent, volume scattering coefficient) reveals ambiguous ranges for the two spectral components. Analyses of model outputs and of physical measurements reported in the literature yield practical constraints on roughness spectrum parameter settings appropriate for echo-envelope-based sediment classification procedures.

  11. Status of the NEXT Ion Thruster Long-Duration Test After 10,100 hr and 207 kg Demonstrated

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.

    2008-01-01

    The NASA s Evolutionary Xenon Thruster (NEXT) program is developing the next-generation ion propulsion system with significant enhancements beyond the state-of-the-art in ion propulsion to provide future NASA science missions with enhanced mission capabilities at a low total development cost. As part of a comprehensive thruster service life assessment utilizing both testing and analyses, a Long-Duration Test (LDT) was initiated to validate and qualify the NEXT propellant throughput capability to a qualification-level of 450 kg, 1.5 times the mission-derived throughput requirement of 300 kg. This wear test is being conducted with a modified, flight-representative NEXT engineering model ion thruster, designated EM3. As of June 21, 2007, the thruster has accumulated 10,100 hr of operation at the thruster full-input-power of 6.9 kW with 3.52 A beam current and 1800 V beam power supply voltage. The thruster has processed 207 kg of xenon and demonstrated a total impulse of 8.5 106 N-s; the highest total impulse ever demonstrated by an ion thruster in the history of space propulsion. Thruster performance tests are conducted periodically over the entire NEXT throttle table with input power ranging 0.5 to 6.9 kW. Overall ion thruster performance parameters including thrust, input power, specific impulse, and thruster efficiency have been nominal with little variation to date. Lifetime-limiting component erosion rates have been consistent with the NEXT service life assessment, which predicts the earliest failure sometime after 750 kg of xenon propellant throughput; well beyond the mission-derived lifetime requirement. The NEXT wear test data confirm that the erosion of the discharge keeper orifice, enlarging of nominal-current-density accelerator grid aperture cusps, and the decrease in cold grid-gap observed during the NSTAR Extended Life Test have been mitigated. This paper presents the status of the NEXT LDT to date.

  12. Lidar Measurements of the MLT Thermal Structure At Maui, HI (20.7çN) And Starfire Optical Range, NM (35çN)

    NASA Astrophysics Data System (ADS)

    Chu, X.; Gardner, C. S.; Franke, S. J.; Liu, A. Z.; Swenson, G. R.

    2004-12-01

    The University of Illinois Na wind/temperature lidar was coupled to large astronomical telescopes at the Starfire Optical Range (SOR) in Albuquerque, New Mexico (35.0çN, 106.5çW), and at the Maui Space Surveillance Complex on the top of the Haleakala in Maui, Hawaii (20.7çN, 156.3çW). Hundreds of hours of high-quality temperature and wind data have been collected at these two locations. This provided us a good opportunity to study the subtropical thermal structure of the mesosphere and lower thermosphere (MLT) region, and make comparisons with mid-latitudes. We also compared the observations with the MSIS-00 model. Both locations exhibit mesospheric temperature inversion layers (MIL) between 85 and 100 km, which are not predicted by the MSIS-00 model. The amplitudes of the Maui MILs are about half of those at SOR and the Maui MILs have a smaller width compared to the SOR MILs. The Maui lidar temperatures are generally warmer than the MSIS-00 predictions, while the SOR lidar data are comparable to the MSIS-00 except in the MIL altitude range. Both SOR and Maui mesopause temperatures are coldest in mid-summer and warmest during the mesopause transition periods. However, the Maui mesopause is warmer than the SOR, and the amplitude of the mesopause temperature variations at Maui is much smaller than at SOR. Two distinct levels of mesopause altitudes are clearly shown in the SOR seasonal data with a low altitude around 86.5 km in summer (May through August) and a high altitude around 101 km during the rest of the year. Abrupt transitions between the two stable levels occur in early May and early September. At Maui, the lidar measurements indicate a low mesopause altitude near 87.5 km in July when averaging over a 10-h period centered at local midnight. Tides strongly influence the MLT temperature and the mesopause structure. The composite night in July shows that the lowest temperature is near 87.5 km at the beginning of the night and then switches to a higher

  13. Design of a high charge (10 - 100 nC) and short pulse (2 - 5 ps) rf photocathode gun for wakefield acceleration.

    SciTech Connect

    Gai, W.

    1998-07-16

    In this paper we present a design report on a 1-1/2 cell, L Band RF photocathode gun that is capable of generating and accelerating electron beams with peak currents >10 kA. We have performed simulation for bunch intensities in the range of 10-100 nC with peak axial electrical field at the photocathode of 30-100 MV/m. Unlike conventional short electron pulse generation, this design does not require magnetic pulse compression. Based on numerical simulations using SUPERFISH and PARMELA, this design will produce 20-100 nC beam at 18 MeV with rms bunch length 0.6-1.25 mm and normalized transverse emittance 30-108 mm mrad. Applications of this beam for wakefield acceleration is also discussed.

  14. CFD Analysis of Coolant Flow in VVER-440 Fuel Assemblies with the Code ANSYS CFX 10.0

    SciTech Connect

    Toth, Sandor; Legradi, Gabor; Aszodi, Attila

    2006-07-01

    From the aspect of planning the power upgrading of nuclear reactors - including the VVER-440 type reactor - it is essential to get to know the flow field in the fuel assembly. For this purpose we have developed models of the fuel assembly of the VVER-440 reactor using the ANSYS CFX 10.0 CFD code. At first a 240 mm long part of a 60 degrees segment of the fuel pin bundle was modelled. Implementing this model a sensitivity study on the appropriate meshing was performed. Based on the development of the above described model, further models were developed: a 960 mm long part of a 60-degree-segment and a full length part (2420 mm) of the fuel pin bundle segment. The calculations were run using constant coolant properties and several turbulence models. The impacts of choosing different turbulence models were investigated. The results of the above-mentioned investigations are presented in this paper. (authors)

  15. Evaluation of the diffusion size classifier (meDiSC) for the real-time measurement of particle size and number concentration of nanoaerosols in the range 20-700 nm.

    PubMed

    Bau, Sébastien; Jacoby, Jonathan; Witschger, Olivier

    2012-03-01

    In the frame of assessing exposure to nanostructured particles, the aim of this work is to study the performance of a new device devoted to the real-time measurement of nanostructured aerosol: the meDiSC (Diffusion Size Classifier, Matter Engineering, Switzerland). This instrument is based on unipolar diffusion charging of particles which are then collected successively in diffusion and filtration stages. From currents measured in these stages, the instrument is capable of determining aerosol mean size and number concentration. These data were compared to reference measurements regarding monodisperse aerosols in a range from 20 to 700 nm; the relative biases were found unsatisfying. This led us to investigate the principle of the instrument. Consequently, the charging law of the diffusion charger was experimentally established, as well as the calibration curve allowing the determination of the mean size of the particles. The latter analysis was completed by a model based on diffusion theory. Our results indicate the possibility to improve the range of size measurement up to 350 nm. Measured particle size and number concentration were also used to calculate geometric surface-area concentration; the experimental data were compared to a reference calculated surface-area concentration. The results demonstrate the possibility to evaluate this parameter within acceptable uncertainty. In a second step, the meDiSC was challenged with polydisperse aerosols. It was observed that meDiSC overestimates particle size by a factor 1.7, while particle number concentrations are found within ±40% of the reference. The model applied to polydisperse aerosols indicates that polydispersity little influences particle size up to 300 nm while geometric standard deviation remains below 1.7.

  16. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    SciTech Connect

    Karcı, Özgür; Dede, Münir

    2014-10-01

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ~12 fm/√Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system.

  17. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    NASA Astrophysics Data System (ADS)

    Karcı, Özgür; Dede, Münir; Oral, Ahmet

    2014-10-01

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ˜12 fm/√Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system.

  18. Experimental determination of the steady-state charging probabilities and particle size conservation in non-radioactive and radioactive bipolar aerosol chargers in the size range of 5-40 nm

    NASA Astrophysics Data System (ADS)

    Kallinger, Peter; Szymanski, Wladyslaw W.

    2015-04-01

    Three bipolar aerosol chargers, an AC-corona (Electrical Ionizer 1090, MSP Corp.), a soft X-ray (Advanced Aerosol Neutralizer 3087, TSI Inc.), and an α-radiation-based 241Am charger (tapcon & analysesysteme), were investigated on their charging performance of airborne nanoparticles. The charging probabilities for negatively and positively charged particles and the particle size conservation were measured in the diameter range of 5-40 nm using sucrose nanoparticles. Chargers were operated under various flow conditions in the range of 0.6-5.0 liters per minute. For particular experimental conditions, some deviations from the chosen theoretical model were found for all chargers. For very small particle sizes, the AC-corona charger showed particle losses at low flow rates and did not reach steady-state charge equilibrium at high flow rates. However, for all chargers, operating conditions were identified where the bipolar charge equilibrium was achieved. Practically, excellent particle size conservation was found for all three chargers.

  19. Experimental investigation of transport of discrete solids with surge flows in a 10.0 cm diameter partially filled pipe

    NASA Astrophysics Data System (ADS)

    Mahajan, B. M.

    1982-01-01

    The transport of discrete solids with surge flows in a partially filled slightly pitched horizontal pipe was investigated. The experimental apparatus, instrumentation, and procedures are described. The experiments were conducted using a cylindrical solid in a 10.0 cm (4 in) diameter pipe. The water surge flows were obtained by discharging different volumes of water into the pipe from a falling head open container which simulated a water closet. Flow induced solid velocities and stream depth histories at various locations along the length of the pipe were measured. The effects of water volume used, pipe slope, and size of the solid on the solid velocities were examined. Solid velocities were compared with the maximum water velocities estimated from the stream depth histories. Also, the distance traversed by the solids in the pipe were measured for those cases in which the solids did not clear the pipe. The solid velocity increased with an increase in water volume used, a decrease in the size of the solid, and an increase in the pipe slope. The solid velocity in the initial reach of the pipe was less than the maximum water velocity; and the solid velocity approaches the maximum water velocity as the solid traveled downstream, except for some experiments with small water volumes.

  20. When Anatase Nanoparticles Become Bulklike: Properties of Realistic TiO2 Nanoparticles in the 1-6 nm Size Range from All Electron Relativistic Density Functional Theory Based Calculations.

    PubMed

    Lamiel-Garcia, Oriol; Ko, Kyoung Chul; Lee, Jin Yong; Bromley, Stefan T; Illas, Francesc

    2017-03-10

    All electron relativistic density functional theory (DFT) based calculations using numerical atom-centered orbitals have been carried out to explore the relative stability, atomic, and electronic structure of a series of stoichiometric TiO2 anatase nanoparticles explicitly containing up to 1365 atoms as a function of size and morphology. The nanoparticles under scrutiny exhibit octahedral or truncated octahedral structures and span the 1-6 nm diameter size range. Initial structures were obtained using the Wulff construction, thus exhibiting the most stable (101) and (001) anatase surfaces. Final structures were obtained from geometry optimization with full relaxation of all structural parameters using both generalized gradient approximation (GGA) and hybrid density functionals. Results show that, for nanoparticles of a similar size, octahedral and truncated octahedral morphologies have comparable energetic stabilities. The electronic structure properties exhibit a clear trend converging to the bulk values as the size of the nanoparticles increases but with a marked influence of the density functional employed. Our results suggest that electronic structure properties, and hence reactivity, for the largest anatase nanoparticles considered in this study will be similar to those exhibited by even larger mesoscale particles or by bulk systems. Finally, we present compelling evidence that anatase nanoparticles become effectively bulklike when reaching a size of ∼20 nm diameter.

  1. Growth and magnetic properties of vertically aligned epitaxial CoNi nanowires in (Sr, Ba)TiO3 with diameters in the 1.8-6 nm range

    NASA Astrophysics Data System (ADS)

    Schuler, V.; Milano, J.; Coati, A.; Vlad, A.; Sauvage-Simkin, M.; Garreau, Y.; Demaille, D.; Hidki, S.; Novikova, A.; Fonda, E.; Zheng, Y.; Vidal, F.

    2016-12-01

    The growth by pulsed laser deposition of fully epitaxial nanocomposites made of Co x Ni1-x nanowires (NW) vertically self-assembled in Sr0.5Ba0.5TiO3/SrTiO3(001) layers is reported. The diameter of the wires can be tuned in the 1.8-6 nm range. The composition of the wires can be controlled, with the growth sequence and the fcc crystallographic structure of the wires preserved for Co content up to 78%. The nanocomposite systems obtained display a uniaxial magnetic anisotropy with out-of-plane easy axis as shown through analysis of ferromagnetic resonance measurements. It is shown that the magnitude of the magnetic anisotropy depends sensitively on the structural quality of the nanocomposites.The energy barrier for magnetization reversal scales as the square of the diameter of the NW and reaches 60 {k}{{B}}{T}{{amb}} for 6 nm diameter, with T amb = 300 K.

  2. Total electron loss, charge transfer, and ionization in proton-hydrogen collisions at 10-100 keV

    NASA Astrophysics Data System (ADS)

    Kołakowska, A.; Pindzola, M. S.; Schultz, D. R.

    1999-05-01

    A three-dimensional lattice solution of the time-dependent Schrödinger equation for low quantum states (n<=3) is combined with classical trajectory Monte Carlo results for high quantum states (n>=4) to predict total electron loss and total charge-transfer cross sections for proton collisions with atomic hydrogen at intermediate energies. The total charge-transfer cross sections range from 5% above to 10% below the furnace target measurements of McClure [Phys. Rev. 148, 47 (1966)], while the total electron-loss cross sections range from 5% to 15% above the pulsed crossed-beams measurements of Shah, Elliot, and Gilbody [J. Phys. B 20, 3501 (1987)]. The calculation of ionization as a difference between electron loss and charge transfer leads to theoretical ionization cross sections that are 10% to 35% larger than the crossed-beams measurements of Shah and Gilbody [J. Phys. B 14, 2361 (1981)] and Shah, Elliott, and Gilbody [J. Phys. B 20, 2481 (1987)].

  3. Gamma-Ray Bursts in the One of the Last Frontiers: the 10-100 GeV Energy Band

    NASA Astrophysics Data System (ADS)

    Tam, P. H. Thomas

    2016-07-01

    Thanks to many space-borne detectors such as the Swift and Fermi satellites and numerous ground-based followed-up telescopes, gamma-ray bursts (GRBs) are now quickly covered in virtually every wavelength in the electromagnetic spectrum. Covering the energy range above 30 MeV, the Fermi-LAT has seen more than a hundred GRBs and have seen tens of photons above 10 GeV from several bright GRBs, limited by its collective area. In this talk, I will review recent GRB observations at >10 GeV up to nearly a day after the burst, including that of GRB 130427A and some recent GRBs, and discuss the corresponding radiation mechanisms in the afterglow at these energies.

  4. Modeling Relativistic Electron Precipitation Bremsstrahlung X-Ray Intensities at 10-100 km Manned Vehicle Altitudes

    NASA Astrophysics Data System (ADS)

    Habash Krause, L.; Gilchrist, B. E.; Nishikawa, K.; Williams, A.

    2013-12-01

    Relativistic electron precipitation (REP) events occur when beams or bunches of relativistic electrons of magnetospheric origin enter the Earth's atmosphere, typically at auroral latitudes. REP events are associated with a variety of space weather effects, including production of transitional and bremsstrahlung radiation, catalytic depletion of stratospheric ozone, and scintillation of transionospheric radio waves. This study examines the intensities of x-rays produced at airliner, manned balloon, and suborbital Reusable Launch Vehicle (sRLV) altitudes. The monoenergetic beam is modeled in cylindrical symmetry using the paraxial ray equation. Bremsstrahlung photon production is calculated using the traditional Sauter-Elwert cross-section, providing x-ray emission spectra differential in energy and angle. Attenuation is computed for a plane-stratified standard atmosphere, and the loss processes include photoionization, Rayleigh and Compton scattering, electron-positron pair production, and photonuclear interaction. Peak altitudes of electron energy deposition and bremsstrahlung x-ray production were calculated for beams of energies from 1 MeV through 100 MeV. The altitude peak of bremsstrahlung deposition was consistently and significantly lower that that of the electron deposition due to the longer mean free paths of x-rays compared to electrons within the atmosphere. For example, for a nadir-directed monoenergetic 5 MeV beam, the peak deposition altitude was calculated to be 42 km, but the resulting bremmstrahlung deposition peaked at 25 km. This has implications for crew and passenger safety, especially with the growth of the space tourism industry that relies on sRLVs with a nominal apogee of 100 km. A survey of results covering the 1-100 MeV spectrum for the three altitude ranges of interest will be presented.

  5. Modeling Relativistic Electron Precipitation Bremsstrahlung X-Ray Intensities at 10-100 km Manned Vehicle Altitudes

    NASA Technical Reports Server (NTRS)

    Krause, L. Habsh; Gilchrist, B. E.; Nishikawa, Ken-Ichi

    2013-01-01

    Relativisitic electron precipitation (REP) events occur when beams or bunches of relativistic electrons of magnetospheric origin enter the Earth's atmosphere, typically at auroral latitudes. REP events are associated with a variety of space weather effects, including production of transitional and bremsstrahlung radiation, catalytic depletion of stratospheric ozone, and scintillation of transionospheric radio waves. This study examines the intensities of x-rays produced at airliner, manned balloon, and space reuseable launch vehicles (sRLVs). The monoenergetic beam is modeled in cylindrical symetry using the paraxial ray equation. Bremsstrahlung photon production is calculated using the traditional Sauter-Elwert cross-section, providing x-ray emission spectra differential in energy and angle. Attenuation is computed for a plane-stratified standard atmosphere, and the loss processes include photoionization, Rayleigh and Compton scattering, electron-positron pair production, and photonuclear interaction. Peak altitudes of electron energy deposition and bremsstrahlung x-ray production were calculated for beams of energies from 1 MeV through 100 MeV. The altitude peak of bremsstrahlung deposition was consistently and significantly lower that that of the electron deposition due to the longer mean free paths of x-rays compared to electrons within the atmosphere. For example, for a nadir-directed monoenergetic 5 MeV beam, the peak deposition altitude was calculated to be 42 km, but the resulting bremsstrahlung deposition peaked at 25 km. This has implications for crew and passenger safety, especially with the growth of the space tourism industry. A survey of results covering the 1-100 MeV spectrum for the three altitude ranges of interest will be presented.

  6. Sub-10 nm nanopantography

    NASA Astrophysics Data System (ADS)

    Tian, Siyuan; Donnelly, Vincent M.; Ruchhoeft, Paul; Economou, Demetre J.

    2015-11-01

    Nanopantography, a massively parallel nanopatterning method over large areas, was previously shown to be capable of printing 10 nm features in silicon, using an array of 1000 nm-diameter electrostatic lenses, fabricated on the substrate, to focus beamlets of a broad area ion beam on selected regions of the substrate. In the present study, using lens dimensional scaling optimized by computer simulation, and reduction in the ion beam image size and energy dispersion, the resolution of nanopantography was dramatically improved, allowing features as small as 3 nm to be etched into Si.

  7. Neutron structure of human carbonic anhydrase II: A hydrogen bonded water network switch is observed between pH 7.8 and 10.0.

    SciTech Connect

    Fisher, Zoe; Langan, Paul; Mustyakimov, Marat; Kovalevsky, Andrey

    2011-01-01

    The neutron structure of wild type human carbonic anhydrase II at pH 7.8 has been determined to 2.0 resolution. Detailed analysis and comparison to the previous determined structure at pH 10.0 shows important differences in protonation of key catalytic residues in the active site as well as a rearrangement of the hydrogen bonded water network. For the first time, a completed hydrogen bonded network stretching from the Zn-bound solvent to the proton shuttling residue His64 has been directed observed.

  8. Neutron structure of human carbonic anhydrase II: a hydrogen-bonded water network "switch" is observed between pH 7.8 and 10.0.

    PubMed

    Fisher, Zoë; Kovalevsky, Andrey Y; Mustyakimov, Marat; Silverman, David N; McKenna, Robert; Langan, Paul

    2011-11-08

    The neutron structure of wild-type human carbonic anhydrase II at pH 7.8 has been determined to 2.0 Å resolution. Detailed analysis and comparison to the previously determined structure at pH 10.0 show important differences in the protonation of key catalytic residues in the active site as well as a rearrangement of the H-bonded water network. For the first time, a completed H-bonded network stretching from the Zn-bound solvent to the proton shuttling residue, His64, has been directly observed.

  9. Microwave ablation at 10.0 GHz achieves comparable ablation zones to 1.9 GHz in ex vivo bovine liver.

    PubMed

    Luyen, Hung; Gao, Fuqiang; Hagness, Susan C; Behdad, Nader

    2014-06-01

    We demonstrate the feasibility of using high-frequency microwaves for tissue ablation by comparing the performance of a 10 GHz microwave ablation system with that of a 1.9 GHz system. Two sets of floating sleeve dipole antennas operating at these frequencies were designed and fabricated for use in ex vivo experiments with bovine livers. Combined electromagnetic and transient thermal simulations were conducted to analyze the performance of these antennas. Subsequently, a total of 16 ablation experiments (eight at 1.9 GHz and eight at 10.0 GHz) were conducted at a power level of 42 W for either 5 or 10 min. In all cases, the 1.9 and 10 GHz experiments resulted in comparable ablation zone dimensions. Temperature monitoring probes revealed faster heating rates in the immediate vicinity of the 10.0 GHz antenna compared to the 1.9 GHz antenna, along with a slightly delayed onset of heating farther from the 10 GHz antenna, suggesting that heat conduction plays a greater role at higher microwave frequencies in achieving a comparably sized ablation zone. The results obtained from these experiments agree very well with the combined electromagnetic/thermal simulation results. These simulations and experiments show that using lower frequency microwaves does not offer any significant advantages, in terms of the achievable ablation zones, over using higher frequency microwaves. Indeed, it is demonstrated that high-frequency microwave antennas may be used to create reasonably large ablation zones. Higher frequencies offer the advantage of smaller antenna size, which is expected to lead to less invasive interstitial devices and may possibly lead to the development of more compact multielement arrays with heating properties not available from single-element antennas.

  10. Albuquerque, NM, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Albuquerque, NM (35.0N, 106.5W) is situated on the edge of the Rio Grande River and flood plain which cuts across the image. The reddish brown surface of the Albuquerque Basin is a fault depression filled with ancient alluvial fan and lake bed sediments. On the slopes of the Manzano Mountains to the east of Albuquerque, juniper and other timber of the Cibola National Forest can be seen as contrasting dark tones of vegetation.

  11. Specific Volumes of the Zr(41.2)Ti(13.8)Cu(12.5)Ni(10.0)Be(22.5) Alloy in the Liquid, Glass, and Crystalline States

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Chung, S. K.; Rhim, W. K.; Johnson, W. L.; Peker, A.; Scruggs, D.

    1997-01-01

    The specific volumes of the Zr(41.2)Ti(3.8)Cu(2.5)Ni(10.0)Be(22.5) alloy as a function of temperature, T, are determined by employing an image digitizing technique and numerical calculation methods applied to the electrostatically levitated spherical alloy. The linear fitting of the volumes of the alloy in the liquid, V(sub l), glass, V(sub g) and crystalline V(sub c), states in the temperature ranges shown in parentheses are V(sub l)(T) = 0.1583 + 8.877 x 10(exp -6) T(cu cm/g) (700-1300 K);V(sub g)(T) = 0.1603 + 5.528 x 10(exp -6) T (400-550 K);V(sub c)(T) = 0.1583 + 6.21 x 10(exp -6)T(400-850 K). The average volume thermal expansion coefficients within the temperature ranges are determined to be 5.32, 3.39. and 3.83 x 10(exp -5) (1/K) for the liquid, glass, and crystalline states, respectively.

  12. Full-vector paleomagnetic secular variation records from latest quaternary sediments of Lake Malawi (10.0°S, 34.3°E)

    NASA Astrophysics Data System (ADS)

    Lund, Steve; Platzman, Ellen; Johnson, Tom

    2016-07-01

    We have conducted a paleomagnetic study of Late Quaternary sediments from Lake Malawi, East Africa, in order to develop a high-resolution record of paleomagnetic secular variation (PSV). This study has recovered PSV records from two cores (3P, 6P) in northern Lake Malawi (10.0°S, 34.3°E). The PSV appears to be recorded in fine-grained detrital magnetite/titanomagnetite grains. Detailed af demagnetization of the natural remanence (NRM) shows that a distinctive characteristic remanence (ChRM) is demagnetized from ∼20 to 80 mT, which decreases simply toward the origin. The resulting directional PSV records for 3P and 6P are easily correlatable with 29 distinct inclination features and 29 declination features. The statistical character of the PSV in both cores is consistent with Holocene PSV noted at other Holocene equatorial sites. Radiocarbon dating of the cores is based on 18 independent radiocarbon dates and four dated stratigraphic horizons that can be correlated into each core. The final directional PSV time series cover the last 24,000 years with an average sediment accumulation rate of ∼30 cm/kyr. We have also developed a relative paleointensity estimate for these PSV records based on normalizing the NRM (after 20 mT af demagnetization) by the SIRM (after 20 mT af demagnetization). Changing sedimentation patterns complicate any attempt to develop a single paleointensity record for the entire core lengths. We have developed a relative paleointensity record for the last 6000 years that has 14 correlatable features including 5 notable peaks in intensity. Three of these peaks are synchronous with paleointensity highs farther north in SE Europe/SW Asia/Egypt but two of the peaks are at times of low paleointensity farther north. We interpret this to indicate that Lake Malawi (10°S) is at least partly under the influence of a different flux-regeneration region of the outer-core dynamo. A relative paleointensity record was also developed for ∼11,000-24,000 YBP; the general pattern appears to be consistent with other published records, but our confidence in the correlations is more limited.

  13. 3 Watt CW OPO tunable 604nm to 616nm for quantum optics applications

    NASA Astrophysics Data System (ADS)

    Henderson, Angus; Halfmann, Thomas; Mieth, Simon

    2012-06-01

    A continuous wave optical parametric oscillator (CW OPO) pumped by a fiber laser has been developed which emits up to 3 Watts of single longitudinal mode radiation tunable in the wavelength range 604nm to 616nm. The device is a modified version of the ``Argos'' Model 2400 commercial product by Lockheed Martin Aculight. A 15 Watt 1064nm fiber laser pumps a CW OPO based upon periodically-poled Lithium Niobate (PPLN). A short section of the nonlinear crystal is poled to allow efficient intracavity sum frequency generation (SFG) between the OPO pump and signal wavelengths to generate orange radiation. The device can be coarsely tuned by matching the poling periods and temperature within the nonlinear crystal to phase-match both OPO and SFG processes simultaneously. Fine mode-hop-free tuning of the orange wavelength of up to 100GHz range can be achieved by applying a voltage to a PZT which tunes the pump laser. By similar intracavity conversion schemes, the system offers the potential of providing high power at wavelengths from 600nm to 1400nm in addition to the direct signal and idler wavelength ranges from 1400nm to 4630nm. Such capability comes without the complexity and reliability issues which are inherent in dye and Ti:Sapphire systems. Details of the OPO system performance and its use in quantum optics applications will be provided.

  14. Laser damage database at 1064 nm

    SciTech Connect

    Rainer, F.; Gonzales, R.P.; Morgan, A.J.

    1990-03-01

    In conjunction with our diversification of laser damage testing capabilities, we have expanded upon a database of threshold measurements and parameter variations at 1064 nm. This includes all tests at low pulse-repetition frequencies (PRF) ranging from single shots to 120 Hz. These tests were conducted on the Reptile laser facility since 1987 and the Variable Pulse Laser (VPL) facility since 1988. Pulse durations ranged from 1 to 16 ns. 10 refs., 14 figs.

  15. Photobiomodulation of human adipose-derived stem cells using 810nm and 980nm lasers operates via different mechanisms of action.

    PubMed

    Wang, Yuguang; Huang, Ying-Ying; Wang, Yong; Lyu, Peijun; Hamblin, Michael R

    2017-02-01

    Photobiomodulation (PBM) using red or near-infrared (NIR) light has been used to stimulate the proliferation and differentiation of adipose-derived stem cells. The use of NIR wavelengths such as 810nm is reasonably well accepted to stimulate mitochondrial activity and ATP production via absorption of photons by cytochrome c oxidase. However, the mechanism of action of 980nm is less well understood. Here we study the effects of both wavelengths (810nm and 980nm) on adipose-derived stem cells in vitro. Both wavelengths showed a biphasic dose response, but 810nm had a peak dose response at 3J/cm(2) for stimulation of proliferation at 24h, while the peak dose for 980nm was 10-100 times lower at 0.03 or 0.3J/cm(2). Moreover, 980nm (but not 810nm) increased cytosolic calcium while decreasing mitochondrial calcium. The effects of 980nm could be blocked by calcium channel blockers (capsazepine for TRPV1 and SKF96365 for TRPC channels), which had no effect on 810nm. To test the hypothesis that the chromophore for 980nm was intracellular water, which could possibly form a microscopic temperature gradient upon laser irradiation, we added cold medium (4°C) during the light exposure, or pre-incubated the cells at 42°C, both of which abrogated the effect of 980nm but not 810nm. We conclude that 980nm affects temperature-gated calcium ion channels, while 810nm largely affects mitochondrial cytochrome c oxidase.

  16. A propagation effects handbook for satellite systems design. A summary of propagation impairments on 10-100 GHz satellite links, with techniques for system design. [tropospheric scattering

    NASA Technical Reports Server (NTRS)

    Kaul, R.; Wallace, R.; Kinal, G.

    1980-01-01

    This handbook provides satellite system engineers with a concise summary of the major propagation effects experienced on Earth-space paths in the 10 to 100 GHz frequency range. The dominant effect, attenuation due to rain, is dealt with in terms of both experimental data from measurements made in the U.S. and Canada, and the mathematical and conceptual models devised to explain the data. Rain systems, rain and attenuation models, depolarization and experimental data are described. The design techniques recommended for predicting propagation effects in Earth-space communications systems are presented. The questions of where in the system design process the effects of propagation should be considered, and what precautions should be taken when applying the propagation results are addressed in order to bridge the gap between the propagation research data and the classical link budget analysis of Earth-space communications system.

  17. 551 nm Generation by sum-frequency mixing of intracavity pumped Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Dong, Y.; Li, S. T.; Zhang, X. H.

    2012-02-01

    We present for the first time a Nd:YAG laser emitting at 1319 nm intracavity pumped by a 946 nm diode-pumped Nd:YAG laser. A 809 nm laser diode is used to pump the first Nd:YAG crystal emitting at 946 nm, and the second Nd:YAG laser emitting at 1319 nm intracavity pumped at 946 nm. Intracavity sumfrequency mixing at 946 and 1319 nm was then realized in a LBO crystal to reach the yellow range. We obtained a continuous-wave output power of 158 mW at 551 nm with a pump laser diode emitting 18.7 W at 809 nm.

  18. 15 CFR 10.0 - General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... current with respect to advancing technology and marketing practices. (e) Role of the National Institute of Standards & Technology. The National Institute of Standards & Technology (NIST) administers these... installation procedures. Economic growth is promoted through: (1) Reduction of manufacturing costs,...

  19. 15 CFR 10.0 - General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., performance criteria, inspection requirements, marking requirements, testing equipment, test procedures and..., clarifications, appeals) should be addressed to the Office of Product Standards Policy, National Institute...

  20. 15 CFR 10.0 - General.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., performance criteria, inspection requirements, marking requirements, testing equipment, test procedures and... purchase, installation, and use of the product being standardized. (b) Requirements for Department of... organization concerned with the manufacture, production, packaging, distribution, testing, consumption, or...

  1. Characterization of LANDSAT Panels Using the NIST BRDF Scale from 1100 nm to 2500 nm

    NASA Technical Reports Server (NTRS)

    Markham, Brian; Tsai, Benjamin K.; Allen, David W.; Cooksey, Catherine; Yoon, Howard; Hanssen, Leonard; Zeng, Jinan; Fulton, Linda; Biggar, Stuart; Markham, Brian

    2010-01-01

    Many earth observing sensors depend on white diffuse reflectance standards to derive scales of radiance traceable to the St Despite the large number of Earth observing sensors that operate in the reflective solar region of the spectrum, there has been no direct method to provide NIST traceable BRDF measurements out to 2500 rim. Recent developments in detector technology have allowed the NIST reflectance measurement facility to expand the operating range to cover the 250 nm to 2500 nm range. The facility has been modified with and additional detector using a cooled extended range indium gallium arsenide (Extended InGaAs) detector. Measurements were made for two PTFE white diffuse reflectance standards over the 1100 nm to 2500 nm region at a 0' incident and 45' observation angle. These two panels will be used to support the OLI calibration activities. An independent means of verification was established using a NIST radiance transfer facility based on spectral irradiance, radiance standards and a diffuse reflectance plaque. An analysis on the results and associated uncertainties will be discussed.

  2. Sub-10 nm patterning using EUV interference lithography.

    PubMed

    Päivänranta, Birgit; Langner, Andreas; Kirk, Eugenie; David, Christian; Ekinci, Yasin

    2011-09-16

    Extreme ultraviolet (EUV) lithography is currently considered as the leading technology for high-volume manufacturing below sub-20 nm feature sizes. In parallel, EUV interference lithography based on interference transmission gratings has emerged as a powerful tool for industrial and academic research. In this paper, we demonstrate nanopatterning with sub-10 nm resolution using this technique. Highly efficient and optimized molybdenum gratings result in resolved line/space patterns down to 8 nm half-pitch and show modulation down to 6 nm half-pitch. These results show the performance of optical nanopatterning in the sub-10 nm range and currently mark the record for photon-based lithography. Moreover, an efficient phase mask completely suppressing the zeroth-order diffraction and providing 50 nm line/space patterns over large areas is evaluated. Such efficient phase masks pave the way towards table-top EUV interference lithography systems.

  3. 248nm silicon photoablation: Microstructuring basics

    NASA Astrophysics Data System (ADS)

    Poopalan, P.; Najamudin, S. H.; Wahab, Y.; Mazalan, M.

    2015-05-01

    248nm pulses from a KrF excimer laser was used to ablate a Si wafer in order to ascertain the laser pulse and energy effects for use as a microstructuring tool for MEMS fabrication. The laser pulses were varied between two different energy levels of 8mJ and 4mJ while the number of pulses for ablation was varied. The corresponding ablated depths were found to range between 11 µm and 49 µm, depending on the demagnified beam fluence.

  4. 248nm silicon photoablation: Microstructuring basics

    SciTech Connect

    Poopalan, P.; Najamudin, S. H.; Wahab, Y.; Mazalan, M.

    2015-05-15

    248nm pulses from a KrF excimer laser was used to ablate a Si wafer in order to ascertain the laser pulse and energy effects for use as a microstructuring tool for MEMS fabrication. The laser pulses were varied between two different energy levels of 8mJ and 4mJ while the number of pulses for ablation was varied. The corresponding ablated depths were found to range between 11 µm and 49 µm, depending on the demagnified beam fluence.

  5. Diffuse optical spectroscopy of breast tissue extended to 1100 nm

    NASA Astrophysics Data System (ADS)

    Taroni, Paola; Bassi, Andrea; Comelli, Daniela; Farina, Andrea; Cubeddu, Rinaldo; Pifferi, Antonio

    2009-09-01

    The feasibility of in vivo measurements in the range of 1000 to 1100 nm and the potential benefits of operation in that wavelength range for diagnostic applications are investigated. To this purpose, an existing system for time-resolved diffuse spectroscopy is modified to enable in vivo studies to be carried out continuously from 600 to 1100 nm. The optical characterization of collagen powder is extended to 1100 nm and an accurate measurement of the absorption properties of lipid is carried out over the entire spectral range. Finally, the first in vivo absorption and scattering spectra of breast tissue are measured from 10 healthy volunteers between 600 and 1100 nm and tissue composition is evaluated in terms of blood parameters and water, lipid, and collagen content using a spectrally constrained global fitting procedure.

  6. TUNABLE DIODE LASER MEASUREMENTS OF NO2 NEAR 670 NM AND 395 NM. (R823933)

    EPA Science Inventory

    Two single-mode diode lasers were used to record high-resolution absorption spectra of NO2 (dilute in Ar) near 670.2 and 394.5 nm over a range of temperatures (296 to 774 K) and total pressures (2.4 x 10(-2) to 1 atm). A commercial InGaAsP laser was tuned 1.3 cm(-1) at a repetiti...

  7. Sub-180 nm generation with borate crystal

    NASA Astrophysics Data System (ADS)

    Qu, Chen; Yoshimura, Masashi; Tsunoda, Jun; Kaneda, Yushi; Imade, Mamoru; Sasaki, Takatomo; Mori, Yusuke

    2014-10-01

    We demonstrated a new scheme for the generation of 179 nm vacuum-ultraviolet (VUV) light with an all-solid-state laser system. It was achieved by mixing the deep-ultraviolet (DUV) of 198.8 nm and the infrared (IR) of 1799.9 nm. While CsB3O5 (CBO) did not satisfy the phase-matching at around 180 nm, 179 nm output was generated with LiB3O5 (LBO) for the first time. The phase-matching property of LBO at around 180 nm was also investigated. There was small deviation from theoretical curve in the measurement, which is still considered reasonable.

  8. Generation and use of high power 213 nm and 266 nm laser radiation and tunable 210-400 nm laser radiation with BBO crystal matrix array

    DOEpatents

    Gruen, Dieter M.

    2000-01-01

    A 213 nm laser beam is capable of single photon ablative photodecomposition for the removal of a polymer or biological material substrate. Breaking the molecular bonds and displacing the molecules away from the substrate in a very short time period results in most of the laser photon energy being carried away by the displaced molecules, thus minimizing thermal damage to the substrate. The incident laser beam may be unfocussed and is preferably produced by quintupling the 1064 nm radiation from a Nd:YAG solid state laser, i.e., at 213 nm. In one application, the 213 nm laser beam is expanded in cross section and directed through a plurality of small beta barium borate (BBO) crystals for increasing the energy per photon of the laser radiation directed onto the substrate. The BBO crystals are arranged in a crystal matrix array to provide a large laser beam transmission area capable of accommodating high energy laser radiation without damaging the BBO crystals. The BBO crystal matrix array may also be used with 266 nm laser radiation for carrying out single or multi photon ablative photodecomposition. The BBO crystal matrix array may also be used in an optical parametric oscillator mode to generate high power tunable laser radiation in the range of 210-400 nm.

  9. High-speed stimulated Brillouin scattering spectroscopy at 780 nm

    NASA Astrophysics Data System (ADS)

    Remer, Itay; Bilenca, Alberto

    2016-09-01

    We demonstrate a high-speed stimulated Brillouin scattering (SBS) spectroscopy system that is able to acquire stimulated Brillouin gain point-spectra in water samples and Intralipid tissue phantoms over 2 GHz within 10 ms and 100 ms, respectively, showing a 10-100 fold increase in acquisition rates over current frequency-domain SBS spectrometers. This improvement was accomplished by integrating an ultra-narrowband hot rubidium-85 vapor notch filter in a simplified frequency-domain SBS spectrometer comprising nearly counter-propagating continuous-wave pump-probe light at 780 nm and conventional single-modulation lock-in detection. The optical notch filter significantly suppressed stray pump light, enabling detection of stimulated Brillouin gain spectra with substantially improved acquisition times at adequate signal-to-noise ratios (˜25 dB in water samples and ˜15 dB in tissue phantoms). These results represent an important step towards the use of SBS spectroscopy for high-speed measurements of Brillouin gain resonances in scattering and non-scattering samples.

  10. Trends in nanosecond melanosome microcavitation up to 1540 nm

    NASA Astrophysics Data System (ADS)

    Schmidt, Morgan S.; Kennedy, Paul K.; Noojin, Gary D.; Vincelette, Rebecca L.; Thomas, Robert J.; Rockwell, Benjamin A.

    2015-09-01

    Thresholds for microcavitation of bovine and porcine melanosomes were previously reported, using single nanosecond (ns) laser pulses in the visible (532 nm) and the near-infrared (NIR) from 1000 to 1319 nm. Here, we report average radiant exposure thresholds for bovine melanosome microcavitation at additional NIR wavelengths up to 1540 nm, which range from ˜0.159 J/cm2 at 800 nm to 4.5 J/cm2 at 1540 nm. Melanosome absorption coefficients were also estimated, and decreased with increasing wavelength. These values were compared to retinal pigment epithelium coefficients, and to water absorption, over the same wavelength range. Corneal total intraocular energy retinal damage threshold values were estimated and compared to the previous (2007) and recently changed (2014) maximum permissible exposure (MPE) safe levels. Results provide additional data that support the recent changes to the MPE levels, as well as the first microcavitation data at 1540 nm, a wavelength for which melanosome microcavitation may be an ns-pulse skin damage mechanism.

  11. Passive Ranging

    DTIC Science & Technology

    1988-08-01

    1981). 5. R. Courant and D. Hilbert, Methods of Mathematical Physics , Vol. I, English ed., * Interscience, New York, 1953. 32 32 APPENDIX A CALCULATION...K Courant and D. Hilbert, Methods of Mathematical Physics , Vol. I, English ed., * Interscience, New York, 1953. A-8 APPENDIX B * RANGING ACCURACY IN

  12. Efficient laser operation of Nd3+:Lu2O3 at various wavelengths between 917 nm and 1463 nm

    NASA Astrophysics Data System (ADS)

    von Brunn, P.; Heuer, A. M.; Fornasiero, L.; Huber, G.; Kränkel, C.

    2016-08-01

    Even though the first Nd3+-doped sesquioxide lasers have been realized more than 50 years ago, up to now no reports on efficient laser operation of Nd3+:doped sesquioxides can be found. In this work, we review the favorable spectroscopic properties of the sesquioxide Nd3+:Lu2O3 in terms of ground state absorption, stimulated emission, and excited state absorption cross sections as well as the upper level lifetime. Making use of these properties, we achieved efficient laser performance on eight different laser transitions in the wavelength range between 917 nm and 1463 nm under Ti:sapphire laser pumping using state-of-the-art HEM-grown Nd3+:Lu2O3 crystals with good optical quality. At the strongest transition around 1076 nm we determined a slope efficiency of 69%, which represents the highest efficiency ever obtained for a Nd3+-doped sesquioxide. Furthermore, we could generate watt level output powers and high slope efficiencies for seven other transitions. Lasers at 917 nm, 1053 nm, 1108 nm and 1463 nm were realized for the first time and the latter represents one of the longest laser wavelengths obtained on the 4F3/2  →  4I13/2 transition in Nd3+-doped materials.

  13. The Spectrum of Th-Ar Hollow Cathode Lamps in the 691nm to 5804nm region Database

    National Institute of Standards and Technology Data Gateway

    SRD 161 The Spectrum of Th-Ar Hollow Cathode Lamps in the 691nm to 5804nm region Database (Web, free access)   This atlas presents observations of the infra-red (IR) spectrum of a low current Th-Ar hollow cathode lamp with the 2-m Fourier transform spectrometer (FTS) at NIST. These observations establish more than 2400 lines that are suitable for use as wavelength standards in the range 691 nm to 5804 nm. The observations were made in collaboration with the European Southern Observatory (ESO), in order to provide calibration reference data for new high-resolution Echelle spectrographs, such as the Cryogenic High-Resolution IR Echelle Spectrograph ([CRIRES]), ESO's new IR spectrograph at the Very Large Telescope in Chile.

  14. Simultaneous three-wavelength continuous wave laser at 946 nm, 1319 nm and 1064 nm in Nd:YAG

    NASA Astrophysics Data System (ADS)

    Lü, Yanfei; Zhao, Lianshui; Zhai, Pei; Xia, Jing; Fu, Xihong; Li, Shutao

    2013-01-01

    A continuous-wave (cw) diode-end-pumped Nd:YAG laser that generates simultaneous laser at the wavelengths 946 nm, 1319 nm and 1064 nm is demonstrated. The optimum oscillation condition for the simultaneous three-wavelength operation has been derived. Using the separation of the three output couplers, we obtained the maximum output powers of 0.24 W at 946 nm, 1.07 W at 1319 nm and 1.88 W at 1064 nm at the absorbed pump power of 11.2 W. A total output power of 3.19 W for the three-wavelength was achieved at the absorbed pump power of 11.2 W with optical conversion efficiency of 28.5%.

  15. The Missing Solar Irradiance Spectrum: 1 to 7 nm

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.; Lewis, M.; David, M.; Schunk, R. W.; Woods, T. N.; Eparvier, F. G.; Warren, H. P.

    2015-12-01

    During large X-class flares the Earth's upper atmospheric E-region responds immediately to solar photons in the 1 to 7 nm range. The response can change the E-region density by factors approaching 10, create large changes in conductivity, and plague HF communications. GOES-XRS provide 0.1 to 0.8 nm and a 0.05 to 0.4 nm integral channels; SOHO-SEM provided a 0 to 50 nm irradiance; TIMED and SORCE-XPS diode measurements also integrated down to 0.1 nm; and most recently SDO-EVE provided a 0.1 to 7 nm irradiance. For atmospheric response to solar flares the cadence is also crucial. Both GOES and SDO provided integral measurements at 10 seconds or better. Unfortunately these measurements have failed to capture the 1 to 7 nm spectral changes that occur during flares. It is these spectral changes that create the major impact since the ionization cross-section of the dominant atmospheric species, N2 and O2, both contain step function changes in the cross-sections. Models of the solar irradiance over this critical wavelength regime have suffered from the need to model the spectral variability based on incomplete measurements. The most sophisticated empirical model FISM [Chamberlin et al., 2008] used 1 nm spectral binning and various implementations of the above integral measurements to describe the 1 to 7 nm irradiance. Since excellent solar observations exist at other wavelengths it is possible to construct an empirical model of the solar atmosphere and then use this model to infer the spectral distribution at wavelengths below 5 nm. This differential emission measure approach has been used successfully in other contexts [e.g., Warren, 2005, Chamberlin et al., 2009]. This paper contrasts the broadband versus spectrally resolved descriptions of the incoming irradiance that affects the upper atmospheric E-layer. The results provide a prescription of what wavelength resolution would be needed to adequately measure the incoming solar irradiance in the 1 to 7 nm range.

  16. Visible to near IR luminescence spectrum of Radachlorin under excitation at 405 nm

    NASA Astrophysics Data System (ADS)

    Belik, V. P.; Gadzhiev, I. M.; Petrenko, M. V.; Petrov, M. A.; Semenova, I. V.; Vasyutinskii, O. S.

    2016-11-01

    The luminescence spectrum of Radachlorin dissolved in water in the 600-1350 nm spectral range excited by 405 nm light has been recorded at the first time. The spectrum contains a wide band with peaks centered at 662, 715, 940, and 1274 nm. Relative contributions to the spectrum from different sources have been evaluated. Ratio of the singlet oxygen signal to the total signal intensity averaged over the 1240-1300 nm spectral range was determined to be 40%. Isolation of the singlet oxygen signal from the total signal at 1274 nm has been achieved by means of a spectral-resolved TCSPC detection technique.

  17. A Glossary of Range Terminology

    DTIC Science & Technology

    1981-01-01

    GLOSSARY OF RANGE TERMINOLOGY" Final 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(e) S. CONTRACT OR GRANT NUMUER(e) Documentation Group Range Commanders...Council White Sands Missile Range, NM 88002 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK AREA & WORK UNIT NUMBERS Same...ABSOLUTE ADDRESS -- The label or number permanently assigned to a specific storage location, device or register. binary words together with an origin

  18. New antireflective coatings for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Xu, Gu; Guerrero, Douglas J.; Dobson, Norman

    1998-06-01

    New bottom antireflective coatings (BARCs) for 193 nm lithography have been recently developed by Brewer Science Inc. Copolymers of benzyl methacrylate (or benzyl acrylate) and hydroxypropyl methacrylate have been synthesized and used as a main component in 193 nm BARCs. The acrylic copolymers have strong absorbance at 193 nm UV light wavelength. The 193 nm BARCs were formulated in safe solvents such as ethyl lactate and formed by spin-on coating process. Thermosetting of the 193 nm BARCs limited their intermixing with photoresists. These 193 nm BARCs had optical density of about 10 micrometers -1, k equals 0.35, and n equals 1.81. Preliminary oxygen plasma etch rates were > 1.5 times DUV resists. Good profiles at small feature sizes (< 0.20 micrometers ) were achieved with tested photoresists.

  19. High-brightness 800nm fiber-coupled laser diodes

    NASA Astrophysics Data System (ADS)

    Berk, Yuri; Levy, Moshe; Rappaport, Noam; Tessler, Renana; Peleg, Ophir; Shamay, Moshe; Yanson, Dan; Klumel, Genadi; Dahan, Nir; Baskin, Ilya; Shkedi, Lior

    2014-03-01

    Fiber-coupled laser diodes have become essential sources for fiber laser pumping and direct energy applications. Single emitters offer reliable multi-watt output power from a 100 m lateral emission aperture. By their combination and fiber coupling, pump powers up to 100 W can be achieved from a low-NA fiber pigtail. Whilst in the 9xx nm spectral range the single emitter technology is very mature with <10W output per chip, at 800nm the reliable output power from a single emitter is limited to 4 W - 5 W. Consequently, commercially available fiber coupled modules only deliver 5W - 15W at around 800nm, almost an order of magnitude down from the 9xx range pumps. To bridge this gap, we report our advancement in the brightness and reliability of 800nm single emitters. By optimizing the wafer structure, laser cavity and facet passivation process we have demonstrated QCW device operation up to 19W limited by catastrophic optical damage to the 100 μm aperture. In CW operation, the devices reach 14 W output followed by a reversible thermal rollover and a complete device shutdown at high currents, with the performance fully rebounded after cooling. We also report the beam properties of our 800nm single emitters and provide a comparative analysis with the 9xx nm single emitter family. Pump modules integrating several of these emitters with a 105 μm / 0.15 NA delivery fiber reach 35W in CW at 808 nm. We discuss the key opto-mechanical parameters that will enable further brightness scaling of multi-emitter pump modules.

  20. Pattern transfer processes for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Miyoshi, Seiro; Furukawa, Takamitsu; Watanabe, Hiroyuki; Irie, Shigeo; Itani, Toshiro

    2002-07-01

    We describe and evaluate three kinds of pattern transfer processes that are suitable for 157-nm lithography. These transfer processes are 1) a hard mask (HM) process using SiO as a HM material, 2) a HM process using an organic bottom anti-reflecting coating (BARC)/SiN structure, and 3) a bi- layer process using a silicon-containing resist and an organic film as the bottom layer. In all of these processes, the underlayer fo the resist acts as an anti-reflecting layer. For the HM processes, we patterned a newly developed fluorine-containing resist using a 157-nm microstepper, and transferred the resist patterns to the hard mask by reactive ion etching (RIE) with minimal critical dimension shift. Using the HM pattern, we then fabricated a 65nm Wsi/poly-Si gate pattern using a high-NA microstepper (NA=0.85). With the bi-layer process, we transferred a 60nm 1:1 lines and spaces pattern of a newly developed silicon-containing resist to a 300nm-thick organic film by RIE. The fabrication of a 65nm 1:1 gate pattern and 60nm 1:1 organic film patten clearly demonstrated that 157-nm lithography is the best candidate for fabricating sub-70nm node devices.

  1. Can DUV take us below 100 nm?

    NASA Astrophysics Data System (ADS)

    Finders, Jo; Jorritsma, Louis; Eurlings, Mark; Moerman, Richard; van Greevenbroek, Henk; van Schoot, Jan B.; Flagello, Donis G.; Socha, Robert J.; Stammler, Thomas

    2001-09-01

    Currently, the 130 nm SIA node is being implemented at leading edge semiconductor manufacturing facilities. Previously, this node appeared to be the insertion point for 193 nm lithography. However, it is evident that for the majority of applications 248 nm will be the wavelength of choice. This once again raises the question how far DUV lithography (248 nm) will take us. To investigate this, overlay, imaging and productivity related issues have to be considered. Although these items become more and more linked at low k1-factors (e.g. overlay and imaging), this paper will focus on some of the imaging related topics.

  2. Lithography strategy for 65-nm node

    NASA Astrophysics Data System (ADS)

    Borodovsky, Yan A.; Schenker, Richard E.; Allen, Gary A.; Tejnil, Edita; Hwang, David H.; Lo, Fu-Chang; Singh, Vivek K.; Gleason, Robert E.; Brandenburg, Joseph E.; Bigwood, Robert M.

    2002-07-01

    Intel will start high volume manufacturing (HVM) of the 65nm node in 2005. Microprocessor density and performance trends will continue to follow Moore's law and cost-effective patterning solutions capable of supporting it have to be found, demonstrated and developed during 2002-2004. Given the uncertainty regarding the readiness and respective capabilities of 157nm and 193nm lithography to support 65nm technology requirements, Intel is developing both lithographic options and corresponding infrastructure with the intent to use both options in manufacturing. Development and use of dual lithographic options for a given technology node in manufacturing is not a new paradigm for Intel: whenever introduction of a new exposure wavelength presented excessive risk to the manufacturing schedule, Intel developed parallel patterning approaches in time for the manufacturing ramp. Both I-line and 248nm patterning solutions were developed and successfully used in manufacturing of the 350nm node at Intel. Similarly, 248nm and 193nm patterning solutions were fully developed for 130nm node high volume manufacturing.

  3. Measurements of Stokes parameters of materials at 1064-nm and 532-nm wavelengths

    NASA Astrophysics Data System (ADS)

    Tan, Songxin; Narayanan, Ram M.; Kalshoven, James E., Jr.

    2001-09-01

    Laser radar systems have found wide applications in the field of remote sensing. Reflectance as well as polarization features are used together for applications ranging from environmental monitoring to target classification. The Stokes parameters are ideal quantities for characterizing the above features because they provide useful information on both light intensity and polarization state. The University of Nebraska is currently refurbishing an airborne multi-wavelength laser radar system based on the NASA Goddard Space Flight Center (GSFC) developed Airborne Laser Polarimetric Sensor (ALPS). The system uses a Nd:YAG laser operating at wavelengths of 1064 nm and 532 nm, and contains four channels at each wavelength to measure the polarization states. This system was used to measure the Stokes parameters of backscattered laser light from different materials. These included canvas tarp, white paper, plywood, concrete, aluminum plate and anodized aluminum plate. The data provide an understanding of the polarized scattering properties of various materials, and are expected to be useful in developing target discrimination algorithms.

  4. Center and limb solar spectrum in high spectral resolution 225.2 nm to 319.6 nm

    NASA Technical Reports Server (NTRS)

    Kohl, J. L.; Parkinson, W. H.; Kurucz, R. L.

    1978-01-01

    The atlas has been designed to fulfill the need in solar and stellar astronomy, in aeronomy, and in space science for a convenient reference source that provides a detailed and accurate record of the measured solar ultraviolet spectrum in high spectral resolution for the wavelength range from 225.2 nm to 319.6 nm. The atlas also contains a preliminary synthetic solar spectrum with a legend for identifying and describing the features of the synthetic spectrum. Attention is given to aspects of instrumentation, the radiometric calibration, the wavelength scale, background noise random fluctuations and data filtering, intermittent noise, the observational conditions, the experimental uncertainty, the atlas format, references, tables, and plots.

  5. Segmentation of the macular choroid in OCT images acquired at 830nm and 1060nm

    NASA Astrophysics Data System (ADS)

    Lee, Sieun; Beg, Mirza F.; Sarunic, Marinko V.

    2013-06-01

    Retinal imaging with optical coherence tomography (OCT) has rapidly advanced in ophthalmic applications with the broad availability of Fourier domain (FD) technology in commercial systems. The high sensitivity afforded by FD-OCT has enabled imaging of the choroid, a layer of blood vessels serving the outer retina. Improved visualization of the choroid and the choroid-sclera boundary has been investigated using techniques such as enhanced depth imaging (EDI), and also with OCT systems operating in the 1060-nm wavelength range. We report on a comparison of imaging the macular choroid with commercial and prototype OCT systems, and present automated 3D segmentation of the choroid-scleral layer using a graph cut algorithm. The thickness of the choroid is an important measurement to investigate for possible correlation with severity, or possibly early diagnosis, of diseases such as age-related macular degeneration.

  6. Incoherent magnetization reversal in 30-nm Ni particles

    NASA Astrophysics Data System (ADS)

    Ross, C. A.; Chantrell, R.; Hwang, M.; Farhoud, M.; Savas, T. A.; Hao, Y.; Smith, Henry I.; Ross, F. M.; Redjdal, M.; Humphrey, F. B.

    2000-12-01

    The magnetic properties of a 100-nm-period large-area array of regular, 30-nm polycrystalline nickel particles have been studied. The particles are found to reverse incoherently, and their hysteresis behavior has been compared with a computational model over a range of temperatures. Excellent agreement with the model is obtained, indicating that switching of the particles is dominated by the reversal of approximately 10-nm-diameter volumes within each particle. These switching volumes are identified with the columnar grains in the polycrystalline nickel, showing that the microstructure determines the magnetic behavior of the particles. This explains the anisotropy distribution and the onset of superparamagnetism in the sample. Incoherent reversal occurs even though the particles are only 1.5 times the exchange length in nickel, a size at which nearly uniform rotation is expected to occur if the particles were homogeneous.

  7. Long-range ferromagnetic order induced by a donor impurity band exchange in SnO{sub 2}:Er{sup 3+} nanoparticles

    SciTech Connect

    Aragón, F. H.; Coaquira, J. A. H.; Chitta, V. A.; Hidalgo, P.; Brito, H. F.

    2013-11-28

    In this work, the structural and magnetic properties of Er-doped SnO{sub 2} (SnO{sub 2}:Er) nanoparticles are reported. The SnO{sub 2}:Er nanoparticles have been synthesized by a polymer precursor method with Er content from 1.0% to 10.0%. X-ray diffraction results indicate the formation of only the rutile-type structure in all samples. The estimated mean crystallite size shows a decrease from ∼10 to ∼4 nm when the Er content is increased from 1.0% to 10.0%. The particle size values have been corroborated by transmission electron microscopy technique. The thermal dependence of the magnetization is consistent with the 3+ oxidation state of erbium ions for all samples. A strong paramagnetic-like behavior coexisting with a ferromagnetic phase has been determined for samples with Er content below 5.0%. Above this concentration, only a paramagnetic behavior has been determined. Isothermal magnetization curves are consistent with the occurrence of long-range ferromagnetic order mediated by donor electrons forming bound magnetic polarons which overlap to produce a spin-split impurity band.

  8. Simultaneous triple 914 nm, 1084 nm, and 1086 nm operation of a diode-pumped Nd:YVO4 laser

    NASA Astrophysics Data System (ADS)

    Lü, Yanfei; Xia, Jing; Liu, Huilong; Pu, Xiaoyun

    2014-10-01

    We report a diode-pumped continuous-wave (cw) triple-wavelength Nd:YVO4 laser operating at 914, 1084, and 1086 nm. A theoretical analysis has been introduced to determine the threshold conditions for simultaneous triple-wavelength laser. Using a T-shaped cavity, we realized an efficient triple-wavelength operation at 4F3/2→4I9/2 and 4F3/2→4I11/2 transitions for Nd:YVO4 crystal, simultaneously. At an absorbed pump power of 16 W (or 25 W of incident pump power), the maximum output power was 2.3 W, which included 914 nm, 1084 nm, and 1086 nm three wavelengths, and the optical conversion efficiency with respect to the absorbed pump power was 14.4%.

  9. A cesium bromide photocathode excited by 405 nm radiation

    NASA Astrophysics Data System (ADS)

    Maldonado, J. R.; Cheng, Y. T.; Pianetta, P.; Pease, Fabian W.; Hesselink, L.

    2014-07-01

    In several applications, such as electron beam lithography and X-ray differential phase contrast imaging, there is a need for a free electron source with a current density at least 10 A/cm2 yet can be shaped with a resolution down to 20 nm and pulsed. Additional requirements are that the source must operate in a practical demountable vacuum (>1e-9 Torr) and be reasonably compact. In prior work, a photocathode comprising a film of CsBr on metal film on a sapphire substrate met the requirements except it was bulky because it required a beam (>10 W/cm2) of 257 nm radiation. Here, we describe an approach using a 405 nm laser which is far less bulky. The 405 nm laser, however, is not energetic enough to create color centers in CsBr films. The key to our approach is to bombard the CsBr film with a flood beam of about 1 keV electrons prior to operation. Photoelectron efficiencies in the range of 100-1000 nA/mW were demonstrated with lifetimes exceeding 50 h between electron bombardments. We suspect that the electron bombardment creates intraband color centers whence electrons can be excited by the 405 nm photons into the conduction band and thence into the vacuum.

  10. Final report on the torque comparison EURAMET.M.T-S2, measurand torque: 10 N.m, 20 N.m, 40 N.m, 60 N.m, 80 N.m, and 100 N.m

    NASA Astrophysics Data System (ADS)

    Röske, Dirk

    2017-01-01

    The purpose of the EURAMET comparison EURAMET.M.T-S2 was to compare the measuring capabilities up to 100 N.m of a reference-type torque calibration machine of ZAG, Slovenia, with the torque standard machine of the Physikalisch-Technische Bundesanstalt (PTB, Braunschweig, Germany) acting as pilot laboratory. A very stable TT1 torque transducer with well-known properties and two torque measuring bridges was used as travelling standard. According to the technical protocol, torque steps of at least 10 N.m, 20 N.m, 40 N.m, 60 N.m, 80 N.m, and 100 N.m had to be measured both in clockwise and anticlockwise directions. For each of the torque steps and both senses of direction of the torque vector, En values were calculated. The results are in general in good agreement with the claimed measurement uncertainties except for the very first measurement at ZAG with additional support and four plate couplings. It seems to be sufficient in a vertical set-up (vertical torque axis) to use only two flexible couplings and there is no need for a further support between the transducers. The measurements with two couplings fulfill the requirement to the En value and support ZAG's claimed uncertainties of measurement. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  11. Sub-70-nm pattern fabrication using an alternating phase-shifting mask in 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Irie, Shigeo; Kanda, Noriyoshi; Watanabe, Kunio; Suganaga, Toshifumi; Itani, Toshiro

    2002-07-01

    In Selete, we have developed various resolution-enhancement technologies (RETs) such as the alternating phase shifting mask (alt-PSM), attenuated-PSM (att-PSM), and off-axis illumination (OAI). The alt-PSM, for example, reduces the k1 factor and extends the lithographic performance. A problem concerning the alt-PSM is the difference in the transmitted light intensities of the non-phase-shifting region and the phase-shifting region which can cause critical-dimension (CD) placement error. The transmitted light intensities of the two regions can be made equal by side-etching, in which the quartz (Qz) is undercut by wet-etching at the side of the transmitting region. We sought to optimize the mask structure in terms of a high numerical aperture (NA) through a simulation using two kinds of structures with a 157 nm exposure wavelength. The structures were a single-trench structure and a dual-trench structure, with each trench dug in the transmitting region. To attain a high NA (NA equals 0.85), we tried to optimize the parameters of the Cr film thickness, the amount of the undercut (side-etching), and the phase shift. The evaluated line pattern sizes were 70 nm (line/space size equals 70/70 nm, 70/140 nm, 70/210 nm, and 70/350 nm) and 50 nm (line/space size equals 50/50 nm, 50/100 nm, 50/150 nm, and 50/250 nm) at the wafer. Further, using the optimized mask, we calculated the lithographic margin of a sub 70 nm pattern through a simulation. For the 70 nm line patterns, we found that it will be difficult to fabricate precisely a 70 nm line patten using a mask with a single- trench structure. And we also found that the most suitable conditions for the dual-trench structure mask were a 90 nm undercut, a 100 nm Cr film thickness, and a 180 degree(s) phase shift. The exposure latitude at a depth of focus (DOF) of 0.3 micrometers , simulated using the optimized mask, was 5.3% for the 70/70 nm pattern, 3.6% for 70/140 nm 16.0% for 70/210 nm, and 29.3% for 70/350 nm. As the pitch

  12. Sub-10 nm nanopantography

    SciTech Connect

    Tian, Siyuan Donnelly, Vincent M. E-mail: economou@uh.edu; Economou, Demetre J. E-mail: economou@uh.edu; Ruchhoeft, Paul

    2015-11-09

    Nanopantography, a massively parallel nanopatterning method over large areas, was previously shown to be capable of printing 10 nm features in silicon, using an array of 1000 nm-diameter electrostatic lenses, fabricated on the substrate, to focus beamlets of a broad area ion beam on selected regions of the substrate. In the present study, using lens dimensional scaling optimized by computer simulation, and reduction in the ion beam image size and energy dispersion, the resolution of nanopantography was dramatically improved, allowing features as small as 3 nm to be etched into Si.

  13. Fabrication of 10nm diameter carbon nanopores

    SciTech Connect

    Radenovic, Aleksandra; Trepagnier, Eliane; Csencsits, Roseann; Downing, Kenneth H; Liphardt, Jan

    2008-09-25

    The addition of carbon to samples, during imaging, presents a barrier to accurate TEM analysis, the controlled deposition of hydrocarbons by a focused electron beam can be a useful technique for local nanometer-scale sculpting of material. Here we use hydrocarbon deposition to form nanopores from larger focused ion beam (FIB) holes in silicon nitride membranes. Using this method, we close 100-200nm diameter holes to diameters of 10nm and below, with deposition rates of 0.6nm per minute. I-V characteristics of electrolytic flow through these nanopores agree quantitatively with a one dimensional model at all examined salt concentrations.

  14. Gallup, NM, CARE Grant Success Story

    EPA Pesticide Factsheets

    A CARE Grant, Level II award, was made to Gallup, NM to focus on cleaning up the waste stream, reuse and recycling of materials, and reclaiming land for these purposes through outreach, education and organization.

  15. Recent progress in 193-nm antireflective coatings

    NASA Astrophysics Data System (ADS)

    Meador, James D.; Guerrero, Douglas J.; Xu, Gu; Shao, Xie; Dobson, Norman; Claypool, James B.; Nowak, Kelly A.

    1999-06-01

    This paper presents the chemistries and properties of organic, spin-on, bottom antireflective coatings (BARCs) that are designed for 193 nm lithography. All of the BARCs are thermosetting and use dye-attached/incorporated polymers. A first generation product, NEXT, will soon be commercialized. NEXT is built form i-line and deep-UV chemistries with the polymeric constituent being a substitute novolac. This product provide outstanding resolution of 0.16 micrometers L/S with several 193 nm photoresists. Second generation chemical platforms under study include acrylics, polyesters, and polyethers with the 193 nm absorbing chromophore being an aromatic function. The performance of selected BARCs from the four platforms is described, including: optical properties, 193 nm litho, plasma etch rates, Prolith modeling data, spin-bowl and waste line compatibility, and ambient stability.

  16. Generation of Thermospheric OI 845 nm Emission by Bowen Fluorescence

    NASA Astrophysics Data System (ADS)

    Huestis, D. L.; Sharpee, B. D.; Cosby, P. C.; Slanger, T. G.

    2006-12-01

    777 and 845 nm emissions from the 3p-3s multiplets of atomic oxygen are commonly observed at non-auroral latitudes in the terrestrial nightglow. By studying the relative strengths of these emissions we can learn something about the mechanisms that produce them and what they can teach us about the atmosphere. Recently [1] we have used intensity-calibrated sky spectra from the Keck telescopes to investigate the relative strengths of a wide range of O-atom Rydberg lines and have confirmed that electron-ion radiative recombination is a primary source of excitation for both the triplet and quintet systems. Following the intensity of the 777 and 845 nm lines during the night, we find that for most of the night the quintet 777 nm line is consistently stronger than the triplet 845 nm line, with a nearly constant intensity ratio I(777)/I(845) near 2.3, although both intensities fall rapidly as the night progresses. However, late in the night the 845 nm intensity levels off, while the 777 nm intensity continues to fall, and the I(777)/I(845) ratio plunges by a factor of 5-10. We interpret these observations as indicating that the O-atom quintet states are still being excited by the same mechanism as earlier in the night, i.e. radiative recombination, but some triplet states are also being excited by an additional mechanism. Such a mechanism has been proposed before [2-6] but not previously observed directly in the terrestrial nightglow. The oxygen triplet 3d-2p transition at 102.576 nm is in close coincidence with the solar hydrogen Lyman-β line at 102.572 nm. Radiative transport in the hydrogen geocorona will deliver Lyman-β intensity into the Earth's shadow and will produce triplet O(3d 3D) high in the atmosphere, even prior to direct solar illumination. The result is observable in a radiative cascade sequence 3d-3p(1129 nm) → 3p- 3s(845 nm) → 3s-2p(130 nm). A similar effect is observed in the H-α emission, which is also excited by Lyman-β absorption. This process

  17. Scattering matrices of martian dust analogs at 488 nm and 647 nm

    NASA Astrophysics Data System (ADS)

    Dabrowska, Dominika D.; Muñoz, Olga; Moreno, Fernando; Ramos, José L.; Martínez-Frías, Jesús; Wurm, Gerhard

    2015-04-01

    We present measurements of the complete scattering matrix as a function of the scattering angle of five martian dust analogs, namely montmorillonite, two palagonite (JSC-1) samples, basalt, and calcite. The measurements are performed at 488 and 647 nm, covering the scattering angle range from 3° to 177°. The experimental scattering matrices are compared with results of Lorenz-Mie calculations performed for the same size distributions and refractive indices as our analog samples. As expected, we find that scattering matrices of realistic polydispersions of dust particles cannot be replaced by such calculated matrices. In contrast, the measured phase functions for our martian dust analogs may be considered a good approximation for martian dust at the studied wavelengths. Further, because of the sensitivity of polarimetry to particle microphysics, spectro-polarimetric observations from the martian surface appear to be a powerful diagnostic tool to infer the composition of the dust in the martian atmosphere. To facilitate the use of the experimental matrices for multiple-scattering calculations with polarization included, we compute the corresponding synthetic scattering matrices based on the measurements and defined in the full angle range from 0° to 180°.

  18. Electromechanical imaging of biological systems with sub-10 nm resolution

    NASA Astrophysics Data System (ADS)

    Kalinin, Sergei V.; Rodriguez, B. J.; Jesse, S.; Thundat, T.; Gruverman, A.

    2005-08-01

    Electromechanical imaging of tooth dentin and enamel has been performed with sub-10nm resolution using piezoresponse force microscopy. Characteristic piezoelectric domain size and local protein fiber ordering in dentin have been determined. The shape of a single protein fibril in enamel is visualized in real space and local hysteresis loops are measured. Because of the ubiquitous presence of piezoelectricity in biological systems, this approach is expected to find broad application in high-resolution studies of a wide range of biomaterials.

  19. Fabrication of sub-10 nm metal nanowire arrays with sub-1 nm critical dimension control

    NASA Astrophysics Data System (ADS)

    Pi, Shuang; Lin, Peng; Xia, Qiangfei

    2016-11-01

    Sub-10 nm metal nanowire arrays are important electrodes for building high density emerging ‘beyond CMOS’ devices. We made Pt nanowire arrays with sub-10 nm feature size using nanoimprint lithography on silicon substrates with 100 nm thick thermal oxide. We further studied the critical dimension (CD) evolution in the fabrication procedure and achieved 0.4 nm CD control, providing a viable solution to the imprint lithography CD challenge as specified by the international technology roadmap for semiconductors. Finally, we fabricated Pt/TiO2/Pt memristor crossbar arrays with the 8 nm electrodes, demonstrating great potential in dimension scaling of this emerging device.

  20. Extending the wavelength range in the Oclaro high-brightness broad area modules

    NASA Astrophysics Data System (ADS)

    Pawlik, Susanne; Guarino, Andrea; Sverdlov, Boris; Müller, Jürgen; Button, Christopher; Arlt, Sebastian; Jaeggi, Dominik; Lichtenstein, Norbert

    2010-02-01

    The demand for high power laser diode modules in the wavelength range between 793 nm and 1060 nm has been growing continuously over the last several years. Progress in eye-safe fiber lasers requires reliable pump power at 793 nm, modules at 808 nm are used for small size DPSSL applications and fiber-coupled laser sources at 830 nm are used in printing industry. However, power levels achieved in this wavelength range have remained lower than for the 9xx nm range. Here we report on approaches to increasing the reliable power in our latest generations of high power pump modules in the wavelength range between 793 nm and 1060 nm.

  1. Flat Supercontinuum Generation at 1550 nm in a Dispersion-Flattened Microstructure Fibre Using Picosecond Pulse

    NASA Astrophysics Data System (ADS)

    Xu, Yong-Zhao; Ren, Xiao-Min; Wang, Zi-Nan; Zhang, Xia; Huang, Yong-Qing

    2007-03-01

    The generation of a flat supercontinuum of over 80 nm in the 1550 nm region by injecting 1.6 ps 10 GHz repetition rate optical pulses into an 80-m-long dispersion-flattened microstructure fibre is demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 (ps.nm-1.km-1) between 1500 and 1650 nm. The generated supercontinuum ranging from 1513 to 1591 nm has the flatness of +/-1.5 dB and it is not so flat in the range of several nanometres around the pump wavelength 1552 nm. Numerical simulation is also used to study the effect of optical loss, fibre parameters and pumping conditions on supercontinuum generation in the dispersion-flattened microstructure fibre, and can be used for further optimization to generate flat broad spectra.

  2. 2 nm continuously tunable 488nm micro-integrated diode-laser-based SHG light source for Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Braune, M.; Maiwald, M.; Sumpf, B.; Tränkle, G.

    2016-04-01

    Raman spectroscopy in the visible spectral range is of great interest due to resonant Raman effects. Nevertheless, fluorescence and ambient light can mask the weak Raman lines. Shifted excitation Raman difference spectroscopy is a demonstrated tool to overcome this drawback. To apply this method, a light source with two alternating wavelengths is necessary. The spectral distance between these two wavelengths has to be adapted to the width of the Raman signal. According to the sample under investigation the width of the Raman signal could be in the range of 3 cm-1 - 12 cm-1. In this work, a micro-integrated light source emitting at 488 nm with a continuous wavelength tuning range up to 2 nm (83 cm-1) is presented. The pump source, a DFB laser emitting at 976 nm, and a periodically poled lithium niobate (PPLN) ridge waveguide crystal is used for the second harmonic generation (SHG). Both components are mounted on a μ-Peltier-element for temperature control. Here, a common wavelength tuning of the pump wavelength and the acceptance bandwidth of the SHG crystal via temperature is achieved. With the results the light source is suitable for portable Raman and SERDS experiments with a flexible spectral distance between both excitation wavelengths for SERDS with respect to the sample under investigation.

  3. 810nm, 980nm, 1470nm and 1950nm diode laser comparison: a preliminary "ex vivo" study on oral soft tissues

    NASA Astrophysics Data System (ADS)

    Fornaini, Carlo; Merigo, Elisabetta; Sozzi, Michele; Selleri, Stefano; Vescovi, Paolo; Cucinotta, Annamaria

    2015-02-01

    The introduction of diode lasers in dentistry has several advantages, mainly consisting on the reduced size, reduced cost and possibility to beam delivering by optical fibers. At the moment the two diode wavelengths normally utilized in the dental field are 810 and 980 nm for soft tissues treatments. The aim of this study was to compare the efficacy of four different diode wavelengths: 810, 980, 1470 and 1950 nm diode laser for the ablation of soft tissues. Several samples of veal tongue were exposed to the four different wavelengths, at different fluences. The internal temperature of the soft tissues, in the area close to the beam, was monitored with thermocouple during the experiment. The excision quality of the exposed samples have been characterized by means of an optical microscope. Tissue damages and the cut regularity have been evaluated on the base of established criteria. The lowest thermal increase was recorded for 1950 nm laser. Best quality and speed of incision were obtained by the same wavelength. By evaluating epithelial, stromal and vascular damages for all the used wavelengths, the best result, in terms of "tissue respect", have been obtained for 1470 and 1950 nm exposures. From the obtained results 1470 and 1950 nm diode laser showed to be the best performer wavelengths among these used in this "ex vivo" study, probably due to their greatest affinity to water.

  4. Radiation Failures in Intel 14nm Microprocessors

    NASA Technical Reports Server (NTRS)

    Bossev, Dobrin P.; Duncan, Adam R.; Gadlage, Matthew J.; Roach, Austin H.; Kay, Matthew J.; Szabo, Carl; Berger, Tammy J.; York, Darin A.; Williams, Aaron; LaBel, K.; Ingalls, James D.

    2016-01-01

    In this study the 14 nm Intel Broadwell 5th generation core series 5005U-i3 and 5200U-i5 was mounted on Dell Inspiron laptops, MSI Cubi and Gigabyte Brix barebones and tested with Windows 8 and CentOS7 at idle. Heavy-ion-induced hard- and catastrophic failures do not appear to be related to the Intel 14nm Tri-Gate FinFET process. They originate from a small (9 m 140 m) area on the 32nm planar PCH die (not the CPU) as initially speculated. The hard failures seem to be due to a SEE but the exact physical mechanism has yet to be identified. Some possibilities include latch-ups, charge ion trapping or implantation, ion channels, or a combination of those (in biased conditions). The mechanism of the catastrophic failures seems related to the presence of electric power (1.05V core voltage). The 1064 nm laser mimics ionization radiation and induces soft- and hard failures as a direct result of electron-hole pair production, not heat. The 14nm FinFET processes continue to look promising for space radiation environments.

  5. Imaging challenges in 20nm and 14nm logic nodes: hot spots performance in Metal1 layer

    NASA Astrophysics Data System (ADS)

    Timoshkov, V.; Rio, D.; Liu, H.; Gillijns, W.; Wang, J.; Wong, P.; Van Den Heuvel, D.; Wiaux, V.; Nikolsky, P.; Finders, J.

    2013-10-01

    The 20nm Metal1 layer, based on ARM standard cells, has a 2D design with minimum pitch of 64nm. This 2D design requires a Litho-Etch-Litho-Etch (LELE) double patterning. The whole design is divided in 2 splits: Me1A and Me1B. But solution of splitting conflicts needs stitching at some locations, what requires good Critical Dimension (CD) and overlay control to provide reliable contact between 2 stitched line ends. ASML Immersion NXT tools are aimed at 20 and 14nm logic production nodes. Focus control requirements become tighter, as existing 20nm production logic layouts, based on ARM, have about 50-60nm focus latitude and tight CD Uniformity (CDU) specifications, especially for line ends. IMEC inspected 20nm production Metal1 ARM standard cells with a Negative Tone Development (NTD) process using the Process Window Qualification-like technique experimentally and by Brion Tachyon LMC by simulations. Stronger defects were found thru process variations. A calibrated Tachyon model proved a good overall predictability capability for this process. Selected defects are likely to be transferred to hard mask during etch. Further, CDU inspection was performed for these critical features. Hot spots showed worse CD uniformity than specifications. Intra-field CDU contribution is significant in overall CDU budget, where reticle has major impact due to high MEEF of hot spots. Tip-to-Tip and tip-to-line hot spots have high MEEF and its variation over the field. Best focus variation range was determined by best focus offsets between hot spots and its variation within the field.

  6. Observation of Quiet Limb in He I 1083.0 nm, H Paschen alpha1281.8 nm and H Brackett gamma 2166.1 nm lines

    NASA Astrophysics Data System (ADS)

    Prasad Choudhary, Debi

    2016-05-01

    In this paper, we shall present the results of an observational study of the quiet solar limb in the near infrared lines using the New IR Array Camera (NAC) and the vertical spectrograph at the focal plane of McMath-Pierce telescope. The NAC, at the exit port of the spectrograph, was used to record the limb spectrum in HeI 1083.0 nm, Hydrogen Paschen 1281.8 nm and Brackett 2165.5 nm wavelength regions. The NAC is a 1024x1024 InSb Alladin III Detector operating over 1-5 micron range with high density sampling at 0.018 arc second/pixel. The all-reflective optical train minimizes number of surfaces and eliminates ghosts leading to low scatter, ghost-free optics. The close-cycle cryogenic provides a stable cooling environment over six hour period with an accuracy of 0.01K leading to low dark current. The low read out noise combined with low scattered light and dark current makes NAC an ideal detector for making high quality infrared spectral observations of solar limb. The limb spectrums were obtained by placing the spectrograph slit perpendicular to the limb at an interval of 10 degrees around the solar disk. We shall report the intensity profile, line-of-sight velocity and line width distribution around the sun derived from the spectra along the slit.

  7. Diode laser (980nm) cartilage reshaping

    NASA Astrophysics Data System (ADS)

    El Kharbotly, A.; El Tayeb, T.; Mostafa, Y.; Hesham, I.

    2011-03-01

    Loss of facial or ear cartilage due to trauma or surgery is a major challenge to the otolaryngologists and plastic surgeons as the complicated geometric contours are difficult to be animated. Diode laser (980 nm) has been proven effective in reshaping and maintaining the new geometric shape achieved by laser. This study focused on determining the optimum laser parameters needed for cartilage reshaping with a controlled water cooling system. Harvested animal cartilages were angulated with different degrees and irradiated with different diode laser powers (980nm, 4x8mm spot size). The cartilage specimens were maintained in a deformation angle for two hours after irradiation then released for another two hours. They were serially measured and photographed. High-power Diode laser irradiation with water cooling is a cheep and effective method for reshaping the cartilage needed for reconstruction of difficult situations in otorhinolaryngologic surgery. Key words: cartilage,diode laser (980nm), reshaping.

  8. 14nm M1 triple patterning

    NASA Astrophysics Data System (ADS)

    Li, Qiao; Ghosh, Pradiptya; Abercrombie, David; LaCour, Pat; Kanodia, Suniti

    2012-03-01

    With 20nm production becoming a reality, research has started to focus on the technology needs for 14nm. The LELE double patterning used in 20nm production will not be able to resolve M1 for 14nm. Main competing enabling technologies for the 14nm M1 are SADP, EUV, and LELELE (referred as LE3 thereafter) triple patterning. SADP has a number of concerns of 1. density, as a layout geometry needs to stay complete as a whole, and can not be broken; 2. the complexity in SADP mask generation and debug feedback to designers; 3. the subtraction nature of the trim mask further complicates OPC and yield. While EUV does not share those concerns, it faces significant challenges on the manufacturing equipment side. Of the SADP concerns, LE3 only shares that of complexity involved in mask generation and intuitive debug feedback mechanism. It does not require a layout geometry to stay as a whole, and it benefits from the affinity to LELE which is being deployed for 20nm production. From a process point of view, this benefit from affinity to LELE is tremendous due to the data and knowledge that have been collected and will be coming from the LELE deployment. In this paper, we first recount the computational complexity of the 3-colorability problem which is an integral part of a LE3 solution. We then describe graph characteristics that can be exploited such that 3-colorability is equivalent under divide-and-conquer. Also outlined are heuristics, which are generally applied in solving computationally intractable problems, for the 3-colorability problem, and the importance in choosing appropriate worst-case exponential runtime algorithms. This paper concludes with a discussion on the new hierarchical problem that faces 3-colorability but not 2-colorability and proposals for non-3-colorability feedback mechanism.

  9. Aqueous glucose measurement using differential absorption-based frequency domain optical coherence tomography at wavelengths of 1310 nm and 1625 nm

    NASA Astrophysics Data System (ADS)

    John, Pauline; Manoj, Murali; Sujatha, N.; Vasa, Nilesh J.; Rao, Suresh R.

    2015-07-01

    This work presents a combination of differential absorption technique and frequency domain optical coherence tomography for detection of glucose, which is an important analyte in medical diagnosis of diabetes. Differential absorption technique is used to detect glucose selectively in the presence of interfering species especially water and frequency domain optical coherence tomography (FDOCT) helps to obtain faster acquisition of depth information. Two broadband super-luminescent diode (SLED) sources with centre wavelengths 1586 nm (wavelength range of 1540 to 1640 nm) and 1312 nm (wavelength range of 1240 to 1380 nm) and a spectral width of ≍ 60 nm (FWHM) are used. Preliminary studies on absorption spectroscopy using various concentrations of aqueous glucose solution gave promising results to distinguish the absorption characteristics of glucose at two wavelengths 1310 nm (outside the absorption band of glucose) and 1625 nm (within the absorption band of glucose). In order to mimic the optical properties of biological skin tissue, 2% and 10% of 20% intralipid with various concentrations of glucose (0 to 4000 mg/dL) was prepared and used as sample. Using OCT technique, interference spectra were obtained using an optical spectrum analyzer with a resolution of 0.5 nm. Further processing of the interference spectra provided information on reflections from the surfaces of the cuvette containing the aqueous glucose sample. Due to the absorption of glucose in the wavelength range of 1540 nm to 1640 nm, a trend of reduction in the intensity of the back reflected light was observed with increase in the concentration of glucose.

  10. Campbell Systems Sampling Mean Conditions in an Urban Environment at White Sands Missile Range (WSMR), NM

    DTIC Science & Technology

    2006-09-01

    41002 12 Plate Grill Radiation Shields (figure 8).............................................. 8 4.2 Field Study Preparation...8 Figure 8. The 41002 12 plate grill radiation shields. ...................................................................... 8 Figure 9...scientific objectives were addressed: the first was sensing the thermodynamic patterns in an urban environment and the second was placing two groups of

  11. Comparative study of Nd:KGW lasers pumped at 808 nm and 877 nm

    NASA Astrophysics Data System (ADS)

    Huang, Ke; Ge, Wen-Qi; Zhao, Tian-Zhuo; He, Jian-Guo; Feng, Chen-Yong; Fan, Zhong-Wei

    2015-10-01

    The laser performance and thermal analysis of Nd:KGW laser continuously pumped by 808 nm and 877 nm are comparatively investigated. Output power of 670 mW and 1587 mW, with nearly TEM00 mode, are achieved respectively at 808 nm pump and 877 nm pump. Meanwhile, a high-power passively Q-switched Nd:KGW/Cr4+:YAG laser pumped at 877 nm is demonstrated. An average output power of 1495 mW is obtained at pump power of 5.22 W while the laser is operating at repetition of 53.17 kHz. We demonstrate that 877 nm diode laser is a more potential pump source for Nd:KGW lasers.

  12. The dynamics of femtosecond pulsed laser removal of 20 nm Ni films from an interface

    NASA Astrophysics Data System (ADS)

    Schrider, Keegan J.; Torralva, Ben; Yalisove, Steven M.

    2015-09-01

    The dynamics of femtosecond laser removal of 20 nm Ni films on glass substrates was studied using time-resolved pump-probe microscopy. 20 nm thin films exhibit removal at two distinct threshold fluences, removal of the top 7 nm of Ni above 0.14 J/cm2, and removal of the entire 20 nm film above 0.36 J/cm2. Previous work shows the top 7 nm is removed through liquid spallation, after irradiation the Ni melts and rapidly expands leading to tensile stress and cavitation within the Ni film. This work shows that above 0.36 J/cm2 the 20 nm film is removed in two distinct layers, 7 nm and 13 nm thick. The top 7 nm layer reaches a speed 500% faster than the bottom 13 nm layer at the same absorbed fluence, 500-2000 m/s and 300-700 m/s in the fluence ranges studied. Significantly different velocities for the top 7 nm layer and bottom 13 nm layer indicate removal from an interface occurs by a different physical mechanism. The method of measuring film displacement from the development of Newton's rings was refined so it could be shown that the 13 nm layer separates from the substrate within 70 ps and accelerates to its final velocity within several hundred picoseconds. We propose that removal of the bottom 13 nm is consistent with heterogeneous nucleation and growth of vapor at the Ni-glass interface, but that the rapid separation and acceleration of the 13 nm layer from the Ni-glass interface requires consideration of exotic phases of Ni after excitation.

  13. Synthesis of fluorinated materials for 193-nm immersion lithography and 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Yamashita, T.; Ishikawa, T.; Yoshida, T.; Hayamai, T.; Araki, Takayuki; Aoyama, H.; Hagiwara, T.; Itani, Toshiro; Fujii, Kiyoshi

    2005-05-01

    Various fluorinated polymers were synthesized for application in 193-nm immersion lithography with the goal of improving 157-nm photoresist performance. Their fundamental properties were characterized, such as transparency at 193-nm and 157-nm (wavelength) and solubility in water and a standard alkaline developer. High transparency, i.e., absorbance better than 0.3 μm-1 at 193-nm wavelength, was achieved. The dissolution behaviors of them were studied by using the Quartz Crystal Microbalance (QCM) method. We find that the dissolution rate of Poly(norbornene-2-fluoro-2-hexafluoroalchol) (PNB1FVIP) in 0.065N tetramethylammonium hydroxide (TMAH) was >200 times (nm/s) faster than that of the copolymer of tetrafluoroethylene (TFE) and norbornene-2-fluoro-2-hexafluoroalchol (TFE/NB1FVIP). A resist based on TFE/NB1FVIP was able to delineate 75 nm dense lines by exposure at 193-nm (wavelength) with an alternating phase shift mask using a 0.75 NA ArF scanner. The dissolution rates of the fluoropolymers in water and a 0.262N and 0.065 TMAH can be controlled by optimizing counter monomers containing hexafluoroisopropanol (HFA) unit, carboxylic acid unit and so on. In addition, we have collect water contact angle data. This data shows that fluoropolymers can be used as resist cover materials for 193-nm immersion lithography.

  14. White Sands, Carrizozo Lava Beds, NM

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A truly remarkable view of White Sands and the nearby Carrizozo Lava Beds in southeast NM (33.5N, 106.5W). White Sands, site of the WW II atomic bomb development and testing facility and later post war nuclear weapons testing that can still be seen in the cleared circular patterns on the ground.

  15. Radiation Tolerance of 65nm CMOS Transistors

    DOE PAGES

    Krohn, M.; Bentele, B.; Christian, D. C.; ...

    2015-12-11

    We report on the effects of ionizing radiation on 65 nm CMOS transistors held at approximately -20°C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.

  16. The 503nm pigment of Escherichia coli

    PubMed Central

    Kamitakahara, Joyce R.; Polglase, W. J.

    1970-01-01

    The yield of cell protein was one-third less for streptomycin-dependent Escherichia coli B than for the wild-type parent strain when both were grown aerobically on a medium with limiting glucose, but anaerobically the yield of protein was similar for both strains. The transient pigment absorbing at 503nm that is known to be present in E. coli and other organisms was not detectable in streptomycin-dependent mutants nor in a non-dependent (energy-deficient) revertant. When wild-type E. coli B was grown on limiting glucose–salts medium containing 2,4 dinitrophenol, the yield of cell protein was decreased and formation of the 503nm pigment was inhibited. Fumarase, aconitase and glucose 6-phosphate dehydrogenase were de-repressed in E. coli B cells grown with excess of glucose in a medium containing 2,4-dinitrophenol. In air-oxidized, wild-type E. coli B cells, the 503nm pigment appeared before reduced cytochromes when gluconate was the substrate but failed to appear when succinate was the substrate. The results provide evidence for a role of the 503nm pigment in aerobic energy metabolism, possibly as an electron acceptor from NADPH. PMID:4395501

  17. UV Laser Conditioning for Reduction of 351-nm Damage Initiation in Fused Silica

    SciTech Connect

    Brusasco, R M; Penetrante, B M; Peterson, J E; Maricle, S M; Menapace, J A

    2001-12-20

    This paper describes the effect of 355-nm laser conditioning on the concentration of UV-laser-induced surface damage sites on large-aperture fused silica optics. We will show the effect of various 355-nm laser conditioning methodologies on the reduction of surface-damage initiation in fused silica samples that have varying qualities of polishing. With the best, generally available fused silica optic, we have demonstrated that 355-nm laser conditioning can achieve up to 10x reduction in surface damage initiation concentration in the fluence range of 10-14 J/cm{sup 2} (355-nm {at} 3 ns).

  18. VizieR Online Data Catalog: Thorium spectrum from 250nm to 5500nm (Redman+, 2014)

    NASA Astrophysics Data System (ADS)

    Redman, S. L.; Nave, G.; Sansonetti, C. J.

    2014-04-01

    We observed the spectrum of a commercial sealed Th/Ar HCL running at 25mA for almost 15hr starting on 2011 November 2. The region of observation was limited to between 8500/cm and 28000/cm (360nm and 1200nm) by the sensitivity of the silicon photodiode detector. (5 data files).

  19. Evaluation of high quantum efficiency silicon photodiodes for calibration in the 400 nm to 900 nm spectral region

    NASA Technical Reports Server (NTRS)

    Jorquera, Carlos; Bruegge, Carol; Duval, Valerie

    1992-01-01

    The reflectance and internal quantum efficiency (QE) of three single-element photodiodes are determined using two different light-trapping devices. The QED-200 light trapping device which is based on inversion layer photodiodes exhibits the best performance within the short wavelengths of the visible spectrum (VIS), while the A-O device based on p-n photodiodes, performs best in the long wave VIS up to 950 nm. The combination of the two light-traps provides nearly 100 percent external QE coverage from 400 to 950 nm. The reflectances and internal QE were determined within this spectral range for three photodiodes: UV100, an inversion layer photodiode; X-UV100, a shallow diffused n-p photodiode; and 10DPI/SB, a blue-enhanced p-n photodiode.

  20. Efficient 1645-nm Er:YAG laser

    NASA Astrophysics Data System (ADS)

    Young, York E.; Setzler, Scott D.; Snell, Kevin J.; Budni, Peter A.; Pollak, Thomas M.; Chicklis, E. P.

    2004-05-01

    We report a resonantly fiber-laser-pumped Er:YAG laser operating at the eye-safe wavelength of 1645 nm, exhibiting 43% optical efficiency and 54% incident slope efficiency and emitting 7-W average power when repetitively Q switched at 10 kHz. To our knowledge, this is the best performance (conversion efficiency and average power) obtained from a bulk solid-state Q-switched erbium laser. At a 1.1-kHz pulse repetition frequency the laser produces 3.4-mJ pulses with a corresponding peak power of 162 kW. Frequency doubling to produce 822.5-nm, 4.7-kW pulses at 10 kHz was performed to demonstrate the laser's utility.

  1. DNA Charge Transport over 34 nm

    PubMed Central

    Slinker, Jason D.; Muren, Natalie B.; Renfrew, Sara E.; Barton, Jacqueline K.

    2011-01-01

    Molecular wires show promise in nanoscale electronics but the synthesis of uniform, long conductive molecules is a significant challenge. DNA of precise length, by contrast, is easily synthesized, but its conductivity has not been explored over the distances required for nanoscale devices. Here we demonstrate DNA charge transport (CT) over 34 nm in 100-mer monolayers on gold. Multiplexed gold electrodes modified with 100-mer DNA yield sizable electrochemical signals from a distal, covalent Nile Blue redox probe. Significant signal attenuation upon incorporation of a single base pair mismatch demonstrates that CT is DNA-mediated. Efficient cleavage of these 100-mers by a restriction enzyme indicates that the DNA adopts a native conformation that is accessible to protein binding. Similar electron transfer rates are measured through 100-mer and 17-mer monolayers, consistent with rate-limiting electron tunneling through the saturated carbon linker. This DNA-mediated CT distance of 34 nm surpasses most reports of molecular wires. PMID:21336329

  2. Ground-motion prediction equations for the average horizontal component of PGA, PGV, and 5%-damped PSA at spectral periods between 0.01 s and 10.0 s

    USGS Publications Warehouse

    Boore, D.M.; Atkinson, G.M.

    2008-01-01

    This paper contains ground-motion prediction equations (GMPEs) for average horizontal-component ground motions as a function of earthquake magnitude, distance from source to site, local average shear-wave velocity, and fault type. Our equations are for peak ground acceleration (PGA), peak ground velocity (PGV), and 5%-damped pseudo-absolute-acceleration spectra (PSA) at periods between 0.01 s and 10 s. They were derived by empirical regression of an extensive strong-motion database compiled by the 'PEER NGA' (Pacific Earthquake Engineering Research Center's Next Generation Attenuation) project. For periods less than 1 s, the analysis used 1,574 records from 58 mainshocks in the distance range from 0 km to 400 km (the number of available data decreased as period increased). The primary predictor variables are moment magnitude (M), closest horizontal distance to the surface projection of the fault plane (RJB), and the time-averaged shear-wave velocity from the surface to 30 m (VS30). The equations are applicable for M=5-8, RJB<200 km, and VS30= 180-1300 m/s. ?? 2008, Earthquake Engineering Research Institute.

  3. Radiation Status of Sub-65 nm Electronics

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.

    2011-01-01

    Ultra-scaled complementary metal oxide semiconductor (CMOS) includes commercial foundry capabilities at and below the 65 nm technology node Radiation evaluations take place using standard products and test characterization vehicles (memories, logic/latch chains, etc.) NEPP focus is two-fold: (1) Conduct early radiation evaluations to ascertain viability for future NASA missions (i.e. leverage commercial technology development). (2) Uncover gaps in current testing methodologies and mechanism comprehension -- early risk mitigation.

  4. Binary 193nm photomasks aging phenomenon study

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sartelli, Luca; Pogliani, Carlo; Gough, Stuart; Sundermann, Frank; Miyashita, Hiroyuki; Hidenori, Yoshioka; Charras, Nathalie; Brochard, Christophe; Thivolle, Nicolas

    2011-05-01

    193nm binary photomasks are still used in the semiconductor industry for the lithography of some critical layers for the nodes 90nm and 65nm, with high volumes and over long period. These 193nm binary masks seem to be well-known but recent studies have shown surprising degrading effects, like Electric Field induced chromium Migration (EFM) [1] or chromium migration [2] [3] . Phase shift Masks (PSM) or Opaque MoSi On Glass (OMOG) might not be concerned by these effects [4] [6] under certain conditions. In this paper, we will focus our study on two layers gate and metal lines. We will detail the effects of mask aging, with SEM top view pictures revealing a degraded chromium edge profile and TEM chemical analyses demonstrating the growth of a chromium oxide on the sidewall. SEMCD measurements after volume production indicated a modified CD with respect to initial CD data after manufacture. A regression analysis of these CD measurements shows a radial effect, a die effect and an isolated-dense effect. Mask cleaning effectiveness has also been investigated, with sulphate or ozone cleans, to recover the mask quality in terms of CD. In complement, wafer intrafield CD measurements have been performed on the most sensitive structure to monitor the evolution of the aging effect on mask CD uniformity. Mask CD drift have been correlated with exposure dose drift and isolated-dense bias CD drift on wafers. In the end, we will try to propose a physical explanation of this aging phenomenon and a solution to prevent from it occurring.

  5. Optical characterization of 193nm amorphous carbon ARC films

    NASA Astrophysics Data System (ADS)

    Leng, Jingmin; Opsal, Jon; Pois, Heath

    2005-05-01

    In this study, the optical properties of amorphous carbon (aC) ARC films are investigated using an Opti-probe OP7341, and a metrology solution that robustly measures a broad range of process conditions is presented. We find that the aC material is consistent with uni-axial anisotropy, and that this effect may have important implications for photolithography. These results are obtained through the combination of multiple technologies in one tool: spectroscopic ellipsometry (SE); spectroscopic reflectometry or broadband (BB), with a wavelength range of 190-840 nm; single wavelength (673 nm) but multiple incident angle beam profile reflectometry (BPR) and beam profile ellipsometry (BPE), and single wavelength (633nm) absolute ellipsometry (AE). The combination of technologies at multiple angles and wavelengths provides additional optical information and sensitivity not possible with single-technology approaches. A complex wavelength dependent anisotropy model was developed for this analysis, and is compared with a real anisotropy model. The complex anisotropy model and the effective medium approximation (EMA) with two and three components were applied to a set of 12 wafer set with thickness swing aC films in the range of 500-750 Å as well as a second set of 23 pre- and post- etch wafers. The complex anisotropy model clearly has the advantage of best fit the BPR profiles along with the SE Fourier coefficients. The etch rate obtained by the complex anisotropy also showed a much narrower variation as compared with the EMA2 and EMA32 models with the real anisotropy.

  6. Brain lesion induced by 1319nm laser radiation

    NASA Astrophysics Data System (ADS)

    Yang, Zaifu; Chen, Hongxia; Wang, Jiarui; Chen, Peng; Ma, Ping; Qian, Huanwen

    2010-11-01

    The laser-tissue interaction has not been well defined at the 1319 nm wavelength for brain exposure. The goal of this research effort was to identify the behavioral and histological changes of brain lesion induced by 1319 nm laser. The experiment was performed on China Kunming mice. Unilateral brain lesions were created with a continuous-wave Nd:YAG laser (1319nm). The brain lesions were identified through behavioral observation and histological haematoxylin and eosin (H&E) staining method. The behavior change was observed for a radiant exposure range of 97~773 J/cm2. The histology of the recovery process was identified for radiant exposure of 580 J/cm2. Subjects were sacrificed 1 hour, 1 week, 2 weeks, 3 months, 7 months and 13 months after laser irradiation. Results showed that after laser exposure, behavioral deficits, including kyphosis, tail entasia, or whole body paralysis could be noted right after the animals recovered from anesthesia while gradually disappeared within several days and never recurred again. Histologically, the laser lesion showed a typical architecture dependent on the interval following laser treatment. The central zone of coagulation necrosis is not apparent right after exposure but becomes obvious within several days. The nerotic tissue though may persist for a long time, will finally be completely resorbed. No carbonization granules formed under our exposure condition.

  7. 7-nm e-beam resist sensitivity characterization

    NASA Astrophysics Data System (ADS)

    Zweber, Amy; Toda, Yusuke; Sakamoto, Yoshifumi; Faure, Thomas; Rankin, Jed; Nash, Steven; Kagawa, Masayuki; Fahrenkopf, Michael; Isogawa, Takeshi; Wistrom, Richard

    2016-10-01

    Over time mask makers have been driven to low sensitivity e-beam resist materials to meet lithographic patterning needs. For 7-nm logic node, resolution enhancement techniques continue to evolve bringing more complexity on mask and additional mask builds per layer. As demonstrated in literature, low sensitivity materials are needed for low line edge roughness (LER) but impact write tool through put. In characterizing resist sensitivity for 7-nm, we explore more broadly what advantages and disadvantages moving to lower sensitivity resist materials brings, where LER, critical dimension uniformity, resolution, fogging, image placement, and write time results and trends are presented. In this paper, resist material performance are reported for sensitivities ranging from 20 to 130 μC/cm2 at 50% proximity effect correction, where the exposure will be using a single beam platform. Materials examined include negative tone resist types with chemical amplification and positive tone without chemical amplification focusing on overall trends for 7-nm e-beam resist performance.

  8. 3D scanning Hall probe microscopy with 700 nm resolution

    NASA Astrophysics Data System (ADS)

    Dede, M.; Akram, R.; Oral, A.

    2016-10-01

    In this report, we present a three dimensional (3D) imaging of magnetic field vector B → (x,y,z) emanating from the magnetic material surfaces using a scanning Hall probe microscopy (3D-SHPM) down to a 700 nm spatial resolution. The Hall probe is used to measure Bz(x,y) on the specimen surface at different heights with the step size of Δz = 250 nm, as we move away from the surface in z direction, until the field decays to zero. These set of images are then used to get ∂Bz(x,y)/∂x and ∂Bz(x,y)/∂y at different z by numerical differentiation. Using the Maxwell's equations in the source free region, Bx(x,y) and By(x,y) can be calculated by integrating ∂Bz(x,y)/∂x and ∂Bz(x,y)/∂y in the z direction. Alternatively, the gradients can also be measured in the Hall gradiometer configuration directly. The operation of the 3D-SHPM is demonstrated by imaging Bx(x,y), By(x,y) and Bz(x,y) on a hard disk specimen at a 700 nm resolution, using both of these methods at 77 K. The system is capable of operating from 300 K down to 4 K range.

  9. Broad tuning range filtering system with Optune interferometers

    NASA Astrophysics Data System (ADS)

    Miron, Nicolae

    2008-08-01

    An optical system built with two Optune interferometers cascaded according to Vernier principle has attractive tunable band pass filtering properties for numerous applications. Several characteristics of Optune interferometer such as 0.2 dB insertion loss flatness across at least 90 nm interval, no tuning holes across 240 nm tuning range, quasi-periodic free spectral range and 1 dB insertion loss are key parameters to obtain a cascade with 0.1 nm band pass tunable across minimum 90 nm. Several properties of Optune interferometers are analyzed to build a cascade tunable across minimum 90 nm: the relationships between the free spectral ranges, bandwidths and tuning conditions. It is presented also a cascade prototype with two interferometers having 9.72 nm free spectral range and respectively 11.12 nm free spectral range. The cascade band pass is 0.1 nm tunable with 1 pm accuracy to any arbitrary wavelength across 150 nm free spectral range, without any tuning hole. It has 0.125 ms / 100 nm tuning speed, the insertion loss is less than 3 dB, 50 dB contrast, 0.5 dB flatness and 0.2 dB polarization dependent loss. A controller based on digital signal processor monitors the operation of the cascade to achieve optimum tuning performance.

  10. A tunable, single frequency, fiber ring at 1053 nm

    SciTech Connect

    Wilcox, R.B.

    1997-02-21

    This laser is a tunable source designed for applications where a shorter pulse will be chopped from a long Q-switched pulse by electrooptic modulators, then amplified in Nd:phosphate glass. The laser employs ytterbium-doped silica fiber as the gain medium, pumped by a laser diode at 980nm. Gain in Yb:silica is distributed over an 90nm range, making it suitable for operation at many wavelengths. Our previous experiments with this medium demonstrated oscillation over a 50nm wide band. In addition, pumping at 980nm allows the use of stable pump diodes used in erbium-doped fiber amplifiers (EDFA`s). We designed the laser to take advantage of this wideband gain medium, and yet operate on a single cavity mode. A circulator causes unidirectional operation, and allows use of a fiber grating in reflection. This grating has a 0.2 Angstrom bandwidth, and defines the coarse tuning of the laser. It is piezoelectrically stretch tuned to the desired wavelength band. A single mode of the cavity is selected by a piezoelectrically tuned fiber grating Fabry-Perot etalon with 64MHz bandwidth. The laser is Q-switched by a bulk acousto-optic device at lkhz reprate. The loss is controlled to allow the oscillator to lase close to threshold for 500{micro}s before the Q-switch is turned off completely, creating a pulse. This ``pre-lasing`` stabilizes the single mode, since Q-switch pulse builds up from the prelase level. To prevent mode hopping during long term operation, cavity length is feedback controlled. Another piezoelectric device stretches a fiber in the cavity according to an error signal derived from the output optical signal. Due to the long, high loss cavity, the Q-switched pulse is about 3OOns long. The central part of this pulse will be gated by an electrooptic modulator to produce a 30ns square pulse, used for further amplification and modulation.

  11. 75 FR 81437 - Amendment of Class E Airspace; Taos, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... Taos, NM. Decommissioning of the Ski non-directional beacon (NDB) at Taos Regional Airport, Taos, NM... Taos, NM area. Decommissioning of the Ski NDB and cancellation of the NDB approach at Taos...

  12. Deep ultraviolet (254 nm) focal plane array

    NASA Astrophysics Data System (ADS)

    Cicek, Erdem; Vashaei, Zahra; McClintock, Ryan; Razeghi, Manijeh

    2011-10-01

    We report the synthesis, fabrication and testing of a 320 × 256 focal plane array (FPA) of back-illuminated, solarblind, p-i-n, AlxGa1-xN-based detectors, fully realized within our research laboratory. We implemented a novel pulsed atomic layer deposition technique for the metalorganic chemical vapor deposition (MOCVD) growth of crackfree, thick, and high Al composition AlxGa1-xN layers. Following the growth, the wafer was processed into a 320 × 256 array of 25 μm × 25 μm pixels on a 30 μm pixel-pitch and surrounding mini-arrays. A diagnostic mini-array was hybridized to a silicon fan-out chip to allow the study of electrical and optical characteristics of discrete pixels of the FPA. At a reverse bias of 1 V, an average photodetector exhibited a low dark current density of 1.12×10-8 A/cm2. Solar-blind operation is observed throughout the array with peak detection occurring at wavelengths of 256 nm and lower and falling off three orders of magnitude by 285 nm. After indium bump deposition and dicing, the FPA is hybridized to a matching ISC 9809 readout integrated circuit (ROIC). By developing a novel masking technology, we significantly reduced the visible response of the ROIC and thus the need for external filtering to achieve solar- and visible-blind operation is eliminated. This allowed the FPA to achieve high external quantum efficiency (EQE): at 254 nm, average pixels showed unbiased peak responsivity of 75 mA/W, which corresponds to an EQE of ~37%. Finally, the uniformity of the FPA and imaging properties are investigated.

  13. Laser-induced bulk damage of silica glass at 355nm and 266nm

    NASA Astrophysics Data System (ADS)

    Kashiwagi, R.; Aramomi, S.

    2016-12-01

    Laser processing machines using Nd:YAG 3rd harmonic wave (355 nm) and 4th harmonic wave (266 nm) have been developed and put into practical use lately. Due to this, optical elements with high laser durability to 355 nm and 266 nm are required. Silica glass is the optical element which has high UV transmission and high laser durability. Laser-induced surface damage of the silica glass has been studied in detail, but we hardly have the significant knowledge of laserinduced bulk damage. This knowledge is required in order to evaluate the silica glass itself. That is because cracks and scratches on the surface give rise to a higher possibility of damage. Therefore, we studied the laser durability of a variety of the silica glass samples by 1-on-1 and S-on-1 laser-induced bulk damage threshold (LIDT) at 355 nm and 266 nm. In this study, we gained knowledge in three areas about bulk damage to the silica glass. First, the LIDT became lower as shot counts increased. Second, the LIDT decreased as the hydroxyl content in the silica glass increased. Last, the LIDT became higher as the hydrogen concentration in the silica glass increased. Under the UV irradiation, impurities are generated and the silica glass absorbs more light. Therefore, the LIDT decreased as shot counts increased. Also, the hydroxyl in particular generates more impurities, so damage easily occurs. On the other hand, the hydrogen reacts with impurities and absorption is suppressed. Based on these results, we can improve laser durability at 355 nm and 266 nm by reducing the hydroxyl content and increasing the hydrogen concentration in the silica glass.

  14. Yb fiber amplifier at 972.5 nm with frequency quadrupling to 243.1 nm

    NASA Astrophysics Data System (ADS)

    Burkley, Z.; Rasor, C.; Cooper, S. F.; Brandt, A. D.; Yost, D. C.

    2017-01-01

    We demonstrate a continuous-wave ytterbium-doped fiber amplifier which produces 6.3 W at a wavelength of 972.5 nm. We frequency-quadruple this source in two resonant doubling stages to generate 530 mW at 243.1 nm. Radiation at this wavelength is required to excite the 1S-2S transition in atomic hydrogen and could therefore find application in experimental studies of hydrogen and anti-hydrogen.

  15. Photolysis of formic acid at 355 nm

    NASA Astrophysics Data System (ADS)

    Martinez, Denhi; Bautista, Teonanacatl; Guerrero, Alfonso; Alvarez, Ignacio; Cisneros, Carmen

    2015-05-01

    Formic acid is well known as a food additive and recently an application on fuel cell technology has emerged. In this work we have studied the dissociative ionization process by multiphoton absorption of formic acid molecules at 355nm wavelength photons, using TOF spectrometry in reflectron mode (R-TOF). Some of the most abundant ionic fragments produced are studied at different settings of the laser harmonic generator. The dependence of the products on these conditions is reported. This work was supported by CONACYT Project 165410 and PAPIIT IN102613 and IN101215.

  16. Nonlinear absorption properties of DKDP crystal at 263 nm and 351 nm

    NASA Astrophysics Data System (ADS)

    Chai, Xiangxu; Zhu, Qihua; Feng, Bin; Li, Fuquan; Feng, Xi; Wang, Fang; Han, Wei; Wang, Liquan

    2017-02-01

    At the wavelength of 263 nm and 351 nm, the nonlinear absorption curves of 66% deuterated DKDP crystal were measured in the geometries of beam polarizing along the optics axis (E∥Z) and perpendicular to it (E⊥Z). The results indicate that the nonlinear absorption in the E⊥Z geometry is stronger than that in the E∥Z geometry. The nonlinear absorptions at 263 nm and 351 nm are identified to two- and three-photon absorption, respectively. The theoretical fits to the experimental data yields the two-photon absorption coefficients of 0.32 ± 0.03 cm/GW (E⊥Z geometry) and 0.17 ± 0.02 cm/GW (E∥Z geometry) at 263 nm, and the three-photon absorption coefficients of (8.1 ± 1.1) × 10-4 cm3/GW2 (E⊥Z geometry) and (2.2 ± 0.5) × 10-4 cm3/GW2 (E∥Z geometry) at 351 nm.

  17. Linearly polarized, single-frequency, widely tunable Er:Yb bulk laser at around 1550 nm wavelength

    SciTech Connect

    Taccheo, S.; Laporta, P.; Svelto, O.

    1996-11-01

    We report on a 36 nm tunable, single-frequency, linearly polarized Er:Yb:glass laser. A tuning range from 1528 to 1564 nm, with output power ranging from 1 to 8 mW, is achieved. Wavelength tuning and linearly polarized output are simultaneously obtained by using a special polarizing etalon with anisotropic absorption losses. {copyright} {ital 1996 American Institute of Physics.}

  18. DNA charge transport over 34 nm

    NASA Astrophysics Data System (ADS)

    Slinker, Jason D.; Muren, Natalie B.; Renfrew, Sara E.; Barton, Jacqueline K.

    2011-03-01

    Molecular wires show promise in nanoscale electronics, but the synthesis of uniform, long conductive molecules is a significant challenge. Deoxyribonucleic acid (DNA) of precise length, by contrast, is synthesized easily, but its conductivity over the distances required for nanoscale devices has not been explored. Here we demonstrate DNA charge transport (CT) over 34 nm in 100-mer monolayers on gold. Multiplexed gold electrodes modified with 100-mer DNA yield sizable electrochemical signals from a distal, covalent Nile Blue redox probe. Significant signal attenuation upon incorporation of a single base-pair mismatch demonstrates that CT is DNA-mediated. Efficient cleavage of these 100-mers by a restriction enzyme indicates that the DNA adopts a native conformation accessible to protein binding. Similar electron-transfer rates measured through 100-mer and 17-mer monolayers are consistent with rate-limiting electron tunnelling through the saturated carbon linker. This DNA-mediated CT distance of 34 nm surpasses that of most reports of molecular wires.

  19. Photomask etch system and process for 10nm technology node and beyond

    NASA Astrophysics Data System (ADS)

    Chandrachood, Madhavi; Grimbergen, Michael; Yu, Keven; Leung, Toi; Tran, Jeffrey; Chen, Jeff; Bivens, Darin; Yalamanchili, Rao; Wistrom, Richard; Faure, Tom; Bartlau, Peter; Crawford, Shaun; Sakamoto, Yoshifumi

    2015-10-01

    While the industry is making progress to offer EUV lithography schemes to attain ultimate critical dimensions down to 20 nm half pitch, an interim optical lithography solution to address an immediate need for resolution is offered by various integration schemes using advanced PSM (Phase Shift Mask) materials including thin e-beam resist and hard mask. Using the 193nm wavelength to produce 10nm or 7nm patterns requires a range of optimization techniques, including immersion and multiple patterning, which place a heavy demand on photomask technologies. Mask schemes with hard mask certainly help attain better selectivity and hence better resolution but pose integration challenges and defectivity issues. This paper presents a new photomask etch solution for attenuated phase shift masks that offers high selectivity (Cr:Resist > 1.5:1), tighter control on the CD uniformity with a 3sigma value approaching 1 nm and controllable CD bias (5-20 nm) with excellent CD linearity performance (<5 nm) down to the finer resolution. The new system has successfully demonstrated capability to meet the 10 nm node photomask CD requirements without the use of more complicated hard mask phase shift blanks. Significant improvement in post wet clean recovery performance was demonstrated by the use of advanced chamber materials. Examples of CD uniformity, linearity, and minimum feature size, and etch bias performance on 10 nm test site and production mask designs will be shown.

  20. Low-intensity LED (625 and 405 nm) and laser (805 nm) killing of Propionibacterium acnes and Staphylococcus epidermidis

    NASA Astrophysics Data System (ADS)

    Tuchina, Elena S.; Tuchin, Valery V.

    2009-02-01

    In the present work we have investigated in vitro sensitivity of microorganisms P. acnes and S. epidermidis to action of red (625 nm and 405 nm) and infrared (805 nm) radiations in combination with photosensitizes Methylene Blue and Indocyanine Green.

  1. Comparison of 980-nm and 1070-nm in endovenous laser treatment (EVLT)

    NASA Astrophysics Data System (ADS)

    Topaloglu, Nermin; Tabakoglu, Ozgur; Ergenoglu, Mehmet U.; Gülsoy, Murat

    2009-07-01

    The use of endovenous laser treatment for varicose veins has been increasing in recent years. It is a safer technique than surgical vein stripping. Its complications (e.g. bruising, pain) are less than the complications of surgical vein stripping. But best parameters such as optimum wavelength, power, and application duration are still under investigation to clarify uncertainties about this technique. To prevent its complications and improve its clinical outcomes, the exact mechanism of it has to be known. The aim of this study is to investigate the effect of different laser wavelengths on endovenous laser therapy. In this study 980-nm diode laser and 1070-nm fiber laser were used. Human veins were irradiated with 980-nm and 1070-nm lasers at 8 W and 10 W to find the optimal power and wavelength. After laser application, remarkable shrinkage was observed. Inner and outer diameters of the veins also narrowed for both of the laser types. 10 W of 980-nm laser application led to better shrinkage results.

  2. Dual illumination OCT at 1050nm and 840nm for whole eye segment imaging

    NASA Astrophysics Data System (ADS)

    Fan, Shanhui; Qin, Lin; Dai, Cuixia; Zhou, Chuanqing

    2014-11-01

    We presented an improved dual channel dual focus spectral domain optical coherence tomography (SD-OCT) with two illuminations at 840 nm and 1050 nm for whole eye segment imaging and biometry in vivo. The two light beams were coupled and optically optimized to scan the anterior and posterior segment of the eye simultaneously. This configuration with dichroic mirrors integrated in the sample arm enables us to acquire images from the anterior segment and retina effectively with minimum loss of sample signal. In addition, the full resolved complex (FRC) method was applied to double the imaging depth for the whole anterior segment imaging by eliminating the mirror image. The axial resolution for 1050 nm and 840 nm OCT was 14 μm and 8 μm in air, respectively. Finally, the system was successfully tested in imaging the unaccommodated and accommodated eyes. The preliminary results demonstrated the significant improvements comparing with our previous dual channel SD-OCT configuration in which the two probing beams had the same central wavelength of 840 nm.

  3. AGN flickering on 10-100 kyr timescales

    NASA Astrophysics Data System (ADS)

    Sartori, Lia F.; Schawinski, Kevin; Kill, Bill; Maksym, Peter; Koss, Michael; Argo, Megan; Urry, Meg; Wong, Ivy; Lintott, Chris

    2016-08-01

    The study of AGN variability on timescales of 10^4-10^5 years is important in order to understand the BH - host galaxy interaction and coevolution. The discovery of "Hanny's Voorwerp" (HV), an extended emission line region associated with the nearby galaxy IC 2497, provided us with a laboratory to study AGN variability over such timescales. HV was illuminated by a strong quasar in IC 2497, but this quasar significantly shut down in the last 200 kyrs. Thanks to its recent shutdown we can now explore the host galaxy unimpeded by the presence of a quasar dominating the observations, while the Voorwerp preserves the echoes of its past activity. Recent studies on the optical properties of hard X-ray selected AGN suggest that AGN may flicker on and off hundreds or thousands times with each burst lasting ~10^5 yrs. Systems similar to IC 2497 and HV, the so-called Voorwerpjes, allow us to constrain the last stages of the AGN lifecycle. On the other hand, we recently suggested that the switch on phase may be observed in the so-called optically elusive AGN. In this talk I will review both observational evidence and results from simulation work which support this picture, and explain how optically elusive AGN and Voorwerpjes galaxies can help us to understand different phases of the AGN lifecycle. Moreover, I will discuss possible implications for AGN feedback, BH - host galaxy coevolution, and the analogy between AGN and X-ray binaries accretion physics.

  4. Sequence Polishing Library (SPL) v10.0

    SciTech Connect

    Oberortner, Ernst

    2016-06-03

    The Sequence Polishing Library (SPL) is a suite of software tools in order to automate "Design for Synthesis and Assembly" workflows. Specifically: - The SPL "Converter" tool converts files among the following sequence data exchange formats: CSV, FASTA, GenBank, and Synthetic Biology Open Language (SBOL). - The SPL "Juggler" tool optimizes the codon usages of DNA coding sequences according to an optimization strategy, a user-specific codon usage table and genetic code. In addition, the SPL "Juggler" can translate amino acid sequences into DNA sequences. - The SPL "Polisher" verifies NA sequences against DNA synthesis constraints, such as GC content, repeating k-mers, and restriction sites. In case of violations, the "Polisher" reports the violations in a comprehensive manner. The "Polisher" tool can also modify the violating regions according to an optimization strategy, a user-specific codon usage table and genetic code. - The SPL "Partitioner" decomposes large DNA sequences into smaller building blocks with partial overlaps that enable an efficient assembly. The "Partitioner" enables the user to configure the characteristics of the overlaps, which are mostly determined by the utilized assembly protocol, such as length, GC content, or melting temperature.

  5. Spectroscopy of Pluto at six longitudes, 380-930 nm

    NASA Astrophysics Data System (ADS)

    Cruikshank, Dale P.; Pinilla-Alonso, Noemi; Lorenzi, Vania; Grundy, Will M.; Licandro, Javier; Binzel, Richard P.

    2014-11-01

    We have obtained spectra of the Pluto-Charon pair (unresolved) in the wavelength range 380-930 nm with resolution ~450 at six roughly equally spaced longitudes. The data were taken in May and June, 2014, with the 4.2-m Isaac Newton Telescope at Roque de Los Muchachos Observatory in the Canary Islands, using the ACAM (auxiliary-port camera) in spectrometer mode, and using two solar analog stars. The new spectra clearly show absorption bands of solid CH4 at 620, 728, and 850-910 nm, which were known from earlier work. The 620-nm CH4 band is intrinsically very weak, and its appearance indicates a long optical pathlength through the ice. This is especially true if it arises from CH4 dissolved in N2 ice. Earlier work (Owen et al. Science 261, 745, 1993) on the near-infrared spectrum of Pluto (1-2.5 µm) has shown that the CH4 bands are shifted to shorter wavelengths because the CH4 occurs as a solute in beta-phase crystalline N2. The optical pathlength through the N2 crystals must be on the order of several cm to produce the N2 band observed at 2.15 µm. The new spectra exhibit a pronounced red slope across the entire wavelength range; the slope is variable with longitude, and differs in a small but significant way from that measured at comparable longitudes by Grundy & Fink (Icarus 124, 329, 1996) in their 15-year study of Pluto’s spectrum (500-1000 nm). The new spectra will provide an independent means for calibrating the color filter bands on the Multispectral Visible Imaging Camera (MVIC) (Reuter et al. Space Sci. Rev. 140, 129, 2008) on the New Horizons spacecraft, which will encounter the Pluto-Charon system in mid-2015. They will also form the basis of modeling the spectrum of Pluto at different longitudes to help establish the nature of the non-ice component(s) of Pluto’s surface. It is presumed that the non-ice component is the source of the yellow-red coloration of Pluto, which is known to be variable across the surface.

  6. Spectroscopy of Pluto, 380-930 Nm at Six Longitudes

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Pinilla-Alonso, N.; Lorenzi, V.; Grundy, William; Licandro, J.; Binzel, R. P.

    2014-01-01

    We have obtained spectra of the Pluto-Charon pair (unresolved) in the wavelength range 380-930 nm with resolution approx..450 at six roughly equally spaced longitudes. The data were taken in May and June, 2014, with the 4.2-m Isaac Newton Telescope at Roque de Los Muchachos Observatory in the Canary Islands, using the ACAM (auxiliary-port camera) in spectrometer mode, and using two solar analog stars. The new spectra clearly show absorption bands of solid CH4 at 620, 728, and 850-910 nm, which were known from earlier work. The 620-nm CH4 band is intrinsically very weak, and its appearance indicates a long optical path-length through the ice. This is especially true if it arises from CH4 dissolved in N2 ice. Earlier work (Owen et al. Science 261, 745, 1993) on the near-infrared spectrum of Pluto (1-2.5 microns) has shown that the CH4 bands are shifted to shorter wavelengths because the CH4 occurs as a solute in beta-phase crystalline N2. The optical path-length through the N2 crystals must be on the order of several cm to produce the N2 band observed at 2.15 microns. The new spectra exhibit a pronounced red slope across the entire wavelength range; the slope is variable with longitude, and differs in a small but significant way from that measured at comparable longitudes by Grundy & Fink (Icarus 124, 329, 1996) in their 15-year study of Pluto's spectrum (500-1000 nm). The new spectra will provide an independent means for calibrating the color filter bands on the Multispectral Visible Imaging Camera (MVIC) (Reuter et al. Space Sci. Rev. 140, 129, 2008) on the New Horizons spacecraft, which will encounter the Pluto-Charon system in mid-2015. They will also form the basis of modeling the spectrum of Pluto at different longitudes to help establish the nature of the non-ice component(s) of Pluto's surface. It is presumed that the non-ice component is the source of the yellow-red coloration of Pluto, which is known to be variable across the surface.

  7. 308-nm excimer laser in endodontics

    NASA Astrophysics Data System (ADS)

    Liesenhoff, Tim

    1992-06-01

    Root canal preparation was performed on 20 extracted human teeth. After opening the coronal pulp, the root canals were prepared by 308 nm excimer laser only. All root canals were investigated under SEM after separation in the axial direction. By sagittal separation of the mandibles of freshly slaughtered cows, it was possible to get access to the tissues and irradiate under optical control. Under irradiation of excimer laser light, tissue starts to fluoresce. It was possible to demonstrate that each tissue (dentin, enamel, bone, pulpal, and connective tissue) has a characteristic spectral pattern. The SEM analyses showed that it is well possible to prepare root canals safely. All organic soft tissue has been removed by excimer laser irradiation. There was no case of via falsa. The simultaneous spectroscopic identification of the irradiated tissue provides a safe protection from overinstrumentation. First clinical trials on 20 patients suffering of chronical apical parodontitis have been carried out successfully.

  8. Microscope illumination systems for 157 nm

    NASA Astrophysics Data System (ADS)

    Pesch, Alexander; Uhlendorf, Kristina; Deparnay, Arnaud; Erdmann, Lars; Kuschnerus, Peter; Engel, Thomas; Brunner, Robert

    2003-05-01

    The image quality of an inspection microscope depends strongly on the performance of the illumination system. Especially in the case of laser-based illumination it is necessary to transform the original beam profile into a homogeneous light spot with a flat top field distribution. Simultaneously, speckles caused by the coherence of the laser have to be reduced. Here we discuss different ways to homogenize the multi mode beam profile of a pulsed compact 157 nm excimer laser. A variety of setups, combining dynamic acting diffusers, microlens arrays and primary lenses were realized and characterized in several geometrical arrangements. The homogenizers were evaluated and characterized especially with respect to the statistical behavior on the integrated pulse number.

  9. Proposed SLR Optical Bench Required to Track Debris Using 1550 nm Lasers

    NASA Technical Reports Server (NTRS)

    Shappirio, M.; Coyle, D. B.; McGarry, J. F.; Bufton, J.; Cheek, J. W.; Clarke, G.; Hull, S. M.; Skillman, D. R.; Stysley, P. R.; Sun, X.; Young, R. P.; Zagwodzki, T.

    2015-01-01

    A previous study has indicated that by using approx.1550 nm wavelengths a laser ranging system can track debris objects in an "eye safe" manner, while increasing the expected return rate by a factor of approx. 2/unit area of the telescope. In this presentation we develop the optical bench required to use approx.1550nm lasers, and integration with a 532nm system. We will use the optical bench configuration for NGSLR as the baseline, and indicate a possible injection point for the 1550 nm laser. The presentation will include what elements may need to be changed for transmitting the required power on the approx.1550nm wavelength, supporting the alignment of the laser to the telescope, and possible concerns for the telescope optics.

  10. On the Stark Widths and Shifts of Ar II 472.68 nm Spectral Line

    SciTech Connect

    Mijatovic, Z.; Gajo, T.; Vujicic, B.; Djurovic, S.; Kobilarov, R.

    2008-10-22

    Stark widths and shifts of Ar II 472.68 nm spectral line were measured from T-tube plasmas. Plasma electron density ranged 1.8-2.210{sup 17} cm{sup -3}, while temperature ranged 20000-43000 K. Obtained results of widths and shifts were compared with measured results of other authors.

  11. Measurement of 100 nm and 60 nm Particle Standards by Differential Mobility Analysis

    PubMed Central

    Mulholland, George W.; Donnelly, Michelle K.; Hagwood, Charles R.; Kukuck, Scott R.; Hackley, Vincent A.; Pui, David Y. H.

    2006-01-01

    The peak particle size and expanded uncertainties (95 % confidence interval) for two new particle calibration standards are measured as 101.8 nm ± 1.1 nm and 60.39 nm ± 0.63 nm. The particle samples are polystyrene spheres suspended in filtered, deionized water at a mass fraction of about 0.5 %. The size distribution measurements of aerosolized particles are made using a differential mobility analyzer (DMA) system calibrated using SRM® 1963 (100.7 nm polystyrene spheres). An electrospray aerosol generator was used for generating the 60 nm aerosol to almost eliminate the generation of multiply charged dimers and trimers and to minimize the effect of non-volatile contaminants increasing the particle size. The testing for the homogeneity of the samples and for the presence of multimers using dynamic light scattering is described. The use of the transfer function integral in the calibration of the DMA is shown to reduce the uncertainty in the measurement of the peak particle size compared to the approach based on the peak in the concentration vs. voltage distribution. A modified aerosol/sheath inlet, recirculating sheath flow, a high ratio of sheath flow to the aerosol flow, and accurate pressure, temperature, and voltage measurements have increased the resolution and accuracy of the measurements. A significant consideration in the uncertainty analysis was the correlation between the slip correction of the calibration particle and the measured particle. Including the correlation reduced the expanded uncertainty from approximately 1.8 % of the particle size to about 1.0 %. The effect of non-volatile contaminants in the polystyrene suspensions on the peak particle size and the uncertainty in the size is determined. The full size distributions for both the 60 nm and 100 nm spheres are tabulated and selected mean sizes including the number mean diameter and the dynamic light scattering mean diameter are computed. The use of these particles for calibrating DMAs and for

  12. DPAL pump system exceeding 3kW at 766nm and 30 GHz bandwidth

    NASA Astrophysics Data System (ADS)

    Koenning, Tobias; McCormick, Dan; Irwin, David; Stapleton, Dean; Guiney, Tina; Patterson, Steve

    2016-03-01

    Due to their low quantum defect, diode pumped alkali metal vapor lasers (DPALs) offer the promise of scalability to very high average power levels while maintaining excellent beam quality. Research on DPALs has progressed to ever increasing power levels across multiple gain media species over the last years, necessitating pump power in the kW range. Each material requires a specific pump wavelength: near 852nm for cesium, 780nm for rubidium, 766nm for potassium, and 670nm for lithium atoms. The shorter pump wavelength below 800nm are outside the typical wavelength range for pump diodes developed for diode pumped solid state lasers (DPSS). The biggest challenge in pumping these materials efficiently is the need for maintaining the narrow gain media absorption band of approximately 0.01nm while greatly increasing power. Typical high power diode lasers achieve spectral widths around 3nm (FWHM) in the near infrared spectrum, but optical gratings may be used internal or external to the cavity to reduce the spectral width. Recently, experimental results have shown yet narrower line widths ranging from picometers at very low power levels to sub-100 picometers for water cooled stacks around 1kW of output power. The focus of this work is the development of a fiber-based pump system for potassium DPAL. The individual tasks are the development of high power 766nm chip material, a fiber-coupled module as a building block, and a scalable system design to address power requirements from hundreds of watts to tens of kilowatts. Results for a 3kW system achieving ~30GHz bandwidth at 766nm will be shown. Approaches for power-scaling and size reduction will be discussed.

  13. Inline detection of Chrome degradation on binary 193nm photomasks

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sippel, Astrid; Wylie, Mark; García-Berríos, Edgardo; Crawford, Charles; Hess, Carl; Sartelli, Luca; Pogliani, Carlo; Miyashita, Hiroyuki; Gough, Stuart; Sundermann, Frank; Brochard, Christophe

    2013-09-01

    mm wafers exposed and the cleaning brought it back almost to its original state after manufacture. Wafer CD, photomask CD and iCDU results can be compared, before and after a standard mask shop cleaning. Measurement points have be chosen in logic areas and SRAM areas, so that their respective behaviours can be studied separately. Transmitted maps before and after cleaning were analysed in terms of CD shift and CDU degradation. The delta map shows a nice correlation with photomask CD shift. iCDU demonstrated the capability to detect a reliable CD range degradation of 5nm on photomask by a comparison between a reference inspection and the current inspection. Die to die inspection mode provides also valuable data, highlighting the degraded chrome sidewalls, more in the photomask centre than on the edges. Ultimately, these results would enable to trigger the preventive cleanings rather than on predefined thresholds. The expected gains for wafer fabs are cost savings (adapted cleanings frequency), increased photomask availability for production, longer photomask lifetime, no additional SEM time neither for photomask nor on wafer.

  14. [Absorption spectra of nucleic acids and related compounds in the spectral region 120--280 nm].

    PubMed

    Kiseleva, M N; Zarochentseva, E P; Dodonova, N Ia

    1975-01-01

    The absorption spectra of thin films of nucleic acids, nucleosides, nucleotides, D-ribose, Na3PO4 in vacuum ultraviolet region are measured. In the spectral region 280--160 nm the absorption spectra consist of the bands of nucleic acid bases. In the range shorter than 160 nm the absorption is determined by phosphate and D-ribose groups. The methods of thin films preparation are discussed.

  15. DFB Lasers Between 760 nm and 16 μm for Sensing Applications

    PubMed Central

    Zeller, Wolfgang; Naehle, Lars; Fuchs, Peter; Gerschuetz, Florian; Hildebrandt, Lars; Koeth, Johannes

    2010-01-01

    Recent years have shown the importance of tunable semiconductor lasers in optical sensing. We describe the status quo concerning DFB laser diodes between 760 nm and 3,000 nm as well as new developments aiming for up to 80 nm tuning range in this spectral region. Furthermore we report on QCL between 3 μm and 16 μm and present new developments. An overview of the most interesting applications using such devices is given at the end of this paper. PMID:22319259

  16. Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light.

    PubMed

    Buonanno, Manuela; Ponnaiya, Brian; Welch, David; Stanislauskas, Milda; Randers-Pehrson, Gerhard; Smilenov, Lubomir; Lowy, Franklin D; Owens, David M; Brenner, David J

    2017-04-01

    We have previously shown that 207-nm ultraviolet (UV) light has similar antimicrobial properties as typical germicidal UV light (254 nm), but without inducing mammalian skin damage. The biophysical rationale is based on the limited penetration distance of 207-nm light in biological samples (e.g. stratum corneum) compared with that of 254-nm light. Here we extended our previous studies to 222-nm light and tested the hypothesis that there exists a narrow wavelength window in the far-UVC region, from around 200-222 nm, which is significantly harmful to bacteria, but without damaging cells in tissues. We used a krypton-chlorine (Kr-Cl) excimer lamp that produces 222-nm UV light with a bandpass filter to remove the lower- and higher-wavelength components. Relative to respective controls, we measured: 1. in vitro killing of methicillin-resistant Staphylococcus aureus (MRSA) as a function of UV fluence; 2. yields of the main UV-associated premutagenic DNA lesions (cyclobutane pyrimidine dimers and 6-4 photoproducts) in a 3D human skin tissue model in vitro; 3. eight cellular and molecular skin damage endpoints in exposed hairless mice in vivo. Comparisons were made with results from a conventional 254-nm UV germicidal lamp used as positive control. We found that 222-nm light kills MRSA efficiently but, unlike conventional germicidal UV lamps (254 nm), it produces almost no premutagenic UV-associated DNA lesions in a 3D human skin model and it is not cytotoxic to exposed mammalian skin. As predicted by biophysical considerations and in agreement with our previous findings, far-UVC light in the range of 200-222 nm kills bacteria efficiently regardless of their drug-resistant proficiency, but without the skin damaging effects associated with conventional germicidal UV exposure.

  17. Photodissociation of the Propargyl (C3D3) Radicals at 248 nm and 193 nm

    SciTech Connect

    Neumark., D.M.; Crider, P.E.; Castiglioni, L.; Kautzman, K.K.

    2009-01-21

    The photodissociation of perdeuterated propargyl (D{sub 2}CCCD) and propynyl (D{sub 3}CCC) radicals was investigated using fast beam photofragment translational spectroscopy. Radicals were produced from their respective anions by photodetachment at 540 nm and 450 nm (below and above the electron affinity of propynyl). The radicals were then photodissociated by 248 nm or 193 nm light. The recoiling photofragments were detected in coincidence with a time- and position-sensitive detector. Three channels were observed: D{sub 2} loss, CD + C{sub 2}D{sub 2}, and CD{sub 3} + C{sub 2}. Obervation of the D loss channel was incompatible with this experiment and was not attempted. Our translational energy distributions for D{sub 2} loss peaked at nonzero translational energy, consistent with ground state dissociation over small (< 1 eV) exit barriers with respect to separated products. Translational energy distributions for the two heavy channels peaked near zero kinetic energy, indicating dissociation on the ground state in the absence of exit barriers.

  18. Evaluation of the Diode laser (810nm,980nm) on dentin tubule diameter following internal bleaching

    PubMed Central

    Kiomarsi, Nazanin; Salim, Soheil; Sarraf, Pegah; Javad-Kharazifard, Mohammad

    2016-01-01

    Background The aim of this study was to evaluate the effect of diode laser irradiation and bleaching materials on the dentinal tubule diameter after laser bleaching. Material and Methods The dentin discs of 40 extracted third molar were used in this experiment. Each disc surface was divided into two halves by grooving. Half of samples were laser bleached at different wavelengths with two different concentrations of hydrogen peroxide. Other half of each disc with no laser bleaching remained as a negative control. Dentin discs were assigned randomly into four groups (n=10) with following hydrogen peroxide and diode laser wavelength specifications; Group 1 (30% - 810 nm), group 2 (30% - 980 nm), group 3 (46% - 810 nm) and group 4 (46% - 980 nm). All specimens were sent for scanning electron microscopic (SEM) analysis in order to measure tubular diameter in laser treated and control halves. Data were analyzed by ANOVA and Tukey test (p<0.05). Results A significant reduction in dentin tubule diameter was observed in groups 1, 2 and 4. There was no significant difference between groups 1 and 2 and between groups 3 and 4 after bleaching. Conclusions The SEM results showed that diode laser was able to reduce dentin tubule diameter and its effect on dentin was dependent on chemical action of bleaching material. Key words:Laser, diode, dentin, tubule, diameter. PMID:27398172

  19. THE SPECTRUM OF THORIUM FROM 250 nm TO 5500 nm: RITZ WAVELENGTHS AND OPTIMIZED ENERGY LEVELS

    SciTech Connect

    Redman, Stephen L.; Nave, Gillian; Sansonetti, Craig J.

    2014-03-01

    We have made precise observations of a thorium-argon hollow cathode lamp emission spectrum in the region between 350 nm and 1175 nm using a high-resolution Fourier transform spectrometer. Our measurements are combined with results from seven previously published thorium line lists to re-optimize the energy levels of neutral, singly, and doubly ionized thorium (Th I, Th II, and Th III). Using the optimized level values, we calculate accurate Ritz wavelengths for 19, 874 thorium lines between 250 nm and 5500 nm (40, 000 cm{sup –1} to 1800 cm{sup –1}). We have also found 102 new thorium energy levels. A systematic analysis of previous measurements in light of our new results allows us to identify and propose corrections for systematic errors in Palmer and Engleman and typographical errors and incorrect classifications in Kerber et al. We also found a large scatter with respect to the thorium line list of Lovis and Pepe. We anticipate that our Ritz wavelengths will lead to improved measurement accuracy for current and future spectrographs that make use of thorium-argon or thorium-neon lamps as calibration standards.

  20. The Spectrum of Thorium from 250 nm to 5500 nm: Ritz Wavelengths and Optimized Energy Levels

    NASA Astrophysics Data System (ADS)

    Redman, Stephen L.; Nave, Gillian; Sansonetti, Craig J.

    2014-03-01

    We have made precise observations of a thorium-argon hollow cathode lamp emission spectrum in the region between 350 nm and 1175 nm using a high-resolution Fourier transform spectrometer. Our measurements are combined with results from seven previously published thorium line lists to re-optimize the energy levels of neutral, singly, and doubly ionized thorium (Th I, Th II, and Th III). Using the optimized level values, we calculate accurate Ritz wavelengths for 19, 874 thorium lines between 250 nm and 5500 nm (40, 000 cm-1 to 1800 cm-1). We have also found 102 new thorium energy levels. A systematic analysis of previous measurements in light of our new results allows us to identify and propose corrections for systematic errors in Palmer & Engleman and typographical errors and incorrect classifications in Kerber et al. We also found a large scatter with respect to the thorium line list of Lovis & Pepe. We anticipate that our Ritz wavelengths will lead to improved measurement accuracy for current and future spectrographs that make use of thorium-argon or thorium-neon lamps as calibration standards.

  1. NXT:1980Di immersion scanner for 7nm and 5nm production nodes

    NASA Astrophysics Data System (ADS)

    de Graaf, Roelof; Weichselbaum, Stefan; Droste, Richard; McLaren, Matthew; Koek, Bert; de Boeij, Wim

    2016-03-01

    Immersion scanners remain the critical lithography workhorses in semiconductor device manufacturing. When progressing towards the 7nm device node for logic and D18 device node for DRAM production, pattern-placement and layer-to-layer overlay requirements keep progressively scaling down and consequently require system improvements in immersion scanners. The on-product-overlay requirements are approaching levels of only a few nanometers, imposing stringent requirements on the scanner tool design in terms of reproducibility, accuracy and stability. In this paper we report on the performance of the NXT:1980Di immersion scanner. The NXT:1980Di builds upon the NXT:1970Ci, that is widely used for 16nm, 14nm and 10nm high-volume manufacturing. We will discuss the NXT:1980Di system- and sub-system/module enhancements that drive the scanner overlay, focus and productivity performance. Overlay, imaging, focus, productivity and defectivity data will be presented for multiple tools. To further reduce the on-product overlay system performance, alignment sensor contrast improvements as well as active reticle temperature conditioning are implemented on the NXT:1980Di. Reticle temperature conditioning will reduce reticle heating overlay and the higher contrast alignment sensor will improve alignment robustness for processed alignment targets. Due to an increased usage of multiple patterning techniques, an increased number of immersion exposures is required. NXT:1980Di scanner design modifications raised productivity levels from 250wph to 275wph. This productivity enhancement provides lower cost of ownership (CoO) for customers using immersion technology.

  2. Electrical properties of sub-100 nm SiGe nanowires

    NASA Astrophysics Data System (ADS)

    Hamawandi, B.; Noroozi, M.; Jayakumar, G.; Ergül, A.; Zahmatkesh, K.; Toprak, M. S.; Radamson, H. H.

    2016-10-01

    In this study, the electrical properties of SiGe nanowires in terms of process and fabrication integrity, measurement reliability, width scaling, and doping levels were investigated. Nanowires were fabricated on SiGe-on oxide (SGOI) wafers with thickness of 52 nm and Ge content of 47%. The first group of SiGe wires was initially formed by using conventional I-line lithography and then their size was longitudinally reduced by cutting with a focused ion beam (FIB) to any desired nanometer range down to 60 nm. The other nanowire group was manufactured directly to a chosen nanometer level by using sidewall transfer lithography (STL). It has been shown that the FIB fabrication process allows manipulation of the line width and doping level of nanowires using Ga atoms. The resistance of wires thinned by FIB was 10 times lower than STL wires which shows the possible dependency of electrical behavior on fabrication method. Project support by the Swedish Foundation for Strategic Research “SSF” (No. EM-011-0002) and the Scientific and Technological Research Council of Turkey (No. TÜBİTAK).

  3. Customized illumination shapes for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Ling, Moh Lung; Chua, Gek Soon; Lin, Qunying; Tay, Cho Jui; Quan, Chenggen

    2008-03-01

    In this paper, a study on customized illumination shape configurations as resolution enhancement for 45nm technology node will be presented. Several new source shape configurations will be explored through simulation based on 193nm immersion lithography on 6% Attenuated Phase Shift Mask. Forbidden pitch effect is commonly encountered in the application of off axis illumination (OAI). The illumination settings are often optimized to allow maximum process window for a pitch. This is done by creating symmetrical distribution of diffraction order on the pupil plane. However, at other pitch, the distribution of diffraction order on the pupil plane results in severe degradation in image contrast and results in significant critical dimension (CD) fluctuation. The problematic pitch is often known as forbidden pitch. It has to be avoided in the design and thus limited the pitch range to be imaged for particular illumination. An approach to modify off axis illumination to minimize the effect of forbidden pitch is explored in this study. The new customized shape for one dimensional line and space pattern is modified from current off axis illumination. Simulation study is done to evaluate the performance some customized shapes. The extent of CD fluctuation and CD through pitch uniformity is analyzed to determine the performance enhancement of the new illumination shapes. From simulation result, the proposed modification have significantly improved the through pitch performance and minimized the effect of forbidden pitch.

  4. En-face OCT system at 1060 nm

    NASA Astrophysics Data System (ADS)

    Neagu, Liviu; Lobo Ribeiro, Antonio B.; Cucu, Radu G.; Bradu, Adrian; Ma, Lisha; Podoleanu, Adrian G.

    2008-09-01

    A highly efficient power optical coherence tomography configuration is implemented using a Multiwave Photonics broadband source centred at 1060 nm wavelength, FWHM = 50 nm and a Mach Zehnder interferometer. The interferometer contains a fibre acousto-optic modulator in each arm. One is driven at a fixed frequency of 40 MHz while the other via an RF Function Generation. In this way, the en-face OCT signal is modulated on a carrier frequency adjustable in the range 0 kHz to 1.5 MHz. A circulator is placed in the sample arm. Light retroreflected from the sample is sent via the circulator to a balanced coupler where it interferes with the reference beam. A translation stage is used in the reference arm to adjust the optical path difference in the interferometer. The result is photodetected using two InGaAs photodetectors followed by a differential amplifier in a balance detection configuration The system has been used to acquire en-face images as well as cross section optical coherence tomography images from skin and embryos based on T-scans (transversal reflectivity profiles).

  5. Pressure Broadening of the Cadmium 326.1 nm Line

    NASA Astrophysics Data System (ADS)

    Roston, G. D.; Helmi, M. S.

    2014-11-01

    The temperature dependence of the Cd line absorption profile at 326.1nm perturbed by inert gases (Xe, Kr, Ar, Ne and He) has been carefully studied over a wide spectral range in both blue and red wings using a high-resolution double-beam spectrometer. The atomic densities of inert gases (Ngas) and cadmium (NCd) was sufficient to study the wing of the Cd line at 326.1nm. The temperature dependence of the studied line profile was analyzed in the framework of the quasi-static theory. The van der Waals coefficient differences (ΔC60 and ΔC61) between the ground X0+ state and the two excited states A30+ and B31 were obtained from the near red wing profile using Kuhn's law. All the results of the well depths with their positions for the ground (X0+), and the excited (31, 30+) were determined. The obtained results are compared with the corresponding theoretical and experimental molecular beam experiments results.

  6. Maskless plasmonic lithography at 22 nm resolution.

    PubMed

    Pan, Liang; Park, Yongshik; Xiong, Yi; Ulin-Avila, Erick; Wang, Yuan; Zeng, Li; Xiong, Shaomin; Rho, Junsuk; Sun, Cheng; Bogy, David B; Zhang, Xiang

    2011-01-01

    Optical imaging and photolithography promise broad applications in nano-electronics, metrologies, and single-molecule biology. Light diffraction however sets a fundamental limit on optical resolution, and it poses a critical challenge to the down-scaling of nano-scale manufacturing. Surface plasmons have been used to circumvent the diffraction limit as they have shorter wavelengths. However, this approach has a trade-off between resolution and energy efficiency that arises from the substantial momentum mismatch. Here we report a novel multi-stage scheme that is capable of efficiently compressing the optical energy at deep sub-wavelength scales through the progressive coupling of propagating surface plasmons (PSPs) and localized surface plasmons (LSPs). Combining this with airbearing surface technology, we demonstrate a plasmonic lithography with 22 nm half-pitch resolution at scanning speeds up to 10 m/s. This low-cost scheme has the potential of higher throughput than current photolithography, and it opens a new approach towards the next generation semiconductor manufacturing.

  7. Faster qualification of 193-nm resists for 100-nm development using photo cell monitoring

    NASA Astrophysics Data System (ADS)

    Jones, Chris M.; Kallingal, Chidam; Zawadzki, Mary T.; Jeewakhan, Nazneen N.; Kaviani, Nazila N.; Krishnan, Prakash; Klaum, Arthur D.; Van Ess, Joel

    2003-05-01

    The development of 100-nm design rule technologies is currently taking place in many R&D facilities across the world. For some critical alyers, the transition to 193-nm resist technology has been required to meet this leading edge design rule. As with previous technology node transitions, the materials and processes available are undergoing changes and improvements as vendors encounter and solve problems. The initial implementation of the 193-nm resits process did not meet the photolithography requirements of some IC manufacturers due to very high Post Exposure Bake temperature sensitivity and consequently high wafer to wafer CD variation. The photoresist vendors have been working to improve the performance of the 193-nm resists to meet their customer's requirements. Characterization of these new resists needs to be carried out prior to implementation in the R&D line. Initial results on the second-generation resists evaluated at Cypress Semicondcutor showed better CD control compared to the aelrier resist with comparable Depth of Focus (DOF), Exposure Latitute, Etch Resistance, etc. In addition to the standard lithography parameters, resist characterization needs to include defect density studies. It was found that the new resists process with the best CD control, resulted in the introduction of orders of magnitude higher yield limiting defects at Gate, Contact adn Local Interconnect. The defect data were shared with the resists vendor and within days of the discovery the resist vendor was able to pinpoint the source of the problem. The fix was confirmed and the new resists were successfully released to production. By including defect monitoring into the resist qualification process, Cypress Semiconductor was able to 1) drive correction actions earlier resulting in faster ramp and 2) eliminate potential yield loss. We will discuss in this paper how to apply the Micro Photo Cell Monitoring methodology for defect monitoring in the photolithogprhay module and the

  8. TO packaged 650nm red semiconductor laser with transparent window

    NASA Astrophysics Data System (ADS)

    Xia, Wei; Zhu, Zhen; Li, Peixu; Su, Jian; Zhang, Xin; Xu, Xiangang

    2016-11-01

    Highly uniform solid-phase Zn-diffusion technique was developed to fabricate transparent windows for 650 nm red laser diodes (LDs). The maximum output power was up to 120 mW, which is three times higher than that for LDs without window structure. The LDs showed excellent thermal characteristics and aging reliability with TO-can package. The characteristic temperature was estimated to be 85 K in the temperature range of 25 65 °C. The LDs showed stable operation of 10 mW at a high temperature of 75 °C. After aging test of 2000 h, the elevated operation current was less than 3%, compared to the initial value. The predicted life time was over 10000 h for 10 mW operation at 75 °C.

  9. High performance diode lasers emitting at 780-820 nm

    NASA Astrophysics Data System (ADS)

    Bao, L.; DeVito, M.; Grimshaw, M.; Leisher, P.; Zhou, H.; Dong, W.; Guan, X.; Zhang, S.; Martinsen, R.; Haden, J.

    2012-03-01

    High power 780-820 nm diode lasers have been developed for pumping and material processing systems. This paper presents recent progress in the development of such devices for use in high performance industrial applications. A newly released laser design in this wavelength range demonstrates thermally limited >25W CW power without catastrophic optical mirror damage (COMD), with peak wallplug efficiency ~65%. Ongoing accelerated lifetesting projects a time to 5% failure of ~10 years at 5 and 8 W operating powers for 95 and 200 μm emitter widths, respectively. Preliminary results indicate the presence and competition of a random and wear-out failure mode. Fiber-coupled modules based on arrays of these devices support >100W reliable operation, with a high 56% peak efficiency (ex-fiber) and improved brightness/reliability.

  10. Laser ablation of polymeric materials at 157 nm

    NASA Astrophysics Data System (ADS)

    Costela, A.; García-Moreno, I.; Florido, F.; Figuera, J. M.; Sastre, R.; Hooker, S. M.; Cashmore, J. S.; Webb, C. E.

    1995-03-01

    Results are presented on the ablation by 157 nm laser radiation of polytetrafluoroethylene (PTFE), polyimide, polyhydroxybutyrate (PHB), poly(methyl methacrylate) (PMMA), and poly(2-hydroxyethyl methacrylate) with 1% of ethylene glycol dimethacrylate as a crosslinking monomer. Direct photoetching of PHB and undoped PTFE is demonstrated for laser fluences ranging from 0.05 to 0.8 J/cm2. The dependence of the ablation process on the polymer structure is analyzed, and insight into the ablation mechanism is gained from an analysis of the data using Beer-Lambert's law and the kinetic model of the moving interface. Consideration of the absorbed energy density required to initiate significant ablation suggests that the photoetching mechanism is similar for all the polymers studied.

  11. NM-Scale Anatomy of an Entire Stardust Carrot Track

    NASA Technical Reports Server (NTRS)

    Nakamura-Messenger, K.; Keller, L. P.; Clemett, S. J.; Messenger, S.

    2009-01-01

    Comet Wild-2 samples collected by NASA s Stardust mission are extremely complex, heterogeneous, and have experienced wide ranges of alteration during the capture process. There are two major types of track morphologies: "carrot" and "bulbous," that reflect different structural/compositional properties of the impactors. Carrot type tracks are typically produced by compact or single mineral grains which survive essentially intact as a single large terminal particle. Bulbous tracks are likely produced by fine-grained or organic-rich impactors [1]. Owing to their challenging nature and especially high value of Stardust samples, we have invested considerable effort in developing both sample preparation and analytical techniques tailored for Stardust sample analyses. Our report focuses on our systematic disassembly and coordinated analysis of Stardust carrot track #112 from the mm to nm-scale.

  12. Wind Measurements with a 355 nm Molecular Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Chen, Huailin; Li, Steven X.

    2000-01-01

    A Doppler lidar system based on the molecular double edge technique is described. The system is mounted in a modified van to allow deployment in field operations. The lidar operates with a tripled Nd:YAG laser at 355 nm, a 45cm aperture telescope and a matching azimuth-over-elevation scanner to allow full sky access. Validated atmospheric wind profiles have been measured from 1.8 km to 35 km with a 178 m vertical resolution. The range dependent rms deviation of the horizontal wind speed is 0.4 - 6 m/s. The results of wind speed and direction are in good agreement with balloon sonde wind measurements made simultaneously at the same location.

  13. Discrete plasticity in sub-10-nm-sized gold crystals

    PubMed Central

    Zheng, He; Cao, Ajing; Weinberger, Christopher R.; Huang, Jian Yu; Du, Kui; Wang, Jianbo; Ma, Yanyun; Xia, Younan; Mao, Scott X.

    2010-01-01

    Although deformation processes in submicron-sized metallic crystals are well documented, the direct observation of deformation mechanisms in crystals with dimensions below the sub-10-nm range is currently lacking. Here, through in situ high-resolution transmission electron microscopy (HRTEM) observations, we show that (1) in sharp contrast to what happens in bulk materials, in which plasticity is mediated by dislocation emission from Frank-Read sources and multiplication, partial dislocations emitted from free surfaces dominate the deformation of gold (Au) nanocrystals; (2) the crystallographic orientation (Schmid factor) is not the only factor in determining the deformation mechanism of nanometre-sized Au; and (3) the Au nanocrystal exhibits a phase transformation from a face-centered cubic to a body-centered tetragonal structure after failure. These findings provide direct experimental evidence for the vast amount of theoretical modelling on the deformation mechanisms of nanomaterials that have appeared in recent years. PMID:21266994

  14. Lasing at 300 nm and below: Optical challenges and perspectives

    SciTech Connect

    Garzella, D.; Couprie, M.E. |; Billardon, M.

    1995-12-31

    The FEL experiment in the visible and near UV on the Super ACO storage ring has given, since 1989, important informations on the SRFEL dynamics and, furthermore, a very good beam stability has been achieved. In addition, the operation at 350 nm with this good stability and a long beam lifetime allowed us to perform the first user experiment in biology and to start with a campaign for using the laser as photons source for experiments in other domains, coupling FEL light and the Synchrotron Radiation. For this, FEL starts to be very competitive with respect to the other conventional laser sources, provided that it could oscillate further in the UV, say at 300 nm and below. So, the real challenge is now given by the lasing at shorter wavelengths and, for this, by the optical technology existing nowadays. Since 1992 the efforts have been concentrating to look for every kind of solution allowing us to overcome the problem of having a very low gain. From an optical point of view, in the range of wavelengths explored, there is a lack of transparents dielectric materials for substrates and coatings. Substrates are required at the same time to be relatively not absorbing (a few tens 10{sup -6}), to have a very good surface quality (RMS roughness below 10 {Angstrom}) because of scattering losses dramatically increasing in this spectral range and, due to the thermal load of the undulator emission, to have adequate thermal characteristics. In order to fulfill all these requirements, a good characterisation and modelisation of the substrates is needed, especially to correlate thermal loading and mechanical deformations from one hand, and roughness and scattering losses from the other hand. Coatings must be not absorbing too and, above all, the most amorphous as possible (this could be obtained with IBS deposition technique), in order to insure a good reproduction of the substrate roughness at the interfaces and on the top layer and an higher resistance to the XUV photons load.

  15. Iodide-mediated photooxidation of arsenite under 254 nm irradiation.

    PubMed

    Yeo, Jiman; Choi, Wonyong

    2009-05-15

    The preoxidation of As(III) to As(V) is a desirable process to increase the removal efficiency of arsenic in water treatment In this work, the photooxidation of As(III) under 254 nm irradiation was investigated in the concentration range of 1-1000 microM in the presence of potassium iodide (typically 100 microM). Although the direct photooxidation of As(III) in water was negligible, the presence of iodide dramatically enhanced the oxidation rate. The quantitative conversion of As(III) to As(V) was achieved. The quantum yields of As(III) photooxidation ranged from 0.08 to 0.6, depending on the concentration of iodide and As(III). The excitation of iodides under 254 nm irradiation led to the generation of iodine atoms and triiodides, which seem to be involved in the oxidation process of As(III). Because the efficiency of iodine atom generation is highly dependent on the presence of suitable electron acceptors,the photooxidation of As(III) was efficient in an air- or N2O-saturated solution but markedly reduced in the N2-saturated solution. The production of H2O2 was also accompanied by the generation of As(V). The addition of excess methanol (OH radical scavenger) did not reduce the photooxidation rate at all, which ruled out the possibility of hydroxyl radical involvement. It was found that the in situ photogenerated triiodides oxidize As(III) with regenerating iodides by completing a cycle. The proposed UV254/KI/As(III) process is essentially an iodide-mediated photocatalysis.

  16. Characteristics of 630nm auroral polarization observed at Pokar Flat, Alaska

    NASA Astrophysics Data System (ADS)

    Shimpei, T.; Kagitani, M.; Sakanoi, T.; Hampton, D. L.

    2014-12-01

    We report the result of OI 630 nm auroral polarization observation at Poker Flat Research Range (Glat=65.12N, Glon=147.43W, Mlat=65.72N) during the period from December 2013 to April 2014. OI 630nm auroral emission is theoretically expected to show linear polarization with degrees up to 17% [Bommier et al., 2011]. The important point is that, the degree of linear polarization depends on energy and velocity anisotropy of precipitating electrons [Fujimoto et al., 1997]. Recent observation data also showed that 630nm auroral emission related to polar rain at high-latitudes linear polarization parallel to field with degrees of 2-7%[Lilensten et al., 2013]. However, these past measurements were limited in the polar cap region and its polarization characteristics are not clear. To examine auroral polarization with an accuracy of 1% polarization degree, we developed an imaging spectrograph which can measure auroral polarization in the wide field-of-view of 130 deg covering the wavelength range from 420 nm to 680 nm (resolution 2 nm). This new instrument enables us to obtain the linear polarization degrees at 557.7 nm and 630 nm auroral emissions simultaneously. Here, we can regard 557.7 nm aurora as a standard polarization light source because it does not produce polarization theoretically. We installed the spectrograph at Poker Flat Research Range and carried out precise calibration to estimate artificial polarization which is produced inside the optical system using an LED light source with a linear polarizer every 3 hours on five nights in December 2013. Since then, automatic operation was continuously carried every night out till the beginning of April 2014.We obtained the linear polarization of 630 nm aurora with degree of 5% showing elevation angle dependence. On the other hand, we unexpectedly measured the polarization of 557.7 nm emission which shows similar polarization property as 630 nm. We are considering two possibilities to interpret the results as follows

  17. Absorption Cross Sections of 2-Nitrophenol in the 295-400 nm Region and Photolysis of 2-Nitrophenol at 308 and 351 nm.

    PubMed

    Sangwan, Manuvesh; Zhu, Lei

    2016-12-22

    2-Nitrophenol is an important component of "brown carbon" in the atmosphere. Photolysis is its dominant gas phase removal process. We have determined the gas phase absorption cross sections of 2-nitrophenol in the 295-400 nm region by using cavity ring-down spectroscopy. 2-Nitrophenol exhibits a broad absorption band over the wavelength region studied, with the peak absorption located at 345 nm. Absorption cross section values range between (2.86 ± 0.18) × 10(-18) and (2.63 ± 0.31) × 10(-20) cm(2)/molecule over the 295-400 nm range. We have investigated the HONO, NO2, and OH formation channels following the gas phase photolysis of 2-nitrophenol at 308 and 351 nm. Direct NO2 formation was not observed. HONO and OH are direct products from 2-nitrophenol photolysis. The average OH quantum yields from the photolysis of 0.5, 1.0, and 2.0 mTorr of 2-nitrophenol are 0.69 ± 0.07 and 0.70 ± 0.07 at 308 and 351 nm. The average HONO quantum yields are 0.34 ± 0.09 and 0.39 ± 0.07 at 308 and 351 nm. The OH and HONO quantum yields are independent of nitrogen carrier gas pressure in the 20-600 Torr range. Oxidant formation rate constants from 2-nitrophenol photolysis have been calculated. Discussions have been made concerning the role of 2-nitrophenol gas phase photolysis in the formation of atmospheric oxidants in regions of high anthropogenic emissions.

  18. Distributed Humidity Sensing in PMMA Optical Fibers at 500 nm and 650 nm Wavelengths.

    PubMed

    Liehr, Sascha; Breithaupt, Mathias; Krebber, Katerina

    2017-03-31

    Distributed measurement of humidity is a sought-after capability for various fields of application, especially in the civil engineering and structural health monitoring sectors. This article presents a method for distributed humidity sensing along polymethyl methacrylate (PMMA) polymer optical fibers (POFs) by analyzing wavelength-dependent Rayleigh backscattering and attenuation characteristics at 500 nm and 650 nm wavelengths. Spatially resolved humidity sensing is obtained from backscatter traces of a dual-wavelength optical time domain reflectometer (OTDR). Backscatter dependence, attenuation dependence as well as the fiber length change are characterized as functions of relative humidity. Cross-sensitivity effects are discussed and quantified. The evaluation of the humidity-dependent backscatter effects at the two wavelength measurements allows for distributed and unambiguous measurement of relative humidity. The technique can be readily employed with low-cost standard polymer optical fibers and commercial OTDR devices.

  19. Polarization properties of lidar scattering from clouds at 347 nm and 694 nm.

    PubMed

    Pal, S R; Carswell, A I

    1978-08-01

    The polarization characteristics of lidar scattering from cumulus and low-lying shower clouds have been measured with a system operating at 694 nm (red) and 347 nm (blue). The backscatter profiles of the polarization components as well as of the total intensity of the return are presented and discussed for the two wavelengths. The linear depolarization ratio delta, which can be used as a measure of the unpolarized multiple scattering, has been obtained at both wavelengths. This quantity has a very low value at cloud base for both wavelengths and increases with pulse penetration. The blue registers generally higher values of a within the cloud. The measured total intensity backscatter functions for both wavelengths are presented and discussed in relation to theoretical calculations of cloud models.

  20. Novel 980-nm and 490-nm light sources using vertical cavity lasers with extended coupled cavities

    NASA Astrophysics Data System (ADS)

    McInerney, John G.; Mooradian, Aram; Lewis, Alan; Shchegrov, Andrei V.; Strzelecka, Eva M.; Lee, Dicky; Watson, Jason P.; Liebman, Michael K.; Carey, Glen P.; Umbrasas, Arvydas; Amsden, Charles A.; Cantos, Brad D.; Hitchens, William R.; Heald, David L.; Doan, Vincent V.; Cannon, J. L.

    2003-04-01

    We have developed novel electrically pumped, surface-emitting lasers emitting at 980 nm with an extended coupled cavity. The concept is scalable from monolithic low power devices all the way to high power extended cavity lasers. The latter have demonstrated 1W cw multi-mode and 0.5 W cw in a TEM00 mode and a single frequency, with 90% coupling efficiency into a single-mode fiber. By inserting a nonlinear optical medium in the external cavity, efficient and compact frequency doubling has been achieved with CW output powers 5-40 mW demonstrated at 490 nm. The latter devices are especially noteworthy due to their very low noise, sub 10 μrad beam pointing stability combined with small size, low power consumption and high efficiency.

  1. A 15 W 1152 nm Raman fiber laser with 6 nm spectral width for Ho3+-doped crystal's pumping source

    NASA Astrophysics Data System (ADS)

    Chen, Xiuyan; Jiang, Huawei

    2016-12-01

    A 11.5 W 1152 nm Raman fiber laser with 6 nm spectral width was demonstrated based on the resonator constructed with one fiber loop mirror and one fiber Bragg grating. By mans of experimental measurement and theoretical calculation, the reflectivity of the fiber loop mirror was confirmed as 0.93. The Yb3+-doped 1090 nm fiber length was about 5 m. When the maximum pumping power of 976 nm laser was 54.8 W, 32.2 W 1090 nm laser was obtained and the optical to optical conversion efficiency from 1090 nm to 1152 nm light was 48%. Finally, the 1152 nm Raman fiber laser was used for pumping Ho3+:LLF crystal, and the 1194 nm fluorescence emission peak was detected for the first time.

  2. Investigations of a dual seeded 1178nm Raman laser system

    NASA Astrophysics Data System (ADS)

    Block, Matthew; Henry, Leanne J.; Klopfer, Michael; Jain, Ravinder

    2016-03-01

    The leakage of 1121 nm power from a resonator cavity because of spectral broadening seriously degrades the performance of a Raman resonator by reducing the 1121 nm circulating power and the 1178 nm output power. Therefore, it is important to understand the conditions which minimize 1121 nm power leakage, maximize 1121 intracavity and 1178 nm output power while enabling a manageable Stimulated Brillouin Scattering gain for narrow linewidth systems. It was found that cavity lengths longer than approximately 40 m didn't result in significantly more 1121 nm linewidth broadening. Relative to the high reflectivity bandwidth of the fiber Bragg gratings, it was found that 4 nm FBGs seemed to optimize 1178 nm amplification while minimizing the amount of 1121 nm power leakage. A two stage high power 1178 nm Raman system was built and 20 W of 1178 nm output power was achieved with a polarization extinction ratio of 21 and nearly diffraction limited beam quality. Linewidth broadening was found to increase as the 1178 nm output increased and was approximately 8 GHz when the 1178 nm output power was 20 W. Because of the linewidth broadening, a co-pumped second Stokes Raman laser system is not useful for the sodium guidestar laser application which requires narrow linewidth.

  3. Multi-watt 589nm fiber laser source

    SciTech Connect

    DAWSON, J W; DROBSHOFF, A D; BEACH, R J; MESSERLY, M J; PAYNE, S A; BROWN, A; PENNINGTON, D M; BAMFORD, D J; SHARPE, S J; COOK, D J

    2006-01-19

    We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichiometric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to >15W using cladding pumped Nd{sup 3+} fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the competing 1088nm 4-level laser transition. At 15W, the 938nm laser has an M{sup 2} of 1.1 and good polarization (correctable with a quarter and half wave plate to >15:1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.

  4. Multi-watt 589nm fiber laser source

    NASA Astrophysics Data System (ADS)

    Dawson, Jay W.; Drobshoff, Alex D.; Beach, Raymond J.; Messerly, Michael J.; Payne, Stephen A.; Brown, Aaron; Pennington, Deanna M.; Bamford, Douglas J.; Sharpe, Scott J.; Cook, David J.

    2006-02-01

    We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichio-metric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to >15W using cladding pumped Nd 3+ fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the 1088nm 4-level laser transition. At 15W, the 938nm laser has an M2 of 1.1 and good polarization (correctable with a quarter and half wave plate to >15:1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.

  5. Electron-induced single event upsets in 28 nm and 45 nm bulk SRAMs

    DOE PAGES

    Trippe, J. M.; Reed, R. A.; Austin, R. A.; ...

    2015-12-01

    In this study, we present experimental evidence of single electron-induced upsets in commercial 28 nm and 45 nm CMOS SRAMs from a monoenergetic electron beam. Upsets were observed in both technology nodes when the SRAM was operated in a low power state. The experimental cross section depends strongly on both bias and technology node feature size, consistent with previous work in which SRAMs were irradiated with low energy muons and protons. Accompanying simulations demonstrate that δ-rays produced by the primary electrons are responsible for the observed upsets. Additional simulations predict the on-orbit event rates for various Earth and Jovian environmentsmore » for a set of sensitive volumes representative of current technology nodes. The electron contribution to the total upset rate for Earth environments is significant for critical charges as high as 0.2 fC. This value is comparable to that of sub-22 nm bulk SRAMs. Similarly, for the Jovian environment, the electron-induced upset rate is larger than the proton-induced upset rate for critical charges as high as 0.3 fC.« less

  6. A robust 45 nm gate-length CMOSFET for 90 nm Hi-speed technology

    NASA Astrophysics Data System (ADS)

    Lim, K. Y.; Chan, V.; Rengarajan, R.; Lee, H. K.; Rovedo, N.; Lim, E. H.; Yang, S.; Jamin, F.; Nguyen, P.; Lin, W.; Lai, C. W.; Teh, Y. W.; Lee, J.; Kim, L.; Luo, Z.; Ng, H.; Sudijono, J.; Wann, C.; Yang, I.

    2006-04-01

    We have developed a robust 45 nm gate-length CMOSFET for 90 nm node high performance application. Aggressive gate length and gate dielectric scaling along with optimized strain engineering enable high performance device similar to 65 nm node CMOSFET [Nakahara Y, et al. IEDM Tech Dig 2003;281] We have utilized oxy-nitride gate with post-nitridation anneal, high ramp rate spike anneal, low temperature spacer scheme and stress controlled SiN contact etch stop liner process in order to improve drive current as well as transistor short-channel roll-off. In particular, we will focus on the study of middle-of-line (MOL) process parameters, (i.e. MOL thermal expense and mechanical stress from contact etch stop liner) on transistor performance and reliability. Based on the study, we have obtained device exhibit drive-current of 900/485 μA/μm for NMOSFET and PMOSFET, respectively, at standard supply voltage of 1 V.

  7. Electron-induced single event upsets in 28 nm and 45 nm bulk SRAMs

    SciTech Connect

    Trippe, J. M.; Reed, R. A.; Austin, R. A.; Sierawski, B. D.; Weller, R. A.; Funkhouser, E. D.; King, M. P.; Narasimham, B.; Bartz, B.; Baumann, R.; Schrimpf, R. D.; Labello, R.; Nichols, J.; Weeden-Wright, S. L.

    2015-12-01

    In this study, we present experimental evidence of single electron-induced upsets in commercial 28 nm and 45 nm CMOS SRAMs from a monoenergetic electron beam. Upsets were observed in both technology nodes when the SRAM was operated in a low power state. The experimental cross section depends strongly on both bias and technology node feature size, consistent with previous work in which SRAMs were irradiated with low energy muons and protons. Accompanying simulations demonstrate that δ-rays produced by the primary electrons are responsible for the observed upsets. Additional simulations predict the on-orbit event rates for various Earth and Jovian environments for a set of sensitive volumes representative of current technology nodes. The electron contribution to the total upset rate for Earth environments is significant for critical charges as high as 0.2 fC. This value is comparable to that of sub-22 nm bulk SRAMs. Similarly, for the Jovian environment, the electron-induced upset rate is larger than the proton-induced upset rate for critical charges as high as 0.3 fC.

  8. Branching ratios and anisotropy parameters in ICl photolysis from 400 to 570 nm using slice imaging

    SciTech Connect

    Samartzis, Peter C.; Kitsopoulos, Theofanis N.

    2010-07-07

    ICl photolysis in the visible region of the spectrum (400-570 nm) is studied using the slice imaging technique. The Cl({sup 2}P{sub 1/2})/Cl({sup 2}P{sub 3/2}) branching ratio between the I({sup 2}P{sub 3/2})+Cl({sup 2}P{sub 3/2}) and I({sup 2}P{sub 3/2})+Cl({sup 2}P{sub 1/2}) channels is extracted from the iodine photofragment images and it is found to range from 0 to 2.5, rising from 570 to 490 nm and dropping at higher photolysis energies. The I+Cl angular distribution exhibits a similar trend, changing from purely perpendicular at 570 nm to isotropic at 545 nm, fairly parallel at 490 nm and again perpendicular at 440 nm. Following previous work, we discuss these changes in light of avoided curve crossing and determine the crossing probability as a function of wavelength. The angular anisotropy parameter beta of the second channel ranges between 0.6 and 1.4.

  9. Narrowband filters for the FUV range

    NASA Astrophysics Data System (ADS)

    Rodríguez-de Marcos, Luis; Larruquert, Juan I.; Méndez, José A.; Aznárez, José A.; Fu, Liping

    2015-05-01

    We address the design, fabrication, and characterization of transmittance filters for the Ionosphere Photometer instrument (IP), developed by the Center for Space Science and Applied Research (CSSAR). IP, a payload of Feng-Yun 3D meteorological satellite, to be launched on 2016, is aimed to perform photometry measurements of Earth's ionosphere by the analysis of the OI (135.6 nm) spectral line and N2 Lyman-Birge-Hopfield (LBH, 140-180 nm) band, both of them in the far ultraviolet (FUV) range. The most convenient procedure to isolate a spectral band is the use of tunable transmittance filters. In many applications the intensity of the ultraviolet, visible and infrared background is higher than the intensity of the target FUV lines; therefore one of the most important requirements for transmittance filters is to reject (by reflecting and/or by absorbing) as efficiently as possible the visible and close ranges. In the FUV range, (Al/MgF2)n transmittance filters are the most common, and they are suitable to reject the visible and adjacent ranges. These materials present unique properties in this range: MgF2 is transparent down to ˜115 nm and Al has a very low refractive index in the FUV that contrasts well with MgF2. Narrowband tunable filters with very low transmittance at long wavelengths are achievable. The main data on the preparation and characterization of IP filters by Grupo de Óptica de Láminas Delgadas (GOLD) is detailed. In this proceeding we present (Al/MgF2)3 filters peaked at either 135.6 nm or at the center of the LBH band (˜160 nm). Filters were characterized in the 125-800 nm range (143-800 nm range for the LBH filter). After some storage in a desiccator, both coatings kept a transmittance of ~0.14 at their target wavelengths, with visible-to-peak transmittance ratios of 1.2·10-4 (OI filter) and 1.3·10-4 (LBH filter). One filter tuned at each target wavelength was exposed to ~300 Gy 60Co gamma dose, with no significant transmittance change.

  10. Mapping the Use of Engineered NM in Quebec's Industries and Research Laboratories

    NASA Astrophysics Data System (ADS)

    Ostiguy, Claude; Emond, Claude; Dossa, Inès; Malki, Yasmina; Boily, Chantale; Roughley, David; Plavski, Anton; Endo, Charles-Anica

    2013-04-01

    Engineered NanoMaterials (NM) offer an opportunity to develop a wide variety of new products with unique properties but many studies have shown potential OHS risks specific to NM. Addressing these risks requires knowledge about release of NM into the workplaces. This research aimed to map the state of nanotechnology OHS practices in Quebec through a questionnaire following a first contact by telephone when possible and by compiling the type and volumes of NM used as well as gathering information related to the working conditions and OHS aspects. This survey was conducted among 1310 Quebec industries and 653 researchers working in different specialties potentially involved in the development/production/distribution/integration of NM and use of NM containing products. Overall, 90 questionnaires, including 51 from the industries, were completed. These showed that NM are mainly used into the powder form, in many different sectors and deserve a wide range of markets. The prevention measures implemented vary widely from a workplace to another but about one third of the participants report that they have implemented NP adapted prevention measures but they remain worried on some specific operations. More than 50% of the participants request more information about the safe laboratory/plant design, toxicity, regulation, good work practices and prevention measures, efficiency of personal protective equipment and environmental impacts.

  11. The dynamics of femtosecond pulsed laser removal of 20 nm Ni films from an interface

    SciTech Connect

    Schrider, Keegan J.; Yalisove, Steven M.; Torralva, Ben

    2015-09-21

    The dynamics of femtosecond laser removal of 20 nm Ni films on glass substrates was studied using time-resolved pump-probe microscopy. 20 nm thin films exhibit removal at two distinct threshold fluences, removal of the top 7 nm of Ni above 0.14 J/cm{sup 2}, and removal of the entire 20 nm film above 0.36 J/cm{sup 2}. Previous work shows the top 7 nm is removed through liquid spallation, after irradiation the Ni melts and rapidly expands leading to tensile stress and cavitation within the Ni film. This work shows that above 0.36 J/cm{sup 2} the 20 nm film is removed in two distinct layers, 7 nm and 13 nm thick. The top 7 nm layer reaches a speed 500% faster than the bottom 13 nm layer at the same absorbed fluence, 500–2000 m/s and 300–700 m/s in the fluence ranges studied. Significantly different velocities for the top 7 nm layer and bottom 13 nm layer indicate removal from an interface occurs by a different physical mechanism. The method of measuring film displacement from the development of Newton's rings was refined so it could be shown that the 13 nm layer separates from the substrate within 70 ps and accelerates to its final velocity within several hundred picoseconds. We propose that removal of the bottom 13 nm is consistent with heterogeneous nucleation and growth of vapor at the Ni-glass interface, but that the rapid separation and acceleration of the 13 nm layer from the Ni-glass interface requires consideration of exotic phases of Ni after excitation.

  12. Effects of 946-nm thermal shift and broadening on Nd3+:YAG laser performance

    NASA Astrophysics Data System (ADS)

    Seyed Ebrahim, Pourmand; Ghasem, Rezaei

    2015-12-01

    Spectroscopic properties of flashlamp pumped Nd3+:YAG laser are studied as a function of temperature in a range from -30 °C to 60 °C. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of 4F3/2 → 4I9/2 are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature. The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is, thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state. Project supported by Estahban Branch, Islamic Azad University.

  13. Component validation of direct diode 488nm lasers in BD Accuri C6 flow cytometers

    NASA Astrophysics Data System (ADS)

    Chen, Wei P.; Luo, Ningyi D.

    2016-03-01

    The 488nm laser is the most important excitation light source of flow cytometry. The indirect diode (frequency-doubled diode) 488nm lasers are used in the excitation of Becton Dickinson (BD) AccuriTM C6. For using cost effective lasers, we have validated direct diode 488nm lasers as the replacement component of frequency-doubled diode laser. BD Bioscience issued the protocols to cover wavelength, power, noise, and polarization at the operation temperature range of cytometer. Pavilion Integration Corporation (PIC) tested 6 samples as the component validation of direct diode 488nm lasers based on the protocols from BD Biosciences. BD Bioscience also tested one of laser samples to further validate the test results of power, noise, and polarization from PIC.

  14. Quantum dot insertions in VCSELs from 840 to 1300 nm: growth, characterization, and device performance

    NASA Astrophysics Data System (ADS)

    Ledentsov, N. N.; Lott, J. A.; Shchukin, V. A.; Quast, H.; Hopfer, F.; Fiol, G.; Mutig, A.; Moser, P.; Germann, T.; Strittmatter, A.; Karachinsky, L. Y.; Blokhin, S. A.; Novikov, I. I.; Nadtochi, A. M.; Zakharov, N. D.; Werner, P.; Bimberg, D.

    2009-02-01

    Presently VCSELs covering a significant spectral range (840-1300 nm) can be produced based on quantum dot (QD) active elements. Herein we report progress on selected QD based vertical-cavity surface-emitting lasers (VCSELs) suitable for high-speed operation. An open eye diagram at 20 Gb/s with error-free transmission (a bit-error-rate < 10-15) is achieved at 850 nm. The 850 nm QD VCSELs also achieve error-free 20 Gb/s single mode transmission operation through multimode fiber without the use of optical isolation. Our 980 nm-range QD VCSELs achieve error free transmission at 25 Gb/s at up to 150°C. These 980 nm devices operate in a temperature range of 25-85°C without current or modulation voltage adjustment. We anticipate that the primary application areas of QD VCSELs are those that require degradation-robust operation under extremely high current densities. Temperature stability at ultrahigh current densities, a forte of QDs, is needed for ultrahigh-speed (> 40 Gb/s) current-modulated VCSELs for a new generation of local and storage area networks. Finally we discuss aspects of QD vertical extended-cavity surface emitting lasers with ultra high power density per emitting surface for high power (material processing) and frequency conversion (display) applications.

  15. Short-term clinical outcomes of laser supported periodontal treatment concept using Er,Cr:YSGG (2780nm) and diode (940 nm): a pilot study

    NASA Astrophysics Data System (ADS)

    Odor, Alin A.; Violant, Deborah; Badea, Victoria; Gutknecht, Norbert

    2016-03-01

    Backgrounds: Er,Cr:YSGG (2780nm) and diode (940 nm) lasers can be used adjacent to the conventional periodontal treatment as minimally invasive non-surgical devices. Aim: To describe the short-term clinical outcomes by combining Er,Cr:YSGG (2780nm) and diode 940 nm lasers in non-surgical periodontal treatment. Materials and methods: A total of 10 patients with periodontal disease (mild, moderate, severe) - 233 teeth and 677 periodontal pockets ranging from 4 mm to 12 mm - were treated with Er,Cr:YSGG (2780nm) and diode (940 nm) lasers in adjunct to manual and piezoelectric scaling and root planning (SRP). Periodontal parameters such as mean probing depth (PD), mean clinical attachment level (CAL) and mean bleeding on probing (BOP) were evaluated at baseline and 6 months after the laser treatment using an electronic periodontal chart. Results: At baseline, the mean PD was 4.06 ± 1.06 mm, mean CAL was 4.56 ± 1.43 mm, and mean BOP was 43.8 ± 23.84 %. At 6 months after the laser supported periodontal treatments the mean PD was 2.6 ± 0.58 mm (p <0.001), mean CAL was 3.36 ± 1.24 mm (p <0.001) and mean BOP was 17 ± 9.34 % (p <0.001). Also 3 patients showed radiographic signs of bone regeneration. Conclusion: The combination of two laser wavelengths in adjunct to SRP offers significant improvements of periodontal clinical parameters such as PD, CAL and BOP. Keywords: Laser supported periodontal treatment concept, Er,Cr:YSGG and diode 940nm lasers, Scaling and root planning, Minimally invasive non-surgical device

  16. Range Reference Notebook

    DTIC Science & Technology

    2006-10-15

    rifle grenade (inert), tin can lid, 15” tent peg 3 Table FRD-7. Fort Ritchie Sector 3 Representative Examples of Non-MEC Clutter Description 1/2...Appendix B—Indirect Fire Range Examples SITES ( ADI ) Adak Naval Air Facility, AK, Mitt Lake Mortar Range (FRI) Fort Ritchie...example range. B- ADI -1 Indirect-Fire Range,: Adak, AK, Mitt Lake Mortar Range Impact Area Site-Specific References – Adak NAF Foster Wheeler

  17. Cell projection use in maskless lithography for 45nm and 32nm logic nodes

    NASA Astrophysics Data System (ADS)

    Manakli, S.; Komami, H.; Takizawa, M.; Mitsuhashi, T.; Pain, L.

    2009-03-01

    Due to the ever-increasing cost of equipment and mask complexity, the use of optical lithography for integrated circuit manufacturing is increasingly more complex and expensive. Recent workshops and conferences in semiconductor lithography underlined that one alternative to support sub-32nm technologies is mask-less lithography option using electron beam technology. However, this direct write approach based on variable shaped beam principle (VSB) is not sufficient in terms of throughput, i.e. of productivity. New direct write techniques like multibeam systems are under development, but these solutions will not be mature before 2012. The use of character/cell projection (CP) on industrial VSB tools is the first step to deal with the throughput concerns. This paper presents the status of the CP technology and evaluates its possible use for the 45nm and 32nm logic nodes. It will present standard cell and SRAM structures that are printed as single characters using the CP technique. All experiments are done using the Advantest tool (F3000) which can project up to 100 different cells per layer. Cell extractions and design have been performed with the design and software solution developed by D2S. In this paper, we first evaluate the performance gain that can be obtained with the CP approach compared to the standard VSB approach. This paper also details the patterning capability obtained by using the CP concept. An evaluation of the CD uniformity and process stability is also presented. Finally this paper discusses about the improvements of this technique to address high resolution and to improve the throughput concerns.

  18. New single-layer positive photoresists for 193-nm photolithography

    NASA Astrophysics Data System (ADS)

    Okoroanyanwu, Uzodinma; Shimokawa, Tsutomu; Byers, Jeff D.; Medeiros, David R.; Willson, C. Grant; Niu, Qingshang J.; Frechet, Jean M. J.; Allen, Robert D.

    1997-07-01

    New series of chemically amplified, single layer, positive tone photoresists for 193 nm lithography have been developed. These resists were formulated from a series of cycloaliphatic co- and terpolymers of 2-methyl propyl bicyclo(2.2.1)hept-2- ene-5-carboxylate (carbo-tert-butoxynorbornene), bicyclo(2.2.1)hept-2-ene carboxylic acid (norbornene carboxylic acid), 8-methyl-8-carboxy tetracyclo(4,4,0.12,5,17,10)dodec-3-ene (methyltetracyclododecene carboxylic acid), norbornenemethanol, and maleic anhydride, which were synthesized by free radical, vinyl addition and ring opening metathesis polymerization techniques. The polymers derived from ring opening metathesis polymerization have bee successfully hydrogenated to provide yet another member of this group of materials. The cycloaliphatic polymer backbones provide etch resistance, mechanical properties and stability to radiation. The lithographic function is provided by carefully tailored pendant groups, which include an acid functionality that is masked by protecting groups that undergo acid catalyzed thermolysis as well as polar groups that influence the adhesion, wetability and dissolution properties of the polymer. The polymers are soluble in common organic solvents and have glass transition temperatures ranging from less than 60 degrees Celsius to higher than 250 degrees Celsius depending on their specific structure and mode of polymerization. They are at least as transparent at 193 nm as the corresponding acrylics. Their dry etch resistance varies with the formulation, but the base polymers etch more slowly than novolac under conditions typically used to pattern polysilicon. Upon exposure and baking, the resists have demonstrated high sensitivities (9-25 mJ/cm2), and 0.16 micrometer features have bean resolved.

  19. A Long-Range Precision Ranging System

    NASA Technical Reports Server (NTRS)

    Easterling, Mahlon

    1961-01-01

    A technique is presented that may be used for precision real-time continuous range measuring at long ranges. The technique uses a carrier that is phase modulated by a pseudo-random binary sequence. The characteristics of the sequence that make it acquirable are discussed. The general form of a receiver capable of tracking the carrier is given and is shown to be a kind of phase-locked loop. A two-loop system capable of tracking a pseudo-random sequence and its clock is given. The combination of the receiver and the sequence tracking system form a ranging receiver. The power division necessary between the carrier and the sidebands is shown to be determined by the noise bandwidths of the two tracking systems. The bandwidths necessary for tracking space probes and Earth satellites are given and some experiments in radar-tracking Earth satellites are described. Based on these experiments, estimates are made of the useful range of such a system in tracking space probes.

  20. Manufacturability of 2x-nm devices with EUV tool

    NASA Astrophysics Data System (ADS)

    Tawarayama, Kazuo; Nakajima, Yumi; Kyoh, Suigen; Aoyama, Hajime; Matsunaga, Kentaro; Magoshi, Shunko; Tanaka, Satoshi; Hayashi, Yumi; Mori, Ichiro

    2011-04-01

    Due to the promising development status of EUVL as a practical lithography technology for the 2x-nm node, we are continuing to evaluate its process liability using the EUV1 at Selete, which has an Off-Axis illumination capability. The resolution limit of the EUV1 for L&S patterns is currently 18 nm for dipole illumination, and 16 nm for aggressive dipole illumination. This study examined the critical points of EUVL for device manufacturing through wafer processes. The yield obtained from electrical measurements indicates the maturity of the technology, including the resist process, the tool, and the mask. Optimization of the resist and RIE processes significantly improved the yield. The final yields obtained from electrical measurements were 100% for hp 30 nm, 70% for hp 28 nm, and 40% for hp 26 nm. These results demonstrate EUV lithography to be a practical technology that is now suitable for 2x nm semiconductor manufacture.

  1. The complex evolution of strain during nanoscale patterning of 60 nm thick strained silicon layer directly on insulator

    NASA Astrophysics Data System (ADS)

    Moutanabbir, O.; Reiche, M.; Erfurth, W.; Naumann, F.; Petzold, M.; Gösele, U.

    2009-06-01

    The strain behavior in nanoscale patterned biaxial tensile strained Si layer on insulator is investigated in 60-nm-thick nanostructures with dimensions in the 80-400 nm range. The in-plane strain is evaluated by using UV micro-Raman. We found that less than 30% of the biaxial strain is maintained in the 200×200 nm2 nanostructures. This relaxation, due to the formation of free surfaces, becomes more important in smaller nanostructures. The strain is completely relieved at 80 nm. This phenomenon is described based on detailed three-dimensional finite element simulations. The anisotropic relaxation in rectangular nanostructures is also discussed.

  2. Chemical Mechanical Planarization (CMP) Metrology for 45/32 nm Technology Generations

    SciTech Connect

    Nutsch, A.; Pfitzner, L.

    2007-09-26

    In-plane geometrical defects on wafer surfaces following Chemical Mechanical Planarization (CMP) processing in the lateral millimeter range and in vertical dimensions in the nanometer range are of increasing importance. They will become a severe yield limiting factor in the 32 nm generations and below. At the wafer edge these defects are known as edge roll off (ERO). The feasibility of measuring flatness and geometry of bare silicon wafers and patterned wafers from different process steps as e.g. shallow trench isolation (STI) and interconnect metallization was successfully demonstrated using wave front sensing. The used wave front sensing methods were according to Makyoh and Shack Hartmann. The specifications achieved were for the Makyoh method a lateral resolution of 2.4 mm and for Shack Hartmann method 1.1 mm. The vertical resolution was 100 nm for the Makyoh method and 50 nm for the Shack Hartmann method.

  3. Passive infrared ranging

    NASA Astrophysics Data System (ADS)

    Leonpacher, N. K.

    1983-12-01

    The range of an infrared source was estimated by analyzing the atmospheric absorption by CO2 in several wavelength intervals of its spectrum. These bandpasses were located at the edge of the CO2 absorption band near 2300 1/cm (4.3 micron). A specific algorithm to predict range was determined based on numerous computer generated spectra. When tested with these spectra, range estimates within 0.8 km were obtained for ranges between 0 and 18 km. Accuracy decreased when actual source spectra were tested. Although actual spectra were available only for ranges to 5 km, 63% of these spectra resulted in range estimates that were within 1.6 km of the actual range. Specific spectral conditions that affected the range predictions were found. Methods to correct the deficiencies were discussed. Errors from atmospheric variations, and the effects of background noise, were also investigated. Limits on accuracy and range resolution were determined.

  4. Ultraviolet 320 nm laser excitation for flow cytometry.

    PubMed

    Telford, William; Stickland, Lynn; Koschorreck, Marco

    2017-02-27

    Although multiple lasers and high-dimensional analysis capability are now standard on advanced flow cytometers, ultraviolet (UV) lasers (usually 325-365 nm) remain an uncommon excitation source for cytometry. This is primarily due to their cost, and the small number of applications that require this wavelength. The development of the Brilliant Ultraviolet (BUV fluorochromes, however, has increased the importance of this formerly niche excitation wavelength. Historically, UV excitation was usually provided by water-cooled argon- and krypton-ion lasers. Modern flow cytometers primary rely on diode pumped solid state lasers emitting at 355 nm. While useful for all UV-excited applications, DPSS UV lasers are still large by modern solid state laser standards, and remain very expensive. Smaller and cheaper near UV laser diodes (NUVLDs) emitting at 375 nm make adequate substitutes for 355 nm sources in many situations, but do not work as well with very short wavelength probes like the fluorescent calcium chelator indo-1. In this study, we evaluate a newly available UV 320 nm laser for flow cytometry. While shorter in wavelength that conventional UV lasers, 320 is close to the 325 nm helium-cadmium wavelength used in the past on early benchtop cytometers. A UV 320 nm laser was found to excite almost all Brilliant Ultraviolet dyes to nearly the same level as 355 nm sources. Both 320 nm and 355 nm sources worked equally well for Hoechst and DyeCycle Violet side population analysis of stem cells in mouse hematopoetic tissue. The shorter wavelength UV source also showed excellent excitation of indo-1, a probe that is not compatible with NUVLD 375 nm sources. In summary, a 320 nm laser module made a suitable substitute for conventional 355 nm sources. This laser technology is available in a smaller form factor than current 355 nm units, making it useful for small cytometers with space constraints. © 2017 International Society for Advancement of Cytometry.

  5. Sidewall spacer quadruple patterning for 15nm half-pitch

    NASA Astrophysics Data System (ADS)

    Xu, Ping; Chen, Yongmei; Chen, Yijian; Miao, Liyan; Sun, Shiyu; Kim, Sung-Woo; Berger, Ami; Mao, Daxin; Bencher, Christ; Hung, Raymond; Ngai, Chris

    2011-04-01

    193nm immersion lithography, with the single-exposure resolution limitation of half-pitch 38nm, has extended its patterning capability to about 20nm using the double-patterning technique[1]. Despite the non-trivial sub-20nm patterning challenges, several NAND Flash manufacturers are already pursuing for sub-16nm patterning technology. 25nm NAND flash memory has already begun production in 2010, and given the typical 2-year scaling cycle, sub-16nm NAND devices should see pilot or mass production as early as 2014. Using novel patterning techniques such as sidewall spacer quadruple patterning (upon 120nm to 128nm pitch using dry ArF lithography) or triple patterning (upon 90nm pitch using immersion ArF lithography), we are able to extend optical lithography to sub-16nm half-pitch and demonstrate the lithographic performance that can nearly meet the ITRS roadmap requirements. In this paper, we conduct an in-depth review and demonstration of sidewall spacer quadruple patterning; including 300mm wafer level data of the mean values and CDU along with a mathematical assessment of the various data pools for sub-16nm lines and spaces. By understanding which processes (lithography, deposition, and etch) define the critical dimension of each data pool, we can make predictions of CDU capability for the sidewall spacer quad patterning. Our VeritySEM4i CD SEM tool demonstrated high measurement yield during fully automated measurements, which enables accurate lines, spaces and CDU measurements of the sub-16nm. The patterns generated from the sidewall spacer quadruple patterning techniques are used as a hardmask to transfer sub-16nm lines and spaces patterns to underneath amorphous silicon and silicon oxide layers, or poly silicon layer for 1X STI or poly gate applications.

  6. Optical breakdown threshold investigation of 1064 nm laser induced air plasmas

    SciTech Connect

    Thiyagarajan, Magesh; Thompson, Shane

    2012-04-01

    We present the theoretical and experimental measurements and analysis of the optical breakdown threshold for dry air by 1064 nm infrared laser radiation and the significance of the multiphoton and collisional cascade ionization process on the breakdown threshold measurements over pressures range from 10 to 2000 Torr. Theoretical estimates of the breakdown threshold laser intensities and electric fields are obtained using two distinct theories namely multiphoton and collisional cascade ionization theories. The theoretical estimates are validated by experimental measurements and analysis of laser induced breakdown processes in dry air at a wavelength of 1064 nm by focusing 450 mJ max, 6 ns, 75 MW max high-power 1064 nm IR laser radiation onto a 20 {mu}m radius spot size that produces laser intensities up to 3 - 6 TW/cm{sup 2}, sufficient for air ionization over the pressures of interest ranging from 10 to 2000 Torr. Analysis of the measured breakdown threshold laser intensities and electric fields are carried out in relation with classical and quantum theoretical ionization processes, operating pressures. Comparative analysis of the laser air breakdown results at 1064 nm with corresponding results of a shorter laser wavelength (193 nm) [M. Thiyagarajan and J. E. Scharer, IEEE Trans. Plasma Sci. 36, 2512 (2008)] and a longer microwave wavelength (10{sup 8} nm) [A. D. MacDonald, Microwave Breakdown in Gases (Wiley, New York, 1966)]. A universal scaling analysis of the breakdown threshold measurements provided a direct comparison of breakdown threshold values over a wide range of frequencies ranging from microwave to ultraviolet frequencies. Comparison of 1064 nm laser induced effective field intensities for air breakdown measurements with data calculated based on the collisional cascade and multiphoton breakdown theories is used successfully to determine the scaled collisional microwave portion. The measured breakdown threshold of 1064 nm laser intensities are then

  7. Efficient Coupling of 527 nm Laser Beam Power to a Long Scalelength Plasma

    SciTech Connect

    Moody, J D; Divol, L; Glenzer, S H; MacKinnon, A J; Froula, D H; Gregori, G; Kruer, W L; Meezan, N B; Suter, L J; Williams, E A; Bahr, R; Seka, W

    2005-08-24

    We experimentally demonstrate that application of laser smoothing schemes including smoothing by spectral dispersion (SSD) and polarization smoothing (PS) increases the intensity range for efficient coupling of frequency doubled (527 nm) laser light to a long scalelength plasma with n{sub e}/n{sub cr} = 0.14 and T{sub e} = 2 keV.

  8. 78 FR 77023 - Proposed Establishment of Class E Airspace; Tucumcari, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... VHF Omni-Directional Radio Range Tactical Air Navigation Aid (VORTAC), Tucumcari, NM, to facilitate vectoring of Instrument Flight Rules (IFR) aircraft under control of Albuquerque Air Route Traffic Control Center (ARTCC). The FAA is proposing this action to enhance the safety and management of...

  9. Bismuth-doped telecommunication fibres for lasers and amplifiers in the 1400-1500-nm region

    SciTech Connect

    Dvoirin, V V; Mashinskii, V M; Medvedkov, O I; Dianov, Evgenii M; Umnikov, A A; Gur'yanov, Aleksei N

    2009-06-30

    Bismuth-doped optical fibres fully compatible with standard telecommunication fibres are developed. Lasers based on such fibres emitting in the spectral range 1430-1500 nm with an efficiency of up to 7.6% at room temperature and up to 10.5% at a temperature of -65{sup 0}C are fabricated. (waveguides. optical fibres)

  10. 78 FR 78300 - Proposed Establishment of Class E Airspace; Albuquerque, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...This action proposes to establish Class E airspace at the Albuquerque VHF Omni-Directional Radio Range Tactical Air Navigation Aid (VORTAC), Albuquerque, NM, to facilitate vectoring of Instrument Flight Rules (IFR) aircraft under control of Albuquerque Air Route Traffic Control Center (ARTCC). The FAA is proposing this action to enhance the safety and management of aircraft operations within......

  11. 78 FR 78299 - Proposed Establishment of Class E Airspace; Truth or Consequences, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...This action proposes to establish Class E airspace at the Truth or Consequences VHF Omni-Directional Radio Range Tactical Air Navigation Aid (VORTAC), Truth or Consequences, NM, to facilitate vectoring of Instrument Flight Rules (IFR) aircraft under control of Albuquerque Air Route Traffic Control Center (ARTCC). The FAA is proposing this action to enhance the safety and management of aircraft......

  12. Short-wavelength infrared laser activates the auditory neurons: comparing the effect of 980 vs. 810 nm wavelength.

    PubMed

    Tian, Lan; Wang, Jingxuan; Wei, Ying; Lu, Jianren; Xu, Anting; Xia, Ming

    2017-02-01

    Research on auditory neural triggering by optical stimulus has been developed as an emerging technique to elicit the auditory neural response, which may provide an alternative method to the cochlear implants. However, most previous studies have been focused on using longer-wavelength near-infrared (>1800 nm) laser. The effect comparison of different laser wavelengths in short-wavelength infrared (SWIR) range on the auditory neural stimulation has not been previously explored. In this study, the pulsed 980- and 810-nm SWIR lasers were applied as optical stimuli to irradiate the auditory neurons in the cochlea of five deafened guinea pigs and the neural response under the two laser wavelengths was compared by recording the evoked optical auditory brainstem responses (OABRs). In addition, the effect of radiant exposure, laser pulse width, and threshold with the two laser wavelengths was further investigated and compared. The one-way analysis of variance (ANOVA) was used to analyze those data. Results showed that the OABR amplitude with the 980-nm laser is higher than the amplitude with the 810-nm laser under the same radiant exposure from 10 to 102 mJ/cm(2). And the laser stimulation of 980 nm wavelength has lower threshold radiant exposure than the 810 nm wavelength at varied pulse duration in 20-500 μs range. Moreover, the 810-nm laser has a wider optimized pulse duration range than the 980-nm laser for the auditory neural stimulation.

  13. Time Scales for Viscous Flow, Atomic Transport, and Crystallization in the Liquid and Supercooled Liquid States of Zr{sub 41.2 } Ti{sub 1 3.8} Cu{sub 12.5} Ni{sub 10.0} Be{sub 22.5}

    SciTech Connect

    Masuhr, A.; Waniuk, T.A.; Busch, R.; Johnson, W.L.

    1999-03-01

    The shear viscosity of liquid Zr{sub 41.2} Ti{sub 13.8} Cu{sub 12.5} Ni{sub 10.0} Be{sub 22.5} has been measured. At the liquidus temperature we find an extremely high viscosity of 2.5thinspthinspPathinsps, favoring glass formation. At deep supercooling the time scales for the diffusion of small and medium sized atoms as reported in the literature decouple from the internal relaxation time as probed by our viscosity measurements. Similarly, crystallization from the supercooled liquid state can be described with an effective diffusivity that scales with the viscosity at high temperatures and is Arrhenius-like at deep supercooling. {copyright} {ital 1999} {ital The American Physical Society}

  14. Expression of NM23 in human melanoma progression and metastasis.

    PubMed Central

    Easty, D. J.; Maung, K.; Lascu, I.; Véron, M.; Fallowfield, M. E.; Hart, I. R.; Bennett, D. C.

    1996-01-01

    NM23 is a putative metastasis-suppressor gene for some human cancers. Here we have studied NM23 expression during melanoma progression using Northern blotting and immunocytochemistry. There was no significant difference in the average amounts of NM23 mRNA between cell lines derived from metastatic and primary melanomas. The level of NM23 mRNA was also determined for three pairs of poorly metastatic parental (P) and their highly metastatic variant (M) cell lines; the ratios for M/P were 1.2, 0.98 and 0.80. Next we used immunocytochemistry to study NM23 protein in normal skin, benign naevi and primary and metastatic melanomas. Melanocytes in all normal skin and benign samples were positive for NM23; however most primary melanomas (7/11) were not stained by the antibody. All metastatic melanoma samples (5/5) were positively stained. Findings were similar with an antiserum reactive with both forms of NM23 (H1 and H2), and with an antibody specific for NM23-H1. No relationship was apparent between NM23 immunoreactivity in primary tumours and their aggressiveness or prognosis. Hence, in contrast to the situation described for murine melanoma, the amount of NM23 mRNA or protein in human melanoma did not correlate inversely with metastasis. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8679442

  15. RADIO RANGING DEVICE

    DOEpatents

    Nieset, R.T.

    1961-05-16

    A radio ranging device is described. It utilizes a super regenerative detector-oscillator in which echoes of transmitted pulses are received in proper phase to reduce noise energy at a selected range and also at multiples of the selected range.

  16. Tau ranging revisited

    NASA Technical Reports Server (NTRS)

    Tausworthe, R. C.

    1987-01-01

    It is shown that a ranging receiver with a sufficient and reasonable number of correlators is competitive with the current sequential component ranging system by some 1.5 to 2.5 dB. The optimum transmitter code, the optimum receiver, and a near-maximum-lilelihood range-estimation algorithm are presented.

  17. Long Range Technology Planning.

    ERIC Educational Resources Information Center

    Ambron, Sueann, Ed.

    1986-01-01

    This summary of a meeting of the Apple Education Advisory Council, on long range technology plans at the state, county, district, and school levels, includes highlights from group discussions on future planning, staff development, and curriculum. Three long range technology plans at the state level are provided: Long Range Educational Technology…

  18. New rotationally resolved spectra of Pluto-Charon from 350 - 900 nm

    NASA Astrophysics Data System (ADS)

    Throop, Henry B.; Grundy, Will; Olkin, Cathy B.; Young, Leslie A.; Sickafoose, Amanda A.

    2015-11-01

    We are using the 11-meter Southern African Large Telescope (SALT) to acquire high-resolution rotationally resolved visible spectra of Pluto-Charon. We use the Robert Stobie Spectrograph (RSS) to observe Pluto-Charon from 350 nm to 900 nm. At 500 nm, resolution is 0.05 nm (R ~ 10,0000) and SNR per spectral resolution element is ~ 500.We planned observations for 13 dates during June-September 2014, and 13 more dates during June-September 2015. The observations for each season were spaced so as to equally sample Pluto's 6.5-day rotational period. As of the abstract submission, we have data from 11 nights (2014) and 9 nights (2015) in hand. Most of the observations were taken with observations of solar-type star HD 146233 to determine the surface reflectivity.Our results will provide constraint on the composition and spatial distribution of material on Pluto's surface, enabling comparison to previous epochs and near-infrared results, and giving a ground-truth for New Horizons' July 2015 flyby. In addition, our data will allow us to search for new spectral features in the range 350 nm to 600 nm, at a sensitivity substantially higher than previously published searches.

  19. Wettability control of a polymer surface through 126 nm vacuum ultraviolet light irradiation

    NASA Astrophysics Data System (ADS)

    Hozumi, Atsushi; Shirahata, Naoto; Nakanishi, Youichiro; Asakura, Shuuichi; Fuwa, Akio

    2004-07-01

    The control of the surface wettability of poly (methyl methacrylate) (PMMA) substrates has been successfully demonstrated using an Ar2* excimer lamp radiating 126 nm vacuum ultraviolet (VUV) light. Each of the samples was exposed to 126 nm VUV light in air over the pressure range of 2×10-4-105 Pa. Although at the process pressures of 10, 103, and 105 Pa, the PMMA surfaces became relatively hydrophilic, the degree of hydrophilicity depended markedly on the pressure. The minimum water contact angles of the samples treated at 10, 103, and 105 Pa were about 50°, 33°, and 64°, respectively. These values were larger than those of PMMA substrates hydrophilized through 172 nm VUV irradiation conducted under the same conditions. On the other hand, after 126 nm VUV irradiation conducted under the high vacuum condition of 2×10-4 Pa, the PMMA substrate surface became carbon-rich, probably due to preferential cross-linking reactions, as evidenced by x-ray photoelectron spectroscopy. This surface was hydrophobic, showing a water contact angle of about 101°. Although the 126 nm VUV-irradiated surfaces appeared relatively smooth when observed by atomic force microscope, very small particles with diameters of 30-60 nm, which probably originated from the readhesion of photodecomposed products, existed on all of the sample surfaces. .

  20. Isothermal annealing of a 620 nm optical absorption band in Brazilian topaz crystals

    NASA Astrophysics Data System (ADS)

    Isotani, Sadao; Matsuoka, Masao; Albuquerque, Antonio Roberto Pereira Leite

    2013-04-01

    Isothermal decay behaviors, observed at 515, 523, 562, and 693 K, for an optical absorption band at 620 nm in gamma-irradiated Brazilian blue topaz were analyzed using a kinetic model consisting of O- bound small polarons adjacent to recombination centers (electron traps). The kinetic equations obtained on the basis of this model were solved using the method of Runge-Kutta and the fit parameters describing these defects were determined with a grid optimization method. Two activation energies of 0.52±0.08 and 0.88±0.13 eV, corresponding to two different structural configurations of the O- polarons, explained well the isothermal decay curves using first-order kinetics expected from the kinetic model. On the other hand, thermoluminescence (TL) emission spectra measured at various temperatures showed a single band at 400 nm in the temperature range of 373-553 K in which the 620 nm optical absorption band decreased in intensity. Monochromatic TL glow curve data at 400 nm extracted from the TL emission spectra observed were found to be explained reasonably by using the knowledge obtained from the isothermal decay analysis. This suggests that two different structural configurations of O- polarons are responsible for the 620 nm optical absorption band and that the thermal annealing of the polarons causes the 400 nm TL emission band.

  1. Implications of the temperature dependence of Nd:YAG spectroscopic values for low temperature laser operation at 946 nm

    NASA Astrophysics Data System (ADS)

    Yoon, S. J.; Mackenzie, J. I.

    2014-05-01

    We present our measurements of the key spectroscopic properties over the temperature range of 77 K to 450 K for Nd3+ ions doped in Y3Al5O12 (YAG). From room to liquid nitrogen temperature (LNT), the peak absorption cross section around 808 nm increased by almost 3 times, in conjunction the bandwidth of this absorption line reduced by the same factor. At LNT the peak of the absorption line was blue shifted by 0.25 nm with respect to that at 300 K. The fluorescence spectrum between 850 nm - 1450 nm was measured, from which the emission cross sections for the three main transitions were calculated. One note of particular interest for the dominant emission wavelengths around 1064nm and 1061nm (4F3/2 --> 4I11/2) was the switch in their relative strength below 170K, and at LNT the 1061 nm line has almost twice the cross section as at 1064nm.. The fluorescence and lifetime of the upper laser level (4F3/2) was measured and the effective emission cross section determined by the Fuchtbauer-Ladenburg (F-L) method. The effective emission cross section for 946 nm (R1 --> Z5) increased by more than two times over the 300 K to 77 K range. A numerical fit for the temperature dependent emission cross section at 946 nm and 1064 nm and also calculated absorption coefficient at 808 nm pump diode laser have also obtained from the measured spectroscopic data.

  2. A precise measurement of lunar spectral irradiance from 450 nm to 1000 nm

    NASA Astrophysics Data System (ADS)

    Cramer, C. E.; Lykke, K.; Woodward, J. T.; Smith, A. W.

    2013-12-01

    Although the Moon is our nearest celestial neighbor, our knowledge of its absolute spectral irradiance is an order of magnitude less precise than our knowledge of the best-calibrated stars, including the Sun. A precise determination of the Moon's absolute spectral irradiance has the potential to improve on-orbit calibrations of Earth-observing instruments and extend atmospheric monitoring techniques based on Sun photometry to nighttime measurements based on lunar spectrophotometry. Observations of the Moon have already been used to track changes in satellite sensor response at the sub-percent level, relying on a model of lunar irradiance developed by the United States Geological Survey to predict time-dependent changes in lunar irradiance. The absolute scale of this model, however, is not known accurately enough to allow the Moon to specify an absolute scale for instrument response on orbit or to bridge gaps in various climate data records. We report initial measurements of lunar spectral irradiance with an uncertainty below 1 % from 420 nm to 1000 nm and compare them with the USGS model. Our measurement uncertainty meets the radiometric calibration requirement for many climate data records derived from satellite images, including those for vegetation, aerosols, and snow and ice albedo. It therefore opens the possibility of using the Moon as a calibration standard to bridge gaps in satellite coverage and validate atmospheric retrieval algorithms. Our measurement technique also yields detailed information about the atmosphere at the measurement site, suggesting that lunar observations are a possible solution for aerosol monitoring during the polar winter and can provide nighttime measurements to complement aerosol data collected with Sun photometers. Our measurement, made with a novel apparatus, is an order of magnitude more accurate than the previous state-of-the-art and has continuous spectral coverage, removing the need to interpolate between filter passbands.

  3. Telemetry Ranging: Signal Processing

    NASA Astrophysics Data System (ADS)

    Hamkins, J.; Kinman, P.; Xie, H.; Vilnrotter, V.; Dolinar, S.

    2016-02-01

    This article describes the details of the signal processing used in a telemetry ranging system in which timing information is extracted from the downlink telemetry signal in order to compute spacecraft range. A previous article describes telemetry ranging concepts and architecture, which are a slight variation of a scheme published earlier. As in that earlier work, the telemetry ranging concept eliminates the need for a dedicated downlink ranging signal to communicate the necessary timing information. The present article describes the operation and performance of the major receiver functions on the spacecraft and the ground --- many of which are standard tracking loops already in use in JPL's flight and ground radios --- and how they can be used to provide the relevant information for making a range measurement. It also describes the implementation of these functions in software, and performance of an end-to-end software simulation of the telemetry ranging system.

  4. Measurements of Soot Mass Absorption Coefficients from 300 to 660 nm

    NASA Astrophysics Data System (ADS)

    Renbaum-Wolff, Lindsay; Fisher, Al; Helgestad, Taylor; Lambe, Andrew; Sedlacek, Arthur; Smith, Geoffrey; Cappa, Christopher; Davidovits, Paul; Onasch, Timothy; Freedman, Andrew

    2016-04-01

    Soot, a product of incomplete combustion, plays an important role in the earth's climate system through the absorption and scattering of solar radiation. In particular, the assumed mass absorption coefficient (MAC) of soot and its variation with wavelength presents a significant uncertainty in the calculation of radiative forcing in global climate change models. As part of the fourth Boston College/Aerodyne soot properties measurement campaign, we have measured the mass absorption coefficient of soot produced by an inverted methane diffusion flame over a spectral range of 300-660 nm using a variety of optical absorption techniques. Extinction and absorption were measured using a dual cavity ringdown photoacoustic spectrometer (CRD-PAS, UC Davis) at 405 nm and 532 nm. Scattering and extinction were measured using a CAPS PMssa single scattering albedo monitor (Aerodyne) at 630 nm; the absorption coefficient was determined by subtraction. In addition, the absorption coefficients in 8 wavelength bands from 300 to 660 nm were measured using a new broadband photoacoustic absorption monitor (UGA). Soot particle mass was quantified using a centrifugal particle mass analyzer (CPMA, Cambustion), mobility size with a scanning mobility particle sizer (SMPS, TSI) and soot concentration with a CPC (Brechtel). The contribution of doubly charged particles to the sample mass was determined using a Single Particle Soot Photometer (DMT). Over a mass range of 1-8 fg, corresponding to differential mobility diameters of ~150 nm to 550 nm, the value of the soot MAC proved to be independent of mass for all wavelengths. The wavelength dependence of the MAC was best fit to a power law with an Absorption Ångstrom Coefficient slightly greater than 1.

  5. Telemetry-Based Ranging

    NASA Technical Reports Server (NTRS)

    Hamkins, Jon; Vilnrotter, Victor A.; Andrews, Kenneth S.; Shambayati, Shervin

    2011-01-01

    A telemetry-based ranging scheme was developed in which the downlink ranging signal is eliminated, and the range is computed directly from the downlink telemetry signal. This is the first Deep Space Network (DSN) ranging technology that does not require the spacecraft to transmit a separate ranging signal. By contrast, the evolutionary ranging techniques used over the years by NASA missions, including sequential ranging (transmission of a sequence of sinusoids) and PN-ranging (transmission of a pseudo-noise sequence) whether regenerative (spacecraft acquires, then regenerates and retransmits a noise-free ranging signal) or transparent (spacecraft feeds the noisy demodulated uplink ranging signal into the downlink phase modulator) relied on spacecraft power and bandwidth to transmit an explicit ranging signal. The state of the art in ranging is described in an emerging CCSDS (Consultative Committee for Space Data Systems) standard, in which a pseudo-noise (PN) sequence is transmitted from the ground to the spacecraft, acquired onboard, and the PN sequence is coherently retransmitted back to the ground, where a delay measurement is made between the uplink and downlink signals. In this work, the telemetry signal is aligned with the uplink PN code epoch. The ground station computes the delay between the uplink signal transmission and the received downlink telemetry. Such a computation is feasible because symbol synchronizability is already an integral part of the telemetry design. Under existing technology, the telemetry signal cannot be used for ranging because its arrival-time information is not coherent with any Earth reference signal. By introducing this coherence, and performing joint telemetry detection and arrival-time estimation on the ground, a high-rate telemetry signal can provide all the precision necessary for spacecraft ranging.

  6. 32nm node technology development using interference immersion lithography

    NASA Astrophysics Data System (ADS)

    Sewell, Harry; McCafferty, Diane; Markoya, Louis; Hendrickx, Eric; Hermans, Jan; Ronse, Kurt

    2005-05-01

    The 38nm and 32nm lithography nodes are the next major targets for optical lithography on the Semiconductor Industry Roadmap. The recently developed water-based immersion lithography using ArF illumination will be able to provide an optical solution for lithography at the 45nm node, but it will not be able to achieve the 38nm or the 32nm nodes as currently defined. To achieve these next lithographic nodes will require new, very high refractive index fluids to replace the water used in current immersion systems. This paper describes tests and experiments using an interference immersion lithography test jig to develop key technology for the 32nm node. Interference imaging printers have been available for years, and with the advent of Immersion Lithography, they have a new use. Interference immersion image printing offers users a rapid, cost-effective way to develop immersion lithography, particularly at extremely high resolutions. Although it can never replace classical lens-based lithography systems for semiconductor device production, it does offer a way to develop resist and fluid technology at a relatively low cost. Its simple image-forming format offers easy access to the basic physics of advanced imaging. Issues such as: Polarization of the image forming light rays; Fluid/resist interaction during exposure; Topcoat film performance; and the Line Edge Roughness (LER) of resists at extremely high resolutions can all be readily studied. Experiments are described and results are provided for work on: 32nm imaging tests; high refractive index fluid testing using 193nm wavelength at resolutions well beyond current lens-based system capabilities; and polarization configuration testing on 45nm, 38nm, and 32nm L/S features. Results on the performance of resists and topcoats are reported for 32nm L/S features.

  7. Research on 9xx nm diode laser for direct and pumping applications

    NASA Astrophysics Data System (ADS)

    Sebastian, J.; Hülsewede, R.; Pietrzak, A.; Zorn, M.; Wölz, M.; Meusel, J.; Schröder, M.; Wittschirk, Th.

    2015-02-01

    High-power laser bars and single emitters have proven as attractive light sources for many industrial applications such as direct material processing or as pump sources for solid state and fiber-lasers. There is also a great interest in quasi-CW laser bars for high-energy projects. These applications require a continuous improvement of laser diodes for reliable optical output powers, high electrical-to-optical efficiencies, brightness and costs. In this paper JENOPTIK presents an overview of recent research for highly efficient CW and quasi-CW laser devices emitting in a wide wavelength range between 880 nm and 1020 nm. The last research results concern the 9xx single emitters and laser arrays. The 9xx nm 12 W single emitters and 976 nm 55 W laser arrays have efficiencies above 65%. New life time tests for single emitter devices currently exceed 1300 hours of reliable operation at room temperature and over 1500 hours at 45°C. Because of the small far field distribution of the optical power, the high output power and the small near field the 55 W arrays show a brightness of 75 MW x cm-2sr-1 with 95% power content. The technology for new generation 940 nm high fill-factor bars has been currently extended to emission wavelengths of 976 nm and 1020 nm with excellent results: 200 W output power with 63% efficiency using passive cooling. The innovative design of the laser structure enables, moreover, the realization of 500 W 880 nm quasi-CW laser bars with wall-plug efficiencies of 55% and a narrow fast-axis divergence angle of 40° (95% power content).

  8. Detection limits of 405 nm and 633 nm excited PpIX fluorescence for brain tumor detection during stereotactic biopsy

    NASA Astrophysics Data System (ADS)

    Markwardt, Niklas; Götz, Marcus; Haj-Hosseini, Neda; Hollnburger, Bastian; Sroka, Ronald; Stepp, Herbert; Zelenkov, Petr; Rühm, Adrian

    2016-04-01

    5-aminolevulinic-acid-(5-ALA)-induced protoporphyrin IX (PpIX) fluorescence may be used to improve stereotactic brain tumor biopsies. In this study, the sensitivity of PpIX-based tumor detection has been investigated for two potential excitation wavelengths (405 nm, 633 nm). Using a 200 μm fiber in contact with semi-infinite optical phantoms containing ink and Lipovenös, PpIX detection limits of 4.0 nM and 200 nM (relating to 1 mW excitation power) were determined for 405 nm and 633 nm excitation, respectively. Hence, typical PpIX concentrations in glioblastomas of a few μM should be well detectable with both wavelengths. Additionally, blood layers of selected thicknesses were placed between fiber and phantom. Red excitation was shown to be considerably less affected by blood interference: A 50 μm blood layer, for instance, blocked the 405- nm-excited fluorescence completely, but reduced the 633-nm-excited signal by less than 50%. Ray tracing simulations demonstrated that - without blood layer - the sensitivity advantage of 405 nm rises for decreasing fluorescent volume from 50-fold to a maximum of 100-fold. However, at a tumor volume of 1 mm3, which is a typical biopsy sample size, the 633-nm-excited fluorescence signal is only reduced by about 10%. Further simulations revealed that with increasing fiber-tumor distance, the signal drops faster for 405 nm. This reduces the risk of detecting tumor tissue outside the needle's coverage, but diminishes the overlap between optically and mechanically sampled volumes. While 405 nm generally offers a higher sensitivity, 633 nm is more sensitive to distant tumors and considerably superior in case of blood-covered tumor tissue.

  9. High-power pulsed 976-nm DFB laser diodes

    NASA Astrophysics Data System (ADS)

    Zeller, Wolfgang; Kamp, Martin; Koeth, Johannes; Worschech, Lukas

    2010-04-01

    Distributed feedback (DFB) laser diodes nowadays provide stable single mode emission for many different applications covering a wide wavelength range. The available output power is usually limited because of catastrophical optical mirror damage (COD) caused by the small facet area. For some applications such as trace gas detection output powers of several ten milliwatts are sufficiently high, other applications like distance measurement or sensing in harsh environments however require much higher output power levels. We present a process combining optimizations of the layer structure with a new lateral design of the ridge waveguide which is fully compatible with standard coating and passivation processes. By implementing a large optical cavity with the active layer positioned not in the middle of the waveguide layers but very close to the upper edge, the lasers' farfield angles can be drastically reduced. Furthermore, the travelling light mode can be pushed down into the large optical cavity by continuously decreasing the ridge waveguide width towards both laser facets. The light mode then spreads over a much larger area, thus reducing the surface power density which leads to significantly higher COD thresholds. Laterally coupled DFB lasers based on this concept emitting at wavelengths around 976 nm yield hitherto unachievable COD thresholds of 1.6 W under pulsed operation. The high mode stability during the 50 ns pulses means such lasers are ideally suited for high precision distance measurement or similar tasks.

  10. Solution voltammetry of 4 nm magnetite iron oxide nanoparticles.

    PubMed

    Roberts, Joseph J P; Westgard, John A; Cooper, Laura M; Murray, Royce W

    2014-07-30

    The voltammetry of solution-dispersed magnetite iron oxide Fe3O4 nanoparticles is described. Their currents are controlled by nanoparticle transport rates, as shown with potential step chronoamperometry and rotated disk voltammetry. In pH 2 citrate buffer with added NaClO4 electrolyte, solution cyclic voltammetry of these nanoparticles (average diameter 4.4 ± 0.9 nm, each containing ca. 30 Fe sites) displays an electrochemically irreversible oxidation with E(PEAK) at ca. +0.52 V and an irreversible reduction with E(PEAK) at ca. +0.2 V vs Ag/AgCl reference electrode. These processes are presumed to correspond to the formal potentials for one-electron oxidation of Fe(II) and reduction of Fe(III) at their different sites in the magnetite nanoparticle structure. The heterogeneous electrode reaction rates of the nanoparticles are very slow, in the 10(-5) cm/s range. The nanoparticles are additionally characterized by a variety of tools, e.g., TEM, UV/vis, and XPS spectroscopies.

  11. A stable 657nm laser for a Ca atom interferometer

    NASA Astrophysics Data System (ADS)

    Neyenhuis, Brian; Erickson, Christopher; Tang, Rebecca; Doermann, Greg; van Zijll, Marshall; Durfee, Dallin

    2006-05-01

    We will present an extremely stable laser to be used in an atom interferometer. A 657nm grating-stabilized diode laser is locked to a high-finesse cavity using the Pound-Drever-Hall method. Utilizing a feedback circuit with a bandwidth of 5 MHz we see a laser linewidth less than one kHz. In addition to a relatively high bandwidth, our circuit design allows for mode-hop-free scanning over a large range. We are also working on several improvements which should further reduce our linewidth; we are improving passive mechanical and thermal stability of the laser and the optical cavity and plan to change to a higher finesse cavity, we have designed and are testing a more stable current driver based on an updated Hall-Libbrecht design, and we calculating an optimized multiple-input feedback transfer function for our system. We will also present the measurement of the resonances of our optical cavity relative to the Ca intercombination line using a high-temperature vapor cell.

  12. Technique for cellular microsurgery using the 193-nm excimer laser.

    PubMed

    Palanker, D; Ohad, S; Lewis, A; Simon, A; Shenkar, J; Penchas, S; Laufer, N

    1991-01-01

    A new cell surgery technique has been developed to produce well-defined alterations in cells and tissue without detectable heating and/or other structural damage in the surroundings. The technique involves the use of an argon fluoride excimer laser, in the deep ultraviolet (UV) region of the spectrum at 193 nm, which is guided through a glass pipette filled with a positive air pressure. To demonstrate the method, holes were drilled in the zona pellucida of mouse oocytes. The diameter of the drilled hole was determined by the pipette tip size, and its depth by an energy emitted per pulse and number of pulses. Scanning electron microscopy of the drilled mouse oocytes showed uniform, round, well-circumscribed holes with sharp edges. Oocytes that had their zona pellucida drilled with this new method fertilized in vitro and developed to the blastocyst stage in a rate similar to that of control group. These results demonstrate the nonperturbing nature of this cold laser microsurgical procedure. In addition to the extension of our results for clinical in vitro fertilization purposes, such as enhancement of fertilization and embryo biopsy, there are wide-ranging possible uses of our method in fundamental and applied investigations that require submicron accuracy in cellular alteration.

  13. Narrow linewidth broadband tunable semiconductor laser at 840 nm with dual acousto-optic tunable configuration for OCT applications

    NASA Astrophysics Data System (ADS)

    Chamorovskiy, Alexander; Shramenko, Mikhail V.; Lobintsov, Andrei A.; Yakubovich, Sergei D.

    2016-03-01

    We demonstrate a tunable narrow linewidth semiconductor laser for the 840 nm spectral range. The laser has a linear cavity comprised of polarization maintaining (PM) fiber. A broadband semiconductor optical amplifier (SOA) in in-line fiber-coupled configuration acts as a gain element. It is based on InGaAs quantum-well (QW) active layer. SOA allows for tuning bandwidth exceeding 25 nm around 840 nm. Small-signal fiber-to-fiber gain of SOA is around 30 dB. A pair of acousto-optic tunable filters (AOTF) with a quasi-collinear interaction of optical and acoustic waves are utilized as spectrally selective elements. AOTF technology benefits in continuous tuning, broadband operation, excellent reproducibility and stability of the signal, as well as a high accuracy of wavelength selectivity due to the absence of mechanically moving components. A single AOTF configuration has typical linewidth in 0.05-0.15 nm range due to a frequency shift obtained during each roundtrip. A sequential AOTF arrangement enables instantaneous linewidth generation of <0.01 nm by compensating for this shift. Linewidth as narrow as 0.0036 nm is observed at 846 nm wavelength using a scanning Fabry-Perot interferometer with 50 MHz spectral resolution. Output power is in the range of 1 mW. While the majority of commercial tunable sources operate in 1060-1550 nm spectral ranges, the 840 nm spectral range is beneficial for optical coherence tomography (OCT). The developed narrow linewidth laser can be relevant for OCT with extended imaging depth, as well as spectroscopy, non-destructive testing and other applications.

  14. Micron Accurate Absolute Ranging System: Range Extension

    NASA Technical Reports Server (NTRS)

    Smalley, Larry L.; Smith, Kely L.

    1999-01-01

    The purpose of this research is to investigate Fresnel diffraction as a means of obtaining absolute distance measurements with micron or greater accuracy. It is believed that such a system would prove useful to the Next Generation Space Telescope (NGST) as a non-intrusive, non-contact measuring system for use with secondary concentrator station-keeping systems. The present research attempts to validate past experiments and develop ways to apply the phenomena of Fresnel diffraction to micron accurate measurement. This report discusses past research on the phenomena, and the basis of the use Fresnel diffraction distance metrology. The apparatus used in the recent investigations, experimental procedures used, preliminary results are discussed in detail. Continued research and equipment requirements on the extension of the effective range of the Fresnel diffraction systems is also described.

  15. Compressive laser ranging.

    PubMed

    Babbitt, Wm Randall; Barber, Zeb W; Renner, Christoffer

    2011-12-15

    Compressive sampling has been previously proposed as a technique for sampling radar returns and determining sparse range profiles with a reduced number of measurements compared to conventional techniques. By employing modulation on both transmission and reception, compressive sensing in ranging is extended to the direct measurement of range profiles without intermediate measurement of the return waveform. This compressive ranging approach enables the use of pseudorandom binary transmit waveforms and return modulation, along with low-bandwidth optical detectors to yield high-resolution ranging information. A proof-of-concept experiment is presented. With currently available compact, off-the-shelf electronics and photonics, such as high data rate binary pattern generators and high-bandwidth digital optical modulators, compressive laser ranging can readily achieve subcentimeter resolution in a compact, lightweight package.

  16. The temperature dependence of refractive index of hemoglobin at the wavelengths 930 and 1100 nm

    NASA Astrophysics Data System (ADS)

    Lazareva, Ekaterina N.; Tuchin, Valery V.

    2016-04-01

    In this study, the refractive index of hemoglobin was measured at different temperatures within a physiological range and above that is characteristic to light-blood interaction at laser therapy. Measurements were carried out using the multi-wavelength Abbe refractometer (Atago, Japan). The refractive index was measured at two NIR wavelengths of 930 nm and 1100 nm. Samples of hemoglobin solutions with concentration of 80, 120 and 160 g/l were investigated. The temperature was varied between 25 and 55 °C. It was shown that the dependence of the refractive index of hemoglobin is nonlinear with temperature, which may be associated with changes in molecular structure of hemoglobin.

  17. Two-photon absorption and Kerr coefficients of silicon for 850-2200 nm

    NASA Astrophysics Data System (ADS)

    Bristow, Alan D.; Rotenberg, Nir; van Driel, Henry M.

    2007-05-01

    The degenerate two-photon absorption coefficient β and Kerr nonlinearity n2 are measured for bulk Si at 300K using 200fs pulses with carrier wavelength of 850<λ<2200nm for which indirect gap transitions occur. With a broad peak near the indirect gap and maximum value of 2±0.5cm/GW, the dispersion of β compares favorably with theoretical calculations of Garcia and Kalyanaraman [J. Phys. B 39, 2737 (2006)]. Within our wavelength range, n2 varies by a factor of 4 with a peak value of 1.2×10-13cm2/W at λ =1800nm.

  18. Hard-x-ray microscopy with Fresnel zone plates reaches 40 nm Rayleigh resolution

    SciTech Connect

    Chu, Y. S.; Yi, J. M.; De Carlo, F.; Shen, Q.; Lee, Wah-Keat; Wu, H. J.; Wang, C. L.; Wang, J. Y.; Liu, C. J.; Wang, C. H.; Wu, S. R.; Chien, C. C.; Hwu, Y.; Tkachuk, A.; Yun, W.; Feser, M.; Liang, K. S.; Yang, C. S.; Je, J. H.; Margaritondo, G.

    2008-03-10

    Substantial improvements in the nanofabrication and characteristics of gold Fresnel zone plates yielded unprecedented resolution levels in hard-x-ray microscopy. Tests performed on a variety of specimens with 8-10 keV photons demonstrated a first-order lateral resolution below 40 nm based on the Rayleigh criterion. Combined with the use of a phase contrast technique, this makes it possible to view features in the 30 nm range; good-quality images can be obtained at video rate, down to 50 ms/frame. The important repercussions on materials science, nanotechnology, and the life sciences are discussed.

  19. Improved ranging systems

    NASA Technical Reports Server (NTRS)

    Young, Larry E.

    1989-01-01

    Spacecraft range measurements have provided the most accurate tests, to date, of some relativistic gravitational parameters, even though the measurements were made with ranging systems having error budgets of about 10 meters. Technology is now available to allow an improvement of two orders of magnitude in the accuracy of spacecraft ranging. The largest gains in accuracy result from the replacement of unstable analog components with high speed digital circuits having precisely known delays and phase shifts.

  20. Automatic range selector

    DOEpatents

    McNeilly, Clyde E.

    1977-01-04

    A device is provided for automatically selecting from a plurality of ranges of a scale of values to which a meter may be made responsive, that range which encompasses the value of an unknown parameter. A meter relay indicates whether the unknown is of greater or lesser value than the range to which the meter is then responsive. The rotatable part of a stepping relay is rotated in one direction or the other in response to the indication from the meter relay. Various positions of the rotatable part are associated with particular scales. Switching means are sensitive to the position of the rotatable part to couple the associated range to the meter.

  1. Lactones in 193 nm resists: What do they do?

    NASA Astrophysics Data System (ADS)

    Ito, Hiroshi; Truong, Hoa D.; Brock, Phil J.

    2008-03-01

    Lactones are almost ubiquitously employed in 193 nm resists to increase the polarity of hydrophobic alicyclic polymers. What else do lactones do in 193 nm resists? We studied the behavior of methacrylate (MA) resists consisting of different protecting groups, hexafluoroalcohols, and norbornane lactone methacrylate (NLM, 2-oxo-3-oxatricyclo[4.2.1.04,8]nonan-5-yl methacrylate). When the protecting group is large [ethylcyclooctyl (ECO) and methyladamantyl (MAd)], thinning of the resist film that occurs in highly exposed areas upon postexposure bake (PEB) is significantly smaller than what is expected from the polymer composition. When the concentration of isopropylhexafluoroalcohol methacrylate (iPrHFAMA) is increased in the ECOMA-NLM polymer, the thinning increases and reaches 100% of theory and the ECOMA-norbornenehexafluoroalcohol methacrylate (NBHFAMA) resist loses quantitative thickness in highly-exposed areas upon PEB at 90 °C. This indicates that small lactones which are more basic than esters can trap deprotection fragments especially when the protecting group is large. Such entrapment was detected by IR spectroscopy and also observed at temperatures as high as 200 °C in thermogravimetric analysis (TGA). Incorporation of lactone appears to decrease the bake temperature sensitivity and the sensitivity of the resist perhaps due to trapping of photochemically generated acids by basic lactone. The lactone ring can be hydrolyzed during aqueous base development but does not seem to affect the dissolution rate, indicating that hydrolysis occurs in aqueous base solution after dissolution. Poly(methacrylic acid-NLM) dissolves as fast as poly(methacrylic acid) in 0.26 N tetramethylammonium hydroxide (TMAH) aqueous solution. While exposed P(ECOMA 47-NLM 53) resist dissolves in 0.26 N developer at about the same rate as authentically prepared poly(methacrylic acid 47-NLM 53), the dissolution rate of highly-exposed P(MAdMA 44-NLM 56) resist is much slower, indicating

  2. Laser-Matter Interactions with a 527 nm Drive

    SciTech Connect

    Glenzer, S; Niemann, C; Witman, P; Wegner, P; Mason, D; Haynam, C; Parham, T; Datte, P

    2007-02-16

    The primary goal of this Exploratory Research is to develop an understanding of laser-matter interactions with 527-nm light (2{omega}) for studies of interest to numerous Laboratory programs including inertial confinement fusion (ICF), material strength, radiation transport, and hydrodynamics. In addition, during the course of this work we will develop the enabling technology and prototype instrumentation to diagnose a high fluence laser beam for energy, power, and near field intensity profile at 2{omega}. Through this Exploratory Research we have established an extensive experimental and modeling data base on laser-matter interaction with 527 nm laser light (2{omega}) in plasma conditions of interest to numerous Laboratory programs. The experiments and the laser-plasma interaction modeling using the code pF3D have shown intensity limits and laser beam conditioning requirements for future 2{omega} laser operations and target physics experiments on the National Ignition Facility (NIF). These findings have set requirements for which present radiation-hydrodynamic simulations indicate the successful generation of relevant pressure regimes in future 2{omega} experiments. To allow these experiments on the NIF, optics and optical mounts were prepared for the 18mm Second Harmonic Generation Crystal (SHG crystal) that would provide the desired high conversion efficiency from 1{omega} to 2{omega}. Supporting experimental activities on NIF included high-energy 1{omega} shots at up to 22kJ/beamline (4MJ full NIF 1{omega} equivalent energy) that demonstrated, in excess, the 1{omega} drive capability of the main laser that is required for 2{omega} operations. Also, a very extensive 3{omega} campaign was completed (see ''The National Ignition Facility Laser Performance Status'' UCRL-JRNL-226553) that demonstrated that not only doubling the laser, but also tripling the laser (a much more difficult and sensitive combination) met our model predictions over a wide range of laser

  3. Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

    NASA Astrophysics Data System (ADS)

    Pretel, H.; Oliveira, J. A.; Lizarelli, R. F. Z.; Ramalho, L. T. O.

    2009-02-01

    The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)2), divided in groups of 15 teeth each, and analyzed on 7th, 25th, and 60th day. Group GI - only Ca(OH)2, GII - laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip's area of 0.00785 cm2, power 50 mW, application time 20 s, dose 255 J/cm2, energy 2 J. Teeth were capped with Ca(OH)2, Ca(OH)2 cement and restored with amalgam. All groups presented pulp repair. On 25th day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60th day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm.

  4. Range gated imaging experiments using gated intensifiers

    SciTech Connect

    McDonald, T.E. Jr.; Yates, G.J.; Cverna, F.H.; Gallegos, R.A.; Jaramillo, S.A.; Numkena, D.M.; Payton, J.; Pena-Abeyta, C.R.

    1999-03-01

    A variety of range gated imaging experiments using high-speed gated/shuttered proximity focused microchannel plate image intensifiers (MCPII) are reported. Range gated imaging experiments were conducted in water for detection of submerged mines in controlled turbidity tank test and in sea water for the Naval Coastal Sea Command/US Marine Corps. Field experiments have been conducted consisting of kilometer range imaging of resolution targets and military vehicles in atmosphere at Eglin Air Force Base for the US Air Force, and similar imaging experiments, but in smoke environment, at Redstone Arsenal for the US Army Aviation and Missile Command (AMCOM). Wavelength of the illuminating laser was 532 nm with pulse width ranging from 6 to 12 ns and comparable gate widths. These tests have shown depth resolution in the tens of centimeters range from time phasing reflected LADAR images with MCPII shutter opening.

  5. On high speed transmission with the 850nm VCSELs

    NASA Astrophysics Data System (ADS)

    Turkiewicz, Jarosław P.; Chorchos, Łukasz; Puerta Ramirez, Rafael; Vegas Olmos, Juan Jose; Ledentsov, Nikolay

    2016-09-01

    One of the key research challenges is development of energy efficient high bit rate data interconnects. The most promising solutions are based on 850 nm vertical cavity surface emitting lasers (VCSEL) and multi mode fibre (MMF). In this paper options to realize energy efficient 850 nm data interconnects are discussed and evaluated.

  6. Agriculture, Forestry, Range Resources

    NASA Technical Reports Server (NTRS)

    Crea, W. J., Jr.

    1973-01-01

    Significant results obtained from ERTS-1 observations of agriculture, forestry, and range resources are summarized. Four major parts are covered: (1) crop classification and mensuration; (2) timber and range resources survey and classification; (3) soil survey and mapping; and (4) subdiscipline areas.

  7. Laser ranging data analysis

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Near real-time Lageos laser ranging data are analyzed in terms of range bias, time bias, and internal precision, and estimates for earth orientation parameters X(sub p), Y(sub p), and UT1 are obtained. The results of these analyses are reported in a variety of formats. Copies of monthly summaries from November, 1986 through November, 1987 are included.

  8. Long Range Facilities Planning

    DTIC Science & Technology

    1982-04-01

    Richard Muther range facilities Many alterna- analysis indi- cated that if NASSCO ever expected to surpass its output of the last several years, current...Marine Engineers (SNAME) SP-1 Panel Meeting. The Maritime Administration had Richard Muther (an authority on long range facility planning) address a

  9. High-power, Yb-fiber-laser-pumped, picosecond parametric source tunable across 752-860 nm.

    PubMed

    Kumar, S Chaitanya; Kimmelma, O; Ebrahim-Zadeh, M

    2012-05-01

    We report a stable, high-power source of picosecond pulses in the near-infrared based on intracavity second harmonic generation (SHG) of a MgO:PPLN optical parametric oscillator synchronously pumped at 81 MHz by a mode-locked Yb-fiber laser. By exploiting the large spectral acceptance bandwidth for Type I (oo→e) SHG in β-BaB2O4 and a 5 mm crystal, we have generated picosecond pulses over 752-860 nm spectral range under minimal angle tuning, with as much as 3.5 W of output power at 778 nm and >2  W over 73% of the tuning range, in good beam quality with TEM00 spatial profile and M2<1.4. The SHG output pulses have durations of 15.2 ps, with a spectral bandwidth of ∼3.4  nm at 784 nm. In addition, the oscillator simultaneously provides a signal power of >1  W over 1505-1721 nm (25 THz) and idler power >1.8  W over 2787-3630 nm (25 THz), corresponding to a total (signal plus idler) tuning range of 1059 nm. The SHG, signal, and idler output exhibit passive long-term power stability better than 1.6%, 1.3%, and 1.6% rms, respectively, over 14 h.

  10. Electron beam inspection of 16nm HP node EUV masks

    NASA Astrophysics Data System (ADS)

    Shimomura, Takeya; Narukawa, Shogo; Abe, Tsukasa; Takikawa, Tadahiko; Hayashi, Naoya; Wang, Fei; Ma, Long; Lin, Chia-Wen; Zhao, Yan; Kuan, Chiyan; Jau, Jack

    2012-11-01

    EUV lithography (EUVL) is the most promising solution for 16nm HP node semiconductor device manufacturing and beyond. The fabrication of defect free EUV mask is one of the most challenging roadblocks to insert EUVL into high volume manufacturing (HVM). To fabricate and assure the defect free EUV masks, electron beam inspection (EBI) tool will be likely the necessary tool since optical mask inspection systems using 193nm and 199nm light are reaching a practical resolution limit around 16nm HP node EUV mask. For production use of EBI, several challenges and potential issues are expected. Firstly, required defect detection sensitivity is quite high. According to ITRS roadmap updated in 2011, the smallest defect size needed to detect is about 18nm for 15nm NAND Flash HP node EUV mask. Secondly, small pixel size is likely required to obtain the high sensitivity. Thus, it might damage Ru capped Mo/Si multilayer due to accumulated high density electron beam bombardments. It also has potential of elevation of nuisance defects and reduction of throughput. These challenges must be solved before inserting EBI system into EUV mask HVM line. In this paper, we share our initial inspection results for 16nm HP node EUV mask (64nm HP absorber pattern on the EUV mask) using an EBI system eXplore® 5400 developed by Hermes Microvision, Inc. (HMI). In particularly, defect detection sensitivity, inspectability and damage to EUV mask were assessed. As conclusions, we found that the EBI system has capability to capture 16nm defects on 64nm absorber pattern EUV mask, satisfying the sensitivity requirement of 15nm NAND Flash HP node EUV mask. Furthermore, we confirmed there is no significant damage to susceptible Ru capped Mo/Si multilayer. We also identified that low throughput and high nuisance defect rate are critical challenges needed to address for the 16nm HP node EUV mask inspection. The high nuisance defect rate could be generated by poor LWR and stitching errors during EB writing

  11. Home range and travels

    USGS Publications Warehouse

    Stickel, L.F.; King, John A.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  12. Thin bilayer resists for 193-nm and future photolithography II

    NASA Astrophysics Data System (ADS)

    Hishiro, Yoshi; Hyatt, Michael

    2007-03-01

    Bilayer, Si-containing resists are a technique of interest and a strong candidate to replace chemical vapor deposition (CVD) hardmask processes for small critical dimensions (CDs). Previously, we proposed a very thin film approach using bilayer resists for future lithography, defined the requirements for the resists, and demonstrated 55nm transferred patterns with high aspect ratios using 2-beam interferometer exposure. In this paper, we have demonstrated smaller-than- 60nm transferred patterns with a high numerical aperture (NA) scanner, as well as 45nm and 40nm transferred patterns with a 2-beam system using a 20% Si-containing thin bilayer resist. Immersion scanner exposure and a 35nm CD with 2- beam system were also studied.

  13. Applications of the 308-nm excimer laser in dermatology

    NASA Astrophysics Data System (ADS)

    Farkas, A.; Kemeny, L.

    2006-05-01

    Excimer lasers contain a mixture of a noble inert gas and a halogen, which form excited dimers only in the activated state. High-energy current is used to produce these dimers, which have a very short lifetime, and after their fast dissociation they release the excitation energy through ultraviolet photons. The application of these lasers proved to be successful in medicine, including the field of ophthalmology, cardiology, angiology, dentistry, orthopaedics, and, in recent years, dermatology. For medical purposes, the 193-nm argon fluoride, the 248-nm krypton fluoride, the 351-nm xenon fluoride, and the 308-nm xenon chloride lasers are used. Recently, the 308-nm xenon chloride laser has gained much attention as a very effective treatment modality in dermatological disorders. It was successfully utilized in psoriasis; later, it proved to be useful in handling other lightsensitive skin disorders and even in the treatment of allergic rhinitis. This review summarizes the possible applications of this promising tool in dermatology.

  14. Imaging budgets for EUV optics: ready for 22-nm node and beyond

    NASA Astrophysics Data System (ADS)

    Bienert, Marc; Göhnemeier, Aksel; Natt, Oliver; Lowisch, Martin; Gräupner, Paul; Heil, Tilmann; Garreis, Reiner; van Ingen Schenau, Koen; Hansen, Steve

    2009-03-01

    We derive an imaging budget from the performance of EUV optics with NA = 0.32, and demonstrate that the 22nm node requirements are met. Based on aerial image simulations, we analyze the impact of all relevant contributors, ranging from conventional quantities, like straylight or aberrations, to EUV-specific topics, namely influence of 3D mask effects and facetted illumination pupils. As test structures we consider dense to isolated lines, contact holes, and 2D elbows. We classify the contributions in a hierarchical order according to their weight in the CDU budget and identify the main drivers. The underlying physical mechanisms causing different contributions to be critical or less significant are clarified. Finally, we give an outlook for the 16nm and 11nm nodes. Future developments in optics manufacturing will keep the budgets controlled, thereby paving the way to enable printing of these upcoming nodes.

  15. Diffuse optical characterization of collagen absorption from 500 to 1700 nm

    NASA Astrophysics Data System (ADS)

    Sekar, Sanathana Konugolu Venkata; Bargigia, Ilaria; Mora, Alberto Dalla; Taroni, Paola; Ruggeri, Alessandro; Tosi, Alberto; Pifferi, Antonio; Farina, Andrea

    2017-01-01

    Reduction in scattering, high absorption, and spectral features of tissue constituents above 1000 nm could help in gaining higher spatial resolution, penetration depth, and specificity for in vivo studies, opening possibilities of near-infrared diffuse optics in tissue diagnosis. We present the characterization of collagen absorption over a broadband range (500 to 1700 nm) and compare it with spectra presented in the literature. Measurements were performed using a time-domain diffuse optical technique. The spectrum was extracted by carefully accounting for various spectral distortion effects, due to sample and system properties. The contribution of several tissue constituents (water, lipid, collagen, oxy, and deoxy-hemoglobin) to the absorption properties of a collagen-rich in vivo bone location, such as radius distal in the 500- to 1700-nm wavelength region, is also discussed, suggesting bone diagnostics as a potential area of interest.

  16. Broadly tunable (440-670 nm) solid-state organic laser with disposable capsules

    NASA Astrophysics Data System (ADS)

    Mhibik, Oussama; Leang, Tatiana; Siove, Alain; Forget, Sébastien; Chénais, Sébastien

    2013-01-01

    An innovative concept of thin-film organic solid-state laser is proposed, with diffraction-limited output and a broad tuning range covering the visible spectrum under UV optical pumping. The laser beam is tunable over 230 nm, from 440 to 670 nm, with a 3 nm full width at half maximum typical spectral width. The structure consists of a compact fixed bulk optical cavity, a polymeric intracavity etalon for wavelength tuning, as well as five different disposable glass slides coated with a dye-doped polymer film, forming a very simple and low-cost gain medium. The use of interchangeable/disposable "gain capsules" is an alternative solution to photodegradation issues, since gain chips can be replaced without realignment of the cavity. The laser lifetime of a single chip in ambient conditions and without encapsulation was extrapolated to be around 107 pulses at a microjoule energy-per-pulse level.

  17. Temporal characteristics of the solar UV flux and He I line at 1083 nm

    NASA Technical Reports Server (NTRS)

    Donnelly, R. F.; Repoff, T. P.; Harvey, J. W.; Heath, D. F.

    1985-01-01

    It is pointed out that the solar UV flux in the 170- to 210-nm range is important because it photodissociates O2 in the terrestrial atmosphere and thereby initiates the production of ozone and other odd-oxygen chemistry in the stratosphere. The 210- to 290-nm solar UV flux heats the stratosphere. There is consequently a great interest in the temporal variations of the solar UV flux and its relation to ground-based measures of solar activity which may be useful in estimating the UV flux variations. The present investigation is concerned with daily values of 205-nm solar UV flux data measured with the aid of the Nimbus 7 satellite during the period from November 1978 to November 1982, taking into account also measurements of the equivalent width of the He I solar absorption line at 1083 at the National Solar Observatory. Attention is given to an analysis of the data, episodes of activity, and long-term variations.

  18. Range Safety Systems

    NASA Technical Reports Server (NTRS)

    Schrock, Kenneth W.; Humphries, Ricky H. (Technical Monitor)

    2002-01-01

    The high kinetic and potential energy of a launch vehicle mandates there be a mechanism to minimize possible damage to provide adequate safety for the launch facilities, range, and, most importantly, the general public. The Range Safety System, sometimes called the Flight Termination System or Flight Safety System, provides the required level of safety. The Range Safety System section of the Avionics chapter will attempt to describe how adequate safety is provided, the system's design, operation, and it's interface with the rest of the launch vehicle.

  19. Challenges in the Plasma Etch Process Development in the sub-20nm Technology Nodes

    NASA Astrophysics Data System (ADS)

    Kumar, Kaushik

    2013-09-01

    For multiple generations of semiconductor technologies, RF plasmas have provided a reliable platform for critical and non-critical patterning applications. The electron temperature of processes in a RF plasma is typically several electron volts. A substantial portion of the electron population is within the energy range accessible for different types of electron collision processes, such as electron collision dissociation and dissociative electron attachment. When these electron processes occur within a small distance above the wafer, the neutral species, radicals and excited molecules, generated from these processes take part in etching reactions impacting selectivity, ARDE and micro-loading. The introduction of finFET devices at 22 nm technology node at Intel marks the transition of planar devices to 3-dimensional devices, which add to the challenges to etch process in fabricating such devices. In the sub-32 nm technology node, Back-end-of-the-line made a change with the implementation of Trench First Metal Hard Mask (TFMHM) integration scheme, which has hence gained traction and become the preferred integration of low-k materials for BEOL. This integration scheme also enables Self-Aligned Via (SAV) patterning which prevents via CD growth and confines via by line trenches to better control via to line spacing. In addition to this, lack of scaling of 193 nm Lithography and non-availability of EUV based lithography beyond concept, has placed focus on novel multiple patterning schemes. This added complexity has resulted in multiple etch schemes to enable technology scaling below 80 nm Pitches, as shown by the memory manufacturers. Double-Patterning and Quad-Patterning have become increasingly used techniques to achieve 64 nm, 56 nm and 45 nm Pitch technologies in Back-end-of-the-line. Challenges associated in the plasma etching of these multiple integration schemes will be discussed in the presentation. In collaboration with A. Ranjan, TEL Technology Center, America

  20. Wavelength dependence on the forensic analysis of glass by nanosecond 266 nm and 1064 nm laser induced breakdown spectroscopy

    SciTech Connect

    Cahoon, Erica M.; Almirall, Jose R.

    2010-05-01

    Laser induced breakdown spectroscopy can be used for the chemical characterization of glass to provide evidence of an association between a fragment found at a crime scene to a source of glass of known origin. Two different laser irradiances, 266 nm and 1064 nm, were used to conduct qualitative and quantitative analysis of glass standards. Single-pulse and double-pulse configurations and lens-to-sample-distance settings were optimized to yield the best laser-glass coupling. Laser energy and acquisition timing delays were also optimized to result in the highest signal-to-noise ratio corresponding to the highest precision and accuracy. The crater morphology was examined and the mass removed was calculated for both the 266 nm and 1064 nm irradiations. The analytical figures of merit suggest that the 266 nm and 1064 nm wavelengths are capable of good performance for the forensic chemical characterization of glass. The results presented here suggest that the 266 nm laser produces a better laser-glass matrix coupling, resulting in a better stoichiometric representation of the glass sample. The 266 nm irradiance is therefore recommended for the forensic analysis and comparison of glass samples.

  1. Variation of cell spreading on TiO2 film modified by 775 nm and 388 nm femtosecond laser irradiation

    NASA Astrophysics Data System (ADS)

    Tsukamoto, M.; Shinonaga, T.; Sato, Y.; Chen, P.; Nagai, A.; Hanawa, T.

    2014-03-01

    Titanium (Ti) is one of the most used biomaterials in metals. However, Ti is typically artificial materials. Thus, it is necessary for improving the biocompatibility of Ti. Recently, coating of the titanium dioxides (TiO2) film on Ti plate has been proposed to improve biocompatibility of Ti. We have developed coating method of the film on Ti plate with an aerosol beam. Periodic structures formation on biomaterials was also a useful method for improving the biocompatibility. Direction of cell spreading might be controlled along the grooves of periodic microstructures. In our previous study, periodic nanostructures were formed on the film by femtosecond laser irradiation at fundamental wave (775 nm). Period of the periodic nanostructures was about 230 nm. In cell test, cell spreading along the grooves of the periodic nanostructures was observed although it was not done for the film without the periodic nanostructures. Then, influence of the period of the periodic nanostructures on cell spreading has not been investigated yet. The period might be changed by changing the laser wavelength. In this study, the periodic nanostructures were created on the film with femtosecond laser at 775nm and 388 nm, respectively. After cell test, cell spreading along the grooves of the periodic nanostructures was observed on 775 nm and 388nm laser irradiated areas. Distribution of direction of cell spreading on laser irradiated area was also examined. These results suggested that controlling the cell spreading on periodic nanostructures with period of 230 nm was better than that with period of 130 nm.

  2. A continuous wave 10 W cryogenic fiber amplifier at 1015 nm and frequency quadrupling to 254 nm.

    PubMed

    Steinborn, R; Koglbauer, A; Bachor, P; Diehl, T; Kolbe, D; Stappel, M; Walz, J

    2013-09-23

    A stable, continuous wave, single frequency fiber amplifier system at 1015 nm with 10 W output power is presented. It is based on a large mode double clad fiber cooled to liquid nitrogen temperature. The amplified light is frequency quadrupled to 254 nm and used for spectroscopy of the 6¹S → 6³P transition in mercury.

  3. Portable Raman spectroscopy using retina-safe (1550 nm) laser excitation

    NASA Astrophysics Data System (ADS)

    Brouillette, Carl; Smith, Wayne; Donahue, Michael; Huang, Hermes; Shende, Chetan; Sengupta, Atanu; Inscore, Frank; Patient, Michael; Farquharson, Stuart

    2012-06-01

    The use of portable Raman analyzers to identify unknown substances in the field has grown dramatically during the past decade. Measurements often require the laser beam to exit the confines of the sample compartment, which increases the potential of eye or skin damage. This is especially true for most commercial analyzers, which use 785 nm laser excitation. To overcome this safety concern, we have built a portable FT-Raman analyzer using a 1550 nm retina-safe excitation laser. Excitation at 1550 nm falls within the 1400 to 2000 nm retina-safe range, so called because the least amount of damage to the eye occurs in this spectral region. In contrast to wavelengths below 1400 nm, the retina-safe wavelengths are not focused by the eye, but are absorbed by the cornea, aqueous and vitreous humor. Here we compare the performance of this system to measurements of explosives at shorter wavelengths, as well as its ability to measure surface-enhanced Raman spectra of several chemicals, including the food contaminant melamine.

  4. Ultralow-Power Electronic Trapping of Nanoparticles with Sub-10 nm Gold Nanogap Electrodes.

    PubMed

    Barik, Avijit; Chen, Xiaoshu; Oh, Sang-Hyun

    2016-10-12

    We demonstrate nanogap electrodes for rapid, parallel, and ultralow-power trapping of nanoparticles. Our device pushes the limit of dielectrophoresis by shrinking the separation between gold electrodes to sub-10 nm, thereby creating strong trapping forces at biases as low as the 100 mV ranges. Using high-throughput atomic layer lithography, we manufacture sub-10 nm gaps between 0.8 mm long gold electrodes and pattern them into individually addressable parallel electronic traps. Unlike pointlike junctions made by electron-beam lithography or larger micron-gap electrodes that are used for conventional dielectrophoresis, our sub-10 nm gold nanogap electrodes provide strong trapping forces over a mm-scale trapping zone. Importantly, our technology solves the key challenges associated with traditional dielectrophoresis experiments, such as high voltages that cause heat generation, bubble formation, and unwanted electrochemical reactions. The strongly enhanced fields around the nanogap induce particle-transport speed exceeding 10 μm/s and enable the trapping of 30 nm polystyrene nanoparticles using an ultralow bias of 200 mV. We also demonstrate rapid electronic trapping of quantum dots and nanodiamond particles on arrays of parallel traps. Our sub-10 nm gold nanogap electrodes can be combined with plasmonic sensors or nanophotonic circuitry, and their low-power electronic operation can potentially enable high-density integration on a chip as well as portable biosensing.

  5. Dual-layer dye-filled developer-soluble BARCs for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Meador, James D.; Beaman, Carol; Stroud, Charlyn; Lowes, Joyce A.; Zhu, Zhimin; Guerrero, Douglas J.; Mercado, Ramil-Marcelo L.; Drain, David

    2008-03-01

    A family of dye-filled developer-soluble bottom anti-reflective coatings (BARCs) has been developed for use in 193-nm microlithography. This new dye-filled chemical platform easily provides products covering a wide range of optical properties. The light-sensitive and positive-working BARCs use a transparent polymeric binder and a polymeric dye in a thermally crosslinking formulation, with the cured products then being photochemically decrosslinked prior to development. The cured BARC films are imaged and removed with developer in the same steps as the covering photoresist. Two dye-filled BARCs with differing optical properties were developed via a series of DOEs and then used as a dual-layer BARC stack. Lithography with this BARC stack, using a 193-nm resist, gave 150-nm L/S (1:1). A 193-nm dual-layer BARC stack (gradient optical properties) from the well-established dye-attached family of light-sensitive BARCs also gave 150-nm L/S (1:1) with the same resist. However, the latter provided much improved line shape with no scumming. The targeted application for light-sensitive dual-layer BARCs is high-numerical aperture (NA) immersion lithography where a single-layer BARC will not afford the requisite reflection control.

  6. O2 absorption cross sections /187-225 nm/ from stratospheric solar flux measurements

    NASA Astrophysics Data System (ADS)

    Herman, J. R.; Mentall, J. E.

    1982-10-01

    The absorption cross sections of molecular oxygen are calculated in the wavelength range from 187 to 230 nm from solar flux measurements obtained within the stratosphere. Within the Herzberg continuum wavelength region the molecular oxygen cross sections are found to be about 30% smaller than the laboratory results of Shardanand and Rao (1977) from 200 to 210 nm and about 50% smaller than those of Hasson and Nicholls (1971). At wavelengths longer than 210 nm the cross sections agree with those of Shardanand and Rao. The effective absorption cross sections of O2 in the Schumann-Runge band region from 187 to 200 nm are calculated and compared to the empirical fit given by Allen and Frederick (1982). The calculated cross sections indicate that the transmissivity of the atmosphere may be underestimated by the use of the Allen and Frederic cross sections between 195 and 200 nm. The ozone column content between 30 and 40 km and the relative ozone cross sections are determined from the same solar flux data set.

  7. O2 absorption cross sections /187-225 nm/ from stratospheric solar flux measurements

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Mentall, J. E.

    1982-01-01

    The absorption cross sections of molecular oxygen are calculated in the wavelength range from 187 to 230 nm from solar flux measurements obtained within the stratosphere. Within the Herzberg continuum wavelength region the molecular oxygen cross sections are found to be about 30% smaller than the laboratory results of Shardanand and Rao (1977) from 200 to 210 nm and about 50% smaller than those of Hasson and Nicholls (1971). At wavelengths longer than 210 nm the cross sections agree with those of Shardanand and Rao. The effective absorption cross sections of O2 in the Schumann-Runge band region from 187 to 200 nm are calculated and compared to the empirical fit given by Allen and Frederick (1982). The calculated cross sections indicate that the transmissivity of the atmosphere may be underestimated by the use of the Allen and Frederic cross sections between 195 and 200 nm. The ozone column content between 30 and 40 km and the relative ozone cross sections are determined from the same solar flux data set.

  8. A cesium bromide photocathode excited by 405 nm radiation

    SciTech Connect

    Maldonado, J. R.; Cheng, Y. T.; Pease, Fabian W.; Hesselink, L.; Pianetta, P.

    2014-07-14

    In several applications, such as electron beam lithography and X-ray differential phase contrast imaging, there is a need for a free electron source with a current density at least 10 A/cm{sup 2} yet can be shaped with a resolution down to 20 nm and pulsed. Additional requirements are that the source must operate in a practical demountable vacuum (>1e-9 Torr) and be reasonably compact. In prior work, a photocathode comprising a film of CsBr on metal film on a sapphire substrate met the requirements except it was bulky because it required a beam (>10 W/cm{sup 2}) of 257 nm radiation. Here, we describe an approach using a 405 nm laser which is far less bulky. The 405 nm laser, however, is not energetic enough to create color centers in CsBr films. The key to our approach is to bombard the CsBr film with a flood beam of about 1 keV electrons prior to operation. Photoelectron efficiencies in the range of 100–1000 nA/mW were demonstrated with lifetimes exceeding 50 h between electron bombardments. We suspect that the electron bombardment creates intraband color centers whence electrons can be excited by the 405 nm photons into the conduction band and thence into the vacuum.

  9. Fabrication of 30 nm inter-electrode gap co-planar tunnel junctions with buried electrodes

    NASA Astrophysics Data System (ADS)

    Itoua, S.; Joachim, C.; Rousset, B.; Fabre, N.

    1994-05-01

    Co-planar tunnel junctions with a gap length in the 30 nm range have been fabricated using a 20 keV scanning electron microscope and a Au-Pd lift-off. The junction electrodes are less than 200 nm in width and are buried in the SiO2 substrate. This makes the gap surface accessible for atomic force microscope characterization and for local modification. Des jonctions tunnels co-planaires avec une largeur de coupure inférieure à 30 nm ont été fabriquées en utilisant un masqueur électronique à 20 keV et un procédé de lift-off d'un alliage Au-Pd. Les électrodes de la jonction ont moins de 200 nm de largeur et sont enterrées à la surface de SiO2. La mesure de la topographie de la surface de la coupure avec un microscope à force atomique montre une rugosité de moins de 1 nm.

  10. Preliminary error budget for an optical ranging system: Range, range rate, and differenced range observables

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Finger, M. H.

    1990-01-01

    Future missions to the outer solar system or human exploration of Mars may use telemetry systems based on optical rather than radio transmitters. Pulsed laser transmission can be used to deliver telemetry rates of about 100 kbits/sec with an efficiency of several bits for each detected photon. Navigational observables that can be derived from timing pulsed laser signals are discussed. Error budgets are presented based on nominal ground stations and spacecraft-transceiver designs. Assuming a pulsed optical uplink signal, two-way range accuracy may approach the few centimeter level imposed by the troposphere uncertainty. Angular information can be achieved from differenced one-way range using two ground stations with the accuracy limited by the length of the available baseline and by clock synchronization and troposphere errors. A method of synchronizing the ground station clocks using optical ranging measurements is presented. This could allow differenced range accuracy to reach the few centimeter troposphere limit.

  11. EUV reticle inspection with a 193nm reticle inspector

    NASA Astrophysics Data System (ADS)

    Broadbent, William; Inderhees, Gregg; Yamamoto, Tetsuya; Lee, Isaac; Lim, Phillip

    2013-06-01

    The prevailing industry opinion is that EUV Lithography (EUVL) will enter High Volume Manufacturing (HVM) in the 2015 - 2017 timeframe at the 16nm HP node. Every year the industry assesses the key risk factors for introducing EUVL into HVM - blank and reticle defects are among the top items. To reduce EUV blank and reticle defect levels, high sensitivity inspection is needed. To address this EUV inspection need, KLA-Tencor first developed EUV blank inspection and EUV reticle inspection capability for their 193nm wavelength reticle inspection system - the Teron 610 Series (2010). This system has become the industry standard for 22nm / 3xhp optical reticle HVM along with 14nm / 2xhp optical pilot production; it is further widely used for EUV blank and reticle inspection in R and D. To prepare for the upcoming 10nm / 1xhp generation, KLA-Tencor has developed the Teron 630 Series reticle inspection system which includes many technical advances; these advances can be applied to both EUV and optical reticles. The advanced capabilities are described in this paper with application to EUV die-to-database and die-to-die inspection for currently available 14nm / 2xhp generation EUV reticles. As 10nm / 1xhp generation optical and EUV reticles become available later in 2013, the system will be tested to identify areas for further improvement with the goal to be ready for pilot lines in early 2015.

  12. Sub-30-nm defect removal on EUV substrates

    NASA Astrophysics Data System (ADS)

    Rastegar, Abbas; Eichenlaub, Sean; Kadaksham, Arun John; House, Matt; Cha, Brian; Yun, Henry

    2009-01-01

    Naturally occurring sub 30 nm defects on quartz and Low Thermal Expansion Material (LTEM) substrates were characterized by using Atomic Force Microscope(AFM). Our data indicates that a majority of defects on the incoming substrate are hard defects including large, flat particles with a height less than 5 nm, tiny particles with a size of 10 nm to 30 nm SEVD and pits with a depth of about 9 nm. All the soft particles added by handling with sizes of >50 nm can be removed with a single cleaning process. At least four cleaning cycles are required to remove all of the remaining embedded particles. However, after particle removal in their initial location a shallow pit remains. Based on detailed characterization of defect and surface by AFM, we propose that these hard particles are added during the glass polishing step and therefore it is important to revisit the glass Chemical Mechanical Polishing (CMP) processes and optimize them for defect reduction. A qualitative value for particle removal efficiency (PRE) of >99% was obtained for 20 nm Poly Styrene Latex Sphere (PSL) deposited particles on surface of glass.

  13. (abstract) Determination of the Specific Heat and Total Hemispherical Total Emissivity of the Highly Undercooled Zr(sub 41.2)Ti(sub 13.8)Cu(sub 12.5)Ni(sub 10.0)Be(sub 22.5) Alloy

    NASA Technical Reports Server (NTRS)

    Busch, R.; Kim, Y. J.; Johnson, W. L.; Rulison, A. J.; Rhim, W. K.

    1995-01-01

    High temperature high vacuum electrostatic levitation was combined with DSC experiments to determine the specific heat C(sub p) of the undercooled Zr(sub 41.2)Ti(sub 13.8)Cu(sub 12.5)Ni(sub 10.0)Be(sub 22.5) liquid as a function of temperature. The containerless approach made it possible to undercool the melt to the glass transition temperature without inducing nucleation. Because the cooling process was purely radiative, noncontact temperature measurement techniques could be used to determine the specific heat to total hemispherical emissivity ratio, C(sub p)/epsilon(sub t), for the undercooled liquid region. Using C(sub p) values which were independently obtained by DSC, epsilon(sub t) could be determined. With knowledge of C(sub p) of the undercooled liquid it was possible to determine other thermodynamic properties such as Gibbs free energy and entropy as a function of undercooling.

  14. Photomask technology for 32nm node and beyond

    NASA Astrophysics Data System (ADS)

    Hikichi, Ryugo; Ishii, Hiroyuki; Migita, Hidekazu; Kakehi, Noriko; Shimizu, Mochihiro; Takamizawa, Hideyoshi; Nagano, Tsugumi; Hashimoto, Masahiro; Iwashita, Hiroyuki; Suzuki, Toshiyuki; Hosoya, Morio; Ohkubo, Yasushi; Ushida, Masao; Mitsui, Hideaki

    2008-05-01

    193nm-immersion lithography is the most promising technology for 32nm-node device fabrication. At the 32nm technology-node, the performance of photomasks, not only phase-shift masks but also binary masks, needs to be improved, especially in "resolution" and "CD accuracy". To meet sub-100nm resolution with high precision, further thinning of resist thickness will be needed. To improve CD performance, we have designed a new Cr-on-glass (COG) blank for binary applications, having OD-3 at 193nm. This simple Cr structure can obtain superior performance with the conventional mask-making process. Since the hardmask concept is one of the alternative solutions, we have also designed a multilayered binary blank. The new COG blank (NTARC) was fully dry-etched with over 25% shorter etching time than NTAR7, which is a conventional COG blank. Thinner resist (up to 200nm) was possible for NTARC. NTARC with 200nm-thick resist showed superior resolution and CD linearity in all pattern categories. On the other hand, the multilayered binary stack gives us a wide etching margin for several etching steps. Super thin resist (up to 100nm) was suitable by using a Cr-hardmask on a MoSi-absorber structure (COMS). The COMS blanks showed superior performance, especially in tiny clear patterns, such as the isolated hole pattern. We confirmed that these new photomask blanks, NTARC and COMS, will meet the requirements for 32nm-node and beyond, for all aspects of mask-making.

  15. The research progress of metrological 248nm deep ultraviolent microscope inspection device

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-xin; Li, Qi; Gao, Si-tian; Shi, Yu-shu; Li, Wei; Li, Shi

    2016-01-01

    In lithography process, the precision of wafer pattern to a large extent depends on the geometric dimensioning and tolerance of photomasks when accuracy of lithography aligner is certain. Since the minimum linewidth (Critical Dimension) of the aligner exposing shrinks to a few tens of nanometers in size, one-tenth of tolerance errors in fabrication may lead to microchip function failure, so it is very important to calibrate these errors of photomasks. Among different error measurement instruments, deep ultraviolent (DUV) microscope because of its high resolution, as well as its advantages compared to scanning probe microscope restrained by measuring range and scanning electron microscope restrained by vacuum environment, makes itself the most suitable apparatus. But currently there is very few DUV microscope adopting 248nm optical system, means it can attain 80nm resolution; furthermore, there is almost no DUV microscope possessing traceable calibration capability. For these reason, the National Institute of Metrology, China is developing a metrological 248nm DUV microscope mainly consists of DUV microscopic components, PZT and air supporting stages as well as interferometer calibration framework. In DUV microscopic component, the Köhler high aperture transmit condenser, DUV splitting optical elements and PMT pinhole scanning elements are built. In PZT and air supporting stages, a novel PZT actuating flexural hinge stage nested separate X, Y direction kinematics and a friction wheel driving long range air supporting stage are researched. In interferometer framework, a heterodyne multi-pass interferometer measures XY axis translation and Z axis rotation through Zerodur mirror mounted on stage. It is expected the apparatus has the capability to calibrate one dimensional linewidths and two dimensional pitches ranging from 200nm to 50μm with expanded uncertainty below 20nm.

  16. Remote Raman spectra of benzene obtained from 217 meters using a single 532 nm laser pulse.

    PubMed

    Chen, Teng; Madey, John M J; Price, Frank M; Sharma, Shiv K; Lienert, Barry

    2007-06-01

    This report describes a mobile Raman lidar system that has been developed for spectral measurements of samples located remotely at ranges of hundreds of meters. The performance of this system has been quantitatively verified in a lidar calibration experiment using a hard target of standardized reflectance. A new record in detection range was achieved for remote Raman systems using 532 nm laser excitation. Specifically, Raman spectra of liquid benzene were measured with an integration time corresponding to a single 532 nm laser pulse at a distance of 217 meters. The single-shot Raman spectra at 217 meters demonstrated high signal-to-noise ratio and good resolution sufficient for the unambiguous identification of the samples of interest. The transmitter consists of a 20 Hz Nd:YAG laser emitting at 532 nm and 1064 nm and a 178 mm telescope through the use of which allows the system to produce a focused beam at the target location. The receiver consists of a large custom telescope (609 mm aperture) and a Czerny-Turner monochromator equipped with two fast photomultiplier tubes.

  17. EUV mask inspection study for sub-20nm device

    NASA Astrophysics Data System (ADS)

    Shin, Inkyun; Yoon, Gisung; Na, Ji Hoon; Chung, Paul D. H.; Jeon, Chan-Uk

    2012-11-01

    Reflected light inspection has been used to inspect EUVL mask which consists of multi layers and metal absorber. However, sub-wavelength half pitch patterns and reflected inspection make unprecedented phenomenon like tone inversion. These lead EUV inspection more difficult in detectability and inspectability for separating out defects and false. In this study, we report the evaluation result of inspection dependency of illumination conditions like OAI(Off-Axis Illumination), sigma and polarization for sub-20nm EUVL PDM(programmed defect mask). With inspection of sub- 20nm device mask, we finally address the inspection feasibility for sub-20nm device and the future direction of inspection technology.

  18. 80 nm tunable DBR-free semiconductor disk laser

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Albrecht, A. R.; Cederberg, J. G.; Sheik-Bahae, M.

    2016-07-01

    We report a widely tunable optically pumped distributed Bragg reflector (DBR)-free semiconductor disk laser with 6 W continuous wave output power near 1055 nm when using a 2% output coupler. Using only high reflecting mirrors, the lasing wavelength is centered at 1034 nm and can be tuned up to a record 80 nm by using a birefringent filter. We attribute such wide tunability to the unique broad effective gain bandwidth of DBR-free semiconductor disk lasers achieved by eliminating the active mirror geometry.

  19. High-Performance 1645-nm Er: YAG Laser

    DTIC Science & Technology

    2007-09-25

    laser set-up is shown in Figure 1. An IPG Photonics TEM00 erbium fiber laser , which provided 20 W cw power at 1532.4 nm, was used in these experi...output of the resonantly fiber - laser -pumped Er:AYG laser at 1645 nm using 0.25% doped crystal out- performed the 0.5% doped crystal. In addition to the...the advantages of small quantum defect and small thermal load for the laser materials. High-brightness erbium fiber pump lasers at 1532 nm not only

  20. Comparison of lidar water vapor measurements using Raman scatter at 266 nm and 532 nm

    SciTech Connect

    Balsiger, F.; Philbrick, C.R.

    1996-12-31

    The performance of the Lidar Atmospheric Profile Sensor (LAPS) instrument for measurements of water vapor in the lower troposphere has been investigated. LAPS is an automated lidar system that measures water vapor from the vibrational Raman backscatter in the visible and in the ultraviolet wavelength range. The authors present a comparison of water vapor profiles measured with the lidar and balloon sondes as well as measured with the two lidar channels. With the UV channels it is possible to infer ozone profiles in the boundary layer. Data are presented that reveal the high variability of the water vapor in the boundary layer.

  1. Relationship between shelf-life and optical properties of Yuanhuang pear in the region of 400-1150 nm

    NASA Astrophysics Data System (ADS)

    He, Xueming; Fu, Xiaping; Rao, Xiuqin; Fang, Zhenhuan

    2016-05-01

    The main goals of this study are to investigate the potential of absorption coefficient for the prediction of water contents in `Yuanhuang' pear and analyze the relationship between the shelf-life and bulk optical properties in the range of 900-1050 nm. An automated integrating sphere (AIS) system was used to measure the total reflectance, total transmittance of pear flesh tissues in visible-Near infrared (Vis-NIR) range. These two measurements were used to estimate the absorption coefficient μa and reduced scattering coefficient μ's of pear samples by using an inverse adding doubling (IAD) light propagation model. The detection accuracy of the AIS system was verified by using both liquid (Intralipid-20% as scatterer) and solid phantom (TiO2 as scatterer, carbon black as absorber). The relative error of measurement of μ's of liquid phantom with four different concentration (0.5%,1%,1.5%,2%) at 632.8 nm, 751 nm, 833 nm are less than 10% except for 2% concentration at 833 nm, and the relative error of measurement μa and μ's of solid phantom at 525.4 nm, 632.1 nm, 710.3 nm and 780.1 nm are less than 5% except for the μa at 525.4 nm. A total of 140 samples were used to conduct the moisture measurement, and drying method was used. Predictive models for moisture content from μa data were constructed using partial least squares regression (PLSR). The coefficient of correlation of calibration set (Rc) and validation set (Rp) were 0.50 and 0.45 respectively. The relationship between the shelf-life and optical properties was analyzed by dividing pear samples into three categories according to the actual shelf-life, and calculating classification accuracy by using actual and calculated shelf-life grade.

  2. Measurements of the complex refractive index of volcanic ash at 450, 546.7, and 650 nm

    NASA Astrophysics Data System (ADS)

    Ball, J. G. C.; Reed, B. E.; Grainger, R. G.; Peters, D. M.; Mather, T. A.; Pyle, D. M.

    2015-08-01

    The detection and quantification of volcanic ash is extremely important to the aviation industry, civil defense organizations, and those in peril from volcanic ashfall. To exploit the remote sensing techniques that are used to monitor a volcanic cloud and return information on its properties, the effective complex refractive index of the volcanic ash is required. This paper presents the complex refractive index determined in the laboratory at 450.0 nm, 546.7 nm, and 650.0 nm for volcanic ash samples from eruptions of Aso (Japan), Grímsvötn (Iceland), Chaitén (Chile), Etna (Italy), Eyjafjallajökull (Iceland), Tongariro (New Zealand), Askja (Iceland), Nisyros (Greece), Okmok (Alaska), Augustine (Alaska), and Spurr (Alaska). The Becke line method was used to measure the real part of the refractive index with an accuracy of 0.01. The values measured differed between eruptions and were in the range 1.51-1.63 at 450.0 nm, 1.50-1.61 at 546.7 nm, and 1.50-1.59 at 650.0 nm. A novel method is introduced to derive the imaginary part of the refractive index from the attenuation of light by ash. The method has a precision in the range 10-3-10-4. The values for the ash imaginary refractive index ranged 0.22-1.70 × 10-3 at 450.0 nm, 0.16-1.93 × 10-3 at 546.7 nm, and 0.15-2.08 × 10-3 at 650.0 nm. The accuracy of Becke and attenuation methods was assessed by measuring the complex refractive index of Hoya neutral density glass and found to have an accuracy of <0.01 and <2 × 10-5 for the real and imaginary parts of the refractive index, respectively.

  3. Final Environmental Assessment for the Radar Cross-Section Advanced Measurement Site Comprehensive Project at White Sands Missile Range, NM

    DTIC Science & Technology

    2005-04-01

    with other federal agencies concerning measures to avoid harm to listed species An endangered species is one that is in danger of extinction ...will continue to apply to areas not attaining it. (d) Entire state except for the Pecos- Permian Air Basin (AQCR 155), which includes De Baca, Chaves...Curry, Quay, and Roosevelt Counties. (e) Within the Pecos- Permian Air Basin. m Within corporate limits of municipalities in the Pecos- Permian air

  4. ACTIVE MEDIA: Photoprocesses in laser-active media operating in the 400 nm range. II. Photochemical processes

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Rimma T.; Kopylova, T. N.; Degtyarenko, K. M.; Sergeev, A. K.; Nesterenko, S. N.; Mayer, G. V.; Afanas'ev, N. B.; Vereskun, V. N.

    1996-09-01

    The quantum yield of phototransformations, the relative yields of photoproducts, and the half-life of active media based on 2-4(pyridyl)-5-(4-methophenyl) oxazole (4PyPO) and of the substituted derivatives of dipyrazolinylbenzene (PDPDP) were investigated as a function of the concentration of the solution, the length of the active medium, and the parameters of the pump pulses generated by an XeCl laser. The results obtained are interpreted with the help of the data on the lasing efficiency and on the induced-absorption spectra.

  5. Laser Ranging Simulation Program

    NASA Technical Reports Server (NTRS)

    Piazolla, Sabino; Hemmati, Hamid; Tratt, David

    2003-01-01

    Laser Ranging Simulation Program (LRSP) is a computer program that predicts selected aspects of the performances of a laser altimeter or other laser ranging or remote-sensing systems and is especially applicable to a laser-based system used to map terrain from a distance of several kilometers. Designed to run in a more recent version (5 or higher) of the MATLAB programming language, LRSP exploits the numerical and graphical capabilities of MATLAB. LRSP generates a graphical user interface that includes a pop-up menu that prompts the user for the input of data that determine the performance of a laser ranging system. Examples of input data include duration and energy of the laser pulse, the laser wavelength, the width of the laser beam, and several parameters that characterize the transmitting and receiving optics, the receiving electronic circuitry, and the optical properties of the atmosphere and the terrain. When the input data have been entered, LRSP computes the signal-to-noise ratio as a function of range, signal and noise currents, and ranging and pointing errors.

  6. Wideband thulium-holmium-doped fiber source with combined forward and backward amplified spontaneous emission at 1600-2300  nm spectral band.

    PubMed

    Honzatko, Pavel; Baravets, Yauhen; Kasik, Ivan; Podrazky, Ondrej

    2014-06-15

    We have experimentally demonstrated two extremely wideband amplified spontaneous emission (ASE) sources. High bandwidth is achieved by combining the backward and forward ASEs generated in thulium-holmium-doped fiber using appropriate wideband couplers. The ASE source optimized for flat spectral power density covers a spectral range from 1527 to 2171 nm at a -10  dB level. The ASE source optimized for spectroscopy features an enhancement with respect to single-mode fiber (SMF) coupled halogen lamps within the spectral range from 1540 nm to more than 2340 nm covering the 800 nm bandwidth.

  7. 76 FR 76801 - New Mexico Disaster #NM-00024

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ... Mexico Disaster NM-00024 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a... New Mexico (FEMA- 4047-DR), dated 11/23/2011. Incident: Flooding. Incident Period: 08/19/2011...

  8. Compact frequency-quadrupled pulsed 1030nm fiber laser

    NASA Astrophysics Data System (ADS)

    McIntosh, Chris; Goldberg, Lew; Cole, Brian; DiLazaro, Tom; Hays, Alan D.

    2016-03-01

    A compact 1030nm fiber laser for ultraviolet generation at 257.5nm is presented. The laser employs a short length of highly-doped, large core (20μm), coiled polarization-maintaining ytterbium-doped double-clad fiber pumped by a wavelength-stabilized 975nm diode. It is passively Q-switched via a Cr4+:YAG saturable absorber and generates 2.4W at 1030nm in a 110μJ pulse train. Lithium triborate (LBO) and beta-barium borate (BBO) are used to achieve 325mW average power at the fourth harmonic. The laser's small form factor, narrow linewidth and modest power consumption are suitable for use in a man-portable ultraviolet Raman explosives detection system.

  9. RadNet Air Data From Navajo Lake, NM

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Navajo Lake, NM from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  10. RadNet Air Data From Albuquerque, NM

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Albuquerque, NM from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  11. RadNet Air Data From Carlsbad, NM

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Carlsbad, NM from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  12. Generation of third harmonic picosecond pulses at 355 nm by sum frequency mixing in periodically poled MgSLT crystal

    NASA Astrophysics Data System (ADS)

    Kaltenbach, André; Schönau, Thomas; Lauritsen, Kristian; Tränkle, Günther; Erdmann, Rainer

    2015-02-01

    Third harmonic 355nm picosecond pulses are generated by sum frequency mixing in a periodically poled magnesium doped stoichiometric lithium tantalate (PPMgSLT) crystal. The third harmonic generation is based on the 1064nm radiation of a gain-switched distributed feedback (DFB) diode laser which is amplified by a two-stage fiber amplifier. The diode laser is freely triggerable at variable repetition rates up to 80MHz and provides optical pulses of 65 ps FWHM duration and pulse energies in the range of 5 pJ. The 355nm third harmonic generation is realized in a two-step conversion process. First, the 1064nm fundamental radiation is frequency-doubled to 532 nm, afterwards both frequencies are mixed in the PPMgSLT crystal to 355 nm. The UV-radiation shows a pulse width of 60 ps, a good beam profile and stable pulse energy over a wide range of repetition rates by proprietary pump power management. At 355nm a pulse peak power of 5.3W was achieved with 192W pulse peak power of the fundamental radiation.

  13. Study on damage of K9 glass under 248nm ultraviolet pulsed laser irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Xi; Fang, Xiaodong

    2015-04-01

    The damage of K9 glass under 248nm ultraviolet pulsed laser irradiation was studied. The laser pulse energy was kept within the range of 60mJ to 160mJ, and the repetition rate was adjusted within the range of 1Hz to 40Hz. The damage morphologies of single-pulse and multi-pulse laser irradiation were characterized by optical microscope, and the damage mechanism was discussed. The experimental results indicated that the damage of K9 glass irradiated by 248nm ultraviolet laser mainly followed the thermal-mechanical coupling mechanism and the damage threshold of K9 glass was 2.8J/cm2. The intensity of damage area increased gradually with the increase of the laser pulse number. It was shown that accumulation effect of laser induced damage to K9 glass was obvious.

  14. Note: Broadly tunable all-fiber ytterbium laser with 0.05 nm spectral width based on multimode interference filter

    SciTech Connect

    Mukhopadhyay, Pranab K. Gupta, Pradeep K.; Singh, Amarjeet; Sharma, Sunil K.; Bindra, Kushvinder S.; Oak, Shrikant M.

    2014-05-15

    A multimode interference filter with narrow transmission bandwidth and large self-imaging wavelength interval is constructed and implemented in an ytterbium doped fiber laser in all-fiber format for broad wavelength tunability as well as narrow spectral width of the output beam. The peak transmission wavelength of the multimode interference filter was tuned with the help of a standard in-fiber polarization controller. With this simple mechanism more than 30 nm (1038 nm–1070 nm) tuning range is demonstrated. The spectral width of the output beam from the laser was measured to be 0.05 nm.

  15. Trajectory scoring in rectangular coordinates using transponder-interrogator range and range rate data

    SciTech Connect

    Hollowell, J.

    1989-01-01

    Range and range rate measurements taken from a transponder-interrogator ranging system are processed via an extended Kalman filter and an extended Kalman smoother to provide an accurate time-position history of a vehicle's trajectory by estimating the errors in the vehicle's inertial navigation system. The necessary equations are derived in rectangular coordinates. As such, they are only valid for low altitude flights over a small geographic area. The equations are implemented in a FORTRAN program which is used to process flight data gathered at Edgewood, NM. 5 refs., 65 figs., 3 tabs.

  16. Time-resolved hydrino continuum transitions with cutoffs at 22.8 nm and 10.1 nm

    NASA Astrophysics Data System (ADS)

    Mills, R. L.; Lu, Y.

    2011-09-01

    Spectra of low energy, high current pinch discharges in pure hydrogen, oxygen, nitrogen, and helium were recorded in the EUV region, and continuum radiation was only observed from hydrogen [www.blacklightpower.com/pdf/GEN3_Harvard.pdf; Int. J. Hydrogen Energy 35, 8446 (2010); Cent. Eur. J. Phys. 8, 318 (2010)]. The continuum radiation bands at 10.1 and 22.8 nm and going to longer wavelengths for theoretically predicted transitions of hydrogen to lower-energy, so called "hydrino" states, was observed first at blacklight power, Inc. (BLP) and reproduced at the Harvard center for astrophysics (CfA). Considering the low energy of 5.2 J per pulse, the observed radiation in the energy range of about 120 eV to 40 eV and reference experiments, no conventional explanation was found to be plausible, including electrode metal emission, Bremsstrahlung radiation, ion recombination, molecular or molecular ion band radiation, and instrument artifacts involving radicals and energetic ions reacting at the CCD and H2 re-radiation at the detector chamber. To further study these continuum bands assigned to hydrinos, time resolved spectra were performed that showed a unique delay of the continuum radiation of about 0.1 μs and a duration of < 2 μs following the high-voltage pulse consistent with the mechanism of recombination to form the optimal high-density atomic hydrogen in the pinch that permits the H-H interactions to cause the hydrino transitions and corresponding emission.

  17. Picosecond holmium fibre laser pumped at 1125 \\ {\\text{nm}}

    NASA Astrophysics Data System (ADS)

    Kamynin, V. A.; Filatova, S. A.; Zhluktova, I. V.; Tsvetkov, V. B.

    2016-12-01

    We report a passively mode-locked, all-fibre holmium laser based on nonlinear polarisation rotation. As a pump source use is made of an 1125-{\\text{nm}} ytterbium-doped fibre laser. The pulse repetition rate of the holmium laser is 7.5 {\\text{MHz}}, and the pulse duration does not exceed 52 {\\text{ps}} at wavelengths of 2065 and 2080 {\\text{nm}}. The average laser output power reaches 5 {\\text{mW}}.

  18. Investigation of a Pulsed 1550 nm Fiber Laser System

    DTIC Science & Technology

    2015-12-15

    Jain 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT...14. ABSTRACT There is a strong need for a pulsed laser system at eye safe wavelengths for illuminator applications . High power pulsed 1550 nm fiber...system at eye safe wavelengths for illuminator applications . High power pulsed 1550 nm fiber lasers systems are able to generate, shaped, pulses at

  19. 670-nm light treatment reduces complement propagation following retinal degeneration

    PubMed Central

    2012-01-01

    Aim Complement activation is associated with the pathogenesis of age-related macular degeneration (AMD). We aimed to investigate whether 670-nm light treatment reduces the propagation of complement in a light-induced model of atrophic AMD. Methods Sprague–Dawley (SD) rats were pretreated with 9 J/cm2 670-nm light for 3 minutes daily over 5 days; other animals were sham treated. Animals were exposed to white light (1,000 lux) for 24 h, after which animals were kept in dim light (5 lux) for 7 days. Expression of complement genes was assessed by quantitative polymerase chain reaction (qPCR), and immunohistochemistry. Counts were made of C3-expressing monocytes/microglia using in situ hybridization. Photoreceptor death was also assessed using outer nuclear layer (ONL) thickness measurements, and oxidative stress using immunohistochemistry for 4-hydroxynonenal (4-HNE). Results Following light damage, retinas pretreated with 670-nm light had reduced immunoreactivity for the oxidative damage maker 4-HNE in the ONL and outer segments, compared to controls. In conjunction, there was significant reduction in retinal expression of complement genes C1s, C2, C3, C4b, C3aR1, and C5r1 following 670 nm treatment. In situ hybridization, coupled with immunoreactivity for the marker ionized calcium binding adaptor molecule 1 (IBA1), revealed that C3 is expressed by infiltrating microglia/monocytes in subretinal space following light damage, which were significantly reduced in number after 670 nm treatment. Additionally, immunohistochemistry for C3 revealed a decrease in C3 deposition in the ONL following 670 nm treatment. Conclusions Our data indicate that 670-nm light pretreatment reduces lipid peroxidation and complement propagation in the degenerating retina. These findings have relevance to the cellular events of complement activation underling the pathogenesis of AMD, and highlight the potential of 670-nm light as a non-invasive anti-inflammatory therapy. PMID:23181358

  20. Satellite Laser Ranging operations

    NASA Technical Reports Server (NTRS)

    Pearlman, Michael R.

    1994-01-01

    Satellite Laser Ranging (SLR) is currently providing precision orbit determination for measurements of: 1) Ocean surface topography from satellite borne radar altimetry, 2) Spatial and temporal variations of the gravity field, 3) Earth and ocean tides, 4) Plate tectonic and regional deformation, 5) Post-glacial uplift and subsidence, 6) Variations in the Earth's center-of-mass, and 7) Variations in Earth rotation. SLR also supports specialized programs in time transfer and classical geodetic positioning, and will soon provide precision ranging to support experiments in relativity.

  1. Broad host range plasmids.

    PubMed

    Jain, Aayushi; Srivastava, Preeti

    2013-11-01

    Plasmids are and will remain important cloning vehicles for biotechnology. They have also been associated with the spread of a number of diseases and therefore are a subject of environmental concern. With the advent of sequencing technologies, the database of plasmids is increasing. It will be of immense importance to identify the various bacterial hosts in which the plasmid can replicate. The present review article describes the features that confer broad host range to the plasmids, the molecular basis of plasmid host range evolution, and applications in recombinant DNA technology and environment.

  2. Western Aeronautical Test Range

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert D.

    2008-01-01

    This viewgraph presentation reviews the work of the Western Aeronautical Test Range (WATR). NASA's Western Aeronautical Test Range is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). Maps show the general location of the WATR area that is used for aeronautical testing and evaluation. The products, services and facilities of WATR are discussed,

  3. Cs 728 nm Laser Spectroscopy and Faraday Atomic Filter

    NASA Astrophysics Data System (ADS)

    Liu, Zhong-Zheng; Tao, Zhi-Ming; Jiang, Zhao-Jie; Chen, Jing-Biao

    2014-12-01

    We mainly present the 728 nm laser spectroscopy and Faraday atomic filter of Cs atoms with 650 MHz linewidth and 2.6% transmission based on an electrodeless discharge vapor lamp, compared with Rb 728 nm laser spectroscopy. Accidentally, this remarkably strong Cs 728 nm transition from the 6F7/2 state to the 5D5/2 state is only about 2.5 GHz away from the Rb 728 nm transition of the future potential four-level active optical clock, once laser cooled and trapped from the 7S1/2 state to the 5P1/2 state, as we proposed previously. A Faraday atomic filter stabilized 728 nm laser using a Cs electrodeless discharge vapor lamp with a power of 10mW will provide a frequency reference to evaluate the performance of the potential Rb four-level active optical clock at 728 nm with power less than 1 nW by 2.5 GHz heterodyne measurements.

  4. Electron beam inspection methods for imprint lithography at 32 nm

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta; Thompson, Ecron; Sreenivasan, S. V.; Resnick, Douglas J.

    2009-01-01

    Step and Flash Imprint Lithography redefines nanoimprinting. This novel technique involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed leaving a patterned solid on the substrate. Compatibility with existing CMOS processes requires a mask infrastructure in which resolution, inspection and repair are all addressed. The purpose of this paper is to understand the limitations of inspection at half pitches of 32 nm and below. A 32 nm programmed defect mask was fabricated. Patterns included in the mask consisted of an SRAM Metal 1 cell, dense lines, and dense arrays of pillars. Programmed defect sizes started at 4 nm and increased to 48 nm in increments of 4 nm. Defects in both the mask and imprinted wafers were characterized scanning electron microscopy and the measured defect areas were calculated. These defects were then inspected using a KLA-T eS35 electron beam wafer inspection system. Defect sizes as small as 12 nm were detected, and detection limits were found to be a function of defect type.

  5. Defect inspection of imprinted 32 nm half pitch patterns

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta; Thompson, Ecron; McMackin, Ian; Perez, Joseph; Sreenivasan, S. V.; Resnick, Douglas J.

    2008-10-01

    Step and Flash Imprint Lithography redefines nanoimprinting. This novel technique involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed leaving a patterned solid on the substrate. Compatibility with existing CMOS processes requires a mask infrastructure in which resolution, inspection and repair are all addressed. The purpose of this paper is to understand the limitations of inspection at half pitches of 32 nm and below. A 32 nm programmed defect mask was fabricated. Patterns included in the mask consisted of an SRAM Metal 1 cell, dense lines, and dense arrays of pillars. Programmed defect sizes started at 4 nm and increased to 48 nm in increments of 4 nm. Defects in both the mask and imprinted wafers were characterized scanning electron microscopy and the measured defect areas were calculated. These defects were then inspected using a KLA-T eS35 electron beam wafer inspection system. Defect sizes as small as 12 nm were detected, and detection limits were found to be a function of defect type.

  6. Power scaling of laser diode pumped Pr3+:LiYF4 cw lasers: efficient laser operation at 522.6 nm, 545.9 nm, 607.2 nm, and 639.5 nm.

    PubMed

    Gün, Teoman; Metz, Philip; Huber, Günter

    2011-03-15

    We report efficient cw laser operation of laser diode pumped Pr(3+)-doped LiYF4 crystals in the visible spectral region. Using two InGaN laser diodes emitting at λ(P)=443.9 nm with maximum output power of 1 W each and a 2.9-mm-long crystal with a doping concentration of 0.5%, output powers of 938 mW, 418 mW, 384 mW, and 773 mW were achieved for the laser wavelengths 639.5 nm, 607.2 nm, 545.9 nm, and 522.6 nm, respectively. The maximum absorbed pump powers were approximately 1.5 W, resulting in slope efficiencies of 63.6%, 32.0%, 52.1%, and 61.5%, as well as electro-optical efficiencies of 9.4%, 4.2%, 3.8%, and 7.7%, respectively. Within these experiments, laser diode-pumped laser action at 545.9 nm was demonstrated for what is believed to be the first time.

  7. Magneto-optical trap for metastable helium at 389 nm

    SciTech Connect

    Koelemeij, J.C.J.; Stas, R.J.W.; Hogervorst, W.; Vassen, W.

    2003-05-01

    We have constructed a magneto-optical trap (MOT) for metastable triplet helium atoms utilizing the 2 {sup 3}S{sub 1}{yields}3 {sup 3}P{sub 2} line at 389 nm as the trapping and cooling transition. The far-red-detuned MOT (detuning {delta}=-41 MHz) typically contains few times 10{sup 7} atoms at a relatively high ({approx}10{sup 9} cm{sup -3}) density, which is a consequence of the large momentum transfer per photon at 389 nm and a small two-body loss rate coefficient (2x10{sup -10} cm{sup 3}/s<{beta}<1.0x10{sup -9} cm{sup 3}/s). The two-body loss rate is more than five times smaller than in a MOT on the commonly used 2 {sup 3}S{sub 1}{yields}2 {sup 3}P{sub 2} line at 1083 nm. Furthermore, laser cooling at 389 nm results in temperatures somewhat lower than those achieved using 1083 nm. The 389-nm MOT exhibits small losses due to two-photon ionization, which have been investigated as well.

  8. Agriculture, forestry, range resources

    NASA Technical Reports Server (NTRS)

    Crea, W. J.

    1974-01-01

    In the area of crop specie identification, it has been found that temporal data analysis, preliminary stratification, and unequal probability analysis were several of the factors that contributed to high identification accuracies. Single data set accuracies on fields of greater than 80,000 sq m (20 acres) are in the 70- to 90-percent range; however, with the use of temporal data, accuracies of 95 percent have been reported. Identification accuracy drops off significantly on areas of less than 80,000 sq m (20 acres) as does measurement accuracy. Forest stratification into coniferous and deciduous areas has been accomplished to a 90- to 95-percent accuracy level. Using multistage sampling techniques, the timber volume of a national forest district has been estimated to a confidence level and standard deviation acceptable to the Forest Service at a very favorable cost-benefit time ratio. Range specie/plant community vegetation mapping has been accomplished at various levels of success (69- to 90-percent accuracy). However, several investigators have obtained encouraging initial results in range biomass (forage production) estimation and range readiness predictions. Soil association map correction and soil association mapping in new area appear to have been proven feasible on large areas; however, testing in a complex soil area should be undertaken.

  9. Agriculture, forestry, range resources

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.

    1974-01-01

    The necessary elements to perform global inventories of agriculture, forestry, and range resources are being brought together through the use of satellites, sensors, computers, mathematics, and phenomenology. Results of ERTS-1 applications in these areas, as well as soil mapping, are described.

  10. Front Range Branch Officers

    NASA Astrophysics Data System (ADS)

    The Front Range Branch of AGU has installed officers for 1990: Ray Noble, National Center for Atmospheric Research, chair; Sherry Oaks, U.S. Geological Survey, chair-elect; Howard Garcia, NOAA, treasurer; Catharine Skokan, Colorado School of Mines, secretary. JoAnn Joselyn of NOAA is past chair. Members at large are Wallace Campbell, NOAA; William Neff, USGS; and Stephen Schneider, NCAR.

  11. Nonscanning confocal ranging system

    NASA Astrophysics Data System (ADS)

    Sun, P. C.; Arons, E.

    1995-03-01

    We demonstrate a nonscanning confocal ranging system based on spatially incoherent interferometry. Such a system has significant advantages over the conventional confocal imaging system and other interferometric systems. We develop the theory in terms of coherence cells and demonstrate the equivalence of our method to the conventional confocal methods. Experimental results are also provided.

  12. Electric vehicles: Driving range

    NASA Astrophysics Data System (ADS)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  13. RADIO RANGING DEVICE

    DOEpatents

    Bogle, R.W.

    1960-11-22

    A description is given of a super-regenerative oscillator ranging device provided with radiating and receiving means and being capable of indicating the occurrence of that distance between itself and a reflecting object which so phases the received echo of energy of a preceding emitted oscillation that the intervals between oscillations become uniform.

  14. Long Range Plan.

    ERIC Educational Resources Information Center

    Jefferson Coll., Hillsboro, MO.

    This document presents Jefferson College's "Long Range Plan," which is intended to provide the College's governing board, administration, and faculty and staff with a task-oriented blueprint for maximizing the delivery of higher education services to students and the community in a predictable, programmatic, and fiscally sound manner.…

  15. STDN ranging equipment

    NASA Technical Reports Server (NTRS)

    Jones, C. E.

    1975-01-01

    Final results of the Spaceflight Tracking and Data Network (STDN) Ranging Equipment program are summarized. Basic design concepts and final design approaches are described. Theoretical analyses which define requirements and support the design approaches are presented. Design verification criteria are delineated and verification test results are specified.

  16. Agriculture, forest, and range

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The findings and recommendations of the panel for developing a satellite remote-sensing global information system in the next decade are reported. User requirements were identified in five categories: (1) cultivated crops, (2) land resources, (3)water resources, (4)forest management, and (5) range management. The benefits from the applications of satellite data are discussed.

  17. Fact Sheet: Range Complex

    NASA Technical Reports Server (NTRS)

    Cornelson, C.; Fretter, E.

    2004-01-01

    NASA Ames has a long tradition in leadership with the use of ballistic ranges and shock tubes for the purpose of studying the physics and phenomena associated with hypervelocity flight. Cutting-edge areas of research run the gamut from aerodynamics, to impact physics, to flow-field structure and chemistry. This legacy of testing began in the NACA era of the 1940's with the Supersonic Free Flight Tunnel, and evolved dramatically up through the late 1950s with the pioneering work in the Ames Hypersonic Ballistic Range. The tradition continued in the mid-60s with the commissioning of the three newest facilities: the Ames Vertical Gun Range (AVGR) in 1964, the Hypervelocity Free Flight Facility (HFFF) in 1965 and the Electric Arc Shock Tube (EAST) in 1966. Today the Range Complex continues to provide unique and critical testing in support of the Nation's programs for planetary geology and geophysics; exobiology; solar system origins; earth atmospheric entry, planetary entry, and aerobraking vehicles; and various configurations for supersonic and hypersonic aircraft.

  18. Broadband Fourier domain mode-locked laser for optical coherence tomography at 1060 nm

    NASA Astrophysics Data System (ADS)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang; Torzicky, Teresa; Pircher, Michael; Biedermann, Benjamin R.; Pedersen, Christian; Hitzenberger, Christoph K.; Huber, Robert; Andersen, Peter E.

    2012-01-01

    Optical coherence tomography (OCT) in the 1060nm range is interesting for in vivo imaging of the human posterior eye segment (retina, choroid, sclera) due to low absorption in water and deep penetration into the tissue. Rapidly tunable light sources, such as Fourier domain mode-locked (FDML) lasers, enable acquisition of densely sampled three-dimensional datasets covering a wide field of view. However, semiconductor optical amplifiers (SOAs)-the typical laser gain media for swept sources-for the 1060nm band could until recently only provide relatively low output power and bandwidth. We have implemented an FDML laser using a new SOA featuring broad gain bandwidth and high output power. The output spectrum coincides with the wavelength range of minimal water absorption, making the light source ideal for OCT imaging of the posterior eye segment. With a moderate SOA current (270 mA) we achieve up to 100nm total sweep range and 12 μm depth resolution in air. By modulating the current, we can optimize the output spectrum and thereby improve the resolution to 9 μm in air (~6.5 μm in tissue). The average output power is higher than 20mW. Both sweep directions show similar performance; hence, both can be used for OCT imaging. This enables an A-scan rate of 350 kHz without buffering the light source output.

  19. Orthogonally polarized dual-wavelength Nd:LuVO4 laser at 1086 nm and 1089 nm.

    PubMed

    Huang, Y P; Cho, C Y; Huang, Y J; Chen, Y F

    2012-02-27

    A comparison between the fluorescence spectra of the Nd-doped vanadate crystals (Nd:YVO4, Nd:GdVO4, Nd:LuVO4) for the 4F3/2 → 4I11/2 transition is studied. We numerically analyze the condition of gain-to-loss balance via an uncoated intracavity etalon to achieve the dual-wavelength operation. We further experimentally demonstrate the orthogonally polarized dual-wavelength laser with a single Nd:LuVO4 crystal. The simultaneous dual-wavelength Nd:LuVO4 laser at 1085.7 nm in σ polarization and 1088.5 nm in π polarization is realized. At an incident pump power of 12 W, the average output power obtained at 1085.7 nm and 1088.5 nm is 0.4 W and 1.7 W, respectively.

  20. Effect of nanomaterial and media physicochemical properties on Ag NM aggregation kinetics.

    PubMed

    Afshinnia, Kamelia; Sikder, Mithun; Cai, Bo; Baalousha, Mohammed

    2017-02-01

    Nanomaterial (NM) aggregation is a key process determining their environmental, fate behavior and effects. Nanomaterials are typically engineered to remain kinetically stable; however, in environmental and toxicological media, NMs are prone to aggregation. The aggregation kinetics of NM is typically quantified by measuring their attachment efficiency (α) and critical coagulation concentration (CCC). Several studies measured α and CCC for Ag NMs with a major focus on investigating the effects of ionic strength, ion valency and natural organic matter, with few studies investigating other environmental factors such as light and dissolved oxygen and none investigating the effect of particle size, buffer type and concentration, or surface coverage by capping agent. A survey of recent research articles reporting CCC values for Ag NMs reveals substantial variation in experimental conditions and particle stability with CCC values of monovalent and divalent counterions covering a wide range (ca. 25 to infinity for monovalent counterions and 1.6 to infinity for divalent counterions). Here, we rationalize the differences in the CCC values for Ag NMs based on the variability in the experimental conditions, which includes NM and medium physicochemical properties. Capping agents determines NM stability mechanism with citrate, sodium dodecyl sulfate (SDS), and alginate stabilizing NM by electrostatic mechanism; whereas polyvinylpyrrolidone (PVP), casein, dextrin, tween, branched polyethyleneimine (BPEI), and Gum Arabic stabilizing NMs by steric mechanisms. The CCC values for Ag NMs with different capping agents follow the order citrate∼alginate∼SDSNM size and buffer concentration and decreases with light irradiation. For sterically stabilized PVP-Ag NMs, the CCC increases with the coating concentration/surface coverage and completely

  1. Mg 280-nm doublet as a monitor of changes in solar ultraviolet irradiance

    SciTech Connect

    Heath, D.F.; Schlesinger, B.M.

    1986-07-20

    Five years of 160- to 400-nm solar flux measurements by the Solar Backscattered Ultraviolet experiment on Nimbus 7 have been analyzed. The flux in the center of strong lines and at shorter wavelengths varies with periods that correspond to modulation by the rotation of active regions. The modulation is greater at the centers of strong lines and at shorter wavelengths, corresponding to radiation that originates at higher levels in the solar atmosphere. The ratio of the irradiance in the core of the Mg 280-nm line to the irradiance at neighboring wavelengths is used as an index of solar variation. A scaling factor is derived by comparing rotational modulation at other wavelengths with the rotational modulation of the index. The scaled Mg II 280-nm strength successfully represents both rotational and long-term variations across the Al absorption edge near 210 nm. This ratio can therefore provide an empirical representation of long-term ultraviolet solar variability. Scaling factors are derived and changes estimated at several ultraviolet wavelengths. At 204 nm, in the wavelength region that drives atmospheric photochemistry, the solar irradiance drops about 4% from its average level for 1979-1980 to late 1983. The total estimated range of variation of the 27-day averaged (one rotation) 204-nm irradiance is 6%, over the 5 years of measurements. A least squares fit shows that over the 5 years, 27-day averages of 10.7-cm radio flux and of the Mg II index follow a linear relation. The radio flux can therefore be used to estimate changes in the solar ultraviolet for times before the launch of Nimbus 7.

  2. Effect of Crystallization on the Mechanical Properties of Zr{sub 56.7}Cu{sub 15.3}Ni{sub 12.5}Nb{sub 5.0}Al{sub 10.0}Y{sub 0.5} Bulk Amorphous Alloy

    SciTech Connect

    Das, Kakoli; Bandyopadhyay, Amit; Gupta, Yogendra M.

    2005-03-15

    Effects of crystallization behavior on the mechanical properties of Zr{sub 56.7}Cu{sub 15.3}Ni{sub 12.5}Nb{sub 5.0}Al{sub 10.0}Y{sub 0.5} based bulk amorphous alloy (BAA) were studied. Differential scanning calorimetry (DSC) in Ar environment showed three-exothermic peaks at 395, 472 and 659.5 C and one-endothermic peak at 852 C. Following DSC study, as received BAA samples were heat-treated in vacuum at six different temperatures 300, 450, 600, 700, 800 and 850 C. Heat-treated samples were characterized using Vickers microhardness, X-ray diffraction (XRD), differential scanning calorimetry and field emission scanning electron microscopy (FESEM) to study crystallization behavior. It is found that samples heat-treated above the second (472 C) and third (659.5 C) exothermic peaks show high microhardness values compared to the as processed samples, and brittle cracking along the indent diagonal. As processed samples show clear evidence of shear banding. FESEM examination revealed existence of nano-scale precipitates for samples heat-treated at 600 and 700 C, while micro-scale precipitates for 850 C samples. Quasi-static compression tests showed compressive strain to failure decrease with heat-treated samples compared to as received ones. Fracture morphology of the compression test samples changes from vein pattern for as received to flat facets with multiple cracks for heat-treated samples. Indentation fracture toughness values decrease almost an order of magnitude for heat-treated samples compared to as received samples.

  3. Compact Fiber Laser for 589nm Laser Guide Star Generation

    NASA Astrophysics Data System (ADS)

    Pennington, D.; Drobshoff, D.; Mitchell, S.; Brown, A.

    Laser guide stars are crucial to the broad use of astronomical adaptive optics, because they facilitate access to a large fraction of possible locations on the sky. Lasers tuned to the 589 nm atomic sodium resonance can create an artificial beacon at altitudes of 95-105 km, thus coming close to reproducing the light path of starlight. The deployment of multiconjugate adaptive optics on large aperture telescopes world-wide will require the use of three to nine sodium laser guide stars in order to achieve uniform correction over the aperture with a high Strehl value. Current estimates place the minimum required laser power at > 10 W per laser for a continuous wave source, though a pulsed format, nominally 6?s in length at ~ 16.7 kHz, is currently preferred as it would enable tracking the laser through the Na layer to mitigate spot elongation. The lasers also need to be compact, efficient, robust and turnkey. We are developing an all-fiber laser system for generating a 589 nm source for laser-guided adaptive optics. Fiber lasers are more compact and insensitive to alignment than their bulk laser counterparts, and the heat-dissipation characteristics of fibers, coupled with the high efficiencies demonstrated and excellent spatial mode characteristics, make them a preferred candidate for many high power applications. Our design is based on sum-frequency mixing an Er/Yb:doped fiber laser operating at 1583 nm with a 938 nm Nd:silica fiber laser in a periodically poled crystal to generate 589 nm. We have demonstrated 14 W at 1583 nm with an Er/Yb:doped fiber laser, based on a Koheras single frequency fiber oscillator amplified in an IPG Photonics fiber amplifier. The Nd:silica fiber laser is a somewhat more novel device, since the Nd3+ ions must operate on the resonance transition (i.e. 4F3/2-4I9/2), while suppressing ASE losses at the more conventional 1088 nm transition. Optimization of the ratio of the fiber core and cladding permits operation of the laser at room

  4. A self-Q-switched all-fiber erbium laser at 1530 nm using an auxiliary 1570-nm erbium laser.

    PubMed

    Tsai, Tzong-Yow; Fang, Yen-Cheng

    2009-11-23

    We demonstrate a self-Q-switched, all-fiber, tunable, erbium laser at 1530 nm with high pulse repetition rates of 0.9-10 kHz. Through the use of an auxiliary 10-mW, 1570 nm laser that shortened the relaxation time of erbium, sequentially Q-switched pulses with pulse energies between 4 and 6 microJ and pulse widths of 40 ns were steadily achieved. A peak pulse power of 165 W was obtained.

  5. Imaging performance and challenges of 10nm and 7nm logic nodes with 0.33 NA EUV

    NASA Astrophysics Data System (ADS)

    van Setten, Eelco; Schiffelers, Guido; Psara, Eleni; Oorschot, Dorothe; Davydova, Natalia; Finders, Jo; Depre, Laurent; Farys, Vincent

    2014-10-01

    The NXE:3300B is ASML's third generation EUV system and has an NA of 0.33 and is positioned at a resolution of 22nm, which can be extended down to 18nm and below with off-axis illumination at full transmission. Multiple systems have been qualified and installed at customers. The NXE:3300B succeeds the NXE:3100 system (NA of 0.25), which has allowed customers to gain valuable EUV experience. It is expected that EUV will be adopted first for critical Logic layers at 10nm and 7nm nodes, such as Metal-1, to avoid the complexity of triple patterning schemes using ArF immersion. In this paper we will evaluate the imaging performance of (sub-)10nm node Logic M1 on the NXE:3300B EUV scanner. We will show the line-end performance of tip-to-tip and tip-to-space test features for various pitches and illumination settings and the performance enhancement obtained by means of a 1st round of OPC. We will also show the magnitude of local variations. The Logic M1 cell is evaluated at various critical features to identify hot spots. A 2nd round OPC model was calibrated of which we will show the model accuracy and ability to predict hot spots in the Logic M1 cell. The calibrated OPC model is used to predict the expected performance at 7nm node Logic using off-axis illumination at 16nm minimum half pitch. Initial results of L/S exposed on the NXE:3300B at 7nm node resolutions will be shown. An outlook is given to future 0.33 NA systems on the ASML roadmap with enhanced illuminator capabilities to further improve performance and process window.

  6. Analysis of the TMI-2 source range detector response

    SciTech Connect

    Carew, J.F.; Diamond, D.J.; Eridon, J.M.

    1980-01-01

    In the first few hours following the TMI-2 accident large variations (factors of 10-100) in the source range (SR) detector response were observed. The purpose of this analysis was to quantify the various effects which could contribute to these large variations. The effects evaluated included the transmission of neutrons and photons from the core to detector and the reduction in the multiplication of the Am-Be startup sources, and subsequent reduction in SR detector response, due to core voiding. A one-dimensional ANISN slab model of the TMI-2 core, core externals, pressure vessel and containment has been constructed for calculation of the SR detector response and is presented.

  7. Analysis of Cervical Supernatant Samples Luminescence Using 355 nm Laser

    NASA Astrophysics Data System (ADS)

    Vaitkuviene, A.; Gegzna, V.; Kurtinaitiene, R.; Stanikunas, R.; Rimiene, J.; Vaitkus, J.

    2010-05-01

    The biomarker discovery for accurate detection and diagnosis of cervical carcinoma and its malignant precursors represents one of the current challenges in clinical medicine. Laser induced autofluorescence spectra in cervical smear content were fitted to predict the cervical epithelium diagnosis as a lab off "optical biopsy" method. Liquid PAP supernatant sediment dried on Quartz plate spectroscopy was performed by 355 nm Nd YAG microlaser STA-1 (Standa, Ltd). For comparison a liquid supernatant spectroscopy was formed by laboratory "Perkin Elmer LS 50B spetrometer at 290, 300, 310 nm excitations. Analysis of spectrum was performed by approximation using the multi-peaks program with Lorentz functions for the liquid samples and with Gaussian functions for the dry samples. Ratio of spectral components area to the area under whole experimental curve (SPP) was calculated. The spectral components were compared by averages of SPP using Mann-Whitney U-test in histology groups. Results. Differentiation of Normal and HSIL/CIN2+ cases in whole supernatant could be performed by stationary laboratory lamp spectroscopy at excitation 290 nm and emission >379 nm with accuracy AUC 0,69, Sens 0,72, Spec 0,65. Differentiation Normal versus HSIL/CIN2+ groups in dried enriched supernatant could be performed by 355 nm microlaser excitation at emission 405-424 nm with accuracy (AUC 0,96, Sens 0,91, Spec 1.00). Diagnostic algorithm could be created for all histology groups differentiation under 355 nm excitation. Microlaser induced "optical biopsy "looks promising method for cervical screening at the point of care.

  8. Thermodynamics of hydride formation and decomposition in supported sub-10 nm Pd nanoparticles of different sizes

    NASA Astrophysics Data System (ADS)

    Wadell, Carl; Pingel, Torben; Olsson, Eva; Zorić, Igor; Zhdanov, Vladimir P.; Langhammer, Christoph

    2014-05-01

    Hydrogen storage properties of supported Pd nanoparticles with average sizes in the range 2.7-7.6 nm were studied using indirect nanoplasmonic sensing. For each particle size, a series of isotherms was measured and, through Van't Hoff analysis, the changes in enthalpy upon hydride formation/decomposition were determined. Contrary to the expected decrease of the enthalpy, due to increasing importance of surface tension in smaller particles, we observe a very weak size dependence in the size range under consideration. We attribute this to a compensation effect due to an increased fraction of hydrogen atoms occupying energetically favorable subsurface sites in smaller nanoparticles.

  9. Tunable microwave signal generator with an optically-injected 1310 nm QD-DFB laser.

    PubMed

    Hurtado, Antonio; Mee, Jesse; Nami, Mohsen; Henning, Ian D; Adams, Michael J; Lester, Luke F

    2013-05-06

    Tunable microwave signal generation with frequencies ranging from below 1 GHz to values over 40 GHz is demonstrated experimentally with a 1310 nm Quantum Dot (QD) Distributed-Feedback (DFB) laser. Microwave signal generation is achieved using the period 1 dynamics induced in the QD DFB under optical injection. Continuous tuning in the positive detuning frequency range of the quantum dot's unique stability map is demonstrated. The simplicity of the experimental configuration offers promise for novel uses of these nanostructure lasers in Radio-over-Fiber (RoF) applications and future mobile networks.

  10. Magnetoelastically induced magnetic anisotropy transition in [CoO5nm/CoPt7nm]5 multilayer films

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Harumoto, Takashi; Sannomiya, Takumi; Muraishi, Shinji; Nakamura, Yoshio; Shi, Ji

    2016-06-01

    The magnetic anisotropy transition of [CoO5nm/CoPt7nm]5 multilayer film with respect to post-annealing has been studied systematically. It undergoes a smooth transition from longitudinal magnetic anisotropy (LMA) to perpendicular magnetic anisotropy (PMA) upon annealing and returns backward to LMA at high temperature of 550 °C. The strongest PMA of [CoO5nm/CoPt7nm]5 is achieved after post-annealing at 300 °C and the tolerable post-annealing temperature with strong PMA is up to 400 °C, which indicates this multilayer film could be a potential candidate for the PMA application at middle-high-temperature-region between 300 °C and 400 °C. The mechanism responsible for the transition of magnetic anisotropy has been investigated by analyzing CoO/CoPt interface and CoPt layer internal stress. It is found the effective PMA energy is proportional to the in-plane tensile stress of CoPt layer but is inversely proportional to the roughness of CoO/CoPt interface. Finally, by means of low temperature experiment we demonstrate the magnetic anisotropy transition observed in [CoO5nm/CoPt7nm]5 multilayer film is mainly attributed to the change of CoPt layer in-plane tensile stress.

  11. Optical coherence tomography based imaging of dental demineralisation and cavity restoration in 840 nm and 1310 nm wavelength regions

    NASA Astrophysics Data System (ADS)

    Damodaran, Vani; Rao, Suresh Ranga; Vasa, Nilesh J.

    2016-08-01

    In this paper, a study of in-house built optical coherence tomography (OCT) system with a wavelength of 840 nm for imaging of dental caries, progress in demineralisation and cavity restoration is presented. The caries when imaged with the 840 nm OCT system showed minute demineralisation in the order of 5 μm. The OCT system was also proposed to study the growth of lesion and this was demonstrated by artificially inducing caries with a demineralisation solution of pH 4.8. The progress of carious lesion to a depth of about 50-60 μm after 60 hours of demineralisation was clearly observed with the 840 nm OCT system. The tooth samples were subjected to accelerated demineralisation condition at pH of approximately 2.3 to study the adverse effects and the onset of cavity formation was clearly observed. The restoration of cavity was also studied by employing different restorative materials (filled and unfilled). In the case of restoration without filler material (unfilled), the restoration boundaries were clearly observed. Overall, results were comparable with that of the widely used 1310 nm OCT system. In the case of restoration with filler material, the 1310 nm OCT imaging displayed better imaging capacity due to lower scattering than 840 nm imaging.

  12. Fabricating nanopores with diameters of sub-1 nm to 3 nm using multilevel pulse-voltage injection.

    PubMed

    Yanagi, Itaru; Akahori, Rena; Hatano, Toshiyuki; Takeda, Ken-ichi

    2014-05-21

    To date, solid-state nanopores have been fabricated primarily through a focused-electronic beam via TEM. For mass production, however, a TEM beam is not suitable and an alternative fabrication method is required. Recently, a simple method for fabricating solid-state nanopores was reported by Kwok, H. et al. and used to fabricate a nanopore (down to 2 nm in size) in a membrane via dielectric breakdown. In the present study, to fabricate smaller nanopores stably--specifically with a diameter of 1 to 2 nm (which is an essential size for identifying each nucleotide)--via dielectric breakdown, a technique called "multilevel pulse-voltage injection" (MPVI) is proposed and evaluated. MPVI can generate nanopores with diameters of sub-1 nm in a 10-nm-thick Si3N4 membrane with a probability of 90%. The generated nanopores can be widened to the desired size (as high as 3 nm in diameter) with sub-nanometre precision, and the mean effective thickness of the fabricated nanopores was 3.7 nm.

  13. Range expansion of mutualists

    NASA Astrophysics Data System (ADS)

    Muller, Melanie J. I.; Korolev, Kirill S.; Murray, Andrew W.; Nelson, David R.

    2012-02-01

    The expansion of a species into new territory is often strongly influenced by the presence of other species. This effect is particularly striking for the case of mutualistic species that enhance each other's proliferation. Examples range from major events in evolutionary history, such as the spread and diversification of flowering plants due to their mutualism with pollen-dispersing insects, to modern examples like the surface colonisation of multi-species microbial biofilms. Here, we investigate the spread of cross-feeding strains of the budding yeast Saccharomyces cerevisiae on an agar surface as a model system for expanding mutualists. Depending on the degree of mutualism, the two strains form distinctive spatial patterns during their range expansion. This change in spatial patterns can be understood as a phase transition within a stepping stone model generalized to two mutualistic species.

  14. Long Range Materials Research

    DTIC Science & Technology

    1974-12-31

    India, also called bulat steels, are known to have high carbon contents, commonly 1.5 to 2.0% carbon. The high quality of these steels is well...gamma-cementite range, essentially all of the cementite is converted to the spheroidized form. However, during transformation...plus additional cementite In non-spheroldlzed form, typically l>iates. As set forth above, It is Important that essentially

  15. Light beam range finder

    DOEpatents

    McEwan, Thomas E.

    1998-01-01

    A "laser tape measure" for measuring distance which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%.

  16. Light beam range finder

    DOEpatents

    McEwan, T.E.

    1998-06-16

    A ``laser tape measure`` for measuring distance is disclosed which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%. 7 figs.

  17. Long range chromatin organization

    PubMed Central

    Acuña, Luciana I Gómez; Kornblihtt, Alberto R

    2014-01-01

    Splicing is a predominantly co-transcriptional process that has been shown to be tightly coupled to transcription. Chromatin structure is a key factor that mediates this functional coupling. In light of recent evidence that shows the importance of higher order chromatin organization in the coordination and regulation of gene expression, we discuss here the possible roles of long-range chromatin organization in splicing and alternative splicing regulation. PMID:25764333

  18. Photometric Passive Range Sensor

    NASA Astrophysics Data System (ADS)

    Argueta-Diaz, Victor; García-Valenzuela, Augusto

    2008-04-01

    In this paper we present a passive optical ranging method that consists of taking several photometric measurements from the light radiated by an object and deriving the range from these measurements. This passive ranging device uses an iris of radius a, a lens of radius larger than a, and a photodetector of radius p

  19. Front Range Report, Abstracts

    NASA Astrophysics Data System (ADS)

    Spence, William

    The second regional conference of the Front Range Branch, AGU, was attended by more than 80 professionals and some 20 outstanding high school students. The conference included 2 days of interdisciplinary talks, and lots of discussion, that primarily were keyed to geophysical studies of Colorado, Wyoming, and New Mexico. Other talks reported on nonregional, and sometimes global, studies being done by geophypsicists of the Front Range region.Topics included tectonics of the Front Range and the Colorado Plateau, pollution of the Arkansas and Mississippi rivers, and a supreme polluting event that caused the late-Cretaceous extinctions. Other notable talks were on toxic cleanup, microburst (wind shear) detection at U.S. airports, and other meteorological studies. Several talks treated the audience to the excitement of new work and surprise discoveries. The meeting was multimedia, including the playing of two videos through a projection TV and the playing of a fascinating tape between an airport control tower and incoming pilots during a severe microburst event.

  20. Taking the X Architecture to the 65-nm technology node

    NASA Astrophysics Data System (ADS)

    Sarma, Robin C.; Smayling, Michael C.; Arora, Narain; Nagata, Toshiyuki; Duane, Michael P.; Shah, Santosh; Keston, Harris J.; Oemardani, Shiany

    2004-05-01

    The X Architecture is a new way of orienting the interconnect on an integrated circuit using diagonal pathways, as well as the traditional right-angle, or Manhattan, configuration. By enabling designs with significantly less wire and fewer vias, the X Architecture can provide substantial improvements in chip performance, power consumption and cost. Members of the X Initiative semiconductor supply chain consortium have demonstrated the production worthiness of the X Architecture at the 130-nm and 90-nm process technology nodes. This paper presents an assessment of the manufacturing readiness of the X Architecture for the 65-nm technology node. The extent to which current production capabilities in mask writing, lithography, wafer processing, inspection and metrology can be used is discussed using the results from a 65-nm test chip. The project was a collaborative effort amongst a number of companies in the IC fabrication supply chain. Applied Materials fabricated the 65-nm X Architecture test chip at its Maydan Technology Center and leveraged the technology of other X Initiative members. Cadence Design Systems provided the test structure design and chip validation tools, Dai Nippon Printing produced the masks and Canon"s imaging system was employed for the photolithography.

  1. Imaging CIN(3) photodissociation from 234 to 280 nm.

    PubMed

    Samartzis, Peter C; Hansen, Nils; Wodtke, Alec M

    2006-07-07

    We report Cl((2)P(3/2)) and Cl*((2)P(1/2)) fragment images following ClN(3) photolysis in the 234-280 nm region measured by velocity map imaging. Kinetic energy distributions change shape with photolysis wavelength from bimodal at 234 and 240 nm to single peak at 266 and 280 nm. Where two peaks exist, their ratio is significantly different for Cl and Cl* fragments. The single peak of 266 and 280 nm and the faster peak at 234 and 240 nm are assigned to a Cl + linear-N(3) dissociation channel, in agreement with previous work. The slow peak in the bimodal distributions is assigned to the formation of a high energy form (HEF) of N(3). Candidates for the identity of HEF-N(3) are discussed. Combining our data with photofragmentation translational spectroscopy results, we determined the threshold for the appearance of HEF-N(3) at 4.83 +/- 0.17 eV photolysis energy. This threshold behavior is similar to recently reported results on the wavelength dependence of HN(3) photolysis, where the threshold was associated with a ring closed isomer of HN(3) on the S(1) potential energy surface. We also note that the HEF-N(3) formation threshold observed for ClN(3) occurs where the energy available to the products equals the isomerization barrier from linear to cyclic-N(3).

  2. Process liability evaluation for beyond 22nm node using EUVL

    NASA Astrophysics Data System (ADS)

    Tawarayama, Kazuo; Aoyama, Hajime; Matsunaga, Kentaro; Arisawa, Yukiyasu; Uno, Taiga; Magoshi, Shunko; Kyoh, Suigen; Nakajima, Yumi; Inanami, Ryoichi; Tanaka, Satoshi; Kobiki, Ayumi; Kikuchi, Yukiko; Kawamura, Daisuke; Takai, Kosuke; Murano, Koji; Hayashi, Yumi; Mori, Ichiro

    2010-04-01

    Extreme ultraviolet lithography (EUVL) is the most promising candidate for the manufacture of devices with a half pitch of 32 nm and beyond. We are now evaluating the process liability of EUVL in view of the current status of lithography technology development. In a previous study, we demonstrated the feasibility of manufacturing 32-nm-node devices by means of a wafer process that employed the EUV1, a full-field step-and-scan exposure tool. To evaluate yield, a test pattern was drawn on a multilayer resist and exposed. After development, the pattern was replicated in SiO2 film by etching, and metal wires were formed by a damascene process. Resolution enhancement is needed to advance to the 22- nm node and beyond, and a practical solution is off-axis illumination (OAI). This paper presents the results of a study on yield improvement that used a 32-nm-node test chip, and also clarifies a critical issue in the use of EUVL in a wafer process for device manufacture at the 22-nm node and beyond.

  3. Absorption spectrum of DNA for wavelengths greater than 300 nm

    SciTech Connect

    Sutherland, J.C.; Griffin, K.P.

    1981-06-01

    Although DNA absorption at wavelengths greater than 300 nm is much weaker than that at shorter wavelengths, this absorption seems to be responsible for much of the biological damage caused by solar radiation of wavelengths less than 320 nm. Accurate measurement of the absorption spectrum of DNA above 300 nm is complicated by turbidity characteristic of concentrated solutions of DNA. We have measured the absorption spectra of DNA from calf thymus, Clostridium perfringens, Escherichia coli, Micrococcus luteus, salmon testis, and human placenta using procedures which separate optical density due to true absorption from that due to turbidity. Above 300 nm, the relative absorption of DNA increases as a function of guanine-cytosine content, presumably because the absorption of guanine is much greater than the absorption of adenine at these wavelengths. This result suggests that the photophysical processes which follow absorption of a long-wavelength photon may, on the average, differ from those induced by shorter-wavelength photons. It may also explain the lower quantum yield for the killing of cells by wavelengths above 300 nm compared to that by shorter wavelengths.

  4. Broadband (˜300 nm) optical gain in the ZAS (ZrO 2-Al 2O 3-SiO 2) glass activated by chromium

    NASA Astrophysics Data System (ADS)

    Koepke, Cz.; Wisniewski, K.; Piatkowski, D.

    2009-01-01

    The broadband optical gain peaking around 1100 nm has been registered in the ZAS glass activated by Cr 3+ ions. The gain spectrum spreads over ˜300 nm range and on the short wavelength side it is accompanied by the excited state absorption (ESA) of the maximum around 750 nm. The ZAS glass, being designed as a parent glass for more sophisticated glass ceramic (awaited to be a promising laser medium), contrary to this ceramic, appeared itself to be interesting gain medium.

  5. Sequence-specific determination of protein and peptide concentrations by absorbance at 205 nm.

    PubMed

    Anthis, Nicholas J; Clore, G Marius

    2013-06-01

    Quantitative studies in molecular and structural biology generally require accurate and precise determination of protein concentrations, preferably via a method that is both quick and straightforward to perform. The measurement of ultraviolet absorbance at 280 nm has proven especially useful, since the molar absorptivity (extinction coefficient) at 280 nm can be predicted directly from a protein sequence. This method, however, is only applicable to proteins that contain tryptophan or tyrosine residues. Absorbance at 205 nm, among other wavelengths, has been used as an alternative, although generally using absorptivity values that have to be uniquely calibrated for each protein, or otherwise only roughly estimated. Here, we propose and validate a method for predicting the molar absorptivity of a protein or peptide at 205 nm directly from its amino acid sequence, allowing one to accurately determine the concentrations of proteins that do not contain tyrosine or tryptophan residues. This method is simple to implement, requires no calibration, and should be suitable for a wide range of proteins and peptides.

  6. Mutagenesis of mNeptune Red-Shifts Emission Spectrum to 681-685 nm

    PubMed Central

    Li, ZhaoYang; Zhang, ZhiPing; Bi, LiJun; Cui, ZongQiang; Deng, JiaoYu; Wang, DianBing; Zhang, Xian-En

    2016-01-01

    GFP-like fluorescent proteins with diverse emission wavelengths have been developed through mutagenesis, offering many possible choices in cellular and tissue imaging, such as multi-targets imaging, deep tissue imaging that require longer emission wavelength. Here, we utilized a combined approach of random mutation and structure-based rational design to develop new NIR fluorescent proteins on the basis of a far-red fluorescent protein, mNeptune (Ex/Em: 600/650 nm). We created a number of new monomeric NIR fluorescent proteins with the emission range of 681–685 nm, which exhibit the largest Stocks shifts (77–80 nm) compared to other fluorescent proteins. Among them, mNeptune681 and mNeptune684 exhibit more than 30 nm redshift in emission relative to mNeptune, owing to the major role of the extensive hydrogen-bond network around the chromophore and contributions of individual mutations to the observed redshift. Furthermore, the two variants still maintain monomeric state in solution, which is a trait crucial for their use as protein tags. In conclusion, our results suggest that there is untapped potential for developing fluorescent proteins with desired properties. PMID:27119418

  7. E-beam patterning and stability study of sub-22nm HSQ pillars

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Su; Tsai, Ming-Jinn

    2011-04-01

    E-beam exposed HSQ resist pillar (island) is commonly used as the hard mask for dry etching. However, HSQ pillar is prone to collapse without any substrate pre-treatment. CD resolution of HSQ pattern also depends on the aging effect. In this work, factors of (1) designed CD (DCD) (2) dose vs L/S ratio (3) beam current (4) underlayer (UL) (5) post-coat-delay (PCD) time before e-beam writing are studied for forming stable and reproducible sub-22 nm HSQ pillar. Three kinds of underlayer are evaluated, i.e. AR3-600, ZEP520A and TDUR-N700. Experimental results are summarized below. A wider dose window of forming sub-22 nm HSQ pillar with looser L/S ratio or smaller designed CD is obtained. CD variation for all pattern density conditions is due to the proximity effect from beam blur. AR3-600 is shown to be the most suitable UL for HSQ pillar. CD of HSQ pillar increases with thicker AR3-600 layer. PCD range for stable CDs of HSQ pillar with DCD of 20 nm is larger than that with 15 nm.

  8. Large area metal nanowire arrays with tunable sub-20 nm nanogaps.

    PubMed

    Le Thi Ngoc, Loan; Jin, Mingliang; Wiedemair, Justyna; van den Berg, Albert; Carlen, Edwin T

    2013-06-25

    We report a new top-down nanofabrication technology to realize large area metal nanowire (m-NW) arrays with tunable sub-20 nm separation nanogaps without the use of chemical etching or milling of the metal layer. The m-NW array nanofabrication technology is based on a self-regulating metal deposition process that is facilitated by closely spaced and isolated heterogeneous template surfaces that confine the metal deposition into two dimensions, and therefore, electrically isolated parallel arrays of m-NW can be realized with uniform and controllable nanogaps. Au-NW and Ag-NW arrays are presented with high-density ~10(5) NWs cm(-1), variable NW diameters down to ~50 nm, variable nanogaps down to ~5 nm, and very large nanogap length density ~1 km cm(-2). The m-NW arrays are designed and implemented as interdigitated nanoelectrodes for electrochemical applications and as plasmonic substrates where the coupled-mode localized surface plasmon resonance (LSPR) wavelength in the nanogaps between adjacent m-NW dimers can be precisely tuned to match any excitation source in the range from 500 to 1000 nm, thus providing optimal local electromagnetic field enhancement. A spatially averaged (n = 2500) surface-enhanced Raman scattering (SERS) analytical enhancement factor of (1.2 ± 0.1) × 10(7) is demonstrated from a benzenethiol monolayer chemisorbed on a Au-NW array substrate with LSPR wavelength matched to a He-Ne laser source.

  9. Development and characterization of a 22 W narrow-linewidth 3186 nm ultraviolet laser

    NASA Astrophysics Data System (ADS)

    Wang, Jieying; Bai, Jiandong; He, Jun; Wang, Junmin

    2016-10-01

    We demonstrate a high-power narrow-linewidth ultraviolet (UV) laser system at 318.6 nm for direct 6S1/2-nP (n = 70 to 100) Rydberg excitation of cesium atoms. Based on commercial fiber lasers and efficient nonlinear frequency conversion technology, 2.26 W of tunable UV laser power is obtained from cavity-enhanced second harmonic generation following sum-frequency generation of two infrared lasers at 1560.5 nm and 1076.9 nm to 637.2 nm. The maximum doubling efficiency is 57.3%. The typical UV laser power root-mean-square fluctuation is less than 0.87% over 30 minutes, and the continuously tunable range of the UV laser frequency is more than 6 GHz. Its beam quality factors M2 X and M2 Y are 1.16 and 1.48, respectively. This high-performance UV laser has significant potential use in quantum optics and cold atom physics.

  10. Efficient methylammonium lead iodide perovskite solar cells with active layers from 300 to 900 nm

    SciTech Connect

    Momblona, C.; Malinkiewicz, O.; Soriano, A.; Gil-Escrig, L.; Bandiello, E.; Scheepers, M.; Bolink, H. J.; Edri, E.

    2014-08-01

    Efficient methylammonium lead iodide perovskite-based solar cells have been prepared in which the perovskite layer is sandwiched in between two organic charge transporting layers that block holes and electrons, respectively. This configuration leads to stable and reproducible devices that do not suffer from strong hysteresis effects and when optimized lead to efficiencies close to 15%. The perovskite layer is formed by using a dual-source thermal evaporation method, whereas the organic layers are processed from solution. The dual-source thermal evaporation method leads to smooth films and allows for high precision thickness variations. Devices were prepared with perovskite layer thicknesses ranging from 160 to 900 nm. The short-circuit current observed for these devices increased with increasing perovskite layer thickness. The main parameter that decreases with increasing perovskite layer thickness is the fill factor and as a result optimum device performance is obtained for perovskite layer thickness around 300 nm. However, here we demonstrate that with a slightly oxidized electron blocking layer the fill factor for the solar cells with a perovskite layer thickness of 900 nm increases to the same values as for the devices with thin perovskite layers. As a result the power conversion efficiencies for the cells with 300 and 900 nm are very similar, 12.7% and 12%, respectively.

  11. Microsecond gain-switched master oscillator power amplifier (1958 nm) with high pulse energy

    SciTech Connect

    Ke Yin; Weiqiang Yang; Bin Zhang; Ying Li; Jing Hou

    2014-02-28

    An all-fibre master oscillator power amplifier (MOPA) emitting high-energy pulses at 1958 nm is presented. The seed laser is a microsecond gain-switched thulium-doped fibre laser (TDFL) pumped with a commercial 1550-nm pulsed fibre laser. The TDFL operates at a repetition rate f in the range of 10 to 100 kHz. The two-stage thulium-doped fibre amplifier is built to scale the energy of the pulses generated by the seed laser. The maximum output pulse energy higher than 0.5 mJ at 10 kHz is achieved which is comparable with the theoretical maximum extractable pulse energy. The slope efficiency of the second stage amplifier with respect to the pump power is 30.4% at f = 10 kHz. The wavelength of the output pulse laser is centred near 1958 nm at a spectral width of 0.25 nm after amplification. Neither nonlinear effects nor significant amplified spontaneous emission (ASE) is observed in the amplification experiments. (lasers)

  12. Comparison of ArF bilayer resists for sub-90 nm L/S fabrication

    NASA Astrophysics Data System (ADS)

    Hong, Jin; Kim, Hyun-Woo; Lee, Sung-Ho; Woo, Sang-Gyun; Cho, Han-Ku; Han, Woo-Sung

    2003-06-01

    The advent of 193nm ArF lithography opened new era of sub-90nm patterning in DRAM industry. ArF lithography in single layer scheme, however, has limitation in the substrate fabrication of sub-90nm L/S due to the decreased physical thickness of resist less that 3000Å and soft chemical structure of resist. Bilayer scheme, composed of Si-containing top PR and thick organic bottom layer, is gaining attention for its capability of patterning and control of resist thickness as a substitute for single layer. Several resists were evaluated for bilayer process in terms of photo patterning, dry development, bottom PR durability and SEM shrinkage. Resolution down to 80nm was achieved with Si content in the range of 8-9%. Etch selectivity in the dry development was a strong function of Si content and chemical structure of tope PR with pitch size dependence based on O2/N2 gas chemistry in dual frequency plasma tool. Profile control after dry development was subject to change depending on the gas ration (O2/N2) and power. Resist structure was proved to be a key factor in bottom PR durability at the substrate etch condition. Best combination of top and bottom resists in bilayer scheme will be discussed.

  13. Laser System for Precise, Unambiguous Range Measurements

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, Oliver

    2005-01-01

    The Modulation Sideband Technology for Absolute Range (MSTAR) architecture is the basis of design of a proposed laser-based heterodyne interferometer that could measure a range (distance) as great as 100 km with a precision and resolution of the order of 1 nm. Simple optical interferometers can measure changes in range with nanometer resolution, but cannot measure range itself because interference is subject to the well-known integer-multiple-of-2 -radians phase ambiguity, which amounts to a range ambiguity of the order of 1 m at typical laser wavelengths. Existing rangefinders have a resolution of the order of 10 m and are therefore unable to resolve the ambiguity. The proposed MSTAR architecture bridges the gap, enabling nanometer resolution with an ambiguity range that can be extended to arbitrarily large distances. The MSTAR architecture combines the principle of the heterodyne interferometer with the principle of extending the ambiguity range of an interferometer by using light of two wavelengths. The use of two wavelengths for this purpose is well established in optical metrology, radar, and sonar. However, unlike in traditional two-color laser interferometry, light of two wavelengths would not be generated by two lasers. Instead, multiple wavelengths would be generated as sidebands of phase modulation of the light from a single frequency- stabilized laser. The phase modulation would be effected by applying sinusoidal signals of suitable frequencies (typically tens of gigahertz) to high-speed electro-optical phase modulators. Intensity modulation can also be used

  14. High Power 938nm Cladding Pumped Fiber Laser

    SciTech Connect

    Dawson, J; Beach, R; Brobshoff, A; Liao, Z; Payne, S; Pennington, D; Taylor, L; Hackenberg, W; Bonaccini, D

    2002-12-26

    We have developed a Nd:doped cladding pumped fiber amplifier, which operates at 938nm with greater than 2W of output power. The core co-dopants were specifically chosen to enhance emission at 938nm. The fiber was liquid nitrogen cooled in order to achieve four-level laser operation on a laser transition that is normally three level at room temperature, thus permitting efficient cladding pumping of the amplifier. Wavelength selective attenuation was induced by bending the fiber around a mandrel, which permitted near complete suppression of amplified spontaneous emission at 1088nm. We are presently seeking to scale the output of this laser to 10W. We will discuss the fiber and laser design issues involved in scaling the laser to the 10W power level and present our most recent results.

  15. Interaction between Nm23 and the tumor suppressor VHL.

    PubMed

    Lin, Chih-Hung; Dammai, Vincent; Adryan, Boris; Hsu, Tien

    2015-02-01

    Among the anti-tumor genes (tumor suppressors and metastasis suppressors), the von-Hippel Lindau gene and the Nm23 family of genes are among the more intriguing ones. Both are small (long and short forms of VHL are 30 and 19 kD, respectively, and Nm23 is ~17 kD), and both possess diverse molecular and cellular functions. Despite extensive studies, the entire spectra of functions and the molecular function-phenotype correlation of these two proteins have not been completely elucidated. In this report, we present data showing these two proteins interact physically. We also summarize and confirm the previous studies that demonstrated the endocytic function of these two genes and further show that the endocytic function of VHL is mediated through the activity of Nm23. These functional and molecular interactions are evolutionarily conserved from Drosophila to human.

  16. High power narrowband 589 nm frequency doubled fibre laser source.

    PubMed

    Taylor, Luke; Feng, Yan; Calia, Domenico Bonaccini

    2009-08-17

    We demonstrate high-power high-efficiency cavity-enhanced second harmonic generation of an in-house built ultra-high spectral density (SBS-suppressed) 1178 nm narrowband Raman fibre amplifier. Up to 14.5 W 589 nm CW emission is achieved with linewidth Delta nu(589) < 7 MHz in a diffraction-limited beam, with peak external conversion efficiency of 86%. The inherently high spectral and spatial qualities of the 589 nm source are particularly suited to both spectroscopic and Laser Guide Star applications, given the seed laser can be easily frequency-locked to the Na D(2a) emission line. Further, we expect the technology to be extendable, at similar or higher powers, to wavelengths limited only by the seed-pump-pair availability.

  17. Laser Range Camera Modeling

    SciTech Connect

    Storjohann, K.

    1990-01-01

    This paper describes an imaging model that was derived for use with a laser range camera (LRC) developed by the Advanced Intelligent Machines Division of Odetics. However, this model could be applied to any comparable imaging system. Both the derivation of the model and the determination of the LRC's intrinsic parameters are explained. For the purpose of evaluating the LRC's extrinsic parameters, i.e., its external orientation, a transformation of the LRC's imaging model into a standard camera's (SC) pinhole model is derived. By virtue of this transformation, the evaluation of the LRC's external orientation can be found by applying any SC calibration technique.

  18. Thermal and damage data from multiple microsecond pulse trains at 532nm in an in vitro retinal model

    NASA Astrophysics Data System (ADS)

    Denton, Michael L.; Tijerina, Amanda J.; Hoffman, Aaron; Clark, Clifton D.; Noojin, Gary D.; Rickman, John M.; Castellanos, Cherry C.; Shingledecker, Aurora D.; Boukhris, Sarah J.; Thomas, Robert J.; Rockwell, Benjamin A.

    2014-03-01

    An artificially pigmented retinal pigment epithelial (RPE) cell model was used to study the damage rates for exposure to 1, 10, 100, and 1,000 230-μs laser pulses at 532 nm, at two different concentrations of melanosome particles (MPs) per cell. Multiple pulses were delivered at pulse repetition rates of 50 and 99 pulses per second. Standard fluorescence viability indicator dyes and the method of microthermography were used to assess damage and thermal responses, respectively. Although frame rate during microthermography was more than five times slower than the duration of laser pulses, thermal information was useful in refining the BTEC computational model for simulating high-resolution thermal responses by the pigmented cells. When we temporally sampled the thermal model output at a rate similar to our microthermography, the resulting thermal profiles for multiple pulses resembled the thermal experimental profiles. Complementary to the thermal simulations, our computer-generated thresholds were in good agreement with the in vitro data. Findings are examined within the context of common exposure limit definitions in the national and international laser safety standards.

  19. 32 nm imprint masks using variable shape beam pattern generators

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta; Thompson, Ecron; Schmid, Gerard; Stacey, Nick; Perez, Joseph; Maltabes, John; Resnick, Douglas J.; Yeo, Jeongho; Kim, Hoyeon; Eynon, Ben

    2008-05-01

    Imprint lithography has been included on the ITRS Lithography Roadmap at the 32, 22 and 16 nm nodes. Step and Flash Imprint Lithography (S-FIL ®) is a unique method that has been designed from the beginning to enable precise overlay for creating multilevel devices. A photocurable low viscosity monomer is dispensed dropwise to meet the pattern density requirements of the device, thus enabling imprint patterning with a uniform residual layer across a field and across entire wafers. Further, S-FIL provides sub-100 nm feature resolution without the significant expense of multi-element, high quality projection optics or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates. For sub-32 nm device manufacturing, one of the major technical challenges remains the fabrication of full-field 1x templates with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub 32nm node. Here we report the first imprinting results from sub-40 nm full-field patterns, using Samsung's current flash memory production device design. The fabrication of the template is discussed and the resulting critical dimension control and uniformity are discussed, along with image placement results. The imprinting results are described in terms of CD uniformity, etch results, and overlay.

  20. Full-field imprinting of sub-40 nm patterns

    NASA Astrophysics Data System (ADS)

    Yeo, Jeongho; Kim, Hoyeon; Eynon, Ben

    2008-03-01

    Imprint lithography has been included on the ITRS Lithography Roadmap at the 32, 22 and 16 nm nodes. Step and Flash Imprint Lithography (S-FIL (R)) is a unique patterning method that has been designed from the beginning to enable precise overlay to enable multilevel device fabrication. A photocurable low viscosity resist is dispensed dropwise to match the pattern density requirements of the device, thus enabling patterning with a uniform residual layer thickness across a field and across multiple wafers. Further, S-FIL provides sub-50 nm feature resolution without the significant expense of multi-element projection optics or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of imprint masks (templates). For sub-32 nm device manufacturing, one of the major technical challenges remains the fabrication of full-field 1x imprint masks with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub-32nm node. Here we report the first imprinting results from sub-40 nm full-field patterns, using Samsung's current flash memory production device design. The fabrication of the imprint mask and the resulting critical dimension control and uniformity are discussed, along with image placement results. The imprinting results are described in terms of CD uniformity, etch results, and overlay.

  1. Low-loss arrayed waveguide grating at 760 nm.

    PubMed

    Stanton, E J; Spott, A; Davenport, M L; Volet, N; Bowers, J E

    2016-04-15

    An arrayed waveguide grating (AWG) at 760 nm is demonstrated with an insertion loss smaller than 0.5 dB. Interface roughness and waveguide length errors contribute much more to scattering loss and phase errors at 760 nm than at longer wavelengths, thus requiring improved design and fabrication. This Letter details how this is achieved by minimizing interfacial scattering, grating side-order excitation, and phase errors in the AWG. With silicon nitride core and silicon dioxide clad waveguides on silicon, this AWG is compatible with heterogeneously integrated lasers for on-chip spectral beam combining.

  2. Cost-effective tunable 1310nm DWDM transmitter

    NASA Astrophysics Data System (ADS)

    Chorchos, Łukasz; Turkiewicz, Jarosław P.

    2015-09-01

    The growing demand for higher data rate transmissions in local and metropolitan area networks is main reason of developing effective and inexpensive transmission systems. In this paper, study about the possibility to realize 1310 nm tunable DWDM transmitter using commercially available low-cost DFB lasers is presented. Extensive DFB lasers characterization has been performed which led to establish relationships between laser current, operational temperature, emitted wavelength and power. An algorithm to find the laser settings for a desired wavelength grid has been proposed and tested. Generation of the 1310nm DWDM channels with frequency spacing between 120 and 240GHz has been demonstrated.

  3. MiniAERCam Ranging

    NASA Technical Reports Server (NTRS)

    Talley, Tom

    2003-01-01

    Johnson Space Center (JSC) is designing a small, remotely controlled vehicle that will carry two color and one black and white video cameras in space. The device will launch and retrieve from the Space Vehicle and be used for remote viewing. Off the shelf cellular technology is being used as the basis for communication system design. Existing plans include using multiple antennas to make simultaneous estimates of the azimuth of the MiniAERCam from several sites on the Space Station and use triangulation to find the location of the device. Adding range detection capability to each of the nodes on the Space Vehicle would allow an estimate of the location of the MiniAERCam to be made at each Communication And Telemetry Box (CATBox) independent of all the other communication nodes. This project will investigate the techniques used by the Global Positioning System (GPS) to achieve accurate positioning information and adapt those strategies that are appropriate to the design of the CATBox range determination system.

  4. Range Process Simulation Tool

    NASA Technical Reports Server (NTRS)

    Phillips, Dave; Haas, William; Barth, Tim; Benjamin, Perakath; Graul, Michael; Bagatourova, Olga

    2005-01-01

    Range Process Simulation Tool (RPST) is a computer program that assists managers in rapidly predicting and quantitatively assessing the operational effects of proposed technological additions to, and/or upgrades of, complex facilities and engineering systems such as the Eastern Test Range. Originally designed for application to space transportation systems, RPST is also suitable for assessing effects of proposed changes in industrial facilities and large organizations. RPST follows a model-based approach that includes finite-capacity schedule analysis and discrete-event process simulation. A component-based, scalable, open architecture makes RPST easily and rapidly tailorable for diverse applications. Specific RPST functions include: (1) definition of analysis objectives and performance metrics; (2) selection of process templates from a processtemplate library; (3) configuration of process models for detailed simulation and schedule analysis; (4) design of operations- analysis experiments; (5) schedule and simulation-based process analysis; and (6) optimization of performance by use of genetic algorithms and simulated annealing. The main benefits afforded by RPST are provision of information that can be used to reduce costs of operation and maintenance, and the capability for affordable, accurate, and reliable prediction and exploration of the consequences of many alternative proposed decisions.

  5. Western Aeronautical Test Range

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert D.

    2008-01-01

    NASA's Western Aeronautical Test Range (WATR) is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). It is managed by the Aeronautics Test Program (ATP) of the Aeronautics Research Mission Directorate (ARMD) to provide the right facility at the right time. NASA is a tenant on Edwards Air Force Base and has an agreement with the Air Force Flight Test Center to use the land and airspace controlled by the Department of Defense (DoD). The topics include: 1) The WATR supports a variety of vehicles; 2) Dryden shares airspace with the AFFTC; 3) Restricted airspace, corridors, and special use areas are available for experimental aircraft; 4) WATR Products and Services; 5) WATR Support Configuration; 6) Telemetry Tracking; 7) Time Space Positioning; 8) Video; 9) Voice Communication; 10) Mobile Operations Facilities; 11) Data Processing; 12) Mission Control Center; 13) Real-Time Data Analysis; and 14) Range Safety.

  6. First results from simultaneous 527 nm and 351 nm probe beam interactions in a long scalelength plasma

    NASA Astrophysics Data System (ADS)

    Moody, J. D.; MacKinnon, A.; Glenzer, S. H.; Froula, D.; Gregori, G.; Berger, R. L.; Campbell, K.; Divol, L.; Dixit, S.; Suter, L. J.; Williams, E. A.; Bahr, R.; Seka, W.

    2002-11-01

    We investigate the stimulated Raman and Brillouin backscattered light from simultaneous 527 nm and 351 nm probe beams incident on a long scalelength ignition-like plasma. These experiments are important for both determining backscattering physics mechanisms and for evaluating laser power loss expected in planned ignition experiments. The plasma is formed using 18 kJ of 351 nm light from the Omega laser in a 1 ns pulse incident on a gas-filled balloon target. The two probe beams, which are delayed 0.5 ns relative to the plasma forming beams, are separated by 42^rc, have vacuum intensity of <= 7 × 10^14 W/cm^2 and may or may not intersect in the plasma. Self-Thomson scattered light from the 527 nm beam is used to determine the plasma temperatures. We find that in a CH plasma, beam intersection leads to about a factor of 2 increase in the SRS from the 351 nm beam compared to no intersection. Beam intersection does not change the SBS backscattering level studied with a CO2 plasma. We describe the experimental results and simulations using the LASNEX hydrodynamic code and the pF3D laser-plasma wave propagation code. Work performed under the auspicies of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contract number W--7405--ENG--48.

  7. Performance of a high-NA dual-stage 193-nm TWINSCAN Step and Scan system for 80-nm applications

    NASA Astrophysics Data System (ADS)

    de Klerk, Jos; Jorritsma, Louis; van Setten, Eelco; Droste, Richard; du Croo de Jongh, Richard; Hansen, Steven G.; Smith, Dan; van de Kerkhof, Mark A.; van de Mast, Frank; Graeupner, Paul; Rohe, Thomas; Kornitzer, Klaus

    2003-06-01

    As the semiconductor industry looks into the near future to extend manufacturing beyond 100nm, a new optical lithography system was developed by ASML. To achieve the aggressive industry roadmap and enable high volume manufacturing of sub 100nm resolutions at low k1 requires a number of challenges to be overcome. This paper reviews the design, system performance and measurements of a High NA, Dual stage 193nm TWINSCAN system planned for high volume manufacturing for 80nm applications. The overall system capability to effectively measure and control to a high precision the various attributes upon process control necessary for adequate CD control, in the low k1 regime will be shown. This paper will discuss the needed imaging control and the requirement for an extremely stable and matured platform. The system's dynamic, focus, leveling and dose delivery performance will be shown. Additionally, the automated control features of the optical system will be shown that enable the use of the various resolution enhancement techniques (RET) currently under development. The ability to optimize imaging performance with the control and flexibility in the pupil formation optics will be discussed. Finally, experimental results of an in-situ measurement technique with automated feedback control to optimize projection lens aberrations, which has a direct impact to imaging fidelity, will be shown. In summary, the lithographic system functionality and performance needed to achieve 80nm volume manufacturing will be presented.

  8. Extension of 193 nm dry lithography to 45-nm half-pitch node: double exposure and double processing technique

    NASA Astrophysics Data System (ADS)

    Biswas, Abani M.; Li, Jianliang; Hiserote, Jay A.; Melvin, Lawrence S., III

    2006-10-01

    Immersion lithography and multiple exposure techniques are the most promising methods to extend lithography manufacturing to the 45nm node. Although immersion lithography has attracted much attention recently as a promising optical lithography extension, it will not solve all the problems at the 45-nm node. The 'dry' option, (i.e. double exposure/etch) which can be realized with standard processing practice, will extend 193-nm lithography to the end of the current industry roadmap. Double exposure/etch lithography is expensive in terms of cost, throughput time, and overlay registration accuracy. However, it is less challenging compared to other possible alternatives and has the ability to break through the κ I barrier (0.25). This process, in combination with attenuated PSM (att-PSM) mask, is a good imaging solution that can reach, and most likely go beyond, the 45-nm node. Mask making requirements in a double exposure scheme will be reduced significantly. This can be appreciated by the fact that the separation of tightly-pitched mask into two less demanding pitch patterns will reduce the stringent specifications for each mask. In this study, modeling of double exposure lithography (DEL) with att-PSM masks to target 45-nm node is described. In addition, mask separation and implementation issues of optical proximity corrections (OPC) to improve process window are studied. To understand the impact of OPC on the process window, Fourier analysis of the masks has been carried out as well.

  9. Photosynthetic light-harvesting complexes: fluorescent and absorption spectroscopy under two-photon (1200-1500 nm) and one-photon (600-750 nm) excitation by laser femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Stepanenko, Il'ya A.; Kompanets, Viktor O.; Chekalin, Sergey V.; Makhneva, Zoya K.; Moskalenko, Andrey A.; Razjivin, Andrei P.

    2010-09-01

    The pathways of excitation energy transfer (EET) via pigments of the light-harvesting antenna are still in discussion. The bacteriochlorophyll fluorescence of peripheral light-harvesting complexes (LH2) from purple bacteria can be observed upon two-photon excitation (TPE) within 1200-1500 nm spectral range (a broad band near 1300 nm). Earlier the occurrence of this band was taken as an evidence for the participation of "dark" carotenoid S1 state in EET processes (see [Walla et al., Proc. Nat. Acad. Sci. U.S.A. 97, 10808-10813 (2000)] and references in it). However we showed that TPE spectrum of LH2 fluorescence within 1200-1500 nm is not associated with carotenoids [Stepanenko et al., J. Phys. Chem. B. 113(34), 11720-11723 (2009)]. Here we present TPE spectra of fluorescence for chromatophores and lightharvesting complexes LH2 and LH1 from wild-type cells and from carotenoid-depleted or carotenoidless mutant cells of several purple bacteria. The broad band within 1300-1400 nm was found for all preparations. Absorption pump-probe femtosecond spectroscopy applied to LH2 complex from Rb. sphaeroides revealed the similar spectral and kinetic patterns for TPE at 1350 nm and one-photon excitation at 675 nm. Analysis of pigment composition of this complex by high-pressure liquid chromatography showed that even under mild isolation conditions some bacteriochlorophyll molecules were oxidized to 3-acetyl-chlorophyll molecules having the long-wavelength absorption peak in the 650-700 nm range. It is proposed that these 3-acetyl-chlorophyll molecules are responsible for the broad band in TPE spectra within the 1200-1500 nm region.

  10. Photosynthetic light-harvesting complexes: fluorescent and absorption spectroscopy under two-photon (1200-1500 nm) and one-photon (600-750 nm) excitation by laser femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Stepanenko, Il'ya A.; Kompanets, Viktor O.; Chekalin, Sergey V.; Makhneva, Zoya K.; Moskalenko, Andrey A.; Razjivin, Andrei P.

    2011-02-01

    The pathways of excitation energy transfer (EET) via pigments of the light-harvesting antenna are still in discussion. The bacteriochlorophyll fluorescence of peripheral light-harvesting complexes (LH2) from purple bacteria can be observed upon two-photon excitation (TPE) within 1200-1500 nm spectral range (a broad band near 1300 nm). Earlier the occurrence of this band was taken as an evidence for the participation of "dark" carotenoid S1 state in EET processes (see [Walla et al., Proc. Nat. Acad. Sci. U.S.A. 97, 10808-10813 (2000)] and references in it). However we showed that TPE spectrum of LH2 fluorescence within 1200-1500 nm is not associated with carotenoids [Stepanenko et al., J. Phys. Chem. B. 113(34), 11720-11723 (2009)]. Here we present TPE spectra of fluorescence for chromatophores and lightharvesting complexes LH2 and LH1 from wild-type cells and from carotenoid-depleted or carotenoidless mutant cells of several purple bacteria. The broad band within 1300-1400 nm was found for all preparations. Absorption pump-probe femtosecond spectroscopy applied to LH2 complex from Rb. sphaeroides revealed the similar spectral and kinetic patterns for TPE at 1350 nm and one-photon excitation at 675 nm. Analysis of pigment composition of this complex by high-pressure liquid chromatography showed that even under mild isolation conditions some bacteriochlorophyll molecules were oxidized to 3-acetyl-chlorophyll molecules having the long-wavelength absorption peak in the 650-700 nm range. It is proposed that these 3-acetyl-chlorophyll molecules are responsible for the broad band in TPE spectra within the 1200-1500 nm region.

  11. Cavity-enhanced measurements of hydrogen peroxide absorption cross sections from 353 to 410 nm.

    PubMed

    Kahan, Tara F; Washenfelder, Rebecca A; Vaida, Veronica; Brown, Steven S

    2012-06-21

    We report near-ultraviolet and visible absorption cross sections of hydrogen peroxide (H(2)O(2)) using incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS), a recently developed, high-sensitivity technique. The measurements reported here span the range of 353-410 nm and extend published electronic absorption cross sections by 60 nm to absorption cross sections below 1 × 10(-23) cm(2) molecule(-1). We have calculated photolysis rate constants for H(2)O(2) in the lower troposphere at a range of solar zenith angles by combining the new measurements with previously reported data at wavelengths shorter than 350 nm. We predict that photolysis at wavelengths longer than those included in the current JPL recommendation may account for up to 28% of the total hydroxyl radical (OH) production from H(2)O(2) photolysis under some conditions. Loss of H(2)O(2) via photolysis may be of the same order of magnitude as reaction with OH and dry deposition in the lower atmosphere; these processes have very different impacts on HO(x) loss and regeneration.

  12. Fourier domain mode-locked swept source at 1050 nm based on a tapered amplifier.

    PubMed

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang; Biedermann, Benjamin R; Hsu, Kevin; Hansen, Kim P; Sumpf, Bernd; Hasler, Karl-Heinz; Erbert, Götz; Jensen, Ole B; Pedersen, Christian; Huber, Robert; Andersen, Peter E

    2010-07-19

    While swept source optical coherence tomography (OCT) in the 1050 nm range is promising for retinal imaging, there are certain challenges. Conventional semiconductor gain media have limited output power, and the performance of high-speed Fourier domain mode-locked (FDML) lasers suffers from chromatic dispersion in standard optical fiber. We developed a novel light source with a tapered amplifier as gain medium, and investigated the FDML performance comparing two fiber delay lines with different dispersion properties. We introduced an additional gain element into the resonator, and thereby achieved stable FDML operation, exploiting the full bandwidth of the tapered amplifier despite high dispersion. The light source operates at a repetition rate of 116 kHz with an effective average output power in excess of 30 mW. With a total sweep range of 70 nm, we achieved an axial resolution of 15 microm in air (approximately 11 microm in tissue) in OCT measurements. As our work shows, tapered amplifiers are suitable gain media for swept sources at 1050 nm with increased output power, while high gain counteracts dispersion effects in an FDML laser.

  13. Intersatellite range monitoring using optical interferometry.

    PubMed

    Pierce, R; Leitch, J; Stephens, M; Bender, P; Nerem, R

    2008-09-20

    We report on an interferometer designed to provide 1-10 nm/square root(Hz) displacement measurement resolution, in the range 0.01 Hz to 1 Hz, while in low Earth orbit. The interferometer comprises two units, each with its own laser and in separate satellites, which would be in the same orbit separated by approximately 50 km. We discuss the requirements on the interferometer subsystem and describe the optical transponder distance measurement, including a phase locking method to generate a heterodyne beat signal between the two lasers. Design, fabrication, and testing of a "flightlike" engineering model interferometer is outlined, and results from environmental and performance tests are reported.

  14. High-yield fabrication and properties of 1.4 nm nanodiamonds with narrow size distribution

    NASA Astrophysics Data System (ADS)

    Stehlik, Stepan; Varga, Marian; Ledinsky, Martin; Miliaieva, Daria; Kozak, Halyna; Skakalova, Viera; Mangler, Clemens; Pennycook, Timothy J.; Meyer, Jannik C.; Kromka, Alexander; Rezek, Bohuslav

    2016-12-01

    Detonation nanodiamonds (DNDs) with a typical size of 5 nm have attracted broad interest in science and technology. Further size reduction of DNDs would bring these nanoparticles to the molecular-size level and open new prospects for research and applications in various fields, ranging from quantum physics to biomedicine. Here we show a controllable size reduction of the DND mean size down to 1.4 nm without significant particle loss and with additional disintegration of DND core agglutinates by air annealing, leading to a significantly narrowed size distribution (±0.7 nm). This process is scalable to large quantities. Such molecular-sized DNDs keep their diamond structure and characteristic DND features as shown by Raman spectroscopy, infrared spectroscopy, STEM and EELS. The size of 1 nm is identified as a limit, below which the DNDs become amorphous.

  15. Second-harmonic generation of single BaTiO3 nanoparticles down to 22 nm diameter.

    PubMed

    Kim, Eugene; Steinbrück, Andrea; Buscaglia, Maria Teresa; Buscaglia, Vincenzo; Pertsch, Thomas; Grange, Rachel

    2013-06-25

    We investigate the second-harmonic generation (SHG) signal from single BaTiO3 nanoparticles of diameters varying from 70 nm down to 22 nm with a far-field optical microscope coupled to an infrared femtosecond laser. An atomic force microscope is first used to localize the individual particles and to accurately determine their sizes. Power and polarization-dependent measurements on the individual nanoparticles reveal a diameter range between 30 and 20 nm, where deviations from bulk nonlinear optical properties occur. For 22 nm diameter particles, the tetragonal crystal structure is not applicable anymore and competing effects due to the surface to volume ratio or crystallographic modifications are taking place. The demonstration of SHG from such small nanoparticles opens up the possibilities of using them as bright coherent biomarkers. Moreover, our work shows that measuring the SHG of individual nanoparticles reveals critical material properties, opening up new possibilities to investigate ferroelectricity at the nanoscale.

  16. High-yield fabrication and properties of 1.4 nm nanodiamonds with narrow size distribution.

    PubMed

    Stehlik, Stepan; Varga, Marian; Ledinsky, Martin; Miliaieva, Daria; Kozak, Halyna; Skakalova, Viera; Mangler, Clemens; Pennycook, Timothy J; Meyer, Jannik C; Kromka, Alexander; Rezek, Bohuslav

    2016-12-02

    Detonation nanodiamonds (DNDs) with a typical size of 5 nm have attracted broad interest in science and technology. Further size reduction of DNDs would bring these nanoparticles to the molecular-size level and open new prospects for research and applications in various fields, ranging from quantum physics to biomedicine. Here we show a controllable size reduction of the DND mean size down to 1.4 nm without significant particle loss and with additional disintegration of DND core agglutinates by air annealing, leading to a significantly narrowed size distribution (±0.7 nm). This process is scalable to large quantities. Such molecular-sized DNDs keep their diamond structure and characteristic DND features as shown by Raman spectroscopy, infrared spectroscopy, STEM and EELS. The size of 1 nm is identified as a limit, below which the DNDs become amorphous.

  17. High-yield fabrication and properties of 1.4 nm nanodiamonds with narrow size distribution

    PubMed Central

    Stehlik, Stepan; Varga, Marian; Ledinsky, Martin; Miliaieva, Daria; Kozak, Halyna; Skakalova, Viera; Mangler, Clemens; Pennycook, Timothy J.; Meyer, Jannik C.; Kromka, Alexander; Rezek, Bohuslav

    2016-01-01

    Detonation nanodiamonds (DNDs) with a typical size of 5 nm have attracted broad interest in science and technology. Further size reduction of DNDs would bring these nanoparticles to the molecular-size level and open new prospects for research and applications in various fields, ranging from quantum physics to biomedicine. Here we show a controllable size reduction of the DND mean size down to 1.4 nm without significant particle loss and with additional disintegration of DND core agglutinates by air annealing, leading to a significantly narrowed size distribution (±0.7 nm). This process is scalable to large quantities. Such molecular-sized DNDs keep their diamond structure and characteristic DND features as shown by Raman spectroscopy, infrared spectroscopy, STEM and EELS. The size of 1 nm is identified as a limit, below which the DNDs become amorphous. PMID:27910924

  18. Range imaging laser radar

    DOEpatents

    Scott, M.W.

    1990-06-19

    A laser source is operated continuously and modulated periodically (typically sinusoidally). A receiver imposes another periodic modulation on the received optical signal, the modulated signal being detected by an array of detectors of the integrating type. Range to the target determined by measuring the phase shift of the intensity modulation on the received optical beam relative to a reference. The receiver comprises a photoemitter for converting the reflected, periodically modulated, return beam to an accordingly modulated electron stream. The electron stream is modulated by a local demodulation signal source and subsequently converted back to a photon stream by a detector. A charge coupled device (CCD) array then averages and samples the photon stream to provide an electrical signal in accordance with the photon stream. 2 figs.

  19. Range imaging laser radar

    DOEpatents

    Scott, Marion W.

    1990-01-01

    A laser source is operated continuously and modulated periodically (typicy sinusoidally). A receiver imposes another periodic modulation on the received optical signal, the modulated signal being detected by an array of detectors of the integrating type. Range to the target determined by measuring the phase shift of the intensity modulation on the received optical beam relative to a reference. The receiver comprises a photoemitter for converting the reflected, periodically modulated, return beam to an accordingly modulated electron stream. The electron stream is modulated by a local demodulation signal source and subsequently converted back to a photon stream by a detector. A charge coupled device (CCD) array then averages and samples the photon stream to provide an electrical signal in accordance with the photon stream.

  20. Structure, stability, and formation pathways of colloidal gels in systems with short-range attraction and long-range repulsion.

    PubMed

    van Schooneveld, Matti M; de Villeneuve, Volkert W A; Dullens, Roel P A; Aarts, Dirk G A L; Leunissen, Mirjam E; Kegel, Willem K

    2009-04-09

    We study colloidal gels formed upon centrifugation of dilute suspensions of spherical colloids (radius 446 nm) that interact through a long-range electrostatic repulsion (Debye length approximately 850 nm) and a short-range depletion attraction (approximately 12.5 nm), by means of confocal scanning laser microscopy (CSLM). In these systems, at low colloid densities, colloidal clusters are stable. Upon increasing the density by centrifugation, at different stages of cluster formation, we show that colloidal gels are formed that significantly differ in structure. While significant single-particle displacements do not occur on the hour time scale, the different gels slowly evolve within several weeks to a similar structure that is at least stable for over a year. Furthermore, while reference systems without long-range repulsion collapse into dense glassy states, the repulsive colloidal gels are able to support external stress in the form of a centrifugal field of at least 9g.

  1. Coherent 455 nm beam production in a cesium vapor.

    PubMed

    Schultz, J T; Abend, S; Döring, D; Debs, J E; Altin, P A; White, J D; Robins, N P; Close, J D

    2009-08-01

    We observe coherent, cw, 455 nm blue-beam production via frequency upconversion in cesium vapor. Two IR lasers induce strong double excitation in a heated cesium vapor cell, allowing the atoms to undergo a double cascade and produce a coherent, collimated, blue beam copropagating with the two IR pump lasers.

  2. 77 FR 62481 - Radio Broadcasting Services; Crownpoint, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Crownpoint, NM AGENCY: Federal Communications....415 and 1.420. List of Subjects in 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications... preamble, the Federal Communications Commission proposes to amend 47 CFR Part 73 as follows: PART...

  3. 78 FR 72141 - New Mexico Disaster Number NM-00037

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... ADMINISTRATION New Mexico Disaster Number NM-00037 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4148-DR), dated 09/30/2013. Incident: Severe Storms and... Private Non-Profit organizations in the State of New Mexico, dated 09/30/2013, is hereby amended...

  4. 77 FR 55523 - New Mexico Disaster #NM-00029

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-10

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00029 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4079-DR), dated 08/24/2012. Incident: Flooding. Incident Period:...

  5. 78 FR 61999 - New Mexico Disaster #NM-00037

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-10

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00037 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4148-DR), dated 09/30/2013. Incident: Severe Storms and Flooding....

  6. 75 FR 57538 - New Mexico Disaster # NM-00016

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00016 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 1936-DR), dated 09/13/2010. Incident: Severe Storms and Flooding....

  7. 76 FR 81553 - New Mexico Disaster Number NM-00024

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ... ADMINISTRATION New Mexico Disaster Number NM-00024 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4047-DR), dated 11/23/2011. Incident: Flooding. Incident... Non-Profit organizations in the State of New Mexico, dated 11/23/2011, is hereby amended to...

  8. 77 FR 63409 - New Mexico Disaster Number NM-00029

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... ADMINISTRATION New Mexico Disaster Number NM-00029 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4079-DR), dated 08/24/2012. Incident: Flooding. Incident... Non-Profit organizations in the State of NEW MEXICO, dated 08/24/2012, is hereby amended to...

  9. 78 FR 73581 - New Mexico Disaster Number NM-00035

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... ADMINISTRATION New Mexico Disaster Number NM-00035 AGENCY: U.S. Small Business Administration. ACTION: Amendment... Assistance Only for the State of New Mexico (FEMA-4152-DR), dated 10/29/2013. Incident: Severe Storms... disaster declaration for Private Non-Profit organizations in the State of New Mexico, dated 10/29/2013,...

  10. 76 FR 2431 - New Mexico Disaster #NM-00016

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ... ADMINISTRATION New Mexico Disaster NM-00016 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1... Only for the State of New Mexico (FEMA-1936-DR), dated 09/13/2010. Incident: Severe Storms and Flooding... Private Non-Profit organizations in the State of NEW MEXICO, dated 09/13/2010, is hereby amended...

  11. 76 FR 18289 - New Mexico Disaster #NM-00020

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00020 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 1962-DR), dated 03/24/2011. Incident: Severe Winter Storm and Extreme...

  12. 78 FR 66982 - New Mexico Disaster #NM-00035

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION New Mexico Disaster NM-00035 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of New Mexico (FEMA- 4152-DR), dated 10/29/2013. Incident: Severe storms, flooding, and...

  13. 77 FR 41874 - New Mexico Disaster #NM-00025

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-16

    ... ADMINISTRATION New Mexico Disaster NM-00025 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of New Mexico dated 07/09/2012. Incident: Little Bear Fire. Incident Period: 06/04/2012 and continuing. Effective Date:...

  14. 77 FR 47907 - New Mexico Disaster #NM-00025

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-10

    ... ADMINISTRATION New Mexico Disaster NM-00025 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Administrative declaration of a disaster for the State of NEW MEXICO, dated 07/09/2012. Incident: Little Bear Fire. Incident Period: 06/04/2012 through 07/30/2012....

  15. EUV optical design for 100 nm CD imaging system

    SciTech Connect

    Sweeney, D.W.; Hudyma, R.; Chapman, H.B.; Shafer, D.

    1998-04-09

    The imaging specifications for extreme ultraviolet lithography (EUVL) projection optics parallel those of other optical lithographies. Specifications are scaled to reflect the 100 nm critical dimension for the first generation EUVL systems. The design being fabricated for the Engineering Test Stand, an EUVL alpha tool, consists of a condenser with six channels to provide an effective partial coherence factor of 0.7. The camera contains four mirrors; three of the mirrors are aspheres and the fourth is spherical. The design of the optical package has been constrained so that the angles of incidence and the variations in the angle of incidence of all rays allow for uniform multilayer coatings. The multilayers introduce a slight shift in image position and magnification. We have shown that a system aligned with visible light is also aligned at 13.4 nm. Each mirror must be fabricated with an RMS figure error of less than 0.25 nm and better than 0.2 nm RMS roughness. Optical surfaces that exceed each of these specifications individually have been fabricated. The success of EUVL requires that these specifications be met simultaneously.

  16. Microstructure of 100 nm damascene copper overburden and lines

    NASA Astrophysics Data System (ADS)

    Geiss, R. H.; Read, D. T.

    2007-09-01

    A detailed understanding of the crystallography of metallic conductors in modern interconnect systems is essential if we are to understand the influence of processing parameters on performance and reliability. In particular we must be able to evaluate the grain size, crystallographic orientation and residual elastic stress for interconnect lines having widths of tens of nm. Transmission electron microscopy might be the obvious choice, but sample preparation and small sample size make this technique unattractive. On the other hand, electron backscatter diffraction, EBSD, in a scanning electron microscope provides a very attractive tool. Sample preparation can be relatively simple, especially if one investigates the structures immediately after CMP; whole wafers may be measured if desired. One limitation to EBSD is that good diffraction patterns are obtained only from free surfaces and from a limited depth, say a few hundred nm in copper. Here EBSD will be used to compare structures for the pads and 100-nm lines in two variants of a commercial copper damascene interconnect structure. EBSD data collection will be discussed as optimized for characterizing differences in the texture, which were attributed to differences in the processing. By a unique approach to EBSD mapping we found that neither the texture nor the grain size of the overburden, as represented by the contact pads, propagated into the 100 nm lines, though they did propagate into some wider lines.

  17. The Photochemistry of Cyano and Dicyanoacetylene at 193 nm.

    DTIC Science & Technology

    1987-07-28

    Halpern, L. Petway , R. Lu, W.M. Jackson, and V.R. McCrary and W. Nottingham Prepared for submission to the Journal of Chemical Physics Department of...CYANO- AND DICYANOACETYLENE AT 193 NM By J. B. Halpern% L. Petway , R. Lu W. M. Jackson , and V. R. McCrary Department of Chemistry Howard University

  18. 78 FR 66982 - Santa Clara Pueblo Disaster #NM-00039

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... ADMINISTRATION Santa Clara Pueblo Disaster NM-00039 AGENCY: U.S. Small Business Administration. ACTION: Notice... for the Santa Clara Pueblo (FEMA- 4151-DR), dated 10/29/2013. Incident: Severe Storms and Flooding... disaster: Primary Areas: Santa Clara Pueblo. The Interest Rates are: Percent For Physical Damage:...

  19. High average power, narrow band 248 nm alexandrite laser system

    SciTech Connect

    Kuper, J.W.; Chin, T.C.; Papanestor, P.A.

    1994-12-31

    A compact line-narrowed 248 nm solid state laser source operating at 15 mJ {at} 100 Hz PRF was demonstrated. Constraints due to thermal loading of components were addressed. Tradeoffs between pulse energy and repetition rate were investigated. A method for overcoming thermal dephasing in the THG material was achieved by scanning a slab shaped crystal.

  20. Holographic voltage profiling on 75 nm gate architecture CMOS devices.

    PubMed

    Thesen, Alexander E; Frost, Bernhard G; Joy, David C

    2003-04-01

    Voltage profiles of the source-drain region of a CMOS transistor with 75nm gate architecture taken from an off-the-shelf Intel PIII processor are presented. The sample preparation using a dual beam system is discussed as well as details of the electron optical setup of the microscope. Special attention is given to the analysis of the reconstructed holograms.