Science.gov

Sample records for 350-1000 nm obtained

  1. Obtaining 1-10 nm optimal beam spot size in the magnetic quadrupole nanoprobe

    NASA Astrophysics Data System (ADS)

    Dymnikov, A.; Glass, G.

    2012-02-01

    Focusing of high energy charged particles in an octuplet lens system comprised of two Russian quadruplets, defined as the Lafayette Octuplet, is investigated. This octuplet is a zoom system having the same demagnifications, the same focal lengths, and the same positions of the focal points in xz and yz planes as the Russian quadruplet. In this study the matrix method of embedding in the space of the phase moments is used to solve the non-linear equations of motion. With this method all the advantages of the linear differential equations are used, including the independence of the matrizant of the non-linear motion on the choice of the initial point of the phase space. For the same phase volume (or beam current) the spot size is minimized (optimized) by a set of two optimal matching slits: objective and divergence slits. This optimal spot size is a function of the four-dimensional emittance and both geometric and optical parameters of the system. Geometric parameters include total system length, lens lengths, drift spaces, object and working distances, minimum attainable slit openings while optical parameters include demagnifications, spherical and chromatic aberrations. The optimal beam spot size and appropriate optimal slits have been found as functions of the emittance of the system for different geometries. It is shown that the octuplets investigated here allow the possibility to obtain 1-10 nm optimal beam spot sizes. The influence of the beam energy spread on the optimal beam spot size is studied.

  2. 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.

  3. Three-dimensional locations of gold-labeled proteins in a whole mount eukaryotic cell obtained with 3nm precision using aberration-corrected scanning transmission electron microscopy.

    PubMed

    Dukes, Madeline J; Ramachandra, Ranjan; Baudoin, Jean-Pierre; Gray Jerome, W; de Jonge, Niels

    2011-06-01

    Three-dimensional (3D) maps of proteins within the context of whole cells are important for investigating cellular function. However, 3D reconstructions of whole cells are challenging to obtain using conventional transmission electron microscopy (TEM). We describe a methodology to determine the 3D locations of proteins labeled with gold nanoparticles on whole eukaryotic cells. The epidermal growth factor receptors on COS7 cells were labeled with gold nanoparticles, and critical-point dried whole-mount cell samples were prepared. 3D focal series were obtained with aberration-corrected scanning transmission electron microscopy (STEM), without tilting the specimen. The axial resolution was improved with deconvolution. The vertical locations of the nanoparticles in a whole-mount cell were determined with a precision of 3nm. From the analysis of the variation of the axial positions of the labels we concluded that the cellular surface was ruffled. To achieve sufficient stability of the sample under electron beam irradiation during the recording of the focal series, the sample was carbon coated. A quantitative method was developed to analyze the stability of the ultrastructure after electron beam irradiation using TEM. The results of this study demonstrate the feasibility of using aberration-corrected STEM to study the 3D nanoparticle distribution in whole cells.

  4. 50W CW visible laser source at 589nm obtained via frequency doubling of three coherently combined narrow-band Raman fibre amplifiers.

    PubMed

    Taylor, Luke R; Feng, Yan; Calia, Domenico Bonaccini

    2010-04-12

    We demonstrate the cascaded coherent collinear combination of a seed-split triplet of 1178nm high-power narrow-band (sub-1.5MHz) SBS-suppressed CW Raman fibre amplifiers via nested free-space constructive quasi-Mach-Zehnder interferometry, after analysing the combination of the first two amplifiers in detail. Near-unity combination and cascaded-combination efficiencies are obtained at all power levels up to a maximum P(1178) > 60W. Frequency doubling of this cascaded-combined output in an external resonant cavity yields P(589) > 50W with peak conversion efficiency eta(589) ~85%. We observe no significant differences between the SHG of a single, combined pair or triplet of amplifiers. Although the system represents a successful power scalability demonstrator for fibre-based Na-D(2a)-tuned mesospheric laser-guide-star systems, we emphasise its inherent wavelength versatility and consider its spectroscopic and near-diffraction-limited qualities equally well suited to other applications.

  5. Maximum frequency of oscillation of 1.3 THz obtained by using an extended drain-side recess structure in 75-nm-gate InAlAs/InGaAs high-electron-mobility transistors

    NASA Astrophysics Data System (ADS)

    Takahashi, Tsuyoshi; Kawano, Yoichi; Makiyama, Kozo; Shiba, Shoichi; Sato, Masaru; Nakasha, Yasuhiro; Hara, Naoki

    2017-02-01

    A maximum frequency of oscillation (f max) of 1.3 THz was achieved using an extended drain-side recess structure of InAlAs/InGaAs high-electron-mobility transistors (HEMTs), although the gate length was relatively long at 75 nm. The high f max was improved by reducing the drain output conductance (g d). The use of an asymmetric gate recess structure and double-side doping above and below a channel region were effective in reducing g d. Further improvements in transconductance (g m) and g d were achieved by reducing the distance between the source and gate electrodes.

  6. Changes in Precipitation Sources over Glacial/Interglacial MIS 11 and 12 Examined by Δ17O of SiO2 Obtained from Diatoms along the Valles Caldera Lake Core, NM

    NASA Astrophysics Data System (ADS)

    Gibbons, J.; Sharp, Z. D.; Fawcett, P. J.

    2015-12-01

    Quantitative estimates of the isotopic composition of paleo-lake water have been made using 18O/16O (ẟ18O) in diatom silica (Dodd and Sharp, GCA, 2010). Post-mortem diatom silica equilibrates with ambient lake water within six months, chronicling the bulk oxygen isotope composition of the lake and resulting in silica that is near the quartz-water fractionation line (Dodd et al, GGG, 2012). The δ18O values of lacustrine diatoms from the Valles Caldera, NM, vary by ~25‰ between glacial and interglacial periods and suggest a collapse of the summer monsoon that currently provides 50% of the modern precipitation in NM. Triple oxygen isotope measurements of diatom silica may serve as a proxy for the isotopic composition of the lake water and as an estimate of paleo-humidity over the precipitation source. The deuterium excess parameter (d= ẟD - 8 ẟ18O) has been used along ice cores as a source relative humidity index, but is difficult to make in lake sediments. Instead, high precision 17O-excess (∆17O) measurements (=ẟ17O - 0.528 ẟ18O) may provide paleo-humidity information. Landais et al. (GRL, 2008) found a ∆17O difference of 0.02‰ in the Vostok ice core between glacial and interglacial times, interpreted as a function of changing relative humidity of the precipitation source. A 0.03‰ change was observed in glacial (∆17O=-0.22‰) and interglacial (∆17O=-0.19‰) diatom silica along the Valles Caldera lake core. Further information regarding the δ18O value of meteoric water can be calculated from paired δ18O-δ17O measurements. The combined δ18O-δ17O values of interglacial diatoms suggest a δ18Ometeoric water value of -9‰. Modern δ18O value of monsoonal precipitation in NM is ~-10‰. The δ18O of glacial diatoms suggest a δ18Ometeoric water = -20‰. Modern δ18O value of winter precipitation in NM is ~-20‰. These results suggest that the seasonality of precipitation in New Mexico can be inferred based on changes in the relative

  7. 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.

  8. 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%.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Obtaining and maintaining funding

    SciTech Connect

    Beverly Hartline

    1996-04-01

    Obtaining and maintaining funding is important for individuals, groups, institutions, and fields. This challenge is easier during times of abundant and growing resources than it is now, when funding is tight and shrinking. Thus, to obtain and maintain funding will require: maintaining healthy funding levels for all of science; maintaining healthy funding levels for the field(s) you work in; and competing successfully for the available funds. Everyone should pay attention to the overall prospects for science funding and dedicate some effort to working with others to grow the constituency for science. Public support is likely an important prerequisite for keeping future science budgets high. In this context, researchers should share with society at large the benefits of their research, so that taxpayers can see and appreciate some return from the federal investment in science. Assuming this effort is successful, and there continue to be government and private organizations with substantial resources to invest in research, what can the individual investigator do to improve her chances? She can be clear about her goal(s) and carefully plan her effort to make maximum progress for minimum resources, especially early in her career while she is establishing a solid professional reputation. Specific useful strategies include: brainstorm funding options and select the most promising one(s); be persistent but flexible, responsive to new information and changing circumstances; provide value and assistance to prospective funding sources both before and after receiving funding; know the funding agents and what their goals are, they are the customers; promise a lot and always deliver more; build partnerships and collaboration to leverage interest and resources; and develop capabilities and ideas with a promising, irresistible future. There is no guarantee of success. For the best chances, consistently contribute positively and productively in all your efforts, and continue to

  2. 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.

  3. Obtaining an equivalent beam

    NASA Technical Reports Server (NTRS)

    Butler, Thomas G.

    1990-01-01

    In modeling a complex structure the researcher was faced with a component that would have logical appeal if it were modeled as a beam. The structure was a mast of a robot controlled gantry crane. The structure up to this point already had a large number of degrees of freedom, so the idea of conserving grid points by modeling the mast as a beam was attractive. The researcher decided to make a separate problem of of the mast and model it in three dimensions with plates, then extract the equivalent beam properties by setting up the loading to simulate beam-like deformation and constraints. The results could then be used to represent the mast as a beam in the full model. A comparison was made of properties derived from models of different constraints versus manual calculations. The researcher shows that the three-dimensional model is ineffective in trying to conform to the requirements of an equivalent beam representation. If a full 3-D plate model were used in the complete representation of the crane structure, good results would be obtained. Since the attempt is to economize on the size of the model, a better way to achieve the same results is to use substructuring and condense the mast to equivalent end boundary and intermediate mass points.

  4. 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

  5. Spectroscopic Classification of PSN J14324449+0953123

    NASA Astrophysics Data System (ADS)

    Valenti, S.; Sand, D.; Parrent, J. T.; Graham, M. L.; Howell, D. A.

    2013-02-01

    We report spectroscopic observation of PSN J14324449+0953123 (listed on the IAU Central Bureau's TOCP page). A spectrum (range 350-1000 nm) obtained robotically on Feb. 18.70 UT with the FLOYDS (FTS) spectrograph shows it to be a young type-II supernova. The spectrum shows a blue continuum with a broad feature at ~ 4600A. The Balmer lines are not visible. Comparisons with a library of supernova spectra using the "GELATO" code (Harutyunyan et al.

  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. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Sub-10 nm lateral spatial resolution in scanning capacitance microscopy achieved with solid platinum probes

    NASA Astrophysics Data System (ADS)

    Bussmann, E.; Williams, C. C.

    2004-02-01

    Sub-10 nm resolution can be obtained in scanning capacitance microscopy (SCM) if the probe tip is approximately of the same size. Such resolution is observed, although infrequently, with present commercially available probes. To acquire routine sub-10 nm resolution, a solid Pt metal probe has been developed with a sub-10 nm tip radius. The probe is demonstrated by SCM imaging on a cross-sectioned 70 nm gatelength field-effect transistor (FET), a shallow implant (n+/p, 24 nm junction depth), and an epitaxial staircase (p, ˜75 nm steps). Sub-10 nm resolution is demonstrated on the FET device over the abrupt meeting between a silicon-on-insulator oxide layer and a neighboring Si region. Comparable resolution is observed on the implant structure, and quantitative SCM dopant profiling is performed on it with sub-10 nm accuracy. Finally, the epitaxial staircase structure is quantitatively profiled demonstrating the accuracy obtained in quantitative profiling with the tips.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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%.

  19. 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).

  20. 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

  1. 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.

  2. 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.

  3. High-efficiency fiber laser at 1018 nm using Yb-doped phosphosilicate fiber.

    PubMed

    Wang, Jianhua; Chen, Gui; Zhang, Lei; Hu, Jinmeng; Li, Jinyan; He, Bing; Chen, Jinbao; Gu, Xijia; Zhou, Jun; Feng, Yan

    2012-10-10

    A high-efficiency fiber laser at 1018 nm using homemade Yb-doped phosphosilicate fiber is demonstrated. The fiber shows blueshifted emission spectrum compared to Yb-doped aluminosilicate fiber, and is considered favorable for the short wavelength Yb-doped fiber laser. With a 7 m gain fiber, up to 22.8 W output at 1018 nm is achieved with an optical efficiency of 53%. The amplified spontaneous emission at 1030 nm is suppressed to 50 dB below the 1018 nm laser. This work shows that highly-efficient fiber laser at 1018 nm can be obtained with Yb-doped phosphosilicate fiber.

  4. Nd:YAG laser diode-pumped directly into the emitting level at 938 nm.

    PubMed

    Sangla, Damien; Balembois, François; Georges, Patrick

    2009-06-08

    We present the first demonstration of Nd:YAG laser pumped directly in band at 938 nm with a high-brightness fiber-coupled laser diode. Up to 6 W of CW laser emission at 1064 nm have been obtained under an absorbed pump power of 28 W at 938 nm. A comparison between 808 nm and 938 nm pumping, realized by thermal cartography, demonstrates the very low heat generation of in-band pumping. Numerical simulations were also implemented to study and discuss the laser performance of our system.

  5. 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.

  6. 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.

  7. Barometric coefficients for different neutron multiplicities according to ESA NM data (Israel) and data of University "Roma Tre" NM (Italy)

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Iucci, N.; Sternlieb, A.; Villoresi, G.; Zukermann, I. G.

    2001-08-01

    On the basis of hourly data obtained by neutron monitor (NM) of Emilio Segre' Observatory (height 2025 ma bove s. l., cut-off rigidity for vertical direction 10.8 GV) and by NM of University "Roma Tre" (about sea level, cutoff rigidity 6.7 GV) we determine barometric coefficients both stations for total neutron intensity and for multiplicities m ≥ 1, m ≥ 2, m ≥ 3, m ≥ 4, m ≥ 5, m ≥ 6, m ≥ 7,a nd m ≥ 8, as well as for m=1, m=2, m=3, m=4, m=5, m=6,a nd m=7. We determine also for each hour the effective multiplicity for m ≥ 8 and estimate the barometricc oefficient for for both NM sections. We used hourly data from June 1998 up to April 2001, and we excludedp eriods when above the NM of Emilio Segre' Observatoryw as snow. We compare obtained results with expected according to the theory of meteorological effects for totaln eutron component and for neutron multiplicities.

  8. Characterization of SAL605 negative resist at {lambda}=13 nm

    SciTech Connect

    La Fontaine, B.; Ciarlo, D.; Gaines, D.P.; Kania, D.R.

    1996-05-24

    We have characterized the response of the negative resist SAL605 in the extreme ultraviolet ({lambda}=13 nm). The sensitivity was found to be {approx}1 mJ/cm{sup 3} for all conditions studied. We have identified processing conditions leading to high ({gamma}{gt}4) contrast. The resist response was modeled using Prolith/2 and the development parameters were obtained from the exposure curves.

  9. 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.

  10. Depth-of-focus (DoF) analysis of a 193nm superlens imaging structure.

    PubMed

    Shi, Zhong; Kochergin, Vladimir; Wang, Fei

    2009-10-26

    We present a design of a 193 nm superlens imaging structure to enable the printing of 20 nm features. Optical image simulations indicate that the 20 nm resolution is feasible for both the periodic grating feature and the two-slit feature. Nominal depth-of-focus (DoF) position for both features is identified through the image contrast calculations. Simulations show that the two features have a common nominal dose at the nominal DoF to resolve 20 nm critical dimension when a suitable dielectric material is placed between mask and superlens layer. A DoF of micro8 nm is shown to be obtainable for the 20 nm half-pitch grating feature while the respective DoF for the two-slit feature is less than 8 nm which potentially can be enhanced by employing existing lithographic resolution enhancement techniques.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Advances in 193 nm excimer lasers for mass spectrometry applications

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Esser, Hans-Gerd; Bonati, Guido

    2016-03-01

    Ongoing progress in mass analysis applications such as laser ablation inductively coupled mass spectrometry of solid samples and ultraviolet photoionization mediated sequencing of peptides and proteins is to a large extent driven by ultrashort wavelength excimer lasers at 193 nm. This paper will introduce the latest improvements achieved in the development of compact high repetition rate excimer lasers and elaborate on the impact on mass spectrometry instrumentation. Various performance and lifetime measurements obtained in a long-term endurance test over the course of 18 months will be shown and discussed in view of the laser source requirements of different mass spectrometry tasks. These sampling type applications are served by excimer lasers delivering pulsed 193 nm output of several mJ as well as fast repetition rates which are already approaching one Kilohertz. In order to open up the pathway from the laboratory to broader market industrial use, sufficient component lifetimes and long-term stable performance behavior have to be ensured. The obtained long-term results which will be presented are based on diverse 193 nm excimer laser tube improvements aiming at e.g. optimizing the gas flow dynamics and have extended the operational life the laser tube for the first time over several billion pulses even under high duty-cycle conditions.

  17. 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.

  18. Study of the emission spectra of a 1320-nm semiconductor disk laser and its second harmonic

    SciTech Connect

    Gochelashvili, K S; Derzhavin, S I; Evdokimova, O N; Zolotovskii, I O; Podmazov, S V

    2016-03-31

    The spectral characteristics of an optically pumped external-cavity semiconductor disk laser near λ = 1320 nm are studied experimentally. Intracavity second harmonic generation is obtained using an LBO nonlinear crystal. The output power at a wavelength of 660 nm in the cw regime was 620 mW, and the peak power in the pulsed regime was 795 mW. (lasers)

  19. 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.

  20. 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.

  1. 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

  2. Preparation of sub-100-nm beta-lactoglobulin (BLG) nanoparticles.

    PubMed

    Ko, Sanghoon; Gunasekaran, Sundaram

    2006-12-01

    Sub-100-nm nanoparticles were prepared from beta-lactoglobulin (BLG) with a narrow size distribution by a desolvation method using glutaraldehyde for cross-linking. With pre-heating of the BLG solution to 60 degrees C and subsequent pH readjustment to 9.0, nanoparticles of 59 +/- 5 nm were obtained with improved uniformity. Bovine serum albumin (BSA) nanoparticles, prepared under similar conditions for comparison, were larger and less uniform. The half-width of 80% particle distribution was used to compare the uniformity of particle size distribution. The stability of the nanoparticles was investigated by degradation tests at neutral and acidic pHs with and without proteolytic enzymes, trypsin and pepsin. The degradation time, determined by a graphical approach, was used to compare the relative stabilities of BLG and BSA nanoparticles. The particles of BLG were more stable than those of BSA in acidic and neutral media with and without added enzymes.

  3. 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.

  4. Ultraviolet (250-550  nm) absorption spectrum of pure water.

    PubMed

    Mason, John D; Cone, Michael T; Fry, Edward S

    2016-09-01

    Data for the spectral light absorption of pure water from 250 to 550 nm have been obtained using an integrating cavity made from a newly developed diffuse reflector with a very high UV reflectivity. The data provide the first scattering-independent measurements of absorption coefficients in the spectral gap between well-established literature values for the absorption coefficients in the visible (>400  nm) and UV (<200  nm). A minimum in the absorption coefficient has been observed in the UV at 344 nm; the value is 0.000811±0.000227  m-1.

  5. All-solid-state parametric Raman anti-Stokes laser at 508 nm.

    PubMed

    Mildren, R P; Coutts, D W; Spence, D J

    2009-01-19

    We report a parametric anti-Stokes Raman laser using potassium gadolinium tungstate, generating output chiefly at the first anti-Stokes at 508 nm. The compact 4.5 cm long device is pumped by a Q-switched 532 nm laser and uses an off-axis Stokes resonator to provide non-collinear phase matching between the pump and the generated Stokes and anti-Stokes fields. Anti-Stokes output energies up 0.27 mJ were obtained at a conversion efficiency from the pump of 0.46%. Second- and third-order anti-Stokes lines at 486 nm and 465 nm were also observed.

  6. 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).

  7. 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.

  8. 1064 nm rotational Raman lidar for particle extinction and lidar-ratio profiling: cirrus case study

    NASA Astrophysics Data System (ADS)

    Haarig, Moritz; Engelmann, Ronny; Ansmann, Albert; Veselovskii, Igor; Whiteman, David N.; Althausen, Dietrich

    2016-09-01

    For the first time, vertical profiles of the 1064 nm particle extinction coefficient obtained from Raman lidar observations at 1058 nm (nitrogen and oxygen rotational Raman backscatter) are presented. We applied the new technique in the framework of test measurements and performed several cirrus observations of particle backscatter and extinction coefficients, and corresponding extinction-to-backscatter ratios at the wavelengths of 355, 532, and 1064 nm. The cirrus backscatter coefficients were found to be equal for all three wavelengths keeping the retrieval uncertainties in mind. The multiple-scattering-corrected cirrus extinction coefficients at 355 nm were on average about 20-30 % lower than the ones for 532 and 1064 nm. The cirrus-mean extinction-to-backscatter ratio (lidar ratio) was 31 ± 5 sr (355 nm), 36 ± 5 sr (532 nm), and 38 ± 5 sr (1064 nm) in this single study. We further discussed the requirements needed to obtain aerosol extinction profiles in the lower troposphere at 1064 nm with good accuracy (20 % relative uncertainty) and appropriate temporal and vertical resolution.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Laser cooling of beryllium ions using a frequency-doubled 626 nm diode laser.

    PubMed

    Cozijn, F M J; Biesheuvel, J; Flores, A S; Ubachs, W; Blume, G; Wicht, A; Paschke, K; Erbert, G; Koelemeij, J C J

    2013-07-01

    We demonstrate laser cooling of trapped beryllium ions at 313 nm using a frequency-doubled extended cavity diode laser operated at 626 nm, obtained by cooling a ridge waveguide diode laser chip to -31°C. Up to 32 mW of narrowband 626 nm laser radiation is obtained. After passage through an optical isolator and beam shaping optics, 14 mW of 626 nm power remains of which 70% is coupled into an external enhancement cavity containing a nonlinear crystal for second-harmonic generation. We produce up to 35 μW of 313 nm radiation, which is subsequently used to laser cool and detect 6×10(2) beryllium ions, stored in a linear Paul trap, to a temperature of about 10 mK, as evidenced by the formation of Coulomb crystals. Our setup offers a simple and affordable alternative for Doppler cooling, optical pumping, and detection to presently used laser systems.

  14. New filter rating method in practice for sub-30-nm lithography process filter

    NASA Astrophysics Data System (ADS)

    Umeda, Toru; Mizuno, Takehito; Tsuzuki, Shuichi; Numaguchi, Toru

    2010-04-01

    A new method for rating retention in lithography process filters has been developed. The method employs a gold nanoparticle contaminant challenge, inductively coupled plasma mass spectrometry as a concentration detector, and dynamic light scattering as a particle size detector, all of which enable accurate, reliable filter retention rating below 30 nm. There is good agreement between results obtained with the new method and results obtained with a conventional polystyrene latex bead challenge. A filter that was rated at 10 nm using extrapolative methods was confirmed to be 10 nm using the new challenge test. Microbridge removal efficiency of polyethylene filters rated by the new method was studied in a 193 nm (dry) lithography process and the new method was verified. When applied to commercially available filters that are rated below 30 nm, the new method revealed significant differences in removal efficiency among similarly labeled filters.

  15. Development of high coherence high power 193nm laser

    NASA Astrophysics Data System (ADS)

    Tanaka, Satoshi; Arakawa, Masaki; Fuchimukai, Atsushi; Sasaki, Yoichi; Onose, Takashi; Kamba, Yasuhiro; Igarashi, Hironori; Qu, Chen; Tamiya, Mitsuru; Oizumi, Hiroaki; Ito, Shinji; Kakizaki, Koji; Xuan, Hongwen; Zhao, Zhigang; Kobayashi, Yohei; Mizoguchi, Hakaru

    2016-03-01

    We have been developing a hybrid 193 nm ArF laser system that consists of a solid state seeding laser and an ArF excimer laser amplifier for power-boosting. The solid state laser consists of an Yb-fiber-solid hybrid laser system and an Er-fiber laser system as fundamentals, and one LBO and three CLBO crystals for frequency conversion. In an ArF power amplifier, the seed laser passes through the ArF gain media three times, and an average power of 110 W is obtained. As a demonstration of the potential applications of the laser, an interference exposure test is performed.

  16. 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.

  17. Thin hardmask patterning stacks for the 22-nm node

    NASA Astrophysics Data System (ADS)

    Zhu, Zhimin; Piscani, Emil; Wang, Yubao; Macie, Jan; Neef, Charles J.; Smith, Brian

    2009-03-01

    This paper presents robust trilayer lithography technology for cutting-edge IC fabrication and double-patterning applications. The goal is to reduce the thickness of a silicon hardmask so that the minimum thickness of the photoresist is not limited by the etch budget and can be optimized for lithography performance. Successful results of pattern etching through a 300-nm carbon layer are presented to prove that a 13.5-nm silicon hardmask is thick enough to transfer the line pattern. Another highlight of this work is the use of a simulation tool to design the stack so that UV light is concentrated at the bottom of the trenches. This design helps to clear the resist in the trenches and prevent resist top loss. An experiment was designed to validate the assumption with 45-nm dense lines at various exposure doses, using an Exitech MS-193i immersion microstepper (NA = 1.3) at the SEMATECH Resist Test Center. Results show that such a stack design obtains very wide CD processing window and is robust for 1:3 line patterning at the diffraction limit, as well as for patterning small contact holes.

  18. Photoelectron Emission Studies in CsBr at 257 nm

    SciTech Connect

    Maldonado, Juan R.; Liu, Zhi; Sun, Yun; Pianetta, Piero A.; Pease, Fabian W.; /Stanford U., Elect. Eng. Dept. /SLAC, SSRL

    2006-09-28

    CsBr/Cr photocathodes were found [1,2] to meet the requirements of a multi-electron beam lithography system operating with a light energy of 4.8 eV (257nm). The fact that photoemission was observed with a light energy below the reported 7.3 eV band gap for CsBr was not understood. This paper presents experimental results on the presence of intra-band gap absorption sites (IBAS) in CsBr thin film photo electron emitters, and presents a model based on IBAS to explain the observed photoelectron emission behavior at energies below band gap. A fluorescence band centered at 330 nm with a FWHM of about 0.34 eV was observed in CsBr/Cr samples under 257 nm laser illumination which can be attributed to IBAS and agrees well with previously obtained synchrotron photoelectron spectra[1] from the valence band of CsBr films.

  19. 450 nm diode laser: A new help in oral surgery

    PubMed Central

    Fornaini, Carlo; Rocca, Jean-Paul; Merigo, Elisabetta

    2016-01-01

    AIM To describe the performance of 450 nm diode laser in oral surgery procedures. METHODS The case described consisted of the removal of a lower lip fibroma through a blue diode laser (λ = 450 nm). RESULTS The efficacy of this device, even at very low power (1W, CW), allows us to obtain very high intra and postoperative comfort for the patient, even with just topical anaesthesia and without needing suture. The healing process was completed in one week and, during the follow-up, the patient did not report any problems, pain or discomfort even without the consumption of any kind of drugs, such as painkillers and antibiotics. The histological examination performed by the pathologist showed a large area of fibrous connective tissue with some portions of epithelium-connective detachments and a regular incision with very scanty areas of carbonization. CONCLUSION The 450 nm diode laser proved of being very efficient in the oral soft tissue surgical procedures, with no side effects for the patients. PMID:27672639

  20. Obtaining Public Records: Reporter Guide

    ERIC Educational Resources Information Center

    Hammond, Betsy

    2013-01-01

    Obtaining public records is essential to covering public education. Fortunately, the law is on the side of reporters: Public agencies generally must disclose their records to the public and to the media--with important exceptions. Public agencies are often reluctant to hand over records, however, even when the law clearly says they should.…

  1. Employment Obtaining and Business Starting

    ERIC Educational Resources Information Center

    Lan, Jian

    2009-01-01

    The implementation of business starting education in higher vocational colleges is of important and realistic meanings for cultivating advanced technology application-type talents and for releasing the employment obtaining pressure of higher vocational students. Based on the analysis on the employment situation of higher vocational graduates, this…

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Obtaining consent for eye donation.

    PubMed

    Diamond, G A; Campion, M; Mussoline, J F; D'Amico, R A

    1987-02-15

    We prospectively studied 100 consecutive deaths at St. Vincent's Hospital and Medical Center in New York City for possible eye donation. Fifty-two patients were unsuitable mainly because of medical contraindications and age at death. Of the 48 suitable candidates, 21 pairs (44%) of eyes were obtained. Sixteen of the 42 eyes (38%) were used for transplantation. Projection of the number of corneas obtainable for transplant in New York City were calculated. The figures indicated that the three-month waiting list of the New York Eye-Bank for Sight Restoration, Inc., could be eradicated if hospitals were able to get seven donors from every 100 deaths suitable for donation, a rate only 16% of that realized in this study.

  11. 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.

  12. Dielectric properties and microstructure of sintered BaTiO3 fabricated by using mixed 150-nm and 80-nm powders with various additives

    NASA Astrophysics Data System (ADS)

    Oh, Min Wook; Kang, Jae Won; Yeo, Dong Hun; Shin, Hyo Soon; Jeong, Dae Yong

    2015-04-01

    Recently, the use of small-sized BaTiO3 particles for ultra-thin MLCC research has increased as a method for minimizing the dielectric layer's thickness in thick film process. However, when particles smaller than 100 nm are used, the reduced particle size leads to a reduced dielectric constant. The use of nanoparticles, therefore, requires an increase in the amount of additive used due to the increase in the specific surface area, thus increasing the production cost. In this study, a novel method of coating 150-nm and 80-nm BaTiO3 powders with additives and mixing them together was employed, taking advantage of the effect obtained through the use of BaTiO3 particles smaller than 100 nm, to conveniently obtain the desired dielectric constant and thermal characteristics. Also, the microstructure and the dielectric properties were evaluated. The additives Dy, Mn, Mg, Si, and Cr were coated on a 150-nm powder, and the additives Dy, Mn, Mg, and Si were coated on 80-nm powder, followed by mixing at a ratio of 1:1. As a result, the microstructure revealed grain formation according to the liquid-phase additive Si; additionally, densification was well realized. However, non-reducibility was not obtained, and the material became a semiconductor. When the amount of added Mn in the 150-nm powder was increased to 0.2 and 0.3 mol%, insignificant changes in the microstructure were observed, and the bulk density after mixing was found to have increased drastically in comparison to that before mixing. Also, non-reducibility was obtained for certain conditions. The dielectric property was found to be consistent with the densification and the grain size. The mixed composition #1-0.3 had a dielectric constant over 2000, and the result somewhat satisfied the dielectric constant temperature dependency for X6S.

  13. 946 nm Diode Pumped Laser Produces 100mJ

    NASA Technical Reports Server (NTRS)

    Axenson, Theresa J.; Barnes, Norman P.; Reichle, Donald J., Jr.

    2000-01-01

    An innovative approach to obtaining high energy at 946 nm has yielded 101 mJ of laser energy with an optical-to-optical slope efficiency of 24.5%. A single gain module resonator was evaluated, yielding a maximum output energy of 50 mJ. In order to obtain higher energy a second gain module was incorporated into the resonator. This innovative approach produced un-surprised output energy of 101 mJ. This is of utmost importance since it demonstrates that the laser output energy scales directly with the number of gain modules. Therefore, higher energies can be realized by simply increasing the number of gain modules within the laser oscillator. The laser resonator incorporates two gain modules into a folded "M-shaped" resonator, allowing a quadruple pass gain within each rod. Each of these modules consists of a diode (stack of 30 microlensed 100 Watt diode array bars, each with its own fiber lens) end-pumping a Nd:YAG laser rod. The diode output is collected by a lens duct, which focuses the energy into a 2 mm diameter flat to flat octagonal pump area of the laser crystal. Special coatings have been developed to mitigate energy storage problems, including parasitic lasing and amplified spontaneous emission (ASE), and encourage the resonator to operate at the lower gain transition at 946 nm.

  14. 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.

  15. Detection of homemade explosives using Raman excitation at 1064 nm

    NASA Astrophysics Data System (ADS)

    Roy, Eric G.; Dentinger, Claire; Robotham, Claude

    2015-05-01

    Raman spectroscopy is a powerful tool for obtaining molecular structure information of a sample. While Raman spectroscopy is a common laboratory based analytical tool, miniaturization of opto-electronic components has allowed handheld Raman analyzers to become commercially available. These handheld systems are utilized by Military and Bomb squad operators tasked with rapidly identifying explosives in the field, sometimes in clandestine laboratories. However, one limitation of many handheld Raman detection systems is strong interference caused by fluorescence of the sample or underlying surface which obscures the characteristic Raman signature of the target analyte. Homemade explosives (HMEs) are produced in clandestine laboratories, and the products under these conditions are typically contaminated with degradation products, contaminants, and unreacted precursors. These contaminations often will have strong fluorescence. In this work, Raman spectra of both commercial explosives and HMEs were collected using a handheld Raman spectrometer with a 1064 nm excitation laser. While Raman scattering generated by a 1064 nm laser is inherently less efficient than excitation at shorter wavelengths, high quality spectra were easily obtained due to significantly reduced fluorescence of HMEs.

  16. 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.

  17. 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.

  18. External-cavity diamond Raman laser performance at 1240 nm and 1485 nm wavelengths with high pulse energy

    NASA Astrophysics Data System (ADS)

    Pashinin, V. P.; Ralchenko, V. G.; Bolshakov, A. P.; Ashkinazi, E. E.; Gorbashova, M. A.; Yurov, V. Yu; Konov, V. I.

    2016-06-01

    We report on an external-cavity diamond Raman laser (DRL) pumped with a Q-switched Nd:YAG and generating at 1st and 2nd Stokes (1240 nm and 1485 nm) with enhanced output energy. The slope efficiency of 54% and output energy as high as 1.2 mJ in single pulse at 1240 nm have been achieved with optimized cavity, while the pulse energy of 0.70 mJ was obtained in the eye-safe spectral region at 1485 nm. Calculations of thermal lensing effect indicate it as a possible reason for the observed decrease in conversion efficiency at the highest pump energies.

  19. Vortex State in Sub-100 nm Magnetic Nanodots.

    NASA Astrophysics Data System (ADS)

    Roshchin, Igor V.

    2006-03-01

    Magnetism of nanostructured magnets, which size is comparable to or smaller than ferromagnetic domain size, offers a great potential for new physics. Detailed knowledge of magnetization reversal and possible magnetic configurations in magnetic nanostructures is essential for high-density magnetic memory. Many theoretical and experimental studies are focused on a magnetic vortex which in addition to a circular in-plane configuration of spins has a core, - the region with out-of-plane magnetization. We present a quantitative study of the magnetic vortex state and the vortex core in sub-100 nm magnetic dots. Arrays of single-layer and bilayer nanodots covering over 1 cm^2 are fabricated using self-assembled nanopores in anodized alumina. This method allows good control over the dot size and periodicity. Magnetization measurements performed using SQUID, VSM, and MOKE indicate a transition from a vortex to a single domain state for the Fe dots. This transition is studied as a function of the magnetic field and dots size. Micromagnetic and Monte Carlo simulations confirm the experimental observations. Thermal activation and exchange bias strongly affect the vortex nucleation field and have a much weaker effect on the vortex annihilation field. Direct imaging of magnetic moments in sub-100 nm dots is extremely difficult and has not been reported yet. Polarized grazing incidence small angle neutron scattering measurements allow dot imaging in reciprocal space. Quantitative analysis of such measurements performed on 65 nm Fe dots yields the vortex core size of ˜15 nm, in good agreement with the 14 nm obtained from the simulations. This work is done in collaboration with Chang-Peng Li, Zhi-Pan Li, S. Roy, S. K. Sinha, (UCSD), Xavier Batlle (U. Barcelona), R. K. Dumas, Kai Liu, (UC Davis), S. Park, R. Pynn, M. R. Fitzsimmons (LANL), J. Mejia Lopez (Pontificia U. Catolica de Chile), D. Altbir, (U. de Santiago de Chile), A. H. Romero (Cinvestav-Unidad Queretaro), and Ivan K

  20. 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.

  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. 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.

  4. 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.

  5. 494 nm blue laser based on sum-frequency mixing of diode pumped Nd3+ lasers

    NASA Astrophysics Data System (ADS)

    Zou, J.; Wang, L. R.

    2012-02-01

    We report for the first time a continuous-wave (CW) blue radiation at 494 nm by intracavity sumfrequency generation of 912 nm Nd:GdVO4 laser and 1079 nm Nd:YAlO3 (Nd:YAP) laser. Using type-I critical phase matching LiB3O5 (LBO) crystal, 494 nm blue laser was obtained by 912 and 1079 nm intra-cavity sum-frequency mixing, and output power of 179 mW was demonstrated. At the output power level of 179 mW, the output power stability is better than 3.5% and laser beam quality M 2 factor is 1.21.

  6. High power single-longitudinal-mode cyan laser at 500.8 nm

    NASA Astrophysics Data System (ADS)

    Hao, E. J.; Li, T.; Wang, Z. D.

    2012-05-01

    An all-solid-state single-longitudinal-mode (SLM) laser at 500.8 nm with 830 mW output power has been demonstrated for the first time. By using a new resonator for doubly resonant, Nd:GdVO4 and Nd:YAG were pumped by two laser diode arrays coupled by optical fiber, respectively. In the two sub-cavities, SLM wavelengths of 1064 and 946 nm were induced by using the twisted-mode technique and then mixed into SLM 500.8 nm laser with sum-frequency technology. The SLM 500.8 nm laser output of 830 mW was obtained at the incident pump power of 20 W for Nd:GdVO4 and 23 W for Nd:YAG. The experimental results showed that the intracavity sum-frequency mixing by twisted-mode technique is an effective method for SLM 500.8 nm laser.

  7. Theoretical and experimental research on the ˜980-nm Yb-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Wang, Yanshan; Ke, Weiwei; Ma, Yi; Sun, Yinhong; Feng, Yujun

    2016-07-01

    The output properties of the ˜980-nm Yb-doped fiber laser versus pump power and core-cladding ratio of gain fiber, also the amplified spontaneous emission (ASE) at different wavelengths of seed laser, are investigated theoretically. An all-fiber amplifier based on different wavelengths of seed laser at 974.4, 977, and 981.7 nm brings the studies on parasitic oscillation and ASE in the ˜980-nm Yb-doped fiber amplifier. Through the theoretical and experimental research, we found that the controlling of three-level ASE around ˜980-nm is pivotal for obtaining a high-power 980-nm Yb-doped fiber amplifier.

  8. Radiometric Quality of the MODIS Bands at 667 and 678nm

    NASA Technical Reports Server (NTRS)

    Meister, Gerhard; Franz, Bryan A.

    2011-01-01

    The MODIS instruments on Terra and Aqua were designed to allow the measurement of chlorophyll fluorescence effects over ocean. The retrieval algorithm is based on the difference between the water-leaving radiances at 667nm and 678nm. The water-leaving radiances at these wavelengths are usually very low relative to the top-of-atmosphere radiances. The high radiometric accuracy needed to retrieve the small fluorescence signal lead to a dual gain design for the 667 and 678nm bands. This paper discusses the benefits obtained from this design choice and provides justification for the use of only one set of gains for global processing of ocean color products. Noise characteristics of the two bands and their related products are compared to other products of bands from 412nm to 2130nm. The impact of polarization on the two bands is discussed. In addition, the impact of stray light on the two bands is compared to other MODIS bands.

  9. Radiometric quality of the MODIS bands at 667 and 678nm

    NASA Astrophysics Data System (ADS)

    Meister, Gerhard; Franz, Bryan A.

    2011-10-01

    The MODIS instruments on Terra and Aqua were designed to allow the measurement of chlorophyll fluorescence effects over ocean. The retrieval algorithm is based on the difference between the water-leaving radiances at 667nm and 678nm. The water-leaving radiances at these wavelengths are usually very low relative to the topof- atmosphere radiances. The high radiometric accuracy needed to retrieve the small fluorescence signal lead to a dual gain design for the 667 and 678nm bands. This paper discusses the benefits obtained from this design choice and provides justification for the use of only one set of gains for global processing of ocean color products. Noise characteristics of the two bands and their related products are compared to other products of bands from 412nm to 2130nm. The impact of polarization on the two bands is discussed. In addition, the impact of stray light on the two bands is compared to other MODIS bands.

  10. Radiometric Quality of the MODIS Bands at 667 and 678nm

    NASA Technical Reports Server (NTRS)

    Meister, Gerhard; Franz, Bryan A.

    2010-01-01

    The MODIS instruments on Terra and Aqua were designed to allow the measurement of chlorophyll fluorescence effects over ocean. The retrieval algorithm is based on the difference between the water-leaving radiances at 667nm and 678nm. The water-leaving radiances at these wavelengths are usually very low relative to the top- of-atmosphere radiances. The high radiometric accuracy needed to retrieve the small fluorescence signal lead to a dual gain design for the 667 and 678nm bands. This paper discusses the benefits obtained from this design choice and provides justification for the use of only one set of gains for global processing of ocean color products. Noise characteristics of the two bands and their related products are compared to other products of bands from 412nm to 2130nm. The impact of polarization on the two bands is discussed. In addition, the impact of stray light on the two bands is compared to other MODIS bands.

  11. How To Obtain Aerial Photographs

    USGS Publications Warehouse

    ,

    1999-01-01

    The U.S. Geological Survey (USGS) maintains an informational data base of aerial photographic coverage of the United States and its territories that dates back to the 1940?s. This information describes photographic projects from the USGS, other Federal, State, and local government agencies, and commercial firms. The pictures on this page show a part of a standard 9- by 9-inch photograph and the results obtained by enlarging the original photograph two and four times. Compare the size of the Qualcomm Stadium, Jack Murphy Field, in San Diego, Calif, and the adjacent parking lot and freeways shown at the different scales. USGS Earth Science Information Center (ESIC) representatives will assist you in locating and ordering photographs. Please submit the completed checklist and a marked map showing your area of interest to any ESIC.

  12. Wavelength-multiplexed pumping with 478- and 520-nm indium gallium nitride laser diodes for Ti:sapphire laser.

    PubMed

    Sawada, Ryota; Tanaka, Hiroki; Sugiyama, Naoto; Kannari, Fumihiko

    2017-02-20

    We experimentally reveal the pump-induced loss in a Ti:sapphire laser crystal with 451-nm indium gallium nitride (InGaN) laser diode pumping and show that 478-nm pumping can reduce such loss. The influence of the pump-induced loss at 451-nm pumping is significant even for a crystal that exhibits higher effective figure-of-merit and excellent laser performance at 520-nm pumping. We demonstrate the power scaling of a Ti:sapphire laser by combining 478- and 520-nm InGaN laser diodes and obtain CW output power of 593 mW.

  13. 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

  14. Continuous 1052, 1064 nm dual-wavelength Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Wang, Xiaozhong; Yuan, Haiyang; Wang, Mingshan; Huang, Wencai

    2016-10-01

    Dual-wavelength lasers are usually obtained through balancing the net gain of the two oscillating lines. Competition between transitions 1052 nm, 1061 nm and 1064 nm is utilized to realize a continuous wave 1052 and 1064 nm dual-wavelength Nd:YAG laser firstly in this paper. A specially designed Fabry-Perot band-pass filter is exploited as output coupler to control the thresholds of the oscillating wavelengths. The maximum power of the dual-wavelength laser is 1.6 W and the slope efficiency is about 10%. The power instability of the output dual-wavelength laser is smaller than ±4% in half an hour. The mechanism presented in this paper may provide a new way to obtain dual-wavelength lasers.

  15. Preliminary characterisation of new glass reference materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by laser ablation-inductively coupled plasma-mass spectrometry using 193 nm, 213 nm and 266 nm wavelengths

    USGS Publications Warehouse

    Guillong, M.; Hametner, K.; Reusser, E.; Wilson, S.A.; Gunther, D.

    2005-01-01

    New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP.

  16. 635nm diode laser biostimulation on cutaneous wounds

    NASA Astrophysics Data System (ADS)

    Solmaz, Hakan; Gülsoy, Murat; Ülgen, Yekta

    2014-05-01

    Biostimulation is still a controversial subject in wound healing studies. The effect of laser depends of not only laser parameters applied but also the physiological state of the target tissue. The aim of this project is to investigate the biostimulation effects of 635nm laser irradiation on the healing processes of cutaneous wounds by means of morphological and histological examinations. 3-4 months old male Wistar Albino rats weighing 330 to 350 gr were used throughout this study. Low-level laser therapy was applied through local irradiation of red light on open skin excision wounds of 5mm in diameter prepared via punch biopsy. Each animal had three identical wounds on their right dorsal part, at which two of them were irradiated with continuous diode laser of 635nm in wavelength, 30mW of power output and two different energy densities of 1 J/cm2 and 3 J/cm2. The third wound was kept as control group and had no irradiation. In order to find out the biostimulation consequences during each step of wound healing, which are inflammation, proliferation and remodeling, wound tissues removed at days 3, 7, 10 and 14 following the laser irradiation are morphologically examined and than prepared for histological examination. Fragments of skin including the margin and neighboring healthy tissue were embedded in paraffin and 6 to 9 um thick sections cut are stained with hematoxylin and eosin. Histological examinations show that 635nm laser irradiation accelerated the healing process of cutaneous wounds while considering the changes of tissue morphology, inflammatory reaction, proliferation of newly formed fibroblasts and formation and deposition of collagen fibers. The data obtained gives rise to examine the effects of two distinct power densities of low-level laser irradiation and compare both with the non-treatment groups at different stages of healing process.

  17. Final report on the torque key komparison CCM.T-K1.2 measurand torque: 0 N.m, 500 N.m, 1000 N.m

    NASA Astrophysics Data System (ADS)

    Röske, Dirk

    2015-01-01

    The purpose of the CIPM subsequent bilateral comparison CCM.T-K1.2 was to link another participant, namely the National Institute of Metrology (Thailand), in short NIMT, to the CCM.T-K1 torque key comparison. The measuring capabilities up to 1000 N.m of dead-weight torque standard machines with supported lever were investigated. The pilot laboratory was the same in both comparisons—it was the Physikalisch-Technische Bundesanstalt (PTB, Braunschweig, Germany). The same two very stable torque transducers with well-known properties were used as travelling standards. The measurements at the participating laboratory were carried out between November 2007 and February 2008. According to the technical protocol, torque steps of 500 N.m and 1000 N.m had to be measured both in clockwise and anticlockwise directions. Corrections had to be applied to the results reported by the participants taking into account the use of different amplifiers, the creep (due to different loading times of the machines) and the environmental conditions in the laboratories (temperature and relative humidity of the ambient air). The results of the pilot laboratory in this bilateral comparison are in very good agreement with the same results obtained in the CCM.T-K1 comparison. For each of the transducers, the two torque steps and both senses of direction of the torque vector, the key comparison reference value of the CCM.T-K1 was taken, and the results of participant NIMT were calculated with respect to these values. The agreement between the results is very good. The smallest expanded (k = 2) relative uncertainty of the machine stated by the participant is 1 × 10-4. The results of the comparison support this uncertainty statement. 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 CCM, according

  18. Compact 498-nm light source based on intracavity sum-frequency Nd:GGG laser

    NASA Astrophysics Data System (ADS)

    Wang, A. G.; Li, Y. L.

    2011-08-01

    We report a coherent cyan radiation at 498 nm by intracavity sum-frequency generation of the 937 and 1062 nm laser-lines of the Nd:GGG crystal. With a diode pump power of 18.2 W, the maximum cyan output power of 186 mW is obtained. The beam quality M2 value is 1.22 in the horizontal plane. The output power stability over 30 min is better than 5%. To the best of our knowledge, this is first work on intracavity sum-frequency generation of a diode pumped Nd:GGG laser at 498 nm.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Quality metric for accurate overlay control in <20nm nodes

    NASA Astrophysics Data System (ADS)

    Klein, Dana; Amit, Eran; Cohen, Guy; Amir, Nuriel; Har-Zvi, Michael; Huang, Chin-Chou Kevin; Karur-Shanmugam, Ramkumar; Pierson, Bill; Kato, Cindy; Kurita, Hiroyuki

    2013-04-01

    The semiconductor industry is moving toward 20nm nodes and below. As the Overlay (OVL) budget is getting tighter at these advanced nodes, the importance in the accuracy in each nanometer of OVL error is critical. When process owners select OVL targets and methods for their process, they must do it wisely; otherwise the reported OVL could be inaccurate, resulting in yield loss. The same problem can occur when the target sampling map is chosen incorrectly, consisting of asymmetric targets that will cause biased correctable terms and a corrupted wafer. Total measurement uncertainty (TMU) is the main parameter that process owners use when choosing an OVL target per layer. Going towards the 20nm nodes and below, TMU will not be enough for accurate OVL control. KLA-Tencor has introduced a quality score named `Qmerit' for its imaging based OVL (IBO) targets, which is obtained on the-fly for each OVL measurement point in X & Y. This Qmerit score will enable the process owners to select compatible targets which provide accurate OVL values for their process and thereby improve their yield. Together with K-T Analyzer's ability to detect the symmetric targets across the wafer and within the field, the Archer tools will continue to provide an independent, reliable measurement of OVL error into the next advanced nodes, enabling fabs to manufacture devices that meet their tight OVL error budgets.

  6. Solid sampling with 193-nm excimer laser ablation

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph

    2007-02-01

    Reproducible and sensitive elemental analysis of solid samples is a crucial task in areas of geology (e.g. microanalysis of fluid inclusions), material sciences, industrial quality control as well as in environmental, forensic and biological studies. To date the most versatile detection method is mass-spectroscopic multi-element analysis. In order to obtain reproducible results, this requires transferring the solid sample into the gas-phase while preserving the sample's stoichiometric composition. Laser ablation in combination with Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) is a proven powerful technique to meet the requirements for reliable solid sample analysis. The sample is laser ablated in an air-tight cell and the aerosol is carried by an inert gas to a micro-wave induced plasma where its constituents are atomized and ionized prior to mass analysis. The 193 nm excimer laser ablation, in particular, provides athermal sample ablation with very precise lateral ablation and controlled depth profiling. The high photon energy and beam homogeneity of the 193 nm excimer laser system avoids elemental fractionation and permits clean ablation of even transmissive solid materials such as carbonates, fluorites and pure quartz.

  7. 1060nm 28-Gbps VCSEL developed at Furukawa

    NASA Astrophysics Data System (ADS)

    Suzuki, Toshihito; Funabashi, Masaki; Shimizu, Hitoshi; Nagashima, Kazuya; Kamiya, Shinichi; Kasukawa, Akihiko

    2014-02-01

    This paper presents recent development results of our 28-Gbps VCSELs featured with double intra-cavity structure and a lasing wavelength of 1060 nm. The double intra-cavity realizes very low cavity loss due to undoped semiconductor bottom DBR and dielectric top DBR layers. Compressively strained InGaAs MQW provides high differential gain that contributes to low power consumption and high reliability. Based on our 10-Gbps VCSEL structure, we carefully optimized MQW, selective oxide structure, cavity length, and doping profile in order to achieve high speed operation while maintaining high reliability and other laser performances. The developed VCSELs exhibit modulation 3 dB-bandwidth exceeding 20 GHz and D-factor of 10 GHz/(mA)1/2. Typical threshold current and slope efficiency are 0.5 mA and 0.5 W/A, respectively. The paper also discusses static and dynamic characteristics of VCSELs with various oxide aperture sizes simultaneously fabricated on the same wafer. For a longer transmission distance and better optical coupling to a multimode fiber, optical lateral confinement is precisely controlled to reduce spectral width as well as far-field pattern. Clearly opened eye diagrams are obtained at a bit rate of 28 Gbps. Bit error rate tests are also performed and 28 Gbps error free transmission has been confirmed over 300 meters of multimode-fiber optimized for 1060 nm with a PRBS pattern length of 231-1.

  8. 1060nm VCSEL for inter-chip optical interconnection

    NASA Astrophysics Data System (ADS)

    Takaki, Keishi; Imai, Suguru; Kamiya, Shinichi; Shimizu, Hitoshi; Kawakita, Yasumasa; Hiraiwa, Koji; Takagi, Tomohiro; Shimizu, Hiroshi; Yoshida, Junji; Ishikawa, Takuya; Tsukiji, Naoki; Kasukawa, Akihiko

    2011-03-01

    The demand for the on board intra-chip optical interconnection as the "Green interconnect" have been growing so rapidly in order to catch up the speed of the performance development of high performance computing systems. In this report, our continuous study results expanding to intra-chip application in terms with power consumption and reliability are shown for the "Green" 1060nm VCSEL arrays developed by Furukawa Electric1. As the basic performance level, the clear eye opening up to 20Gbps was achieved with low power dissipation level of 160fJ/bit with voltage swing level of 130mVpp. This value would be considered as the same level of the 140fJ/bit in 10Gbps operation with 75mVpp. In the reliability test, our large scale FIT rate test had been reached up to 7.8E7 device hours and the estimated FIT rate of 30FIT/ch was obtained from no failure sample and confidence level of 90%. Our wear-out study was performed with high stress test of 170°C ambient temperature and estimated failure rate for 10years service time was 0.3FIT/ch for this mode. Our 1060nm VCSEL with low power consumption level of 140fJ/bit and high reliability of 30FIT/ch would be projected to a light source for intra-chip application.

  9. Size and Purity Control of HPHT Nanodiamonds down to 1 nm

    PubMed Central

    2015-01-01

    High-pressure high-temperature (HPHT) nanodiamonds originate from grinding of diamond microcrystals obtained by HPHT synthesis. Here we report on a simple two-step approach to obtain as small as 1.1 nm HPHT nanodiamonds of excellent purity and crystallinity, which are among the smallest artificially prepared nanodiamonds ever shown and characterized. Moreover we provide experimental evidence of diamond stability down to 1 nm. Controlled annealing at 450 °C in air leads to efficient purification from the nondiamond carbon (shells and dots), as evidenced by X-ray photoelectron spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and scanning transmission electron microscopy. Annealing at 500 °C promotes, besides of purification, also size reduction of nanodiamonds down to ∼1 nm. Comparably short (1 h) centrifugation of the nanodiamonds aqueous colloidal solution ensures separation of the sub-10 nm fraction. Calculations show that an asymmetry of Raman diamond peak of sub-10 nm HPHT nanodiamonds can be well explained by modified phonon confinement model when the actual particle size distribution is taken into account. In contrast, larger Raman peak asymmetry commonly observed in Raman spectra of detonation nanodiamonds is mainly attributed to defects rather than to the phonon confinement. Thus, the obtained characteristics reflect high material quality including nanoscale effects in sub-10 nm HPHT nanodiamonds prepared by the presented method. PMID:26691647

  10. 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.

  11. 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

  12. Nanosecond-time-response temperature measurements using radiation thermometry during 193-nm and 247-nm pulsed light irradiation: comparison of corneal surface temperature histories

    NASA Astrophysics Data System (ADS)

    Ishihara, Miya; Arai, Tsunenori; Sato, Shunichi; Morimoto, Yuji; Obara, Minoru; Kikuchi, Makoto

    2001-07-01

    We have developed the fast time-response measurement of thermal radiation with 15ns rise time to monitor the corneal surface temperature during ArF excimer laser ablation. In this study, e aim to investigate the influence of the relation between the corneal penetration depth and sampling depth of the measurement system on the measured temperature using 193 nm and 247 nm pulsed lights which have different penetration depths of cornea. When the sampling depth was defined as the penetration depth of cornea at the thermal radiation wavelength, we obtained about 3 micrometers of the sampling depth by pulsed photothermal radiometry (PPTR). In the case of the 247 nm light irradiation, where the corneal absorption coefficient at 247 nm was approximately equal to that for the thermal radiation, we found that the measured temperature rises were same as the estimated temperature rises based on the photothermal process. In contrast, in the case of the 193 nm light irradiation, where the absorption coefficient at 193 nm was larger than that for the thermal radiation, we found that the measured temperature rises were lower than the estimated temperature rises.

  13. 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.

  14. 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.

  15. Performance comparison of the 1310nm optical amplifiers

    NASA Astrophysics Data System (ADS)

    Chorchos, Łukasz; Turkiewicz, Jarosław P.

    2016-09-01

    One of the key optical transmission components are optical amplifiers. In this paper studies on the amplification properties of the 1310 nm optical amplifiers are presented. The evaluated optical amplifiers are: semiconductor optical amplifier (SOA) and praseodymium doped fibre amplifier (PDFA). The study is aimed to the dynamic operation in single- and multi- wavelength domain with the high rate signals namely 25 Gbit/s. The maximum obtained gain was 25.0 dB for SOA and 20.9 dB for PDFA. For the SOAs the minimum achieved value of the receiver sensitivity was -11.5 dBm for single channel and -11.5 dBm for DWDM case when for PDFA those values were -11.0 dBm and -10.9 respectively. The main advantage of the PDFA in comparison to the measured SOAs is higher saturation power.

  16. Characterization of a THz CW spectrometer pumped at 1550 nm

    NASA Astrophysics Data System (ADS)

    Yeo, Woon-Gi; Nahar, Niru K.

    2015-07-01

    We present an evaluation of a cost-effective THz CW spectrometer pumped at 1550 nm wavelengths with a fixed delay line. To study the spectral competence of the spectrometer, transmission data is obtained for various organic and inorganic samples. Spectral comparisons of the samples are presented by using THz time domain spectroscopy and vector network analyzer (VNA). Despite the capability of highly resolved transmission spectroscopy, our current system reveals the uncertainty in interferometric output data for phase analysis. Here, we identify the effect of fringing space of raw output data toward frequency resolution, phase analysis, and data acquisition time. We also propose the proper delay line setup for phase analysis for this type of spectrometers.

  17. Dosimetric analysis for low-level laser therapy (LLLT) of the human inner ear at 593 nm and 633 nm

    NASA Astrophysics Data System (ADS)

    Beyer, Wolfgang; Baumgartner, Reinhold; Tauber, Stefan

    1998-12-01

    The administration of low-level-laserlight for irradiation of the inner ear could represented a new therapeutic model for complex diseases of the inner ear. However, successful therapy requires a well-defined light dosimetry based on a dosimetric analysis of the human cochlea that represents a complex anatomy. The light distribution inside the cochlear windings, produced by an irradiation of the tympanic membrane, was quantitatively measured ex vivo for HeNe laser wavelengths of 593 nm and 633 nm. To obtain the space irradiance within an intact cochlea a correction factor of about 6 has been determined by Monte Carlo calculations. It follows from 3 contributions, first the backscattering of light in the bony parts removed during the preparation procedure of the specimen, second the change of index of refraction from the bony parts to air and third some geometrical factors due to the angular distribution of the radiation. The transmission of light across the tympanic cavity and the promontory depends strongly on the wavelength. Due to the observed spatial intensity variations of a factor 10 and more inside the cochlear windings the optimum external light dose has to be chosen with regard to the tonotopy of the ear.

  18. Cosmic ray snow effect in different multiplicities according to Emilio Segre Observatory NM hourly data

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Iucci, N.; Mavromichalaki, H.; Pustilnik, L. A.; Sternlieb, A.; Villoresi, G.; Zukerman, I. G.

    2001-08-01

    On the basis of cosmic ray hourly data obtained by NM of Emilio Segre' Observatory (hight 2025 m above s.l., cut-off rigidity for vertical direction 10.8 GV) we determine the snow effect in CR for total neutron intensity and for multiplicities m?1, m?2, m?3, m?4, m?5, m?6, m?7, and m?8, as well as for m=1, m=2, m=3, m=4, m=5, m=6, and m=7. For comparison and excluding primary CR variations we use also hourly data on neutron multiplicities obtained by NM of University "Roma Tre" (about sea level,cutoff rigidity 6.7 GV) and hourly data of total intensity of NM of the University of Athens (about sea level, cut-off rigidity 8.7 GV). In this paper we will analize effects of snow in periods from 4 January 2000 to 15 April 2000 (with maximal absorption effect about 5%) and from 21 December 2000 up to 31 March 2001 with maximal effect 13% in the total neutron intensity. We use the periods without snow to determine regeression coefficients between primary CR variations observed by NM of Emilio Segre' Observatory, by Rome NM and Athens NM. On the basis of obtained results we develop a method to correct data on snow effect by using several NM hourly data.On the basis of our data we estimate the accuracy with what can be made correction of NM data of stations where the snow effect can be important.

  19. High-power 880-nm diode-directly-pumped passively mode-locked Nd:YVO₄ laser at 1342 nm with a semiconductor saturable absorber mirror.

    PubMed

    Li, Fang-Qin; Liu, Ke; Han, Lin; Zong, Nan; Bo, Yong; Zhang, Jing-Yuan; Peng, Qin-Jun; Cui, Da-Fu; Xu, Zu-Yan

    2011-04-15

    A high-power 880-nm diode-directly-pumped passively mode-locked 1342 nm Nd:YVO₄ laser was demonstrated with a semiconductor saturable absorber mirror (SESAM). The laser mode radii in the laser crystal and on the SESAM were optimized carefully using the ABCD matrix formalism. An average output power of 2.3 W was obtained with a repetition rate of 76 MHz and a pulse width of 29.2 ps under an absorbed pump power of 12.1 W, corresponding to an optical-optical efficiency of 19.0% and a slope efficiency of 23.9%, respectively.

  20. Polymer dots with broadband optical absorption (500 nm - 700 nm) and high-efficiency photoacoustic conversion for in vivo multispectral photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Jian; Yuan, Zhen

    2016-10-01

    Multi-spectral photoacoustic (MSPA) imaging can extract quantitative information of interesting component from morphological photoacoustic image of targets. A probe with an optimal optical absorption can be detected by MSPA imaging with higher sensitivity and specificity. Here we developed a Nano polymers dots (P-dots) for MSPA imaging that has a high photoacoustic conversion efficiency in a broad optical absorbing band (500 nm - 700 nm). In vivo MSPA imaging experiment was successfully performed in mouse model. The relative concentration map of P-dots was exactly obtained from the background of tissues, which demonstrated the potential use of P-dots in the bio-imaging field based on MSPA imaging.

  1. LD end-pumped acousto-optic Q-switched 1319 nm/1338 nm dual-wavelength Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Wu, C. T.; Yu, M.; Wang, C.; Yu, K.; Yu, Y. J.; Chen, X. Y.; Jin, G. Y.

    2016-10-01

    Laser characteristics of acousto-optic Q-switched operation of 1319 nm/1338 nm dual-wavelength composite Nd:YAG laser were studied. Maximum output power of 5.77 W was achieved in CW operation. Under Q-switched operation, the maximum peak power of 3.96 kW and minimum pulse width of 65.6 ns was obtained at repetition frequency of 20 kHz with the duty ratio of 96%. The influence of the duration of the ultrasonic field acted on the Q-switch to the output characteristics of dual-wavelength composite Nd:YAG laser had been reported first time.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. 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

  8. 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.

  9. Vibrational properties of gold nanoparticles obtained by green synthesis

    NASA Astrophysics Data System (ADS)

    Alvarez, Ramón A. B.; Cortez-Valadez, M.; Bueno, L. Oscar Neira; Britto Hurtado, R.; Rocha-Rocha, O.; Delgado-Beleño, Y.; Martinez-Nuñez, C. E.; Serrano-Corrales, Luis Ivan; Arizpe-Chávez, H.; Flores-Acosta, M.

    2016-10-01

    This study reports the synthesis and characterization of gold nanoparticles through an ecological method to obtain nanostructures from the extract of the plant Opuntia ficus-indica. Colloidal nanoparticles show sizes that vary between 10-20 nm, and present various geometric morphologies. The samples were characterized through optical absorption, Raman Spectroscopy and Transmission Electron Microscopy (TEM). Additionally, low energy metallic clusters of Aun (n=2-20 atoms) were modeled by computational quantum chemistry. The theoretical results were obtained with Density Functional Theory (DFT). The predicted results of Au clusters show a tendency and are correlated with the experimental results concerning the optical absorption bands and Raman spectroscopy in gold nanoparticles.

  10. 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.

  11. Highly efficient picosecond diamond Raman laser at 1240 and 1485 nm.

    PubMed

    Warrier, Aravindan M; Lin, Jipeng; Pask, Helen M; Mildren, Richard P; Coutts, David W; Spence, David J

    2014-02-10

    We present a highly efficient picosecond diamond Raman laser synchronously-pumped by a 4.8 W mode-locked laser at 1064 nm. A ring cavity was adopted for efficient operation. With a low-Q cavity for first-Stokes 1240 nm, we have achieved 2.75 W output power at 1240 nm with 59% overall conversion efficiency. The slope efficiency tended towards 76% far above the SRS threshold, approaching the SRS quantum limit for diamond. A high-Q first-Stokes cavity was employed for second-Stokes 1485 nm generation through the combined processes of four-wave mixing and single-pass stimulated Raman scattering. Up to 1.0 W of second-stokes at 1485 nm was obtained, corresponding to 21% overall conversion efficiency. The minimum output pulse duration was compressed relative to the 15 ps pump, producing pulses as short as 9 ps for 1240 nm and 6 ps for 1485 nm respectively.

  12. Room-temperature, continuous-wave, 946-nm Nd:YAG laser pumped by laser-diode arrays and intracavity frequency doubling to 473 nm

    SciTech Connect

    Risk, W.P.; Lenth, W.

    1987-12-01

    We report the use of GaAlAs laser-diode arrays to pump a cw Nd:YAG laser operating on the 946-nm /sup 4/F/sub 3/2/..-->../sup 4/I/sub 9/2/ transition. At room temperature, the lasing threshold was reached with 58 mW of absorbed pump power, and, with 175 mW of absorbed pump power, 42 mW of output power at 946 nm was obtained in a TEM/sub 00/ mode by using 0.7% output coupling. In addition, pumping with an infrared dye laser operating in a pure TEM/sub 00/ mode was used to investigate the effects of reabsorption loss that are characteristic of the 946-nm laser transition. LiIO/sub 3/ was used as an intracavity doubling crystal, and 100 ..mu..W of blue light was generated by using diode-laser pumping in a nonoptimized cavity.

  13. 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

  14. Emission spectroscopy analysis during Nopal cladodes dethorning by laser ablation

    NASA Astrophysics Data System (ADS)

    Peña-Díaz, M.; Ponce, L.; Arronte, M.; Flores, T.

    2007-04-01

    Optical emission spectroscopy of the pulsed laser ablation of spines and glochids from Opuntia (Nopal) cladodes was performed. Nopal cladodes were irradiated with Nd:YAG free-running laser pulses on their body, glochids and spines. Emission spectroscopy analyses in the 350-1000 nm region of the laser induced plasma were made. Plasma plume evolution characterization, theoretical calculations of plasma plume temperature and experiments varying the processing atmosphere showed that the process is dominated by a thermally activated combustion reaction which increases the dethorning process efficiency. Therefore, appropriate laser pulse energy for minimal damage of cladodes body and in the area beneath glochids and spines can be obtained.

  15. 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.}

  16. Fabrication of sub-12 nm thick silicon nanowires by processing scanning probe lithography masks

    SciTech Connect

    Kyoung Ryu, Yu; Garcia, Ricardo; Aitor Postigo, Pablo; Garcia, Fernando

    2014-06-02

    Silicon nanowires are key elements to fabricate very sensitive mechanical and electronic devices. We provide a method to fabricate sub-12 nm silicon nanowires in thickness by combining oxidation scanning probe lithography and anisotropic dry etching. Extremely thin oxide masks (0.3–1.1 nm) are transferred into nanowires of 2–12 nm in thickness. The width ratio between the mask and the silicon nanowire is close to one which implies that the nanowire width is controlled by the feature size of the nanolithography. This method enables the fabrication of very small single silicon nanowires with cross-sections below 100 nm{sup 2}. Those values are the smallest obtained with a top-down lithography method.

  17. 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.

  18. 1300 nm and 890 nm OCT images of oral cancer tissue engineered models and biopsy samples offer complimentary performance (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Boadi, Joseph; Byers, Robert A.; Fernandes, Jon; Mittar, Shweta; Hearnden, Vanessa; Lu, Zenghai; MacNeil, Sheila; Thornhill, Martin; Murdoch, Craig; Hunter, Keith D.; McKechnie, Alasdair; Matcher, Stephen J.

    2016-02-01

    OCT has demonstrated great potential to non-invasively detect oral epithelial cancers, potentially guiding biopsy and surgical resection. On non-ophthalmic tissues the preferred illumination wavelength is 1300 nm. Previous studies on skin have shown that useful image data can also be obtained at shorter wavelengths, with systems at 1060 nm and 820 nm offering reduced depth penetration but higher contrast. Here we apply a similar comparison to tissue engineered models of oral cancer and also to human biopsy samples, generally finding a similar trend. 1300 nm multi-beam OCT (Michelson Diagnostics EX1301) visualises stromal structures and surface keratin more clearly, providing useful image contrast down to around 1 mm. This system was compared with an ultra-high resolution home-built system operating at 890 nm (2.5 micron resolution vs 7.5 micron axial resolution for the EX1301). The UHR system reveals epithelial features more clearly, especially in the DOK pre-invasive cell line model and the biopsy samples. The relative effects of center wavelength vs axial resolution in generating the differential, wavelength-dependent contrast are assessed and the OCT biopsy images are compared with contemporary histology.

  19. Stimulated-emission cross section at 1064 and 1342 nm in Nd:YVO4

    NASA Technical Reports Server (NTRS)

    Tucker, A. W.; Birnbaum, M.; Fincher, C. L.; Erler, J. W.

    1977-01-01

    The stimulated-emission cross sections at 1064 and 1342 nm in Nd:YVO4 were determined by measurement of laser thresholds as a function of output mirror reflectivity. Small samples of Nd:YVO4 and Nd:YAG were end pumped at room temperature with a CW 514.5-nm argon ion laser in an almost identical geometrical arrangement which permitted comparative values to be obtained. Assuming that the pumping quantum efficiency of Nd:YVO is similar to that of Nd:YAG, the stimulated-emission cross sections obtained for the 1064- and 1342-nm transitions were respectively 12 x 10 to the -19th and 6.0 x 10 to the -19th/sq cm.

  20. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA - USEPA DEMONSTRATION PROJECT AT DESERT SANDS MDWCA, NM SIX MONTH EVALUATION

    EPA Science Inventory

    This report documents the activities performed during, and the results obtained from, the first six months of the arsenic removal treatment technology demonstration project at the Desert Sands Mutual Domestic Water Consumers Association (MDWCA) facility in Anthony, NM. The object...

  1. 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.

  2. 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.

  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. Negative-tone imaging with EUV exposure for 14nm hp and beyond

    NASA Astrophysics Data System (ADS)

    Tsubaki, Hideaki; Nihashi, Wataru; Tsuchihashi, Toru; Fujimori, Toru; Momota, Makoto; Goto, Takahiro

    2015-03-01

    Manipulation of dissolution properties by changing organic solvent developer and rinse material provides a novel technology to obtain fine pattern beyond the limitation of imaging system based on alkaline developer. QCM study showed no swelling character in negative-tone imaging (NTI) process even for current developer of n-butyl acetate (nBA). Actually, NTI process has shown advantages on resolution and line-width roughness (LWR) in loose pitch around 30 ~ 45 nm hp as a consequence of its non-swelling character. On the other hand, bridge and collapse limited its resolution below 20 nm hp, indicating that non-negligible amount of swelling still exists for tight pitch resolution. We investigated effects of solubility parameter of organic solvents on resolution below 20 nm hp. A bridge was reduced with a decrease in the solubility parameter dp from nBA. On the other hand, much lower dp caused film remaining due to its extremely slow Rmax. Based on these results, we newly developed FN-DP301 containing organic solvent with smaller dp than nBA. Although rinse solvent gave negligible effects on bridge, there is a clear improvement on pattern collapse only in case of using new rinse solvent of FN-RP311. Lithographic performances of NTI process using nBA and FN-DP301 together with the other organic solvents were described in this paper under exposures with an E-beam and a EUV light. It is emphasized that 14 nm hp resolution was obtained only using FN-DP301 as a developer and FN-RP311 as a rinse under E-beam exposure. NTI showed 43% faster photospeed in comparison with PTI at 16 nm hp, indicating that NTI is applicable to obtain high throughput with maintaining resolution. In addition, sub-20 nm trench was obtained using NTI without bridge under EUV exposure, all of which are attributed to the low swelling character of NTI process. Similarly, NTI was able to print 20 nm dots using NXE:3100 with only a little peeling. Conversely CH patterning was significantly worse with NTI

  5. 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.

  6. Real space soft x-ray imaging at 10 nm spatial resolution

    SciTech Connect

    Chao, Weilun; Fischer, Peter; Tyliszczak, T.; Rekawa, Senajith; Anderson, Erik; Naulleau, Patrick

    2011-04-24

    Using Fresnel zone plates made with our robust nanofabrication processes, we have successfully achieved 10 nm spatial resolution with soft x-ray microscopy. The result, obtained with both a conventional full-field and scanning soft x-ray microscope, marks a significant step forward in extending the microscopy to truly nanoscale studies.

  7. 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

  8. Challenges of 29nm half-pitch NAND Flash STI patterning with 193nm dry lithography and self-aligned double patterning

    NASA Astrophysics Data System (ADS)

    Chiu, M. C.; Lin, Benjamin Szu-Min; Tsai, M. F.; Chang, Y. S.; Yeh, M. H.; Ying, T. H.; Ngai, Chris; Jin, Jaklyn; Yuen, Stephen; Huang, Sem; Chen, Yongmei; Miao, Liyan; Tai, Kevin; Conley, Amiad; Liu, Ian

    2008-11-01

    the complete DP hardmask scheme in terms of etching selectivity, optical properties and stress optimization was another key challenge to balance excellent litho alignment signal strength and straight pattern profiles without line bending effects. Etching efforts also played a very important roll to obtain pattern integrality under such a high aspect ratio (> 10) case through the whole SADP process. Finally, cost analysis for 193nm dry lithography SADP will be compared to 193nm Immersion lithography SADP.

  9. 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.

  10. HSQ double patterning process for 12 nm resolution x-ray zone plates

    SciTech Connect

    Chao, Weilun; Kim, Jihoon; Rekawa, Senajith; Fischer, Peter; Anderson, Erik H.

    2009-06-16

    Soft x-ray zone plate microscopy is a powerful nano-analytic technique used for a wide variety of scientific and technological studies. Pushing its spatial resolution to 10 nm and below is highly desired and feasible due to the short wavelength of soft x-rays. Instruments using Fresnel zone plate lenses achieve a spatial resolution approximately equal to the smallest, outer most zone width. We developed a double patterning zone plate fabrication process based on a high-resolution resist, hydrogen silsesquioxane (HSQ), to bypass the limitations of conventional single exposure fabrication to pattern density, such as finite beam size, scattering in resist and modest intrinsic resist contrast. To fabricate HSQ structures with zone widths in the order of 10 nm on gold plating base, a surface conditioning process with (3-mercaptopropyl) trimethoxysilane, 3-MPT, is used, which forms a homogeneous hydroxylation surface on gold surface and provides good anchoring for the desired HSQ structures. Using the new HSQ double patterning process, coupled with an internally developed, sub-pixel alignment algorithm, we have successfully fabricated in-house gold zone plates of 12 nm outer zones. Promising results for 10 nm zone plates have also been obtained. With the 12 nm zone plates, we have achieved a resolution of 12 nm using the full-field soft x-ray microscope, XM-1.

  11. 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.

  12. 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.

  13. Laser ablation of ceramic Al{sub 2}O{sub 3} at 193 nm and 248 nm: The importance of single-photon ionization processes

    SciTech Connect

    Pelaez, R. J.; Afonso, C. N.; Bator, M.; Lippert, T.

    2013-06-14

    The aim of this work is to demonstrate that single-photon photoionization processes make a significant difference in the expansion and temperature of the plasma produced by laser ablation of ceramic Al{sub 2}O{sub 3} in vacuum as well as to show their consequences in the kinetic energy distribution of the species that eventually will impact on the film properties produced by pulsed laser deposition. This work compares results obtained by mass spectrometry and optical spectroscopy on the composition and features of the plasma produced by laser ablation at 193 nm and 248 nm, i.e., photon energies that are, respectively, above and below the ionization potential of Al, and for fluences between threshold for visible plasma and up to Almost-Equal-To 2 times higher. The results show that the ionic composition and excitation of the plasma as well as the ion kinetic energies are much higher at 193 nm than at 248 nm and, in the latter case, the population of excited ions is even negligible. The comparison of Maxwell-Boltzmann temperature, electron temperatures, and densities of the plasmas produced with the two laser wavelengths suggests that the expansion of the plasma produced at 248 nm is dominated by a single population. Instead, the one produced at 193 nm is consistent with the existence of two populations of cold and hot species, the latter associated to Al{sup +} ions that travel at the forefront and produced by single photon ionization as well as Al neutrals and double ionized ions produced by electron-ion impact. The results also show that the most energetic Al neutrals in the plasma produced at the two studied wavelengths are in the ground state.

  14. 1064-nm Nd:YAG and 980-nm Diode Laser EDTA Agitation on the Retention of an Epoxy-Based Sealer to Root Dentin.

    PubMed

    Macedo, Helena Suleiman de; Messias, Danielle Cristine Furtado; Rached-Júnior, Fuad Jacob; Oliveira, Ligia Teixeira de; Silva-Sousa, Yara Teresinha Correa; Raucci-Neto, Walter

    2016-01-01

    Root canal irrigants are used to minimize the negative effects of smear layer on endodontic sealer retention. The aim of this study was to evaluate the efficacy of agitation of 17% ethylenediaminetetraacetic acid (EDTA) with ultrasonic, 1064-nm Nd:YAG and 980-nm diode laser on the retention of an epoxy-based sealer to the root canal walls. Forty single-rooted bovine teeth were instrumented with ProTaper rotary system and divided into four groups according to the final irrigation protocol (n = 10): (1) 17% EDTA (control); (2) 17% EDTA with 50-s ultrasonic agitation; (3) 17% EDTA with 50-s diode laser (2-W) agitation; and (4) 17% EDTA with 50-s Nd:YAG (1.5-W) laser agitation. After endodontic filling with gutta-percha F5 master cone and Sealer 26, the roots were sectioned at the cervical, middle, and apical root thirds to obtain 1.5-mm slices. Push-out tests were performed using a universal testing machine at a 1 mm/min crosshead speed. Data were analyzed using two-way ANOVA and Tukey's tests (α=0.05). Apical root thirds had significant higher retention values than cervical and middle thirds (p < 0.05). EDTA with 1064-nm Nd:YAG or 980-nm diode laser presented the highest retention values and was significantly different from EDTA with ultrasonic agitation and EDTA only (p < 0.05). Adhesive failures were predominant to EDTA only group. Mixed failures were predominant to all agitation groups. 1064-nm Nd:YAG and 980-nm diode laser EDTA agitation enhanced the retention of the epoxy-based sealer to the root canal walls compared with that due to EDTA only or EDTA with ultrasonic agitation.

  15. 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.

  16. Interpretation of cathodoluminescence spectra obtained from carbonate gangue minerals and breccias, Right Fork area, central Tennessee zinc district

    SciTech Connect

    Kopp, O.C. . Dept. of Geological Sciences); Owen, M.R. . Dept. of Geology); Fuller, E.L. Jr. . Metals and Ceramics Div.)

    1993-03-01

    Spectral patterns (from approximately 350 nm to 750 nm) were obtained for zoned dolomite and unzoned calcite gangue, and dolostone breccia fragments from the Right Fork area in Jackson and Overton Counties, 40 km northeast of the elmwood Mine in the Central Tennessee zinc district. The materials had been analyzed for Fe, Mn, REE, and other trace elements using the synchrotron XRF probe at the National Synchrotron Light Source, Brookhaven National Laboratory. Three distinct zones in dolomite gangue (arbitrarily named zones 4, 5, and 6) could be traced throughout the entire area. The largest number of spectra were obtained for zone 4, which luminesces medium bright red to the eye. The spectra reveal broad peaks in the vicinity of 460 nm and 660 nm; however, spectral deconvolution suggests that the spectra comprise several peaks. The broad peak at 460 nm may consist of overlapping peaks at about 430 nm and 530 nm. Of special interest is the broad peak at 660 nm, which is normally assigned solely to Mn. Shoulders in the range from 700 nm to 725 nm might be due to Fe, which is generally assumed to quench Mn-activated cathodoluminescence. Note that Fe[sup 3+] produces peaks in the vicinity of 550 nm and 710 nm in plagioclase. Intensities determined for zone 4 vary by a factor of 3X and are related to both the Mn concentrations and the Fe/Mn ratios of the individual spots analyzed, even though little, if any, differences in intensity are observed by eye.

  17. 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.

  18. 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.

  19. Laboratory Measurements of the 940, 1130, and 1370 nm Water Vapor Absorption Band Profiles

    NASA Technical Reports Server (NTRS)

    Giver, Lawrence P.; Gore, Warren J.; Pilewskie, P.; Freedman, R. S.; Chackerian, C., Jr.; Varanasi, P.

    2001-01-01

    We have used the solar spectral flux radiometer (SSFR) flight instrument with the Ames 25 meter base-path White cell to obtain about 20 moderate resolution (8 nm) pure water vapor spectra from 650 to 1650 nm, with absorbing paths from 806 to 1506 meters and pressures up to 14 torr. We also obtained a set at 806 meters with several different air-broadening pressures. Model simulations were made for the 940, 1130, and 1370 nm absorption bands for some of these laboratory conditions using the Rothman, et al HITRAN-2000 linelist. This new compilation of HITRAN includes new intensity measurements for the 940 nm region. We compared simulations for our spectra of this band using HITRAN-2000 with simulations using the prior HITRAN-1996. The simulations of the 1130 nm band show about 10% less absorption than we measured. There is some evidence that the total intensity of this band is about 38% stronger than the sum of the HITRAN line intensities in this region. In our laboratory conditions the absorption depends approximately on the square root of the intensity. Thus, our measurements agree that the band is stronger than tabulated in HITRAN, but by about 20%, substantially less than the published value. Significant differences have been shown between Doppler-limited resolution spectra of the 1370 nm band obtained at the Pacific Northwest National Laboratory and HITRAN simulations. Additional new intensity measurements in this region are continuing to be made. We expect the simulations of our SSFR lab data of this band will show the relative importance of improving the HITRAN line intensities of this band for atmospheric measurements.

  20. 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

  1. Multi-watts narrow-linewidth all fiber Yb-doped laser operating at 1179 nm.

    PubMed

    Kalita, Mridu P; Alam, Shaif-Ul; Codemard, Christophe; Yoo, Seongwoo; Boyland, Alexander J; Ibsen, Morten; Sahu, Jayanta K

    2010-03-15

    An all-fiber, narrow-linewidth, high power Yb-doped silica fiber laser at 1179 nm has been demonstrated. More than 12 W output power has been obtained, corresponding to a slope efficiency of 43% with respect to launched pump power, by core-pumping at 1090 nm. In order to increase the pump absorption, the Yb-doped fiber was heated up to 125 degrees C. At the maximum output power, the suppression of amplified spontaneous emission was more than 50 dB. Furthermore, theoretical work confirms that the proposed laser architecture can be easily scaled to higher power.

  2. Fiber-laser pumped actively Q-switched Er:LuYAG laser at 1648 nm

    NASA Astrophysics Data System (ADS)

    Yang, X. F.; Wang, Y.; Zhao, T.; Zhu, H. Y.; Shen, D. Y.

    2016-02-01

    We demonstrated an acousto-optic Q-switched 1648 nm Er:LuYAG laser resonantly pumped by a cladding-pumped Er,Yb fiber laser at 1532 nm. Stable Q-switching operation was obtained with the pulse repetition rate (PRR) varying from 200 Hz to 10 kHz. At PRR of 200 Hz, the laser yielded Q-switched pulses with 3.3 mJ pulse energy and 65 ns pulse duration, corresponding to a peak power of 50.7 kW for 10.4 W of incident pump power.

  3. 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.

  4. Safety and efficacy of 2,790-nm laser resurfacing for chest photoaging.

    PubMed

    Grunebaum, Lisa D; Murdock, Jennifer; Cofnas, Paul; Kaufman, Joely

    2015-01-01

    Chest photodamage is a common cosmetic complaint. Laser treatment of the chest may be higher risk than other areas. The objective of this study was to assess the safety and efficacy of 2,790-nm chest resurfacing for photodamage. Twelve patients with Fitzpatrick skin types I-III were enrolled in this university IRB-approved study. Photo documentation was obtained at baseline and each visit. A test spot with the 2,790-nm resurfacing laser was performed on the chest. Patients who did not have adverse effects from the test spot went on to have a full chest resurfacing procedure. Patients were instructed on standardized aftercare, including sunscreen. A 5-point healing and photodamage improvement scale was used to rate improvement by both investigators and the patients and was obtained at 2 weeks, 1 month, 2 months, and 3 months. One pass chest treatment with the 2,790-nm resurfacing laser at fluences greater than or equal to 3.0 mJ with 10% overlap leads to unacceptable rates of hyperpigmentation. Double pass chest treatment at fluences less than or equal to 2.5 mJ with 10% overlap leads to mild improvement in chest photodamage parameters without significant or persistent adverse effects. Laser treatment of aging/photodamaged chest skin remains a challenge due to the delicacy of chest skin. Mild improvement may be obtained with double pass resurfacing with the 2,790-nm wavelength.

  5. Advanced self-aligned double patterning development for sub-30-nm DRAM manufacturing

    NASA Astrophysics Data System (ADS)

    Shiu, Weicheng; Liu, Hung Jen; Wu, Jan Shiun; Tseng, Tsu-Li; Liao, Chun Te; Liao, Chien Mao; Liu, Jerry; Wang, Troy

    2009-03-01

    /or fancy integration approaches. In our study we purposely apply a more "classical" and relatively conservative integration scheme, with all unit process steps long proven in previous volume production. By carefully optimizing the relative CMP, films deposition, etch and cleaning processes, we are able to demonstrate 30nm line/space patterns by an NA 0.93 dry 193nm scanner with optimal CDU better than 3nm and high frequency line edge roughness (LER) close to 2nm/side. Additionally, by analyzing wafer quality for alignment and alignment residual in various alignment & overlay mark designs, projected residual overlay as little as 4nm can be readily obtained.

  6. All solid-state 191.7 nm deep-UV light source by seventh harmonic generation of an 888 nm pumped, Q-switched 1342 nm Nd:YVO₄ laser with excellent beam quality.

    PubMed

    Koch, Peter; Bartschke, Juergen; L'huillier, Johannes A

    2014-06-02

    In this paper we report on the realization of a deep-UV light source using the 1.3 μm transition of neodymium as pumping wavelength. The 191.7 nm radiation was obtained by generating the seventh harmonic of a high-power Q-switched 1342 nm Nd:YVO4 laser. A cesium lithium borate crystal was used for sum frequency mixing of the sixth harmonic and the fundamental. With a total of four conversion stages, up to 240 mW were achieved, with excellent beam quality at 155 mW (M2 < 1.7) and 190 mW (M2 < 1.9).

  7. Tunable GHz pulse repetition rate operation in high-power TEM(00)-mode Nd:YLF lasers at 1047 nm and 1053 nm with self mode locking.

    PubMed

    Huang, Y J; Tzeng, Y S; Tang, C Y; Huang, Y P; Chen, Y F

    2012-07-30

    We report on a high-power diode-pumped self-mode-locked Nd:YLF laser with the pulse repetition rate up to several GHz. A novel tactic is developed to efficiently select the output polarization state for achieving the stable TEM(00)-mode self-mode-locked operations at 1053 nm and 1047 nm, respectively. At an incident pump power of 6.93 W and a pulse repetition rate of 2.717 GHz, output powers as high as 2.15 W and 1.35 W are generated for the σ- and π-polarization, respectively. We experimentally find that decreasing the separation between the gain medium and the input mirror not only brings in the pulse shortening thanks to the enhanced effect of the spatial hole burning, but also effectively introduces the effect of the spectral filtering to lead the Nd:YLF laser to be in a second harmonic mode-locked status. Consequently, pulse durations as short as 8 ps and 8.5 ps are obtained at 1053 nm and 1047 nm with a pulse repetition rate of 5.434 GHz.

  8. 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.

  9. 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°.

  10. 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.

  11. 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.

  12. 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.

  13. A compact ultranarrow high-power laser system for experiments with 578 nm ytterbium clock transition

    SciTech Connect

    Cappellini, G.; Lombardi, P.; Mancini, M.; Pagano, G.; Pizzocaro, M.; Fallani, L.; Catani, J.

    2015-07-15

    In this paper, we present the realization of a compact, high-power laser system able to excite the ytterbium clock transition at 578 nm. Starting from an external-cavity laser based on a quantum dot chip at 1156 nm with an intra-cavity electro-optic modulator, we were able to obtain up to 60 mW of visible light at 578 nm via frequency doubling. The laser is locked with a 500 kHz bandwidth to an ultra-low-expansion glass cavity stabilized at its zero coefficient of thermal expansion temperature through an original thermal insulation and correction system. This laser allowed the observation of the clock transition in fermionic {sup 173}Y b with a <50 Hz linewidth over 5 min, limited only by a residual frequency drift of some 0.1 Hz/s.

  14. Lasing characteristics of Er/sup 3 +/-doped silica fibers from 1553 up to 1603 nm

    SciTech Connect

    Kimura, Y.; Nakazawa, M.

    1988-07-15

    The laser oscillations from 1553 up to 1603 nm have been demonstrated in Er/sup 3 +/-doped silica fibers with a doping rate of 2500 ppm. Wide changes in laser oscillation wavelengths are due to broad splitting of the upper sublevels in the /sup 4/I/sub 152/ manifold, caused by the random structure of the silica matrix. It has been shown that unpumped parts of the Er/sup 3 +/ ions in the end pumped fiber laser configuration play an important role in the wavelength changes of the laser oscillation. For an absorbed pump power of 320 mW at 514 nm, output power of 0.5 mW was obtained at 1603 nm.

  15. Diode-pumped quasi-three-level Nd:GdV O4-Nd:YAG sum-frequency laser at 464 nm

    NASA Astrophysics Data System (ADS)

    Lu, Jie

    2014-04-01

    We report a laser architecture to obtain continuous-wave (cw) blue radiation at 464 nm. A 808 nm diode pumped a Nd:GdV O4 crystal emitting at 912 nm. A part of the pump power was then absorbed by the Nd:GdV O4 crystal. The remainder was used to pump a Nd:YAG crystal emitting at 946 nm. Intracavity sum-frequency mixing at 912 and 946 nm was then realized in a LiB3O5 (LBO) crystal to produce blue radiation. We obtained a cw output power of 1.52 W at 464 nm with a pump laser diode emitting 18.4 W at 808 nm.

  16. 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

  17. 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.

  18. Long wavelength GaN blue laser (400-490nm) development

    SciTech Connect

    DenBaars, S P; Abare, A; Sink, K; Kozodoy, P; Hansen, M; Bowers, J; Mishra, U; Coldren, L; Meyer, G

    2000-10-26

    Room temperature (RT) pulsed operation of blue nitride based multi-quantum well (MQW) laser diodes grown on c-plane sapphire substrates was achieved. Atmospheric pressure MOCVD was used to grow the active region of the device which consisted of a 10 pair In{sub 0.21}Ga{sub 0.79}N (2.5nm)/In{sub 0.07}Ga{sub 0.93}N (5nm) InGaN MQW. The threshold current density was reduced by a factor of 2 from 10 kA/cm{sup 2} for laser diodes grown on sapphire substrates to 4.8 kA/cm{sub 2} for laser diodes grown on lateral epitaxial overgrowth (LEO) GaN on sapphire. Lasing wavelengths as long as 425nm were obtained. LEDs with emission wavelengths as long as 500nm were obtained by increasing the Indium content. These results show that a reduction in nonradiative recombination from a reduced dislocation density leads to a higher internal quantum efficiency. Further research on GaN based laser diodes is needed to extend the wavelength to 490nm which is required for numerous bio-detection applications. The GaN blue lasers will be used to stimulate fluorescence in special dye molecules when the dyes are attached to specific molecules or microorganisms. Fluorescein is one commonly used dye molecule for chemical and biological warfare agent detection, and its optimal excitation wavelength is 490 nm. InGaN alloys can be used to reach this wavelength.

  19. 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.

  20. 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.

  1. 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.

  2. Nanoporous microtubes obtained from a Cu-Ni metallic wire

    NASA Astrophysics Data System (ADS)

    Marano, Emanuele Francesco; Lussana, Danilo; Castellero, Alberto; Baricco, Marcello

    2016-03-01

    Nanoporous microtubes of a nickel-copper alloy were obtained from a Cu-44Ni-1Mn (wt%) commercial wire (200 μm diameter). A new synthesis method was established through three steps: 1) partial oxidation of the wire at 1173 K in air, 2) removal of the inner unoxidized core by chemical etching, 3) reduction in 10 bar hydrogen atmosphere. During oxidation, the segregation of Cu and Ni occurred because of their different diffusion coefficients in the corresponding oxides. As a consequence, pores were formed by Kirkendall effect and due to selective chemical etching of the different oxides. Additional porosity formed because of volume contraction during reduction with hydrogen. After reduction, the microtube shows a composition gradient from the inner wall (almost pure nickel) to the outer wall (almost pure copper). The process allowed to obtain microtubes with tuneable wall thickness and inner pores around 180 ± 80 nm. The morphological features developed suggest improved capillarity properties for applications in MEMS.

  3. 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.

  4. 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.

  5. 100 nm period gratings produced by lithographically induced self-construction

    NASA Astrophysics Data System (ADS)

    Lei, Xinya; Wu, Lin; Deshpande, Paru; Yu, Zhaoning; Wu, Wei; Ge, Haixiong; Chou, Stephen Y.

    2003-07-01

    In this paper we report a technique that allows a fast replication of sub-100 nm scale patterns in a thin polymer film on a substrate from a patterned mask. Using the new pattern transfer technique, we fabricated 100 nm period polymer gratings with a 50 nm linewidth above a Si substrate as an example to demonstrate its capability of producing sub-100 nm nanostructures with direct industrial applications. In our technique, a mask with protruding patterns is used to induce similar pattern formation in the molten polymer film through an electrohydrodynamic instability process. A solid positive replica of the mask is obtained by cooling the polymer below its glass transition temperature. The mask is removed afterwards for the next fabrication procedure. The polymer structures formed can be used either directly as functional devices or as etching masks for further lithography processes. The mechanism that leads to the instability and subsequent pattern formation in the polymer layer is explained. Several important physical parameters that control the whole instability process are also identified. Our theory and experiments show that the pattern transfer technique developed here is well suited for the fabrication of sub-100 nm surface patterns in thin polymer films.

  6. 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.

  7. Two-photon activation and excitation properties of PA-GFP in the 720-920-nm region.

    PubMed

    Schneider, Marc; Barozzi, Sara; Testa, Ilaria; Faretta, Mario; Diaspro, Alberto

    2005-08-01

    This report covers the two-photon activation and excitation properties of the PA-GFP, a photoactivatable variant of the Aequorea victoria green fluorescent protein in the spectral region from 720 to 920 nm. It is known from this special form of the molecule that it has an increased level of fluorescence emission when excited at 488 nm after irradiation at lambda approximately 413 nm, under single-photon excitation conditions. Here, we show that upon two-photon irradiation, PA-GFP yields activation in the spectral region from 720 to 840 nm. After photoactivation, the excitation spectrum shifts maintaining the very same emission spectrum of the single-photon case for the native and photoactivated protein. Additionally, when comparing the conventional photoactivation at lambda = 405 nm with a two-photon one, a sharper and better controllable three-dimensional volume of activation is obtained.

  8. Development of fluoropolymer for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Shirota, Naoko; Takebe, Yoko; Sasaki, Takashi; Yokokoji, Osamu; Toriumi, Minoru; Masuhara, Hiroshi

    2006-03-01

    We had already developed several series of fluoropolymers, FPRs and FUGUs, having a partially fluorinated monocyclic structure and having acidic hydroxyl group, which acts as dissolution unit into alkaline solution. Then we have optimized these polymers for top-coat as the developer-soluble type in the 193nm immersion lithography. However the hydrophobicity of these polymers were a little poor due to its hydroxyl group. So we thought that the introduction of water repellent moiety into the these polymers structure is effective to improve the their hydrophobicity though the increase of water repellent unit in the polymer leads to lower dissolution rate in developer. To introduce as much as possible of hydrophobicity unit, we selected FUGU as platform, which has larger dissolution rate in developer than that of FPRs, We copolymerized FUGU with higher water-repellent component and obtained three copolymers, FUGU-CoA, FUGU-CoB, and FUGU-CoC. In this paper, we described characteristics and evaluation of these polymers. Most of these polymer showed an improvement of hydrophobicity, in particular FUGU-CoB had excellent hydrophobicity due to introduction bulky containing-fluorine group. In this study, we also investigated the interaction between the water and various polymers by using QCM method. The difference between FUGU and water repellent polymers for swelling behavior to water became clear by analysis of diffusion coefficient. We found that our new co-polymers have excellent diffusion coefficient than FUGU which was confirmed by QCM method used to evaluate water permeability and water diffusion in the materials.

  9. An RGD spacing of 440 nm is sufficient for integrin alpha V beta 3- mediated fibroblast spreading and 140 nm for focal contact and stress fiber formation

    PubMed Central

    1991-01-01

    The synthetic peptide Gly-Arg-Gly-Asp-Tyr (GRGDY), which contains the RGD sequence of several adhesion molecules, was covalently grafted to the surface of otherwise poorly adhesive glass substrates and was used to determine the minimal number of ligand-receptor interactions required for complete spreading of human foreskin fibroblasts. Well- defined adhesion substrates were prepared with GRGDY between 10(-3) fmol/cm2 and 10(4) fmol/cm2. As the adhesion ligand surface concentration was varied, several distinct morphologies of adherent cells were observed and categorized. The population of fully spread cells at 4 h reached a maximum at 1 fmol/cm2, with no further increases up to 10(4) fmol/cm2. Although maximal cell spreading was obtained at 1 fmol/cm2, focal contacts and stress fibers failed to form at RGD surface concentrations below 10 fmol/cm2. The minimal peptide spacings obtained in this work correspond to 440 nm for spreading and 140 nm for focal contact formation, and are much larger than those reported in previous studies with adsorbed adhesion proteins, adsorbed RGD-albumin conjugates, or peptide-grafted polyacrylamide gels. Vitronectin receptor antiserum specific for integrin alpha V beta 3 blocked cell adhesion and spreading on substrates containing 100 fmol/cm2 of surface- bound GRGDY, while fibronectin receptor antiserum specific for alpha 5 beta 1 did not. Furthermore, alpha V beta 3 was observed to cluster into focal contacts in spread cells, but alpha 5 beta 1 did not. It was thus concluded that a peptide-to-peptide spacing of 440 nm was required for alpha V beta 3-mediated cellular spreading, while 140 nm was required for alpha V beta 3-mediated focal contact formation and normal stress fiber organization in human foreskin fibroblasts; these spacings represent much fewer ligands than were previously thought to be required. PMID:1714913

  10. Factors influencing the properties of fluoropolymer-based resists for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Taylor, Gary N.; Xu, Cheng-Bai; Teng, Gary; Leonard, JoAnne; Szmanda, Charles R.; Lawrence, William; Nur, Sassan; Brown, Kirk W.; Stephen, Al

    2002-07-01

    This paper describes characterization and lithographic results for one class of low absorbance fluoropolymers that were developed for use in 157 nm lithography. We discuss basic resist properties such as absorbance, hydrophobicity, thickness, resolution and profile for dense 1:1 and semi- dense 1:1.5-10 L/S features, reflection control and plasma etching resistance as a function of composition. Lithographic results were obtained on two types of substrates, silicon and SiON hardmask anti-reflectant. The results on the anti-reflectant were compared to those obtained from simulations using PROLITH. Some of the conclusions of this investigation are: Lower absorbance resists have higher hydrophobicity and better resolution; Resists with high hydrophobicity have very poor adhesion on SiOn, but have very good adhesion on Si and organic anti-reflectants; Only inorganic anti-reflectants have sufficient absorption to provide very low reflectance in <30nm thick films; 100 nm 1:1 L/S resolution is attained in 205 nm thick resist on Si at a resist absorption of 2.2/micrometers . The profile is tapered due to absorption; Adhesion to SiON has been achieved by polymer modification.

  11. 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.

  12. 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.

  13. 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

  14. Analysis of Optogalvanic Transients at 621.7 nm, 633.4 nm and 640.2 nm of Neon in a Discharge Plasma Fitted with a Monte Carlo Mathematical Model.

    NASA Astrophysics Data System (ADS)

    Ogungbemi, Kayode; Han, Xianming; Blosser, Micheal; Misra, Prabhakar; LASER Spectroscopy Group Collaboration

    2014-03-01

    Optogalvanic transitions have been recorded and fitted for 1s5 - 2p7\\ (621.7 nm), 1s5 - 2p8 (633.4 nm) and 1s5 - 2p9 (640.2 nm) transitions of neon in a Fe-Ne hollow cathode plasma discharge as a function of current (2-19 mA) and time evolution (0-50 microsec). The optogalvanic waveforms have been fitted to a Monte carlo mathematical model. The variation in the excited population of neon is governed by the rate of collision of the atoms involving the common metastable state (1s5) for the three transitions investigated. The concomitant changes in amplitudes and intensities of the optogalvanic signal waveforms associated with these transitions have been studied rigorously and the fitted parameters obtained using the Monte Carlo algorithm to help better understand the physics of the hollow cathode discharge. Thanks to Laser Spectroscopy group in Physics and Astronomy Dept. Howard University Washington DC.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Imaging the internal structure of the guinea pig cochlea using optical coherence tomography at 1310 nm

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Mark K.; de Boer, Johannes F.; Park, Boris H.; Nassif, Nader; Zhao, Yonghua; Chen, Zhongping; Wong, Brian J.

    2001-05-01

    Optical coherence tomography (OCT) was used to obtain cross sectional images of the internal structure of the cochlea in guinea pigs following sacrifice. The 1310 nm source (bandwidth (lambda) equals75 nm) allowed a penetration depth of approximately 1.5 mm. Cross-sectional images (1.87 x 2.00 mm, 10 x 10 micrometers /pixel) were acquired at a frame rate of 1 Hz. Access to the middle ear space was obtained by removing the mastoid bulla. Imaging was performed in situ and also in ex vivo temporal bones. The scala vestibuli, scala media, scala tympani, modiolus and all four and a half turns of the cochlea were identified. These images demonstrate the potential value of OCT for use in determining the internal structures of the cochlea with near-microscopic resolution and at near-real time frame rates.

  2. Nanoporous palladium with sub-10 nm dendrites by electrodeposition for ethanol and ethylene glycol oxidation

    NASA Astrophysics Data System (ADS)

    Cherevko, Serhiy; Kulyk, Nadiia; Chung, Chan-Hwa

    2011-12-01

    High surface area Pd foams with roughness factors of more than 1000 and a specific surface area of 60 m2 g-1 are obtained by electrodeposition. The foams are composed of dendrites with branches on the 10 nm scale. The resulting electrodes show high activity towards the oxidation of C2 alcohols.High surface area Pd foams with roughness factors of more than 1000 and a specific surface area of 60 m2 g-1 are obtained by electrodeposition. The foams are composed of dendrites with branches on the 10 nm scale. The resulting electrodes show high activity towards the oxidation of C2 alcohols. Electronic supplementary information (ESI) available: Details of the experimental conditions, additional SEM images, CVs, pseudo-steady-state curves, and summary table. See DOI: 10.1039/c1nr11316j

  3. Analysis of excited-state Faraday anomalous dispersion optical filter at 1529 nm.

    PubMed

    Xiong, Junyu; Yin, Longfei; Luo, Bin; Guo, Hong

    2016-06-27

    In this work, a detailed theoretical analysis of 1529 nm ES-FADOF (excited state Faraday anomalous dispersion optical filter) based on rubidium atoms pumped by 780 nm laser is introduced, where Zeeman splitting, Doppler broadening, and relaxation processes are considered. Experimental results are carefully compared with the derivation. The results prove that the optimal pumping frequency is affected by the working magnetic field. The population distribution among all hyperfine Zeeman sublevels under the optimal pumping frequency has also been obtained, which shows that 85Rb atoms are the main contribution to the population. The peak transmittance above 90% is obtained, which is in accordance with the experiment. The calculation also shows that the asymmetric spectra observed in the experiment are caused by the unbalanced population distribution among Zeeman sublevels. This theoretical model can be used for all kinds of calculations for FADOF.

  4. 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.

  5. Quantum yield of chlorine-atom formation in the photodissociation of chlorine peroxide (ClOOCl) at 308 nm

    NASA Technical Reports Server (NTRS)

    Molina, M. J.; Colussi, A. J.; Molina, L. T.; Schindler, R. N.; Tso, T.-L.

    1990-01-01

    The production of Cl atoms in the laser flash photolysis of ClOOCl at 308 nm has been investigated by time-resolved atomic resonance fluorescence at 235 K. A value of phi = 1.03 +/-0.12 has been obtained for the primary quantum yield based on an absorption cross section ratio sigma(245)/phi(308) = 22 for ClOOCl at 245 and 308 nm.

  6. 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)

  7. Element-specific hysteresis loop measurements on Individual 35 nm islands with scanning transmission X-ray microscopy.

    PubMed

    Luo, Feng; Eimüller, Thomas; Amaladass, Edward; Lee, Ming Sang; Heyderman, Laura J; Solak, Harun H; Tyliszczak, Tolek

    2012-03-01

    Using scanning transmission X-ray microscopy combined with X-ray magnetic circular dichroism, element-specific hysteresis loops with a 25 nm X-ray probe are obtained on 35 nm Fe/Gd multilayer nanoislands fabricated by extreme ultra-violet interference lithography. Local hysteresis loops measured for the individual islands and the antidot film between the islands display similar behavior resulting from the lateral confinement. Line scan measurements confirm ferrimagnetic coupling between Fe and Gd in the patterned region. The ability to measure magnetization reversal with X-rays at high spatial resolution will provide an important tool for future characterization of sub-50 nm nanostructures.

  8. Spectroscopic and laser properties of SrMoO4:Tm3+ crystal under 1700-nm laser diode pumping

    NASA Astrophysics Data System (ADS)

    Doroshenko, M. E.; Papashvili, A. G.; Dunaeva, E. E.; Ivleva, L. I.; Osiko, V. V.; Jelinkova, H.; Sulc, J.; Nemec, M.

    2016-10-01

    Spectroscopic and laser properties of Tm3+ ions under 1700 nm excitation in SrMoO4 crystal are investigated. Negligible effect of cross-relaxation process (3H4sbnd 3F4, 3H6sbnd 3F4) on population of 3F4 level for thulium concentrations up to 0.25 at.% was demonstrated. Efficient lasing with slope efficiency up to 18% and broadband (over 100 nm) tuning at room temperature under 1700 nm diode pumping were obtained.

  9. 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}}.

  10. 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

  11. 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

  12. Development of high coherence, 200mW, 193nm solid-state laser at 6 kHz

    NASA Astrophysics Data System (ADS)

    Nakazato, T.; Tsuboi, M.; Onose, T.; Tanaka, Y.; Sarukura, N.; Ito, S.; Kakizaki, K.; Watanabe, S.

    2015-02-01

    The high coherent, high power 193-nm ArF lasers are useful for interference lithography and microprosessing applications. In order to achieve high coherence ArF lasers, we have been developing a high coherence 193 nm solid state laser for the seeding to a high power ArF laser. We used the sum frequency mixing of the fourth harmonic (FH) of a 904-nm Ti:sapphire laser with a Nd:YVO4 laser (1342 nm) to generate 193-nm light. The laser system consists of a single-mode Ti:sapphire oscillator seeded by a 904-nm external cavity laser diode, a Pockels cell, a 6-pass amplifier, a 4-pass amplifier, a 2-pass amplifier and a wavelength conversion stage. The required repetition rate of 6 kHz corresponding to the ArF laser, along with a low gain at 904 nm induces serious thermal lens effects; extremely short focal lengths of the order of cm and bi-foci in the vertical and horizontal directions. From the analysis of thermal lens depending on pump intensity, we successfully compensated the thermal lens by dividing a 527-nm pump power with 15, 25 and 28 W to 3-stage amplifiers with even passes, resulting in the output power above 10W with a nearly diffraction limited beam. This 904-nm output was converted to 3.8 W in the second harmonic by LBO, 0.5 W in FH by BBO sequentially. Finally the output power of 230 mW was obtained at 193 nm by mixing the FH with a 1342-nm light in CLBO.

  13. Determination of the chiral indices (n,m) of carbon nanotubes by electron diffraction.

    PubMed

    Qin, Lu-Chang

    2007-01-07

    The atomic structure of a carbon nanotube can be defined by the chiral indices, (n,m), that specify its perimeter vector (chiral vector), with which the diameter and helicity are also determined. The fine electron beam available in a modern Transmission Electron Microscope (TEM) offers a unique and powerful probe to reveal the atomic structure of individual nanotubes. This article covers two aspects related to the use of the electron probe in the TEM for the study of carbon nanotubes: (i) to express the electron diffraction intensity distribution in the electron diffraction patterns of carbon nanotubes and (ii) to obtain the chiral indices (n,m) of carbon nanotubes from their electron diffraction patterns. For a nanotube of given chiral indices (n,m), the electron scattering amplitude from the carbon nanotube can be expressed analytically in closed form using the helical diffraction theory, from which its electron diffraction pattern can be calculated and understood. The reverse problem, i.e., assignment of the chiral indices (n,m) of a carbon nanotube from its electron diffraction pattern, is approached from the relationship between the electron diffraction intensity distribution and the chiral indices (n,m). The first method is to obtain indiscriminately the chiral indices (n,m) by reading directly the intensity distribution on the three principal layer lines, l(1), l(2), and l(3), which have intensities proportional to the square of the Bessel functions of orders m, n, and n + m: I(l1) proportional, variant |J(m) (pidR)|(2), I(l2) proportional, variant |J(n) (pidR)|(2), and I(l3) proportional, variant |J(n+m) (pidR)|(2). The second method is to obtain and use the ratio of the indices n/m = (2D(1)-D(2))/(2D(2)-D(1)) in which D(1) and D(2) are the spacings of principal layer lines l(1) and l(2), respectively. Examples of using these methods are also illustrated in the determination of chiral indices of isolated individual single-walled carbon nanotubes, a bundle

  14. Competition between photochemistry and energy transfer in ultraviolet-excited diazabenzenes. I. Photofragmentation studies of pyrazine at 248 nm and 266 nm

    SciTech Connect

    Sevy, Eric T.; Muyskens, Mark A.; Rubin, Seth M.; Flynn, George W.; Muckerman, James T.

    2000-04-01

    The quantum yield for the formation of HCN from the photodissociation of pyrazine excited at 248 nm and 266 nm is determined by IR diode probing of the HCN photoproduct. HCN photoproducts from excited pyrazine are produced via three different dissociation channels, one that is extremely ''prompt'' and two others that are ''late.'' The total quantum yield from all reaction channels obtained at low quencher gas pressures, {phi}=1.3{+-}0.2 for 248 nm and 0.5{+-}0.3 for 266 nm, is in agreement with preliminary studies of this process as well as recent molecular beam studies. To investigate if HCN production is the result of pyrazine multiphoton absorption, this photodissociation process has been further studied by observing the HCN quantum yield as a function of total quencher gas pressure (10 mTorr pyrazine, balance SF{sub 6}) and as a function of 248 nm laser fluence from 2.8 to 82 mJ/cm2. At the highest SF{sub 6} pressures, the HCN quantum yield shows strong positive correlation with laser fluence, indicating that the ''prompt'' channel is the result of multiphoton absorption; however, at low pressure, the HCN quantum yield is affected little by changing laser fluence, indicating that the majority of the HCN photoproducts at low pressure are produced from pyrazine which has absorbed only one UV photon. At the lowest pressures sampled, HCN produced from the one-photon ''late'' process accounts for more than 95% of all HCN formed (at low laser fluence). At high pressures the single photon ''late'' pyrazine dissociation is quenched, and HCN produced at high quencher gas pressures comes only from the multiphoton absorption channel, which can be clearly observed to depend on laser fluence. The HCN quantum yield as a function of laser intensity at high pressure has been fit to a quadratic function that can be used to determine the amount of ''prompt'' ''unquenched'' HCN produced from multiphoton photodissociation. Additionally, the information theoretic prior functions

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 0.7-NA DUV step-and-scan system for 150-nm imaging with improved overlay

    NASA Astrophysics Data System (ADS)

    van Schoot, Jan B.; Bornebroek, Frank; Suddendorf, Manfred; Mulder, Melchior; van der Spek, Jeroen; Stoeten, Jan; Hunter, Adolph; Ruemmer, Peter

    1999-07-01

    To extend KrF lithography below the 180nm SIA design rule node in manufacturing, an advanced DUV step and scan system utilizing a lens with an NA up to 0.7 will be required to provide sufficient process latitude. Towards the SIA's 150nm design rule node, manufacturing challenges for 248nm lithography include contact hole printing, iso-dense bias control and adequate across the field CD uniformity. All will benefit from higher NA lenses. In the paper, result obtained on a PAS 5500/700B DUV Step and Scan system are presented. The system design is based on the PAS 5500/500 with a new 0.7NA Starlith lens, AERIAL II illuminator and ATHENA advanced alignment system. Imaging of dense and isolated lines at 180nm, 150nm and below as well as 180nm and 160nm contact holes is shown. In addition to imaging performance, image plane deviation, system distortion fingerprints, single-machine overlay and multiple-machine matching results are shown. Using the ATHENA alignment system, alignment reproducibility as well as overlay result on CMP wafers will be shown. It is concluded that this exposure tool is capable of delivering imaging and overlay performance required for mass production at the 150nm design rule node, with potential for R and D applications beyond.

  2. A graphene passively Q-switched Nd:YAG ceramic laser at 1123 nm

    NASA Astrophysics Data System (ADS)

    Men, Shaojie; Liu, Zhaojun; Zhang, Xingyu; Wang, Qingpu; Shen, Hongbin; Bai, Fen; Gao, Liang; Xu, Xiangang; Wei, Rusheng; Chen, Xiufang

    2013-03-01

    A 1123 nm ceramic Nd:YAG laser passively Q-switched by graphene grown on SiC wafer was demonstrated. With a pump power of 8.1 W, an average output power of 332 mW was obtained, corresponding to an optical-to-optical conversion efficiency of 4.1% and a slope efficiency of 7.8%. The pulse width was 875.7 ns with a pulse repetition rate of 46.8 kHz.

  3. Diode-pumped passively mode-locked Nd:GSAG laser at 942 nm.

    PubMed

    Xu, Changwen; Wei, Zhiyi; Zhang, Yongdong; Li, Dehua; Zhang, Zhiguo; Wang, X; Wang, S; Eichler, H J; Zhang, Chunyu; Gao, Chunqing

    2009-08-01

    Stable mode-locking of a diode-pumped Nd:GSAG laser emitting at 942 nm between the 4F2/3-4I9/2 transition has been demonstrated. With a z cavity and a semiconductor saturable absorber mirror passive mode locker, we obtained 8.7 ps pulses at repetition rate of 95.6 MHz and average output power of 510 mW. The total optical efficiency is about 3.1%.

  4. Observations of the Seasonal Polar Icecaps of Mars at 1064 nm

    NASA Technical Reports Server (NTRS)

    Zuber, Maria T.; Smith, David E.

    2003-01-01

    The Mars Orbiter Laser Altimeter (MOLA) is routinely making radiometric observations of Mars at a wavelength of 1064 nm. Although the altimeter function is no longer operational, the MOLA detector continues to measure the reflectivity of the surface. Observations have been obtained almost continuously since the beginning of the Mars Global Surveyor (MGS) mapping mission in February 1999, and are providing measurements relevant to understanding the seasonal cycling of CO2 surface frost.

  5. SOFIA Observatory Obtains 'First Light' Images

    NASA Video Gallery

    NASA's Stratospheric Observatory for Infrared Astronomy, or SOFIA, successfully obtained its "First Light"" images during an overnight flight May 26. Scientists are now processing the data gathered...

  6. Preparation and characterization of sterile and freeze-dried sub-200 nm nanoparticles.

    PubMed

    Konan, Yvette N; Gurny, Robert; Allémann, Eric

    2002-02-21

    The feasibility of producing sterile and freeze-dried polyester nanoparticles was investigated. Various poly(D,L-lactide-co-glycolide) and poly(D,L-lactide) were selected as biodegradable polymers. Using the salting-out procedure, process parameters were optimized to obtain sub-200 nm particles. After purification, the nanoparticle suspensions containing different lyoprotectants were sterilized by filtration. Freeze-drying was performed using vials covered with 0.22 microm membrane filters in order to preserve the suspensions from bacterial contamination. Sterility was assessed on the final product according to pharmacopoeial requirements using the membrane filtration method. With all polymers tested, sub-200 nm particles could be obtained. Nanoparticles with a size as low as 102 nm were prepared with good reproducibility and narrow size distribution. Upon freeze-drying, it appeared that complete redispersion of all types of polyester nanoparticles could be obtained in presence of the lyoprotectants tested such as saccharides while aggregation was observed without lyoprotectant. Sterility testing showed no microbial contamination indicating that sterile nanoparticulate formulations have been achieved.

  7. 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.

  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. Passivation of c-Si surfaces by sub-nm amorphous silicon capped with silicon nitride

    SciTech Connect

    Wan, Yimao Yan, Di; Bullock, James; Zhang, Xinyu; Cuevas, Andres

    2015-12-07

    A sub-nm hydrogenated amorphous silicon (a-Si:H) film capped with silicon nitride (SiN{sub x}) is shown to provide a high level passivation to crystalline silicon (c-Si) surfaces. When passivated by a 0.8 nm a-Si:H/75 nm SiN{sub x} stack, recombination current density J{sub 0} values of 9, 11, 47, and 87 fA/cm{sup 2} are obtained on 10 Ω·cm n-type, 0.8 Ω·cm p-type, 160 Ω/sq phosphorus-diffused, and 120 Ω/sq boron-diffused silicon surfaces, respectively. The J{sub 0} on n-type 10 Ω·cm wafers is further reduced to 2.5 ± 0.5 fA/cm{sup 2} when the a-Si:H film thickness exceeds 2.5 nm. The passivation by the sub-nm a-Si:H/SiN{sub x} stack is thermally stable at 400 °C in N{sub 2} for 60 min on all four c-Si surfaces. Capacitance–voltage measurements reveal a reduction in interface defect density and film charge density with an increase in a-Si:H thickness. The nearly transparent sub-nm a-Si:H/SiN{sub x} stack is thus demonstrated to be a promising surface passivation and antireflection coating suitable for all types of surfaces encountered in high efficiency c-Si solar cells.

  10. 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

  11. 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

  12. Application of 266-nm and 355-nm Nd:YAG laser radiation for the investigation of fuel-rich sooting hydrocarbon flames by raman scattering.

    PubMed

    Egermann, Jan; Seeger, Thomas; Leipertz, Alfred

    2004-10-10

    We describe the use of linear Raman scattering for the investigation of fuel-rich sooting flames. In comparison, the frequency-tripled and -quadrupled fundamental wavelengths of a Nd:YAG laser have been used as an excitation source for study of the applicability of these laser wavelengths for analysis of sooting flames. The results obtained show that, for the investigation of strongly sooting flames, 266-nm excitation is better than 355-nm excitation. Although the entire fluorescence intensity of polycyclic aromatic hydrocarbons (PAHs) decreases with rising excitation wavelength, there is increased interference with the Raman signals by displacement of the spectral region of the Raman signals toward the fluorescence maximum of the laser-induced fluorescence emissions. Besides the broadband signals of PAHs, narrowband emissions of laser-produced C2 occur in the spectra of sooting flames and affect the Raman signals. These C2 emission bands are completely depolarized and can be separated by polarization-resolved detection. A comparison of the laser-induced fluorescence emissions of an ethylene flame with those of a methane flame shows the same spectral features, but the intensity of the emissions is larger by a factor of 5 for the ethylene fuel. Using 266-nm radiation for Raman signal excitation makes possible measurements in the ethylene flame also.

  13. Astrophysical Reaction Rates Obtained By Indirect Techniques

    SciTech Connect

    Tribble, R. E.; Al-Abdullah, T.; Alharbi, A.; Banu, A.; Chen, X.; Clark, H. L.; Fu, C.; Gagliardi, C. A.; Hardy, J. C.; Iacob, V. E.; Lui, Y.-W.; McCleskey, M.; Mukhamedzhanov, A.; Nica, N.; Park, H. I.; Roeder, B.; Simmons, E.; Tabacaru, G.; Tokimoto, Y.; Trache, L.

    2010-08-12

    Indirect techniques have been used to obtain information about reaction rates for several proton capture reactions that occur on short-lived nuclei. The techniques used to carry out the measurements are reviewed and the results obtained are presented. Also future prospects for further measurements with a new facility, T-REX are discussed.

  14. 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.

  15. 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.

  16. 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.

  17. Ready Reference. How To Obtain an ISBN; How To Obtain an ISSN; How To Obtain an SAN.

    ERIC Educational Resources Information Center

    Koltay, Emery

    2003-01-01

    These three articles describe ISBNs (International Standard Book Numbers); ISSNs (International Standard Serial Numbers); and SANs (Standard Address Numbers), for organizations served by the book industry; and explains how to apply to obtain the appropriate numbers. (LRW)

  18. 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.

  19. 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.

  20. 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.

  1. Diode pumped passively Q-switched Nd:LuAG laser at 1442.6 nm

    NASA Astrophysics Data System (ADS)

    Guan, Chen; Liu, Zhaojun; Cong, Zhenhua; Liu, Yang; Xu, Xiaodong; Xu, Jun; Huang, Qingjie; Rao, Han; Chen, Xia; Zhang, Yanmin; Wu, Qianwen; Bai, Fen; Zhang, Sasa

    2017-02-01

    A diode-end-pumped passively Q-switched Nd:LuAG laser at 1442.6 nm was demonstrated with a V3+:YAG crystal as the saturable absorber. Under continuous-wave (CW) operation, the maximum output power of 1.83 W was obtained with an absorbed pumping power of 11.1 W. The corresponding optical-to-optical conversion efficiency was 16.5%. Under Q-switched operation, the maximum average output power of 424 mW was obtained at the same pumping power. The pulse duration and pulse repetition rate were 72 ns and 17.4 kHz, respectively.

  2. Retinal Oximetry with 510-600 nm Light Based on Partial Least-Squares Regression Technique

    NASA Astrophysics Data System (ADS)

    Arimoto, Hidenobu; Furukawa, Hiromitsu

    2010-11-01

    The oxygen saturation distribution in the retinal blood stream is estimated by measuring spectral images and adopting the partial-least squares regression. The wavelengths range used for the calculation is from 510 to 600 nm. The regression model for estimating the retinal oxygen saturation is built on the basis of the arterial and venous blood spectra. The experiment is performed using an originally designed spectral ophthalmoscope. The obtained two-dimensional (2D) oxygen saturation indicates the reasonable oxygen level across the retina. The measurement quality is compared with those obtained using other wavelengths sets and data processing methods.

  3. Extending aggressive low-k1 design rule requirements for 90-nm and 65-nm nodes via simultaneous optimization of NA, illumination, and OPC

    NASA Astrophysics Data System (ADS)

    Roy, Sabita; Van Den Broeke, Douglas J.; Chen, J. F.; Liebchen, Armin; Chen, Ting; Hsu, Stephen D.; Shi, Xuelong; Socha, Robert J.

    2004-05-01

    Under low-k1 patterning constraints, it has been a challenge for the lithography process to meet the aggressive IC design rule requirements for the 90nm and the upcoming 65nm nodes. From the imaging perspective, we see the geometric design rules are largely governed by numerical aperture (NA), illumination settings, and OPC for any resolution enhancement technique (RET) applied mask. We report a case study of exploring a set of process feasible design rule criteria based on a state-of-the-art μProcessor chip that contains three different styles of circuit design - standard library cell (SLC), random logic (RML), and SRAM. To keep the packing density higher for SRAM, the critical criteria for design rules involve achievable minimum pitch, sufficient area of contact-landing pad, minimum line end shortening (LES) to ensure poly endcap, and preferably to have optimum pitch for the placement of Scattering Bars (SB). For RML, the goal is to achieve the printing of ever smaller critical dimension (CD) with a greater CD uniformity control. The SLC should be designed to be comparable with both RML and SRAM devices. Hence, the design rule constraints for CD, space, line end, minimum pitch, and SB placement for SLC cell is critically confined. Unlike the traditional method of assuming a linear scaling for the design rule set, we explore achievable design rule criteria for very low k1 imaging by simultaneously optimizing NA, illumination settings, and OPC (for the optimum placement of SB) for a calibrated process. This is done by analyzing the CD control and the maximum overlapped process window for critical lines, spaces, line ends, and with the respective k1 factor for the three types of circuits. For 90nm node with k1 as low as 0.36, a feasible set of design rules for the μProcessor chip can be obtained using 6% attPSM with 6% exposure latitude at 400nm of overlapped depth of focus. Using the similar approach for the scaled down 65nm 6% attPSM, it resulted inadequate

  4. 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.

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. 25 CFR 162.539 - Must I obtain a WEEL before obtaining a WSR lease?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... AND PERMITS Wind and Solar Resource Leases Wsr Leases § 162.539 Must I obtain a WEEL before obtaining... direct result of energy resource information gathered from a WEEL activity, obtaining a WEEL is not...

  10. Cyclic nucleotide phosphodiesterase activity in 10-nm filaments and microtubule preparations from bovine brain

    PubMed Central

    Runge, Marschall S.; Hewgley, Paula B.; Puett, David; Williams, Robley C.

    1979-01-01

    Cyclic nucleotide phosphodiesterase activity (3′:5′-cyclic-AMP 5′-nucleotidohydrolase, EC 3.1.4.17), which is activatable by Ca2+-dependent regulator protein (CDR), has been identified in cycled microtubule preparations from bovine brain. By using various methods to fractionate the microtubule preparation into subfractions (e.g., phosphocellulose chromatography to obtain purified 6S tubulin and soluble microtubule-associated proteins, and gel exclusion chromatography on Bio-Gel A-150m to obtain 10-nm filaments), we found that all the fractions exhibited some enzymic activity, but that most of the phosphodiesterase activity was localized in the 10-nm filament fraction. By using cyclic GMP as substrate, a specific activity of 921 ± 168 pmol/mg of filament protein·min was determined. Also, 10-nm filaments were prepared directly from brain homogenates by differential centrifugation and gel exclusion chromatography. This fraction also contained phosphodiesterase activity but of slightly lower specific activity (752 ± 9 pmol/mg of protein·min). The filament-associated enzymic activity was stable during storage (-70°C) and to several salt extractions at moderate ionic strength (0.5 M); the latter finding indicates that the phosphodiesterase is not adsorbed to the filaments via nonspecific electrostatic interactions. Although a chelating agent was present in the initial homogenization buffer and generally in all buffers used in preparing fractions, an activator of a smooth muscle phosphodiesterase was released upon boiling the 10-nm filaments. This activator obtained in the boiled supernatant was Ca2+-sensitive, trifluoperazine-sensitive, and stimulated smooth muscle phosphodiesterase to nearly the same extent as purified (exogenous) CDR; thus, it probably represents filament-associated CDR. Images PMID:223149

  11. White light upconversion emissions from Tm3++Ho3++Yb3+ codoped tellurite and germanate glasses on excitation with 798 nm radiation

    NASA Astrophysics Data System (ADS)

    Giri, Neeraj Kumar; Rai, D. K.; Rai, S. B.

    2008-12-01

    White light has been produced using 798 nm laser excitation in Tm3++Ho3++Yb3+ codoped tellurite and germanate glasses. These glasses simultaneously generate the three primary colors, red, green, and blue, on 798 nm excitation. Thus, multicolor emission obtained was tuned to white luminescence by adjusting the Ho3+ ion concentration and excitation power. UV excitation and fluorescence spectra of these triply doped glasses give additional emissions, which do not appear on 798 nm excitation.

  12. Electric Field-Assisted Photochemical Water Splitting Should Operate with 287 nm Light.

    PubMed

    Bachler, Vinzenz; Gärtner, Wolfgang

    2016-05-01

    The major photoreaction of water is the homolytic splitting of one O-H bond starting from the 1(1) B1 excited state (λmax = 167 nm). This reaction produces H• and •OH radicals. The combination of two H• atoms leads to the potential energy carrier dihydrogen. However, the energy required to obtain the photoreactive 1(1) B1 electronic state is about 7.4 eV, which cannot be effectively provided by solar radiation. The sun light spectrum on earth comprises the visible and ultraviolet region, but shows vanishing intensity near 7 eV (177.1 nm). This work provides theoretical evidence that the photoreactive 1(1) B1 state of water can be shifted into the ultraviolet (UV-B) light region (≈287 nm) by including explicitly an electric field in the calculations of the water absorption spectrum. To accomplish such bathochromic shift, a large field strength of 3.08 VÅ(-1) is required. The field-dependent excitation energies were calculated by applying the symmetry-adapted cluster configuration interaction (SAC-CI) procedure. Based on this theoretical analysis, we propose that photochemical water splitting can be accomplished by means of 287 nm light provided the water molecule is favorably oriented by an external electric field and is subsequently activated by a reversal of the field orientation.

  13. Imaging of electrical response of NiOx under controlled environment with sub-25-nm resolution

    DOE PAGES

    Jacobs, Christopher B.; Ievlev, Anton V.; Collins, Liam F.; ...

    2016-07-19

    The spatially resolved electrical response of rf-sputtered polycrystalline NiOx films composed of 40 nm crystallites was investigated under different relative humidity levels (RH). The topological and electrical properties (surface potential and resistance) were characterized using Kelvin probe force microscopy (KPFM) and conductive scanning probe microscopy at 0%, 50%, and 80% relative humidity with sub 25nm resolution. The surface potential of NiOx decreased by about 180 mV and resistance decreased in a nonlinear fashion by about 2 G when relative humidity was increased from 0% to 80%. The dimensionality of surface features obtained through autocorrelation analysis of topological, surface potential andmore » resistance maps increased linearly with increased relative humidity as water was adsorbed onto the film surface. Spatially resolved surface potential and resistance of the NiOx films were found to be heterogeneous, with distinct features that grew in size from about 60 nm to 175 nm between 0% and 80% RH levels, respectively. Here, we find that the changes in the heterogeneous character of the NiO films are consistent through the topological, surface potential, and resistance measurements, suggesting that the nanoscale surface potential and resistance properties converge with the mesoscale properties as water is adsorbed onto the NiOx film.« less

  14. 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.

  15. Segmentation of 830- and 1310-nm LASIK corneal optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Li, Yan; Shekhar, Raj; Huang, David

    2002-05-01

    Optical coherence tomography (OCT) provides a non-contact and non-invasive means to visualize the corneal anatomy at micron scale resolution. We obtained corneal images from an arc-scanning (converging) OCT system operating at a wavelength of 830nm and a fan-shaped-scanning high-speed OCT system with an operating wavelength of 1310nm. Different scan protocols (arc/fan) and data acquisition rates, as well as wavelength dependent bio-tissue backscatter contrast and optical absorption, make the images acquired using the two systems different. We developed image-processing algorithms to automatically detect the air-tear interface, epithelium-Bowman's layer interface, laser in-situ keratomileusis (LASIK) flap interface, and the cornea-aqueous interface in both kinds of images. The overall segmentation scheme for 830nm and 1310nm OCT images was similar, although different strategies were adopted for specific processing approaches. Ultrasound pachymetry measurements of the corneal thickness and Placido-ring based corneal topography measurements of the corneal curvature were made on the same day as the OCT examination. Anterior/posterior corneal surface curvature measurement with OCT was also investigated. Results showed that automated segmentation of OCT images could evaluate anatomic outcome of LASIK surgery.

  16. One-step fabrication of sub-10-nm plasmonic nanogaps for reliable SERS sensing of microorganisms.

    PubMed

    Chen, Jing; Qin, Gaowu; Wang, Jiansheng; Yu, Jiangyu; Shen, Bo; Li, Song; Ren, Yuping; Zuo, Liang; Shen, Wen; Das, Biswajit

    2013-06-15

    Nanoscale gaps in noble metal films can produce intense electromagnetic enhancement. When Raman-active molecules are positioned in these regions, their surface-enhanced Raman scattering (SERS) signals can be dramatically enhanced. However, the lack of convenient and reliable fabrication methods with ultrasmall nanogaps (<10 nm) severely block the application of SERS. Here, we propose a cost-effective and reproducible technique to fabricate the large-area Ag SERS-active substrates which are full of the high-density, sub-10-nm nanogaps by high pressure sputtering, and the enhancement factor (EF) is testified to improve by 10(3) times compared to the continuous Ag film with a smooth surface (the roughness is 0.5 nm) and without nanogaps. Since there are no chemicals used during fabrication, this substrate has a clean surface, which is crucial for acquiring reliable SERS spectra. This SERS-active substrate has then been applied to identify a series of microorganisms, and excellent, reproducible SERS spectra were obtained. Finally, a set of piecewise-linear equations is provided according to the correlation between SERS intensity and rhodamine 6G (R6G) concentration, and the detection limit is calculated to be 0.2×10(-8)M. These results suggest that the high pressure sputtering is an excellent, reliable technique for fabricating sub-10-nm plasmonic nanogaps, and the SERS-based methodology is very promising for being used in biological sensing field.

  17. 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.

  18. Direct laser interference patterning of polystyrene films doped with azo dyes, using 355 nm laser light

    NASA Astrophysics Data System (ADS)

    Broglia, M. F.; Suarez, S.; Soldera, F.; Mücklich, F.; Barbero, C. A.; Bellingeri, R.; Alustiza, F.; Acevedo, D.

    2014-05-01

    The generation of line-like periodic patterns by direct laser interference patterning (DLIP) of polystyrene films (PS) at a wavelength of 355 nm has been investigated. No structuration is achieved in plain PS due to the weak absorption of the polymer at 355 nm. On the other hand, patterning is achieved on films doped (PSd) with an azo dye (2-anisidine → 2-anisidine) which is incorporated in the polymer solution used for film preparation. Periodic micro-structures are generated. DLIP on PSd results in the swelling of the surface at low fluences, while at high laser intensities it causes the ablation of the regions at the interference maxima positions. The results contrast with the usual process of DLIP on PS (at shorter wavelengths, like 266 nm) where only ablation is detected. The results suggest that decomposition of the azo dye is the driving force of the patterning which therefore differ from the patterning obtained when plain PS is irradiated with laser light able to be absorbed by the aromatic ring in PS (e.g. 266 nm). The biocompatibility of these materials and adhesion of cells was tested, the data from in vitro assays shows that fibroblast cells are attached and proliferate extensively on the PSd films.

  19. 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.

  20. In vitro double-integrating-sphere optical properties of tissues between 630 and 1064 nm

    NASA Astrophysics Data System (ADS)

    Beek, J. F.; Blokland, P.; Posthumus, P.; Aalders, M.; Pickering, J. W.; Sterenborg, H. J. C. M.; van Gemert, M. J. C.

    1997-11-01

    The optical properties (absorption and scattering coefficients and the scattering anisotropy factor) were measured in vitro for cartilage, liver, lung, muscle, myocardium, skin, and tumour (colon adenocarcinoma CC 531) at 630, 632.8, 790, 850 and 1064 nm. Rabbits, rats, piglets, goats, and dogs were used to obtain the tissues. A double-integrating-sphere setup with an intervening sample was used to determine the reflectance, and the diffuse and collimated transmittances of the sample. The inverse adding - doubling algorithm was used to determine the optical properties from the measurements. The overall results were comparable to those available in the literature, although only limited data are available at 790 - 850 nm. The results were reproducible for a specific sample at a specific wavelength. However, when comparing the results of different samples of the same tissue or different lasers with approximately the same wavelength (e.g. argon dye laser at 630 nm and HeNe laser at 632.8 nm) variations are large. We believe these variations in optical properties should be explained by biological variations of the tissues. In conclusion, we report on an extensive set of in vitro absorption and scattering properties of tissues measured with the same equipment and software, and by the same group. Although the accuracy of the method requires further improvement, it is highly likely that the other existing data in the literature have a similar level of accuracy.

  1. 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.

  2. Gate patterning in 14 nm and beyond nodes: from planar devices to three dimensional Finfet devices

    NASA Astrophysics Data System (ADS)

    Meng, Lingkuan; Hong, Peizhen; He, Xiaobin; Li, Chunlong; Li, Junjie; Li, Junfeng; Zhao, Chao; Wei, Yayi; Yan, Jiang

    2016-01-01

    In this work, we investigated the challenges encountered in 14 nm node Finfet gate patterning. The patterning process was originated from a 22 nm planar device, in which a SiO2/Si3N4/SiO2 (ONO) multilayer was used as an etch mask. To accommodate with the 3D nature of Finfet structures in 14 nm node, the thickness of Si3N4 has been increased in the investigated process. We found out that the standard ONO mask etch process was no longer effective for gate patterning in 3D Finfet devices. It was observed that the etched mask sidewall was significantly more tapered than that in planar devices, resulting in the final CDs of both mask and dummy gate far wider than those of the planar devices. In order to achieve a desirable gate CD, the formation mechanism causing a severely tapered mask profile was first investigated. Our results suggested that redeposition effect of the etch products on the sidewall played a significant role in controlling etched mask sidewall angle. Then, we proposed a two-step etch process which can improve the anisotropy of ONO mask etch and obtain a steep etch profile with a desirable CD. Using this process, a gate CD of 20 nm was successfully achieved with a desirable profile and a smooth sidewall. Our results have demonstrated that the newly developed etch process is very robust and has a wide process window.

  3. Fabricating vertically aligned sub-20 nm Si nanowire arrays by chemical etching and thermal oxidation.

    PubMed

    Li, Luping; Fang, Yin; Xu, Cheng; Zhao, Yang; Zang, Nanzhi; Jiang, Peng; Ziegler, Kirk J

    2016-04-22

    Silicon nanowires (SiNWs) are appealing building blocks in various applications, including photovoltaics, photonics, and sensors. Fabricating SiNW arrays with diameters <100 nm remains challenging through conventional top-down approaches. In this work, chemical etching and thermal oxidation are combined to fabricate vertically aligned, sub-20 nm SiNW arrays. Defect-free SiNWs with diameters between 95 and 200 nm are first fabricated by nanosphere (NS) lithography and chemical etching. The key aspects for defect-free SiNW fabrication are identified as: (1) achieving a high etching selectivity during NS size reduction; (2) retaining the circular NS shape with smooth sidewalls; and (3) using a directional metal deposition technique. SiNWs with identical spacing but variable diameters are demonstrated by changing the reactive ion etching power. The diameter of the SiNWs is reduced by thermal oxidation, where self-limiting oxidation is encountered after oxidizing the SiNWs at 950 °C for 1 h. A second oxidation is performed to achieve vertically aligned, sub-20 nm SiNW arrays. Si/SiO2 core/shell NWs are obtained before removing the oxidized shell. HRTEM imaging shows that the SiNWs have excellent crystallinity.

  4. Implementation of templated DSA for via layer patterning at the 7nm node

    NASA Astrophysics Data System (ADS)

    Gronheid, Roel; Doise, Jan; Bekaert, Joost; Chan, Boon Teik; Karageorgos, Ioannis; Ryckaert, Julien; Vandenberghe, Geert; Cao, Yi; Lin, Guanyang; Somervell, Mark; Fenger, Germain; Fuchimoto, Daisuke

    2015-03-01

    In recent years major advancements have been made in the directed self-assembly (DSA) of block copolymers (BCP). Insertion of DSA for IC fabrication is seriously considered for the 7nm node. At this node the DSA technology could alleviate costs for double patterning and limit the number of masks that would be required per layer. At imec multiple approaches for inserting DSA into the 7nm node are considered. One of the most straightforward approaches for implementation would be for via patterning through templated DSA (grapho-epitaxy), since hole patterns are readily accessible through templated hole patterning of cylindrical phase BCP materials. Here, the pre-pattern template is first patterned into a spin-on hardmask stack. After optimizing the surface properties of the template the desired hole patterns can be obtained by the BCP DSA process. For implementation of this approach to be implemented for 7nm node via patterning, not only the appropriate process flow needs to be available, but also appropriate metrology (including for pattern placement accuracy) and DSA-aware mask decomposition are required. In this paper the imec approach for 7nm node via patterning will be discussed.

  5. Luminescence study of nanosized Al2O3:Tb3+ obtained by gas-dispersed synthesis

    NASA Astrophysics Data System (ADS)

    Berezovskaya, I. V.; Poletaev, N. I.; Khlebnikova, M. E.; Zatovsky, I. V.; Bychkov, K. L.; Efryushina, N. P.; Khomenko, O. V.; Dotsenko, V. P.

    2016-09-01

    Terbium-doped Al2O3 samples were obtained by gas-dispersed synthesis. It was shown that the resulting powders, with particle sizes of 10-70 nm, consist of a mixture of transition aluminas, among which the δ *-polymorph is dominant. The luminescence properties of Al2O3:Tb3+ have been studied upon excitation in the UV-visible range of the spectrum. It was found that Tb3+ ions cause several groups of inhomogeneously broadened emission bands in the range of 470-640 nm, which are characteristic for disordered materials. In addition, the emission spectra contain a broad band at about 450 nm and several narrower ones in the 680-720 nm region. These features are attributed to surface defects and impurity Cr3+ ions occupying Al3+ octahedral positions, respectively.

  6. Optical properties of cadmium sulfide nanocrystals obtained by the sol-gel method in gelatin

    NASA Astrophysics Data System (ADS)

    Skobeeva, V. M.; Smyntyna, V. A.; Sviridova, O. I.; Struts, D. A.; Tyurin, A. V.

    2008-07-01

    Based on analysis of optical absorption data for CdS nanocrystals obtained by sol-gel technology in gelatin, we have studied the effect of technological factors (reagent concentrations, gelatin concentration) on the growth process and size distribution of the synthesized nanocrystals. Depending on the reagent concentration, we synthesized CdS nanocrystals with mean radii in the range bar r = 1.9 - 2.4 nm . We have shown that for a low gelatin content (1%), nanocrystals of different sizes are formed (1.7 nm and 2.6 nm). With an increase in the gelatin concentration, the size dispersion decreases and nanocrystals of a single mean radius (2.3 nm) are formed. We have established a correlation between the size dispersion and the shape of the photoluminescence spectrum of the CdS nanocrystals.

  7. Antifungal activity of silver nanoparticles obtained by green synthesis.

    PubMed

    Mallmann, Eduardo José J; Cunha, Francisco Afrânio; Castro, Bruno N M F; Maciel, Auberson Martins; Menezes, Everardo Albuquerque; Fechine, Pierre Basílio Almeida

    2015-01-01

    Silver nanoparticles (AgNPs) are metal structures at the nanoscale. AgNPs have exhibited antimicrobial activities against fungi and bacteria; however synthesis of AgNPs can generate toxic waste during the reaction process. Accordingly, new routes using non-toxic compounds have been researched. The proposal of the present study was to synthesize AgNPs using ribose as a reducing agent and sodium dodecyl sulfate (SDS) as a stabilizer. The antifungal activity of these particles against C. albicans and C. tropicalis was also evaluated. Stable nanoparticles 12.5 ± 4.9 nm (mean ± SD) in size were obtained, which showed high activity against Candida spp. and could represent an alternative for fungal infection treatment.

  8. ANTIFUNGAL ACTIVITY OF SILVER NANOPARTICLES OBTAINED BY GREEN SYNTHESIS

    PubMed Central

    MALLMANN, Eduardo José J.; CUNHA, Francisco Afrânio; CASTRO, Bruno N.M.F.; MACIEL, Auberson Martins; MENEZES, Everardo Albuquerque; FECHINE, Pierre Basílio Almeida

    2015-01-01

    Silver nanoparticles (AgNPs) are metal structures at the nanoscale. AgNPs have exhibited antimicrobial activities against fungi and bacteria; however synthesis of AgNPs can generate toxic waste during the reaction process. Accordingly, new routes using non-toxic compounds have been researched. The proposal of the present study was to synthesize AgNPs using ribose as a reducing agent and sodium dodecyl sulfate (SDS) as a stabilizer. The antifungal activity of these particles against C. albicans and C. tropicalis was also evaluated. Stable nanoparticles 12.5 ± 4.9 nm (mean ± SD) in size were obtained, which showed high activity against Candida spp. and could represent an alternative for fungal infection treatment. PMID:25923897

  9. 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.

  10. 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.

  11. 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.

  12. 47 CFR 54.615 - Obtaining services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... provided under § 54.621, that the requester cannot obtain toll-free access to an Internet service provider... that costs the least after consideration of the features, quality of transmission, reliability,...

  13. 47 CFR 54.615 - Obtaining services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... provided under § 54.621, that the requester cannot obtain toll-free access to an Internet service provider... that costs the least after consideration of the features, quality of transmission, reliability,...

  14. 40 CFR 35.6305 - Obtaining supplies.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....6325 through 35.6340, and 35.6350. Supplies obtained with Core Program funds must be for non-site-specific purposes. All purchases of supplies under the Core Program must comply with the requirements...

  15. Mass culture of photobacteria to obtain luciferase

    NASA Technical Reports Server (NTRS)

    Chappelle, E. W.; Picciolo, G. L.; Rich, E., Jr.

    1969-01-01

    Inoculating preheated trays containing nutrient agar with photobacteria provides a means for mass culture of aerobic microorganisms in order to obtain large quantities of luciferase. To determine optimum harvest time, growth can be monitored by automated light-detection instrumentation.

  16. Treatment of biomass to obtain ethanol

    DOEpatents

    Dunson, Jr., James B.; Elander, Richard T.; Tucker, III, Melvin P.; Hennessey, Susan Marie

    2011-08-16

    Ethanol was produced using biocatalysts that are able to ferment sugars derived from treated biomass. Sugars were obtained by pretreating biomass under conditions of high solids and low ammonia concentration, followed by saccharification.

  17. 47 CFR 54.615 - Obtaining services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... provided under § 54.621, that the requester cannot obtain toll-free access to an Internet service provider... thing of value; (6) If the service or services are being purchased as part of an aggregated...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Comparison of 265 nm Femtosecond and 213 nm Nanosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry for Pb Isotope Ratio Measurements.

    PubMed

    Ohata, Masaki; Nonose, Naoko; Dorta, Ladina; Günther, Detlef

    2015-01-01

    The analytical performance of 265 nm femtosecond laser ablation (fs-LA) and 213 nm nanosecond laser ablation (ns-LA) systems coupled with multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) for Pb isotope ratio measurements of solder were compared. Although the time-resolved signals of Pb measured by fs-LA-MC-ICPMS showed smoother signals compared to those obtained by ns-LA-MC-ICPMS, similar precisions on Pb isotope ratio measurements were obtained between them, even though their operating conditions were slightly different. The mass bias correction of the Pb isotope ratio measurement was carried out by a comparison method using a Pb standard solution prepared from NIST SRM 981 Pb metal isotopic standard, which was introduced into the ICP by a desolvation nebulizer (DSN) via a dual-sample introduction system, and it was successfully demonstrated for Pb isotope ratio measurements for either NIST 981 metal isotopic standard or solder by fs-LA-MC-ICPMS since the analytical results agreed well with the certified value as well as the determined value within their standard deviations obtained and the expanded uncertainty of the certified or determined value. The Pb isotope ratios of solder obtained by ns-LA-MC-ICPMS also showed agreement with respect to the determined value within their standard deviations and expanded uncertainty. From these results, it was evaluated that the mass bias correction applied in the present study was useful and both LA-MC-ICPMS could show similar analytical performance for the Pb isotope ratio microanalysis of metallic samples such as solder.

  6. Facile Synthesis of Sub-20 nm Silver Nanowires through a Bromide-Mediated Polyol Method.

    PubMed

    da Silva, Robson Rosa; Yang, Miaoxin; Choi, Sang-Il; Chi, Miaofang; Luo, Ming; Zhang, Chao; Li, Zhi-Yuan; Camargo, Pedro H C; Ribeiro, Sidney José Lima; Xia, Younan

    2016-08-23

    Essentially all of the Ag nanowires reported in the literature have sizes larger than 30 nm in diameter. In this article, we report a simple and robust approach to the synthesis of Ag nanowires with diameters below 20 nm and aspect ratios over 1000 using a one-pot polyol method. The Ag nanowires took a penta-twinned structure, and they could be obtained rapidly (<35 min) and in high morphology purity (>85% of the as-obtained solid product) under atmospheric pressure. The key to the success of this synthesis is to restrain the nanowires from lateral growth by employing both Br(-) ions and poly(vinylpyrrolidone) with a high molecular weight of 1 300 000 g/mol to cap the {100} side faces, together with the use of a syringe pump to slowly introduce AgNO3 into the reaction solution. By optimizing the ratios between the capping agents and AgNO3, we were able to slow down the reduction kinetics and effectively direct the Ag nanowires to grow along the longitudinal direction only. The nanowires showed great mechanical flexibility and could be bent with acute angles without breaking. Because of their small diameters, the transverse localized surface plasmon resonance peak of the Ag nanowires could be pushed down to the ultraviolet region, below 400 nm, making them ideal conductive elements for the fabrication of touch screens, solar cells, and smart windows.

  7. Detection of munitions grade g-series nerve agents using Raman excitation at 1064 nm

    NASA Astrophysics Data System (ADS)

    Roy, Eric; Wilcox, Phillip G.; Hoffland, Soren; Pardoe, Ian

    2015-05-01

    Raman spectroscopy is a powerful tool for obtaining molecular structure information of a sample. While Raman spectroscopy is a common laboratory based analytical tool, miniaturization of opto-electronic components has allowed handheld Raman analyzers to become commercially available. These handheld systems are utilized by Military and First Responder operators tasked with rapidly identifying potentially hazardous chemicals in the field. However, one limitation of many handheld Raman detection systems is strong interference caused by fluorescence of the sample or underlying surface which obscures the characteristic Raman signature of the target analyte. Munitions grade chemical warfare agents (CWAs) are produced and stored in large batches and typically have more impurities from the storage container, degradation, or unreacted precursors. In this work, Raman spectra of munitions grade CWAs were collected using a handheld Raman spectrometer with a 1064 nm excitation laser. While Raman scattering generated by a 1064 nm laser is inherently less efficient than excitation at shorter wavelengths, high quality spectra were easily obtained due to significantly reduced fluorescence of the munitions grade CWAs. The spectra of these less pure, but more operationally relevant, munitions grade CWAs were then compared to spectra of CASARM grade CWAs, as well as Raman spectra collected using the more common 785 nm excitation laser.

  8. Compact soft x-ray transmission microscopy with sub-50 nm spatial resolution.

    PubMed

    Kim, Kyong Woo; Kwon, Youngman; Nam, Ki-Yong; Lim, Jong-Hyeok; Kim, Kyu-Gyum; Chon, Kwon Su; Kim, Byoung Hoon; Kim, Dong Eon; Kim, JinGon; Ahn, Byoung Nam; Shin, Hyun Joon; Rah, Seungyu; Kim, Ki-Ho; Chae, Jin Seok; Gweon, Dae Gab; Kang, Dong Woo; Kang, Sung Hoon; Min, Jin Young; Choi, Kyu-Sil; Yoon, Seong Eon; Kim, Eun-A; Namba, Yoshiharu; Yoon, Kwon-Ha

    2006-03-21

    In this paper, the development of compact transmission soft x-ray microscopy (XM) with sub-50 nm spatial resolution for biomedical applications is described. The compact transmission soft x-ray microscope operates at lambda = 2.88 nm (430 eV) and is based on a tabletop regenerative x-ray source in combination with a tandem ellipsoidal condenser mirror for sample illumination, an objective micro zone plate and a thinned back-illuminated charge coupled device to record an x-ray image. The new, compact x-ray microscope system requires the fabrication of proper x-ray optical devices in order to obtain high-quality images. For an application-oriented microscope, the alignment procedure is fully automated via computer control through a graphic user interface. In imaging studies using our compact XM system, a gold mesh image was obtained with 45 nm resolution at x580 magnification and 1 min exposure. Images of a biological sample (Coscinodiscus oculoides) were recorded.

  9. High-energy directly diode-pumped Q-switched 1617 nm Er:YAG laser at room temperature.

    PubMed

    Wang, Mingjian; Zhu, Liang; Chen, Weibiao; Fan, Dianyuan

    2012-09-01

    We describe high-energy Erbium-doped yttrium aluminum garnet (Er:YAG) lasers operating at 1617 nm, resonantly pumped using 1532 nm fiber-coupled laser diodes. A maximum continuous wave output power of 4.3 W at 1617 nm was achieved with an output coupler of 20% transmission under incident pump power of 29.7 W, resulting in an optical conversion of 14% with respect to the incident pump power. In Q-switched operation, the pulse energy of 11.8 mJ at 100 Hz pulse repetition frequency and 81 ns pulse duration was obtained. This energy is the highest pulse energy reported for a directly diode-pumped Q-switched Er:YAG laser operating at 1617 nm.

  10. 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.

  11. 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.

  12. 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...

  13. 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...

  14. 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:...

  15. 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....

  16. 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....

  17. 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...

  18. 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...

  19. 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,...

  20. 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...

  1. 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...

  2. 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...

  3. 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:...

  4. 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....

  5. 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.

  6. 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

  7. 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:...

  8. 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.

  9. 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.

  10. A novel double patterning approach for 30nm dense holes

    NASA Astrophysics Data System (ADS)

    Hsu, Dennis Shu-Hao; Wang, Walter; Hsieh, Wei-Hsien; Huang, Chun-Yen; Wu, Wen-Bin; Shih, Chiang-Lin; Shih, Steven

    2011-04-01

    Double Patterning Technology (DPT) was commonly accepted as the major workhorse beyond water immersion lithography for sub-38nm half-pitch line patterning before the EUV production. For dense hole patterning, classical DPT employs self-aligned spacer deposition and uses the intersection of horizontal and vertical lines to define the desired hole patterns. However, the increase in manufacturing cost and process complexity is tremendous. Several innovative approaches have been proposed and experimented to address the manufacturing and technical challenges. A novel process of double patterned pillars combined image reverse will be proposed for the realization of low cost dense holes in 30nm node DRAM. The nature of pillar formation lithography provides much better optical contrast compared to the counterpart hole patterning with similar CD requirements. By the utilization of a reliable freezing process, double patterned pillars can be readily implemented. A novel image reverse process at the last stage defines the hole patterns with high fidelity. In this paper, several freezing processes for the construction of the double patterned pillars were tested and compared, and 30nm double patterning pillars were demonstrated successfully. A variety of different image reverse processes will be investigated and discussed for their pros and cons. An economic approach with the optimized lithography performance will be proposed for the application of 30nm DRAM node.

  11. Gain measurements at 5 nm in nickel-like ytterbium

    SciTech Connect

    MacGowan, B.J.; Bourgade, J.L.; Combis, P.; Keane, C.J.; Louis-Jacquet, M.; Matthews, D.L.; Naccache, D.; Stone, G.; Thiell, G.; Whelan, D.A.

    1988-03-01

    Soft x-ray gain has been demonstrated at 5.03 nm within a laser produced plasma of Ni-like ytterbium. Experiments will also be described with higher Z Ni-like ions which can produce even shorter wavelength x-ray laser transition. 3 refs.

  12. 78 FR 67210 - Santa Clara Pueblo Disaster #NM-00038

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Santa Clara Pueblo Disaster NM-00038 AGENCY: U.S. Small Business Administration. ACTION: Notice...: Submit completed loan applications to: U.S. Small Business Administration, Processing and...

  13. EPA Sparks Local Business in Las Cruces, N.M.

    EPA Pesticide Factsheets

    DALLAS - (Feb. 29, 2016) The U.S. Environmental Protection Agency (EPA) is awarding a $300,000 small business contract to Vista Photonics, Inc. in Las Cruces, N.M. The company plans to develop an inexpensive, high-performance, portable air pollution

  14. Blue light (470 nm) effectively inhibits bacterial and fungal growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The activity of blue light (470nm) alone on (1) bacterial viability, and (2) with a food grade photosensitizer on filamentous fungal viability, was studied. Suspensions of the bacteria Leuconostoc mesenteroides (LM), Bacillus atrophaeus (BA), and Pseudomonas aeruginosa (PA) were prepared and aliquo...

  15. Pushing EUV lithography development beyond 22-nm half pitch

    SciTech Connect

    Naulleau, Patrick; Anderson, Christopher N.; Baclea-an, Lorie-Mae; Denham, Paul; George, Simi; Goldberg, Kenneth A.; Goldstein, Michael; Hoef, Brian; Jones, Gideon; Koh, Chawon; La Fontaine, Bruno; Montogomery, Warren; Wallow, Tom

    2009-06-30

    Microfield exposure tools (METs) have and continue to play a dominant role in the development of extreme ultraviolet (EUV) resists and masks. One of these tools is the SEMATECH Berkeley 0.3 numerical aperture (NA) MET. Here we investigate the possibilities and limitations of using the 0.3-NA MET for sub-22-nm half-pitch development. We consider mask resolution limitations and present a method unique to the centrally obscured MET allowing these mask limitations to be overcome. We also explore projection optics resolution limits and describe various illumination schemes allowing resolution enhancement. At 0.3-NA, the 0.5 k1 factor resolution limit is 22.5 nm meaning that conventional illumination is of limited utility for sub-22-nm development. In general resolution enhancing illumination encompasses increased coherence. We study the effect of this increased coherence on line-edge roughness, which along with resolution is another crucial factor in sub-22-nm resist development.

  16. 76 FR 22015 - Amendment of Class E Airspace; Raton, NM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... Municipal Airport/Crews Field, Raton, NM. The FAA is taking this action to enhance the safety and management... additional controlled airspace at Raton Municipal Airport/ Crews Field (76 FR 5305) Docket No. FAA-2010-1239... accommodate new RNAV standard instrument approach procedures at Raton Municipal Airport/Crews Field, Raton,...

  17. O(1)S 557.7nm and O(1)D 630 nm emissions in shuttle thruster plumes

    NASA Technical Reports Server (NTRS)

    Viereck, R. A.; Murad, E.; Pike, C. P.; Mende, S. B.; Swenson, G. A.; Elgin, J. B.; Bernstein, L. S.; Lucid, S.

    1995-01-01

    Radiation resulting from interaction between the effluent cloud of a space shuttle thruster and the ambient atmosphere was observed with a spectograph aboard the shutttle. The spectral measurements were made between 400 and 800 nm with a resolutoion of 3 nm. The primary emissions are identified as NO2, HNO, O(1)D, and O(1)S. These are the first observations od O(1)S emission in the shuttle plume. These data are compared with the previous measurements, and possible excitation mechanisms are discussed. The results are also compared with a Monte Carlo simulation of thruster plume-atmosphere interaction radiation.

  18. 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.

  19. Asymmetric MQW semiconductor optical amplifier with low-polarization sensitivity of over 90-nm bandwidth

    NASA Astrophysics Data System (ADS)

    Nkanta, Julie E.; Maldonado-Basilio, Ramón; Abdul-Majid, Sawsan; Zhang, Jessica; Hall, Trevor J.

    2013-12-01

    An exhausted capacity of current Passive Optical Networks has been anticipated as bandwidth-hungry applications such as HDTV and 3D video become available to end-users. To enhance their performance, the next generation optical access networks have been proposed, using optical carriers allocated within the E-band (1360-1460 nm). It is partly motivated by the low-water peak fiber being manufactured by Corning. At these wavelengths, choices for low cost optical amplifiers, with compact size, low energy consumption and feasibility for integration with other optoelectronic components are limited, making the semiconductor optical amplifiers (SOA) a realistic solution. An experimental characterization of a broadband and low polarization sensitive asymmetric multi quantum well (MQW) SOA operating in the E-band is reported. The SOA device is composed of nine 6 nm In1-xGaxAsyP1-y 0.2% tensile strained asymmetric MQW layers sandwiched between nine latticed matched 6 nm InGaAsP barrier layers. The active region is grown on an n-doped InP substrate and buried by p-doped InGaAsP layers. The SOA devices have 7-degrees tilt anti-reflected coated facets, with 2 μm ridge width, and a cavity length of 900 μm. For input powers of -10 dBm and -20 dBm, a maximum gain of 20 dB at 1360 nm with a polarization insensitivity under 3 dB for over 90 nm bandwidth is measured. Polarization sensitivity of less than 0.5 dB is observed for some wavelengths. Obtained results indicate a promising SOA with broadband amplification, polarization insensitivity and high gain. These SOAs were designed and characterized at the Photonics Technology Laboratory, University of Ottawa, Canada.

  20. Investigation of single lateral mode for 852nm diode lasers with ridge waveguide design

    NASA Astrophysics Data System (ADS)

    Liu, Chu; Guan, Baolu; Mi, Guoxin; Liao, Yiru; Liu, Zhenyang; Li, Jianjun; Xu, Chen

    2016-11-01

    852nm Narrow linewidth lasers can be widely used in the field of ultra-fine spectrum measurement, Cs atomic clock control, satellite and optical fiber communication and so on. Furthermore, the stability of the single lateral mode is a very important condition to guarantee the narrow linewidth lasers. Here we investigate experimentally the influence of the narrow ridge structure and asymmetrical waveguide design on the stability single lateral mode of an 852nm diode laser. According to the waveguide theoretical analysis, ridge mesa etch depth (Δη , related to the refractive index difference of parallel to the junction) and ridge mesa width (the narrower the more control force to low order mode) are the main elements for lateral modes. In this paper, we designed different structures to investigate and verify major factors for lateral mode by experiment, and to confirm our thought. Finally, the 5μm mesa ridge laser, 800nm etch depth, with groove structure obtains excellent steady single lateral mode output by 150mA operating current and 30°C temperature. The optical spectrum FWHM is 0.5nm and side mode suppression ratio is 27dBm with uncoated. The laser with 1mm cavity length showed the threshold current of 50mA, a lasing wavelength of λ = 852.6nm, slope efficiency of above 0.7mW/mA. We accomplished single lateral mode of ridge waveguide edge-emitting lasers which can also be used as a laser source in the ultra-narrow linewidth external cavity laser system.

  1. Data preparation solution for e-beam multiple pass exposure: reaching sub-22nm nodes with a tool dedicated to 45 nm

    NASA Astrophysics Data System (ADS)

    Martin, Luc; Manakli, Serdar; Bayle, Sébastien; Choi, Kang-Hoon; Gutsch, Manuela; Pradelles, Jonathan; Bustos, Jessy

    2011-04-01

    Electron Beam Direct Write (EBDW) lithography is used in the IC manufacturing industry to sustain optical lithography for prototyping applications and low volume manufacturing. It is also used in R&D to develop advanced technologies, ahead of mass production. As microelectronics is now moving towards the 32nm node and beyond, the specifications in terms of dimension control and roughness becomes tighter. In addition, the shrink of the size and pitch of features significantly reduces the process window of lithographic tools. In EBDW, the standard proximity effects corrections only based on dose modulation show difficulties to provide the required Energy Latitude for patterning structures designed below 45nm. A new approach is thus needed to improve the process window of EBDW lithography and push its resolution capabilities. In previous papers, a new writing strategy based on multiple pass exposure has been introduced and optimized to pattern critical dense lines. This new technique consists in adding small electron Resolution Improvement Features (eRIFs) on top of the nominal structures. Then this new design is exposed in two successive passes with optimized doses. Previous studies were led to evaluate this new writing technique and establish rules to optimize the design of the eRIF. Significant improvements have already been demonstrated on SRAM and Logic structures down to the 16nm node. These results were obtained with a tool dedicated to the 45nm node. The next step of this work is thus to automatically implement the eRIF to correct large-scale layouts. In this paper, a new data preparation flow is set up for EBDW lithography. It uses the eRIF solution as a full advanced correction method for critical structures. The specific correction rules established in our previous studies are implemented to improve the CD control and the patterning of corners and line ends. Moreover, the dose and shape of the eRIFs are automatically tuned to best fit the nominal design

  2. Highly efficient continuous-wave Nd:YAG ceramic lasers at 946 nm

    NASA Astrophysics Data System (ADS)

    Zhu, H. Y.; Xu, C. W.; Zhang, J.; Tang, D. Y.; Luo, D. W.; Duan, Y. M.

    2013-07-01

    Highly efficient CW operation of diode-end-pumped Nd:YAG ceramic lasers at 946 nm is experimentally demonstrated. When a 5 mm long in-house fabricated Nd:YAG ceramic was used as the gain medium, a maximum output power of 10.5 W was obtained under an incident pump power of 35 W, corresponding to an optical conversion efficiency of 30%, while, when a 3 mm long ceramic sample was used, a maximum output power of 8.7 W was generated with a slope efficiency of 65% with respect to the absorbed pump power. Both the optical conversion efficiency and slope efficiency are the highest results reported so far for the diode-pumped 946 nm lasers.

  3. Daylight spectra of individual lightning flashes in the 370-690 nm region

    NASA Technical Reports Server (NTRS)

    Orville, R. E.

    1980-01-01

    An optical multichannel analyzer slit spectrometer coupled to a minicomputer was used to record lightning spectra. This is the first successful application of a slit spectrometer to the study of individual lightning flashes and it was accomplished in the daytime. Over 300 spectra were obtained in 1978 and 1979 and are correlated with other experiments in the Thunderstorm Research International Program (TRIP). The spectra duplicate previously published nighttime data but reveal for the first time the relative intensity of H-alpha (656.3 nm) and H-beta (486.1 nm) emissions above their daytime absorption features. These are the characteristic Fraunhofer C and F lines in the solar spectrum. This result suggests that the observation of lightning from space may be accomplished by monitoring the hydrogen emissions from lightning which occur on earth, or on other planets with hydrogen in their atmospheres, such as Jupiter and Venus where lightning recently has been reported.

  4. Refractive index change during exposure for 193-nm chemically amplified resists

    NASA Astrophysics Data System (ADS)

    Oh, Hye-Keun; Sohn, Young-Soo; Sung, Moon-Gyu; Lee, Young-Mi; Lee, Eun-Mi; Byun, Sung Hwan; An, Ilsin; Lee, Kun-Sang; Park, In-Ho

    1999-06-01

    Some of the important areas to be improved for lithography simulation are getting correct exposure parameters and determining the change of refractive index. It is known that the real and imaginary refractive indices are changed during exposure. We obtained these refractive index changes during exposure for 193 nm chemically amplified resists. The variations of the transmittance as well as the resist thickness were measured during ArF excimer laser exposure. We found that the refractive index change is directly related to the concentration of the photo acid generator and de-protected resin. It is important to know the exact values of acid concentration from the exposure parameters since a small difference in acid concentration magnifies the variation in the amplified de-protection during post exposure bake. We developed and used a method to extract Dill ABC exposure parameters for 193 nm chemically amplified resist from the refractive index change upon exposure.

  5. Linewidth characteristics of Raman-shifted dye laser output at 720 and 940 nm

    NASA Astrophysics Data System (ADS)

    Grossmann, B. E.; Singh, U. N.; Cotnoir, L. J.; Wilkerson, T. D.; Higdon, N. S.; Browell, E. V.

    1986-08-01

    Raman conversion efficiency and line broadening are reported for Stokes operation at 720 and 940 nm, with hydrogen and deuterium as the Raman source, and using an Nd:YAG pumped Quanta-Ray PDL-2 dye laser. The dye laser linewidth is 0.2/cm (FWHM) with the grating alone as an intracavity element, and the conversion efficiency at 400 psi was found to be 40 and 20 percent for outputs of 720 and 940 nm, respectively. Pressure broadening coefficients of (9.2 + or - 0.9) x 10 to the -5th per cm/psi for hydrogen, and 7.7 x 10 to the -5th per cm/psi for deuterium, were obtained in good agreement with previous results. The linewidth at the first Stokes wavelength was shown to be determined by pressure broadening in the Raman medium.

  6. Visible laser operation of Pr3+-doped fluoride crystals pumped by a 469 nm blue laser.

    PubMed

    Xu, Bin; Camy, Patrice; Doualan, Jean-Louis; Cai, Zhiping; Moncorgé, Richard

    2011-01-17

    We report continuous-wave (CW) laser operation of Pr3+-doped LiLuY4, LiYF4 and KY3F10 single crystals in the Red, Orange and Green spectral regions by using a new pumping scheme. The pump source is an especially developed compact, slightly tunable and intracavity frequency-doubled diode-pumped Nd:YAG laser delivering a CW output power of 0.9W at 469.12 nm. At this pump wavelength, efficient room temperature laser emissions corresponding to the 3P0→3F2, 3P0→3H6 and 3P1→3H5 Pr3+ transitions are observed. While a maximum slope efficiency of 45% is obtained in the red with Pr:LiYF4, the demonstration is made for the first time of the orange laser operation of Pr:KY3F10 at about 610 nm.

  7. Enhanced efficiency of ultrathin (˜500 nm)-film microcrystalline silicon photonic crystal solar cells

    NASA Astrophysics Data System (ADS)

    De Zoysa, Menaka; Ishizaki, Kenji; Tanaka, Yoshinori; Sai, Hitoshi; Matsubara, Koji; Noda, Susumu

    2017-01-01

    Enhancing the absorption of thin-film microcrystalline silicon solar cells at 600-1000 nm wavelengths is very important to the improvement of the energy conversion efficiency. This can be achieved by creating a large number of resonant modes utilizing two-dimensional photonic crystal band edges, which exceeds the Lambertian limit of absorption in random textures. We focus on suppressing the parasitic absorption of back-reflector metal and doped layers in photonic crystal microcrystalline silicon solar cells. We achieve a high active-area current density of 22.6 mA cm-2 for an ultrathin (˜500 nm)-film silicon layer and obtain an active-area efficiency of ˜9.1%, as independently confirmed by the CSMT of AIST.

  8. Nonlinear optical effects related to saturable and reverse saturable absorption by subphthalocyanines at 532 nm.

    PubMed

    Dini, Danilo; Vagin, Sergej; Hanack, Michael; Amendola, Vincenzo; Meneghetti, Moreno

    2005-08-14

    It is found that both effects of saturable absorption and reverse saturable absorption are obtained with a solution of subphthalocyanine at 532 nm depending on the intensity of 9 ns laser pulses; saturable absorption occurs at lower intensity levels whereas the reverse effect prevails at higher levels; contrary to expectations, subphthalocyanines can behave as reverse saturable absorbers at 532 nm, despite the high linear absorption at this wavelength; data have been fitted with a five-level model which considers three consecutive electronic transitions with absorption cross-section values of 1.4 x 10(-16), 1.0 x 10(-16) and 40 x 10(-16) cm(2), respectively.

  9. Sub-10 nm nano-gap device for single-cluster transport measurements

    SciTech Connect

    Rousseau, J. Morel, R.; Vila, L.; Brenac, A.; Marty, A.; Notin, L.; Beigné, C.

    2014-02-17

    We present a versatile procedure for the fabrication of single electron transistor (SET) devices with nanometer-sized clusters and embedded back gate electrode. The process uses sputtering gas-aggregation for the growth of clusters and e-beam lithography with double angle shadow-edge deposition to obtain electrodes separated by nano-gaps with width below 10 nm. The nano-gap width is easily controlled only by geometrical factors such as deposited thin film thickness and evaporation angles. The usefulness of this technique is demonstrated by measuring the SET behavior of a device with a 4 nm cobalt cluster embedded in alumina, where the Coulomb blockade and incremental cluster charging can be readily identified without resorting to the differential conductivity.

  10. Optimum Biasing for 45 nm Node Chromeless and Attenuated Phase Shift Mask

    NASA Astrophysics Data System (ADS)

    Kang, Young-Min; An, Ilsin; Shin, Dong-Soo; Oh, Hye-Keun

    2008-09-01

    Resolution enhancement technology (RET) refers to a technique that extends the usable resolution of an imaging system without decreasing the wavelength of light or increasing the numerical aperture (NA) of the imaging tool. Off-axis illumination (OAI) and a phase shift mask (PSM) are essentially accompanied by optical proximity correction (OPC) for semiconductor device manufacturing nowadays. A chromeless PSM is compared with an attenuated PSM (att.PSM) to generate a 45 nm dense line and space pattern. To obtain the best possible resolution, a suitable OPC is required with PSM and the most common application of OPC is the use of bias. An optical system with a high NA, a strong OAI, and a proper polarization can decrease k1 to a value well below 0.3. A chromeless PSM has various advantages over alternating PSM such as the lack of necessity for double exposure, small pattern displacement, and the lack of critical dimension (CD) error caused by intensity imbalance. However, a chromeless PSM has some disadvantages. In the case of a 100% transmittance pure chromeless PSM, there is no shading material that is usually deposited on the line pattern for both att.PSM and alternating PSM to control linewidth. Because there is no shading material for such a chromeless PSM, the required resist CD has to be obtained using phase only and it is difficult to control the resist CD through pitch. As expected, a chromeless PSM needs a smaller dose than an att.PSM to generate a desired 45 nm CD with a 1.0 NA. Our simulation results show that a 10 nm bias is optimum for chromeless PSMs. We demonstrate that chromeless PSM and att.PSM technology can be used to achieve a 45 nm node with optimum biased OPC.

  11. Optimum biasing for 45 nm node chromeless and attenuated phase shift mask

    NASA Astrophysics Data System (ADS)

    Kang, Young-Min; Oh, Hye-Keun

    2008-03-01

    Resolution enhancement technology (RET) refers to a technique that extends the usable resolution of an imaging system without decreasing the wavelength of light or increasing the numerical aperture (NA) of the imaging tool. Offaxis illumination (OAI) and a phase shift mask (PSM) are essentially accompanied by optical proximity correction (OPC) for semiconductor device manufacturing nowadays. A chromeless PSM (CLM or CPL) is compared to an attenuated PSM (att.PSM) to make 45 nm dense line and space pattern. To obtain the best possible resolution, a proper OPC is required with CPL and the most common application of OPC technique is the use of space bias. The optical system with a high numerical aperture (NA), a strong OAI, and a proper polarization can decrease the k1 value well below 0.3. CPL has various advantages over alternating PSM such as no necessity of double exposure, small pattern displacement, and no CD error caused by the intensity imbalance. But CPL has some disadvantages. In the case of 100 % transmittance pure CPL, there is no shading material that is usually deposited on the line pattern for both att.PSM and alternating PSM to control the line width. Because of no shading material for CPL, the required resist critical dimension (CD) has to be obtained by using phase only and it is difficult to control the resist CD through pitch. As expected, CPL needs smaller dose than att.PSM to make the desired 45 nm CD with 0.94 NA. Our simulation results showed that 10 nm negative bias is optimum for CPL mask. We demonstrated that CPL mask and att.PSM technology can be used to make 45 nm node by the negative space bias.

  12. Highly transparent superhydrophobic surfaces from the coassembly of nanoparticles (≤100 nm).

    PubMed

    Karunakaran, Raghuraman G; Lu, Cheng-Hsin; Zhang, Zanhe; Yang, Shu

    2011-04-19

    We report a simple and versatile approach to creating a highly transparent superhydrophobic surface with dual-scale roughness on the nanoscale. 3-Aminopropyltrimethoxysilane (APTS)-functionalized silica nanoparticles of two different sizes (100 and 20 nm) were sequentially dip coated onto different substrates, followed by thermal annealing. After hydrophobilization of the nanoparticle film with (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trichlorosilane for 30 min or longer, the surface became superhydrophobic with an advancing water contact angle of greater than 160° and a water droplet (10 μL) roll-off angle of less than 5°. The order of nanoparticles dip coated onto the silicon wafer (i.e., 100 nm first and 20 nm second or vice versa) did not seem to have a significant effect on the resulting apparent water contact angle. In contrast, when the substrate was dip coated with monoscale nanoparticles (20, 50, and 100 nm), a highly hydrophobic surface (with an advancing water contact angle of up to 143°) was obtained, and the degree of hydrophobicity was found to be dependent on the particle size and concentration of the dip-coating solution. UV-vis spectra showed nearly 100% transmission in the visible region from the glass coated with dual-scale nanoparticles, similar to the bare one. The coating strategy was versatile, and superhydrophobicity was obtained on various substrates, including Si, glass, epoxy resin, and fabrics. Thermal annealing enhanced the stability of the nanoparticle coating, and superhydrophobicity was maintained against prolonged exposure to UV light under ambient conditions.

  13. Uncertainties of the Intensity of the 1130 nm Band of Water Vapor

    NASA Technical Reports Server (NTRS)

    Giver, L. P.; Pilewskie, P.; Gore, W. J.; Chackerian, C., Jr.; Varanasi, P.; Bergstrom, R.; Freedman, R. S.

    2001-01-01

    Belmiloud, et al have recently suggested that the HITRAN line intensities in the 1130 nm water vapor band are much too weak. Giver, et at corrected unit conversion errors to make the HITRAN intensities compatible with the original measurements of Mandin, et al, but Belmiloud, et al believe that many of those line intensity measurements were too weak, and they propose the total intensity of the 1130 nm water vapor band is 38% stronger than the sum of the HITRAN line intensities in this region. We have made independent assessments of this proposal using 2 spectra obtained with the Ames 25 meter base path White cell. The first was made using the moderate resolution (8 nm) solar spectral flux radiometer (SSFR) flight instrument with a White cell absorbing path of 506 meters and 10 torr water vapor pressure. Modeling this spectrum using the HITRAN linelist gives a reasonable match, and the model is not compatible when the HITRAN line intensities are increased by 38%. The second spectrum was obtained with a White cell path of 1106 meters and 12 torr water vapor pressure, using a Bomem FTIR with near Doppler width resolution. This spectrum is useful for measuring intensities of isolated weak lines to compare with the measurements of Mandin, et al. Unfortunately, as Belmiloud et al point out, at these conditions the strong lines are much too saturated for good intensity measurements. Our measurements of the weak lines are in reasonable agreement with those of Mandin, et al. Neither of our spectra supports the proposal of Belmiloud et al for a general 38% increase of the absorption intensity in the 1130 nm water vapor band.

  14. 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.

  15. 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.

  16. Multicolor Bioluminescence Obtained Using Firefly Luciferin.

    PubMed

    Kiyama, Masahiro; Saito, Ryohei; Iwano, Satoshi; Obata, Rika; Niwa, Haruki; Maki, Shojiro A

    2016-01-01

    Firefly bioluminescence is widely used in life science research as a useful analysis tool. For example, the adenosine-5`-triphosphate (ATP)-dependent enzymatic firefly bioluminescence reaction has long been utilized as a microbial monitoring tool. Rapid and sensitive firefly luciferin-luciferase combinations are used not only to measure cell viability but also for reporter-gene assays. Recently, bioluminescence was utilized as a noninvasive, real-time imaging tool for living subjects to monitor cells and biological events. However, the number of commercialized luciferase genes is limited and tissue-permeable near-infrared (NIR) region emitting light is required for in vivo imaging. In this review, recent studies describing synthetic luciferin analogues predicted to have red-shifted bioluminescence are summarized. Luciferase substrates emitting red, green, and blue light that were designed and developed in our laboratory are presented. The longest emission wavelength of the synthesized luciferin analogues was recorded at 675 nm, which is within the NIR region. This compound is now commercially available as "Aka Lumine®".

  17. 40 CFR 761.208 - Obtaining manifests.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Obtaining manifests. (a)(1) A generator may use... print the manifest under 40 CFR 262.21 (c) and (e). A registered source may be a: (i) State agency; (ii) Commercial printer; (iii) PCB waste generator, transporter or, designated facility; or (iv) PCB waste...

  18. 40 CFR 761.208 - Obtaining manifests.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 761.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Obtaining manifests. (a)(1) A generator may use...) Commercial printer; (iii) PCB waste generator, transporter or, designated facility; or (iv) PCB waste...

  19. A Guide to Obtaining a Psychology Internship.

    ERIC Educational Resources Information Center

    Megargee, Edwin J.

    This is a guidebook written to help graduate students in clinical psychology from a variety of programs obtain internships at training programs across the country. Chapter 1 discloses the politics and power relationship among internship training directors, university faculties, and internship applicants, and describes how they influence guidelines…

  20. 15 CFR 285.15 - Obtaining documents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS NATIONAL VOLUNTARY LABORATORY ACCREDITATION PROGRAM § 285.15 Obtaining documents. (a) Application forms, NVLAP...; phone: 301-975-4016; fax: 301-926-2884; e-mail: nvlap@nist.gov. (b) Copies of all ISO/IEC documents...

  1. 15 CFR 285.15 - Obtaining documents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS NATIONAL VOLUNTARY LABORATORY ACCREDITATION PROGRAM § 285.15 Obtaining documents. (a) Application forms, NVLAP...; phone: 301-975-4016; fax: 301-926-2884; e-mail: nvlap@nist.gov. (b) Copies of all ISO/IEC documents...

  2. 15 CFR 285.15 - Obtaining documents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE ACCREDITATION AND ASSESSMENT PROGRAMS NATIONAL VOLUNTARY LABORATORY ACCREDITATION PROGRAM § 285.15 Obtaining documents. (a) Application forms, NVLAP...; phone: 301-975-4016; fax: 301-926-2884; e-mail: nvlap@nist.gov. (b) Copies of all ISO/IEC documents...

  3. METHOD OF OBTAINING UNIFORM COATINGS ON GRAPHITE

    DOEpatents

    Campbell, I.E.

    1961-04-01

    A method is given for obtaining uniform carbide coatings on graphite bodies. According to the invention a metallic halide in vapor form is passed over the graphite body under such conditions of temperature and pressure that the halide reacts with the graphite to form a coating of the metal carbide on the surface of the graphite.

  4. Method of Obtaining Uniform Coatings on Graphite

    DOEpatents

    Campbell, I. E.

    1961-04-01

    A method is given for obtaining uniform carbide coatings on graphite bodies. According to the invention a metallic halide in vapor form is passed over the graphite body under such conditions of temperature and pressure that the halide reacts with the graphite to form a coating of the metal carbide on the surface of the graphite.

  5. 40 CFR 35.6305 - Obtaining supplies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... STATE AND LOCAL ASSISTANCE Cooperative Agreements and Superfund State Contracts for Superfund Response....6325 through 35.6340, and 35.6350. Supplies obtained with Core Program funds must be for non-site... §§ 35.6300, 35.6315(b), 35.6325 through 35.6340, and 35.6350, except where these requirements are...

  6. 40 CFR 35.6305 - Obtaining supplies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... STATE AND LOCAL ASSISTANCE Cooperative Agreements and Superfund State Contracts for Superfund Response....6325 through 35.6340, and 35.6350. Supplies obtained with Core Program funds must be for non-site... §§ 35.6300, 35.6315(b), 35.6325 through 35.6340, and 35.6350, except where these requirements are...

  7. 40 CFR 35.6305 - Obtaining supplies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... STATE AND LOCAL ASSISTANCE Cooperative Agreements and Superfund State Contracts for Superfund Response....6325 through 35.6340, and 35.6350. Supplies obtained with Core Program funds must be for non-site... §§ 35.6300, 35.6315(b), 35.6325 through 35.6340, and 35.6350, except where these requirements are...

  8. 40 CFR 35.6305 - Obtaining supplies.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... STATE AND LOCAL ASSISTANCE Cooperative Agreements and Superfund State Contracts for Superfund Response....6325 through 35.6340, and 35.6350. Supplies obtained with Core Program funds must be for non-site... §§ 35.6300, 35.6315(b), 35.6325 through 35.6340, and 35.6350, except where these requirements are...

  9. Obtaining Funding and Support for Undergraduate Research

    ERIC Educational Resources Information Center

    Dorff, Michael; Narayan, Darren A.

    2013-01-01

    Over the past decade there has been a dramatic increase in undergraduate research activities at colleges and universities nationwide. However, this comes at a time when budgets are being tightened and some institutions do not have the resources to pursue new initiatives. In this article we present some ideas for obtaining funding and support for…

  10. Obtaining Grants in the Community College.

    ERIC Educational Resources Information Center

    Fernandes, Linda L.

    Prepared to assist community college educators in obtaining grants from public and private sources, this paper provides instructions on writing a grant proposal and a list of prospective donors. Section 1 discusses the history of philanthropic support for higher education and the ethics of grant-giving. Drawing from Norton J. Kirtz's work,…

  11. 15 CFR 285.15 - Obtaining documents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; phone: 301-975-4016; fax: 301-926-2884; e-mail: nvlap@nist.gov. (b) Copies of all ISO/IEC documents are..., Gaithersburg, MD. For access to the NIST campus, please contact NVLAP by phone at 301-975-4016 or by e-mail at NVLAP@nist.gov to obtain instructions for visitor registration....

  12. High power 888 nm optical fiber end-pumped Nd:YVO4 picosecond regenerative amplifier at hundreds kHz

    NASA Astrophysics Data System (ADS)

    Bai, Zhenao; Fan, Zhongwei; Lian, Fuqiang; Tan, Tan; Bai, Zhenxu; Yang, Chao; Kang, Zhijun; Liu, Chang

    2016-10-01

    This paper describes a demonstration of a high power 888 nm end-pumped Nd:YVO4 picosecond regenerative amplifier operated at high repetition rate. By utilizing an all-fiber mode-locking picosecond laser as seed source and 888 nm continuous wave (CW) as pumping source, we obtained regenerative amplified output at 1064.07 nm with spectrum width 0.16 nm, pulse width of 38 ps, maximum power of 21 W, and the repetition rate is continuously adjustable from 300 to 500 kHz. The regenerative amplifier has high power stability and high compact structure.

  13. Sub-10 nm feature chromium photomasks for contact lithography patterning of square metal ring arrays

    PubMed Central

    Park, Woongkyu; Rhie, Jiyeah; Kim, Na Yeon; Hong, Seunghun; Kim, Dai-Sik

    2016-01-01

    Advances in photolithographic processes have allowed semiconductor industries to manufacture smaller and denser chips. As the feature size of integrated circuits becomes smaller, there has been a growing need for a photomask embedded with ever narrower patterns. However, it is challenging for electron beam lithography to obtain <10 nm linewidths with wafer scale uniformity and a necessary speed. Here, we introduce a photolithography-based, cost-effective mask fabrication method based on atomic layer deposition and overhang structures for sacrificial layers. Using this method, we obtained sub-10 nm square ring arrays of side length 50 μm, and periodicity 100 μm on chromium film, on 1 cm by 1 cm quartz substrate. These patterns were then used as a contact-lithography photomask using 365 nm I-line, to generate metal ring arrays on silicon substrate. PMID:27025277

  14. Arsenic Removal from Drinking Water by Absorptive Media-U.S. EPA Demonstration Project at Desert Sands MDWCA, NM Final Performance Evaluation Report

    EPA Science Inventory

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at the Desert Sands Mutual Domestic Water Consumers Association (MDWCA) facility in Anthony, NM. The objectives of the project were to evalu...

  15. Study of drain-extended NMOS under electrostatic discharge stress in 28 nm and 40 nm CMOS process

    NASA Astrophysics Data System (ADS)

    Wang, Weihuai; Jin, Hao; Dong, Shurong; Zhong, Lei; Han, Yan

    2016-02-01

    Researches on the electrostatic discharge (ESD) performance of drain-extended NMOS (DeNMOS) under the state-of-the-art 28 nm and 40 nm bulk CMOS process are performed in this paper. Three distinguishing phases of avalanche breakdown stage, depletion region push-out stage and parasitic NPN turn on stage of the gate-grounded DeNMOS (GG-DeNMOS) fabricated under 28 nm CMOS process measured with transmission line pulsing (TLP) test are analyzed through TCAD simulations and tape-out silicon verification detailedly. Damage mechanisms and failure spots of GG-DeNMOS under both CMOS processes are thermal breakdown of drain junction. Improvements based on the basic structure adjustments can increase the GG-DeNMOS robustness from original 2.87 mA/μm to the highest 5.41 mA/μm. Under 40 nm process, parameter adjustments based on the basic structure have no significant benefits on the robustness improvements. By inserting P+ segments in the N+ implantation of drain or an entire P+ strip between the N+ implantation of drain and polysilicon gate to form the typical DeMOS-SCR (silicon-controlled rectifier) structure, the ESD robustness can be enhanced from 1.83 mA/μm to 8.79 mA/μm and 29.78 mA/μm, respectively.

  16. Cryogenic Lifetime Studies of 130 nm and 65 nm CMOS Technologies for High-Energy Physics Experiments

    SciTech Connect

    Hoff, James R.; Deptuch, G. W.; Wu, Guoying; Gui, Ping

    2015-06-04

    The Long Baseline Neutrino Facility intends to use unprecedented volumes of liquid argon to fill a time projection chamber in an underground facility. Research is under way to place the electronics inside the cryostat. For reasons of efficiency and economics, the lifetimes of these circuits must be well in excess of 20 years. The principle mechanism for lifetime degradation of MOSFET devices and circuits operating at cryogenic temperatures is hot carrier degradation. Choosing a process technology that is, as much as possible, immune to such degradation and developing design techniques to avoid exposure to such damage are the goals. This, then, requires careful investigation and a basic understanding of the mechanisms that underlie hot carrier degradation and the secondary effects they cause in circuits. In this work, commercially available 130 nm and 65 nm nMOS transistors operating at cryogenic temperatures are investigated. Our results show that both technologies achieve the lifetimes required by the experiment. Minimal design changes are necessary in the case of the 130 nm process and no changes whatsoever are necessary for the 65 nm process.

  17. Very large arrays of individually addressable high-power single-mode laser arrays in the 800- to 1000-nm wavelength range obtained by quantum well intermixing techniques

    NASA Astrophysics Data System (ADS)

    Najda, Stephen P.; Bacchin, Gianluca; Qiu, Bocang C.; Smith, Chris J. M.; Vassalli, O.; Toury, Marion; McDougall, Stewart D.; Hamilton, Craig J.; Marsh, John H.

    2005-04-01

    Quantum well intermixing (QWI) of the facet regions of a semiconductor laser can significantly improve the COD of the device giving high kink power and high reliability. A novel epitaxy design incorporating a graded 'V-profile' layer allows for a reduced vertical far-field and simultaneously suppresses higher order modes to give high power operation. Furthermore, the 'V-profile' layer provides a robust design to improve the ridge etch tolerance to give excellent device performance uniformity across an array. Very large arrays of individually addressable lasers (up to 100 elements) are reported with small pitch size (~100 μm), high single mode power (up to 300 mW) and high uniformity.

  18. Double-Edge Molecular Measurement of Lidar Wind Profiles at 355 nm

    NASA Technical Reports Server (NTRS)

    Flesia, Cristina; Korb, C. Laurence; Hirt, Christian; Einaudi, Franco (Technical Monitor)

    2000-01-01

    We built a direct detection Doppler lidar based on the double-edge molecular technique and made the first molecular based wind measurements using the eyesafe 355 nm wavelength. Three etalon bandpasses are obtained with Step etalons on a single pair of etalon plates. Long-term frequency drift of the laser and the capacitively stabilized etalon is removed by locking the etalon to the laser frequency. We use a low angle design to avoid polarization effects. Wind measurements of 1 to 2 m/s accuracy are obtained to 10 km altitude with 5 mJ of laser energy, a 750s integration, and a 25 cm telescope. Good agreement is obtained between the lidar and rawinsonde measurements.

  19. Direct writing of 150 nm gratings and squares on ZnO crystal in water by using 800 nm femtosecond laser.

    PubMed

    Liu, Jukun; Jia, Tianqing; Zhou, Kan; Feng, Donghai; Zhang, Shian; Zhang, Hongxin; Jia, Xin; Sun, Zhenrong; Qiu, Jianrong

    2014-12-29

    We present a controllable fabrication of nanogratings and nanosquares on the surface of ZnO crystal in water based on femtosecond laser-induced periodic surface structures (LIPSS). The formation of nanogrooves depends on both laser fluence and writing speed. A single groove with width less than 40 nm and double grooves with distance of 150 nm have been produced by manipulating 800 nm femtosecond laser fluence. Nanogratings with period of 150 nm, 300 nm and 1000 nm, and nanosquares with dimensions of 150 × 150 nm2 were fabricated by using this direct femtosecond laser writing technique.

  20. Magnetic Properties of Iron Oxide Nanoparticles Obtained by Laser Evaporation

    NASA Astrophysics Data System (ADS)

    Novoselova, Iu. P.; Samatov, O. M.; Kupriyanova, G. S.; Murzakaev, A. M.; Safronov, A. P.; Kurlyandskaya, G. V.

    2017-01-01

    The paper concentrates on a synthesis of spherical magnetic particles obtained by laser evaporation under various process conditions. Depending on the process conditions, which include the pressure in a process chamber, laser pulse duration, mean laser power, and the type of power gas, the stoichiometry of the material ranges from Fe 2.70 O 4 to Fe 2.84 O 4 , while the average diameter of nanoparticles ranges between 10-23 nm. The nanoparticles have an inverse spinel structure. In terms of the magnetic properties, the samples are a superparamagnetic ensemble. The spherical shape of the majority of nanoparticles as well as the existence of merely one magnetic phase are verified by the characteristics of microwave absorption. A relatively high saturation magnetization and a narrow size distribution of small nanoparticles obtained at 700 mmHg working pressure, 100 ms pulse duration, and 200 W laser power allow the authors to consider these conditions to be the most optimum for the nanopowder synthesis and recommend them for biological applications.

  1. Spectroscopic Classification of ASASSN-16nm, ASASSN-16nn, ASASSN-16no and Gaia16bub/AT2016ice

    NASA Astrophysics Data System (ADS)

    Prieto, J. L.; Madore, B. F.; Shappee, B. J.; Seidel, M. K.; Dong, S.; Stanek, K. Z.

    2016-11-01

    Optical spectra of the supernova candidates ASASSN-16nm/AT2016ijc (ATel #9785), ASASSN-16nn/AT2016ijf (ATel #9785), ASASSN-16no (ATel #9796, #9797), and Gaia16bub/AT2016ice were obtained on UT 2016 November 23-29 with WFCCD mounted on the du Pont 2.5-m telescope at Las Campanas Observatory.

  2. Cell Therapy To Obtain Spinal Fusion

    DTIC Science & Technology

    2010-07-01

    Milwaukee, WI) in anhydrous dichloromethane ( DCM ) under argon overnight. The resulting PEGDA was then precipitated with ether, filtered, lyophilized and...obtained of the left and right legs at 15 µm resolution (eXplore Locus SP; GE Healthcare, London, ON, Canada). A hydroxyapatite phantom was scanned...was then removed via filtration. Sodium chloride (25% W/V) was dissolved in the aqueous filtrate followed by DCM extraction. The organic phase was

  3. 25 CFR 162.539 - Must I obtain a WEEL before obtaining a WSR lease?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Must I obtain a WEEL before obtaining a WSR lease? 162.539 Section 162.539 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER LEASES AND PERMITS Wind and Solar Resource Leases Wsr Leases § 162.539 Must I obtain a WEEL before...

  4. Nonresonant 104 Terahertz Field Enhancement with 5-nm Slits

    PubMed Central

    Suwal, Om Krishna; Rhie, Jiyeah; Kim, Nayeon; Kim, Dai-Sik

    2017-01-01

    Transmission of Terahertz (THz) electromagnetic wave through a substrate is encumbered because of scattering, multiple reflections, absorption, and Fabry–Perot effects when the wave interacts with the substrate. We present the experimental realization of nonresonant electromagnetic field enhancement by a factor of almost 104 in substrate-free 5-nm gold nanoslits. Our nanoslits yielded greater than 90% normalized electric field transmission in the low-frequency THz region; the slit width was 5 nm, and the gap coverage ratio was 10−4 of the entire membrane, 0.42 mm2. This large field enhancement was attributed to gap plasmons generated by the THz wave, which squeezes the charge cross-section, thus enabling very highly dense oscillating charges and strong THz field transmission from the nanoslits. PMID:28368048

  5. Experimental study of 248nm excimer laser etching of alumina

    NASA Astrophysics Data System (ADS)

    Hu, Hongtao; Shao, Jingzhen; Wang, Xi; Fang, Xiaodong

    2016-10-01

    The 248 nm excimer laser etching characteristic of alumina ceramic and sapphire had been studied using different laser fluence and different number of pulses. And the interaction mechanism of 248 nm excimer laser with alumina ceramic and sapphire had been analyzed. The results showed that when the laser fluence was less than 8 J/cm2, the etching depth of alumina ceramic and sapphire were increased with the increase of laser fluence and number of pulses. At the high number pulses and high-energy, the surface of the sapphire had no obvious melting phenomenon, and the alumina ceramic appeared obvious melting phenomenon. The interaction mechanism of excimer laser with alumina ceramics and sapphire was mainly two-photon absorption. But because of the existence of impurities and defects, the coupling between the laser radiation and ceramic and sapphire was strong, and the thermal evaporation mechanism was also obvious.

  6. A 20 nm spin Hall nano-oscillator.

    PubMed

    Dürrenfeld, Philipp; Awad, Ahmad A; Houshang, Afshin; Dumas, Randy K; Åkerman, Johan

    2017-01-19

    Spin Hall nano-oscillators (SHNOs) are an emerging class of pure spin current driven microwave signal generators. Through the fabrication of 20 nm nano-constrictions in Pt/NiFe bilayers, we demonstrate that SHNOs can be scaled down to truly nanoscopic dimensions, with the added benefit of ultra-low operating currents and improved power conversion efficiency. The lateral confinement leads to a strong shape anisotropy field as well as an additional demagnetizing field whose reduction with increasing auto-oscillation amplitude can yield a positive current tunability contrary to the negative tunability commonly observed for localized excitations in extended magnetic layers. Micromagnetic simulations corroborate the experimental findings and suggest that the active magnetodynamic area resides up to 100 nm outside of the nano-constriction.

  7. Single, composite, and ceramic Nd:YAG 946-nm lasers

    NASA Astrophysics Data System (ADS)

    Lan, Rui-Jun; Yang, Guang; Zheng-Ping, Wang

    2015-06-01

    Single, composite crystal and ceramic continuous wave (CW) 946-nm Nd:YAG lasers are demonstrated, respectively. The ceramic laser behaves better than the crystal laser. With 5-mm long ceramic, a CW output power of 1.46 W is generated with an optical conversion efficiency of 13.9%, while the slope efficiency is 17.9%. The optimal ceramic length for a 946-nm laser is also calculated. Project supported by the National Natural Science Foundation of China (Grant No. 61405171), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ014), and the Science and Technology Program of the Shandong Higher Education Institutions of China (Grant No. J13LJ05).

  8. Sub-5 nm, globally aligned graphene nanoribbons on Ge(001)

    DOE PAGES

    Kiraly, Brian; Mannix, Andrew J.; Jacobberger, Robert M.; ...

    2016-05-23

    Graphene nanoribbons (GNRs) hold great promise for future electronics because of their edge and width dependent electronic bandgaps and exceptional transport properties. While significant progress toward such devices has been made, the field has been limited by difficulties achieving narrow widths, global alignment, and atomically pristine GNR edges on technologically relevant substrates. A recent advance has challenged these limits by using Ge(001) substrates to direct the bottom-up growth of GNRs with nearly pristine armchair edges and widths near ~10 nm via atmospheric pressure chemical vapor deposition. In this work, we extend the growth of GNRs on Ge(001) to ultra-high vacuummore » conditions and realize GNRs narrower than 5 nm. Armchair graphene nanoribbons directed along the Ge <110> surface directions are achieved with excellent width control and relatively large bandgaps. As a result, the bandgap magnitude and electronic uniformity make these new materials excellent candidates for future developments in nanoelectronics.« less

  9. Machining of optical microstructures with 157 nm laser radiation

    NASA Astrophysics Data System (ADS)

    Temme, Thorsten; Ostendorf, Andreas; Kulik, Christian J.

    2003-11-01

    The precision machining of glass by laser ablation has been expanded with the short wavelength of the 157 nm of the F2 excimer laser. The high absorption of this wavelength in any optical glass, especially in UV-grade fused silica, offers a new approach to generate high quality surfaces, addressing also micro-optical components. In this paper, the machining of basic diffractive and refractive optical components and the required machining and process technology is presented. Applications that are addressed are cylindrical and rotational symmetrical micro lenses and diffractive optics like phase transmission grating and diffractive optical elements (DOEs). These optical surfaces have been machined into bulk material as well as on fiber end surfaces, to achieve compact (electro) -- optical elements with high functionality and packaging density. The short wavelength of 157 nm used in the investigations require either vacuum or high purity inert gas environments. The influence of different ambient conditions is presented.

  10. Performance of Thin Borosilicate Glass Sheets at 351-nm

    SciTech Connect

    Whitman, P K; Hahn, D; Soules, T; Norton, M; Dixit, S; Donohue, G; Folta, J; Hollingsworth, W; Mainschein-Cline, M

    2004-11-11

    Previously, we reported preliminary results for commercial thin borosilicate glass sheets evaluated for use as a frequently-replaced optic to separate the radiation and contamination produced by the inertial confinement fusion experiments in the National Ignition Facility target chamber from the expensive precision laser optics which focus and shape the 351-nm laser beam. The goal is identification of low cost substrates that can deliver acceptable beam energy and focal spots to the target. The two parameters that dominate the transmitted beam quality are the transmitted wave front error and 351-nm absorption. Commercial materials and fabrication processes have now been identified which meet the beam energy and focus requirements for all of the missions planned for the National Ignition Facility. We present the first data for use of such an optic on the National Ignition Facility laser.

  11. Sub-5 nm, globally aligned graphene nanoribbons on Ge(001)

    SciTech Connect

    Kiraly, Brian; Mannix, Andrew J.; Jacobberger, Robert M.; Fisher, Brandon L.; Arnold, Michael S.; Hersam, Mark C.; Guisinger, Nathan P.

    2016-05-23

    Graphene nanoribbons (GNRs) hold great promise for future electronics because of their edge and width dependent electronic bandgaps and exceptional transport properties. While significant progress toward such devices has been made, the field has been limited by difficulties achieving narrow widths, global alignment, and atomically pristine GNR edges on technologically relevant substrates. A recent advance has challenged these limits by using Ge(001) substrates to direct the bottom-up growth of GNRs with nearly pristine armchair edges and widths near ~10 nm via atmospheric pressure chemical vapor deposition. In this work, we extend the growth of GNRs on Ge(001) to ultra-high vacuum conditions and realize GNRs narrower than 5 nm. Armchair graphene nanoribbons directed along the Ge <110> surface directions are achieved with excellent width control and relatively large bandgaps. As a result, the bandgap magnitude and electronic uniformity make these new materials excellent candidates for future developments in nanoelectronics.

  12. Measured skin damage thresholds for 1314-nm laser exposures

    NASA Astrophysics Data System (ADS)

    Montes de Oca, Cecilia I.; Cain, Clarence P.; Schuster, Kurt J.; Stockton, Kevin; Thomas, James J.; Eggleston, Thomas A.; Roach, William P.

    2003-06-01

    The use of lasers in the infrared region between 1200-1400 nm has steadily increased in various industrial and commercial applications. However, there are few studies documenting damage thresholds for the skin in this region, and current laser safety standards are based on limited data. This study has determined preliminary skin damage thresholds for the Effective Dose for 50% probability (ED50) of a Minimum Visible Lesion (MVL) with laser exposure at 1314nm and 0.35 ms pulse width. An in-vivo pigmented animal model, Yucatan mini-pig (Sus scrofa domestica), was used in this study. The type and extent of tissue damage in the porcine skin was determined through histopathologic examination, and the findings are discussed. Finally, the results of this study were compared to other literature as well as to the existing ANSI Z136.1 (2000) standard for safe use of lasers.

  13. A deep-UV optical frequency comb at 205 nm.

    PubMed

    Peters, E; Diddams, S A; Fendel, P; Reinhardt, S; Hänsch, T W; Udem, Th

    2009-05-25

    By frequency quadrupling a picosecond pulse train from a Ti:sapphire laser at 820 nm we generate a frequency comb at 205 nm with nearly bandwidth-limited pulses. The nonlinear frequency conversion is accomplished by two successive frequency doubling stages that take place in resonant cavities that are matched to the pulse repetition rate of 82 MHz. This allows for an overall efficiency of 4.5 % and produces an output power of up to 70 mW for a few minutes and 25 mW with continuous operation for hours. Such a deep UV frequency comb may be employed for direct frequency comb spectroscopy in cases where it is less efficient to convert to these short wavelengths with continuous wave lasers.

  14. Sub-nm emittance lattice design for CANDLE storage ring

    NASA Astrophysics Data System (ADS)

    Sargsyan, A.; Zanyan, G.; Sahakyan, V.; Tsakanov, V.

    2016-10-01

    The most effective way to increase the brilliance of synchrotron light sources is the reduction of beam emittance. Following the recent developments in low emittance lattice design, a new sub-nm emittance lattice based on implementation of multi-band achromat concept and application of longitudinal gradient bending magnets was developed for CANDLE storage ring. The paper presents the main design considerations, linear and non-linear beam dynamics aspects of the new lattice proposed.

  15. Excimer lasers for superhigh NA 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Paetzel, Rainer; Albrecht, Hans S.; Lokai, Peter; Zschocke, Wolfgang; Schmidt, Thomas; Bragin, Igor; Schroeder, Thomas; Reusch, Christian; Spratte, Stefan

    2003-06-01

    Excimer lasers are widely used as the light source for microlithography scanners. The volume shipment of scanner systems using 193nm is projected to begin in year 2003. Such tools will directly start with super high numerical aperture (NA) in order to take full advantage of the 193nm wavelength over the advanced 248nm systems. Reliable high repetition rate laser light sources enabling high illumination power and wafer throughput are one of the fundamental prerequisites. In addition these light sources must support a very high NA imaging lens of more than 0.8 which determines the output spectrum of the laser to be less than 0.30 pm FWHM. In this paper we report on our recent progress in the development of high repetition rate ultra-narrow band lasers for high NA 193nm microlithography scanners. The laser, NovaLine A4003, is based on a Single Oscillator Ultral Line-narrowed (SOUL) design which yields a bandwidth of less than 0.30pm FWHM. The SOUL laser enables superior optical performance without adding complexity or cost up to the 4 kHz maximum repetition rate. The A4003's high precision line-narrowing optics used in combination with the high repetition rate of 4 kHz yields an output power of 20 W at an extremely narrow spectral bandwidth of less than 0.30 pm FWHM and highest spectral purity of less than 0.75 pm for the 95% energy content. We present performance and reliability data and discuss the key laser parameters. Improvements in the laser-internal metrology and faster regulation control result in better energy stability and improved overall operation behavior. The design considerations for line narrowing and stable laser operation at high repetition rates are discussed.

  16. 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.

  17. MoSi absorber photomask for 32nm node

    NASA Astrophysics Data System (ADS)

    Konishi, Toshio; Kojima, Yosuke; Takahashi, Hiroyuki; Tanabe, Masato; Haraguchi, Takashi; Lamantia, Matthew; Fukushima, Yuichi; Okuda, Yoshimitsu

    2008-05-01

    The development of semiconductor process for 32nm node is in progress. Immersion lithography has been introduced as an extension of 193nm lithograpy. In addition, DPL (Double patterning lithography) is becoming a strong candidate of next generation lithography. The extension of optical lithography increases more mask complexity and tighter specification of photomasks. CD performance is the most important issue in the advanced photomask technology. However, it is expected that conventional mask cannot satisfy the required mask specifications for 32nm node and beyond. Most of CD errors are contributed to the dry etching process. Mask CD variation is greatly influenced by the loading effect from dry etching of the absorber. As the required accuracy of the mask arises, Cr absorber thickness has been gradually thinner. CD linearity with the thinner Cr absorber thickness has better performance. However, it is difficult to apply thinner Cr absorber thickness simply under the condition of OD > 3, which is needed for wafer printing. So, we adopted MoSi absorber instead of conventional Cr absorber, because MoSi absorber has less micro and global loading effect than that of Cr absorber. By using MoSi absorber, we can reduce Cr thickness as a hardmask. The thinner Cr hardmask allows for reduce resist thickness and become same condition for conventional EB resist lithography. The lithography performances were confirmed by the simulation and wafer printing. The new MoSi absorber mask behaves similar to the conventional Cr absorber mask. The adoption of super thin Cr as a hardmask made it possible to reduce resist thickness. By the application of the thin resist and the latest tools, we'll improve the mask performance to meet the 32 nm generation specification.

  18. Quasi-cw 808-nm 300-W laser diode arrays

    NASA Astrophysics Data System (ADS)

    Bezotosnyi, V. V.; Kozyrev, A. A.; Kondakova, N. S.; Kondakov, S. A.; Krokhin, O. N.; Mikaelyan, G. T.; Oleshchenko, V. A.; Popov, Yu. M.; Cheshev, E. A.

    2017-02-01

    Samples of 808-nm quasi-cw laser diode arrays (LDAs) with an output power exceeding 300 W, a pulse duration of 200 μs, and a pulse repetition rate of 100 Hz are developed and fabricated. The main output parameters of a set of five LDAs, including light – current characteristics, current – voltage characteristics, and emission spectra are measured. Preliminary life tests show that the LDA power remains stable for 108 pulses.

  19. 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.

  20. Hard x-ray Zernike microscopy reaches 30 nm resolution.

    SciTech Connect

    Chen, Y.; Chen, T.; Yi, J.; Chu, Y.; Lee, W.-K.; Wang, C.; Kempson, I.; Hwu, Y.; Gajdosik, V.; Margaritondo, G.

    2011-03-30

    Since its invention in 1930, Zernike phase contrast has been a pillar in optical microscopy and more recently in x-ray microscopy, in particular for low-absorption-contrast biological specimens. We experimentally demonstrate that hard-x-ray Zernike microscopy now reaches a lateral resolution below 30?nm while strongly enhancing the contrast, thus opening many new research opportunities in biomedicine and materials science.

  1. Hard x-ray Zernike Microscopy Reaches 30 nm Resolution

    SciTech Connect

    Chen, Y.T.; Chu, Y.; Chen, T-Y.; Yi, J.; Lee, W-K.; Wang, C-L.; Kempson, I. M.; Hwu, Y.; Gajdosik, V.; Margaritondo, G.

    2011-03-30

    Since its invention in 1930, Zernike phase contrast has been a pillar in optical microscopy and more recently in x-ray microscopy, in particular for low-absorption-contrast biological specimens. We experimentally demonstrate that hard-x-ray Zernike microscopy now reaches a lateral resolution below 30 nm while strongly enhancing the contrast, thus opening many new research opportunities in biomedicine and materials science.

  2. The polarization properties of Fe II 614.9 nm

    NASA Technical Reports Server (NTRS)

    Lites, Bruce W.

    1993-01-01

    The anomalous Zeeman splitting of the Fe II line at 614.9 nm results in four unusual properties of the polarization signature of this line in the presence of magnetic fields: the absence of linear polarization, no magnetooptical effect, the independence of intensity at line center from the inclination of the field, and a depolarizing self-absorption. The origin of these properties is illustrated in terms of the transfer of line radiation in an idealized solar atmosphere.

  3. Photodissociation cross section of ClOOCl at 330 nm.

    PubMed

    Jin, Bing; Chen, I-Cheng; Huang, Wen-Tsung; Lien, Chien-Yu; Guchhait, Nikhil; Lin, Jim J

    2010-04-15

    The photolysis rate of ClOOCl is crucial in the catalytic destruction of polar stratospheric ozone. In this work, we determined the photodissociation cross section of ClOOCl at 330 nm with a molecular beam and with mass-resolved detection. The photodissociation cross section is the product of the absorption cross section and the dissociation quantum yield. We formed an effusive molecular beam of ClOOCl at a nozzle temperature of 200 or 250 K and determined its photodissociation probability by measuring the decrease of the ClOOCl intensity upon laser irradiation. By comparing with a reference molecule (Cl(2)), of which the absorption cross section and dissociation quantum yield are well-known, we determined the absolute photodissociation cross section of ClOOCl at 330 nm to be (2.31 +/- 0.11) x 10(-19) cm(2) at 200 K and (2.47 +/- 0.12) x 10(-19) cm(2) at 250 K. Impurity interference has been a well-recognized problem in conventional spectroscopic studies of ClOOCl; our mass-resolved measurement directly overcomes such a problem. This measurement of the ClOOCl photolysis cross section at 330 nm is particularly useful in constraining its atmospheric photolysis rate, which in the polar stratosphere peaks near this wavelength.

  4. 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.

  5. 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.

  6. Characterization of 32nm node BEOL grating structures using scatterometry

    NASA Astrophysics Data System (ADS)

    Zangooie, Shahin; Sendelbach, Matthew; Angyal, Matthew; Archie, Charles; Vaid, Alok; Matthew, Itty; Herrera, Pedro

    2008-03-01

    Implementations of scatterometry in the back end of the line (BEOL) of the devices requires design of advanced measurement targets with attention to CMP ground rule constraints as well as model simplicity details. In this paper we outline basic design rules for scatterometry back end targets by stacking and staggering measurement pads to reduce metal pattern density in the horizontal plane of the device and to avoid progressive dishing problems along the vertical direction. Furthermore, important characteristics of the copper shapes in terms of their opaqueness and uniformity are discussed. It is shown that the M1 copper thicknesses larger than 100 nm are more than sufficient for accurate back end scatterometry implementations eliminating the need for modeling of contributions from the buried layers. AFM and ellipsometry line scans also show that the copper pads are sufficiently uniform with a sweet spot area of around 20 μm. Hence, accurate scatterometry can be done with negligible edge and/or dishing contributions if the measurement spot is placed any where within the sweet spot area. Reference metrology utilizing CD-SEM and CD-AFM techniques prove accuracy of the optical solutions for the develop inspect and final inspect grating structures. The total measurement uncertainty (TMU) values for the process of record line width are of the order of 0.77 nm and 0.35 nm at the develop inspect and final inspect levels, respectively.

  7. The analysis of polarization characteristics on 40nm memory devices

    NASA Astrophysics Data System (ADS)

    Yoo, Minae; Park, Chanha; You, Taejun; Yang, Hyunjo; Min, Young-Hong; Park, Ki-Yeop; Yim, Donggyu; Park, Sungki

    2009-03-01

    Hyper NA system has been introduced to develop sub-60nm node memory devices. Especially memory industries including DRAM and NAND Flash business have driven much finer technology to improve productivity. Polarization at hyper NA has been well known as important optical technology to enhance imaging performance and also achieve very low k1 process. The source polarization on dense structure has been used as one of the major RET techniques. The process capabilities of various layers under specific illumination and polarization have been explored. In this study, polarization characteristic on 40nm memory device will be analyzed. Especially, TE (Transverse Electric) polarization and linear X-Y polarization on hyper NA ArF system will be compared and investigated. First, IPS (Intensity in Preferred State) value will be measured with PMM (Polarization Metrology Module) to confirm polarization characteristic of each machine before simulation. Next simulation will be done to estimate the CD variation impact of each polarization to different illumination. Third, various line and space pattern of DRAM and Flash device will be analyzed under different polarized condition to see the effect of polarization on CD of actual wafer. Finally, conclusion will be made for this experiment and future work will be discussed. In this paper, the behavior of 40nm node memory devices with two types of polarization is presented and the guidelines for polarization control is discussed based on the patterning performances.

  8. Auditory nerve impulses induced by 980 nm laser.

    PubMed

    Guan, Tian; Zhu, Kai; Chen, Fei; He, Yonghong; Wang, Jian; Wu, Mocun; Nie, Guohui

    2015-08-01

    The discovery that a pulsed laser could trigger an auditory neural response inspired ongoing research on cochlear implants activated by optical stimulus rather than by electrical current. However, most studies to date have used visible light (532 nm) or long-wavelength near-infrared (>1840  nm ) and involved making a hole in the cochlea. This paper investigates the effect of optical parameters on the optically evoked compound action potentials (oCAPs) from the guinea pig cochlea, using a pulsed semiconductor near-infrared laser (980 nm) without making a hole in the cochlea. Synchronous trigger laser pulses were used to stimulate the cochlea, before and after deafening, upon varying the pulse duration (30–1000  μs ) and an amount of radiant energy (0–53.2  mJ/cm 2 ). oCAPs were successfully recorded after deafening. The amplitude of the oCAPs increased as the infrared radiant energy was increased at a fixed 50  μs pulse duration, and decreased with a longer pulse duration at a fixed 37.1  mJ/cm 2 radiant energy. The latency of the oCAPs shortened with increasing radiant energy at a fixed pulse duration. With a higher stimulation rate, the amplitude of the oCAPs’ amplitude decreased.

  9. 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.

  10. Remote-sensing vibrometry at 1550 nm wavelength

    NASA Astrophysics Data System (ADS)

    Dräbenstedt, A.; Sauer, J.; Rembe, C.

    2012-06-01

    Laser-Doppler vibrometry (LDV) is a proven technique for vibration analysis of mechanical structures. A wavelength of 633 nm is usually employed because of the availability of the relatively inexpensive Helium-Neon laser source which has a good coherence behavior. However, coherence break-down through the beat of multiple longitudinal modes and the limited detector carrier-to-noise-ratio (CNR) at a measurement laser power of 1 mW have prevented a wide use of LDV in remote sensing applications. Such applications in civil engineering are bridges, towers or wind turbines. The lower photon energy of IR light at 1550 nm wavelength increases the CNR by a factor 2.4. This helps especially in the condition where the carrier power decreases below the FM threshold. We have designed a heterodyne interferometer which allows the shot noise limited detection at 1550 nm wavelength close to the theoretical possible CNR. We present calculations of the fundamental noise contributions in interferometric light detection for a comparison of the achievable CNR between common HeNe vibrometers and IR vibrometers. The calculations are backed by measurements that show the devices working close to the theoretical limits. The achievable noise level of the demodulated velocity signal is shown in dependence from the standoff distance. Our novel heterodyne interferometer has been transferred to the Polytec product RSV-150. An application example of this new sensor will be demonstrated.

  11. 50 nm DNA nanoarrays generated from uniform oligonucleotide films.

    PubMed

    Noh, Hyunwoo; Hung, Albert M; Choi, Chulmin; Lee, Ju Hun; Kim, Jin-Yeol; Jin, Sungho; Cha, Jennifer N

    2009-08-25

    One of the most challenging but potentially rewarding goals in nanoscience is the ability to direct the assembly of nanoscale materials into functional architectures with high yields, minimal steps, and inexpensive procedures. Despite their unique physical properties, the inherent difficulties of engineering wafer-level arrays of useful devices from nanoscale materials in a cost-effective manner have provided serious roadblocks toward technological impact. To address nanoscale features while still maintaining low fabrication costs, we demonstrate here an inexpensive printing method that enables repeated patterning of large-area arrays of nanoscale materials. DNA strands were patterned over 4 mm areas with 50 nm resolution by a soft-lithographic subtraction printing process, and DNA hybridization was used to direct the assembly of sub-20 nm materials to create highly ordered two-dimensional nanoparticle arrays. The entire printing and assembly process was accomplished in as few as three fabrication steps and required only a single lithographically templated silicon master that could be used repeatedly. The low-cost procedures developed to generate nanoscale DNA patterns can be easily extended toward roll-to-roll assembly of nanoscale materials with sub-50 nm resolution and fidelity.

  12. Influence of humidity on photochemical ozone generation with 172nm xenon excimer lamps

    NASA Astrophysics Data System (ADS)

    Salvermoser, M. J.; Kogelschatz, U.; Murnick, D. E.

    2009-08-01

    The reaction kinetics of photochemical ozone (O{3}) generation in humid air and oxygen (O{2}) using efficient, narrow band vacuum ultra violet (VUV) 172 nm xenon excimer lamps is discussed. Trace amounts of water (H{2}O) vapor in the process gas leads to hydroxyl (OH) and hydroperoxy (HO{2}) radical formation. These radicals drive a catalytic O{3} destruction cycle limiting O{3} saturation concentration. This catalytic O{3} destruction cycle was included into a quantitative kinetic model describing photochemical O{3} production. Experimental O{3} saturation concentrations obtained with coaxial VUV driven photochemical O{3} generators compare satisfactorily with the models predictions.

  13. Polarimetry diagnostic on OMEGA EP using a 10-ps, 263-nm probe beam

    SciTech Connect

    Davies, A. Haberberger, D.; Boni, R.; Ivancic, S.; Brown, R.; Froula, D. H.

    2014-11-15

    A polarimetry diagnostic was built and characterized for magnetic-field measurements in laser-plasma experiments on the OMEGA EP laser. This diagnostic was built into the existing 4ω (263-nm) probe system that employs a 10-ps laser pulse collected with an f/4 imaging system. The diagnostic measures the rotation of the probe beam's polarization. The polarimeter uses a Wollaston prism to split the probe beam into orthogonal polarization components. Spatially localized intensity variations between images indicate polarization rotation. Magnetic fields can be calculated by combining the polarimetry data with the measured plasma density profile obtained from angular filter refractometry.

  14. Fast profile measurement of micrometer-sized tapered fibers with better than 50-nm accuracy

    NASA Astrophysics Data System (ADS)

    Warken, Florian; Giessen, Harald

    2004-08-01

    The forward scattering of light illuminating a transparent dielectric cylinder, such as a tapered fiber, from the side can be understood as interference of the diffracted, reflected, and transmitted light. Additionally, light can be resonantly coupled into the fiber if a multiple of the wavelength matches the circumference. Using a suitable laser setup with a novel evaluation algorithm allows us to quickly extract the fiber radius from the complex diffraction pattern, obtaining an accuracy of better than 50 nm. We demonstrate experimentally our method, which is noncontact and allows one to simultaneously measure the profile of a several-centimeter-long fiber waist with a diameter near the diffraction limit.

  15. Effects of the 755-nm Alexandrite laser on fine dark facial hair: review of 90 cases.

    PubMed

    Uyar, Belkiz; Saklamaz, Ali

    2012-05-01

    Laser hair removal is a relatively effective method for thick hair. Despite the risk for induction of fine hair growth, application of laser for fine dark hair is sometimes inevitable. We investigate the effects of 755-nm Alexandrite laser on fine dark facial hair and evaluate the induction rates of fine hair growth and case satisfaction. In the present study, the thickening rate of hairs (33.33%) was found to be higher than the previously published rates. However, reduction of hair density can be obtained when the laser sessions are continued.

  16. Diode pumped CW and passively Q-switched Nd:LGGG laser at 1062 nm

    NASA Astrophysics Data System (ADS)

    Yang, H.; Jia, Z. T.; Zhang, B. T.; He, J. L.; Liu, S. D.; Yang, Y.; Tao, X. T.

    2012-05-01

    We report a Nd:LGGG laser at 1062 nm in the operations of the continuous-wave (CW) and passively Q-switching. The maximum CW output power of 5.62 W was obtained, corresponding to an optical-to-optical conversion efficiency of 49.0% and slope efficiency of 55.9%. By using Cr4+:YAG with initial transmission of 94% as the saturable absorber, for the first time, we got the maximum passively Q-switched output power of 1.21 W, accompanied with a highest pulse repetition rate of 27.1 kHz and a shortest pulse width of 9.1 ns.

  17. Nonlinear refraction properties of nickel oxide thin films at 800 nm

    SciTech Connect

    Melo, Ronaldo P. Jr. de; Silva, Blenio J. P. da; Santos, Francisco Eroni P. dos; Azevedo, A.; Araujo, Cid B. de

    2009-11-01

    Measurements of the nonlinear refractive index, n{sub 2}, of nickel oxide films prepared by controlled oxidation of nickel films deposited on substrates of soda-lime glass are reported. The structure and morphology of the samples were characterized by scanning electron microscopy, atomic force microscopy, and x-ray diffractometry. Samples of excellent optical quality were prepared. The nonlinear measurements were performed using the thermally managed eclipse Z-scan technique at 800 nm. A large value of n{sub 2}approx =10{sup -12} cm{sup 2}/W and negligible nonlinear absorption were obtained.

  18. Poly(ethylene terephthalate) surface modification by deep UV (172 nm) irradiation

    SciTech Connect

    Zhengmao Zhua; Michael J. Kelley

    2004-09-01

    The prospects of obtaining desired surface-mediated characteristics while retaining bulk-mediated physical properties and avoiding potential environmental issues with wet chemical technology lends considerable appeal to photochemical approaches. We investigated the response of poly(ethylene terephthalate) to 172 nm UV from a xenon excimer lamp in the absence of oxygen, using XPS, ToF/SIMS, and AFM. The main effects are increasing loss of a C=O moiety and carboxylic acid production without effect on topography up to a total fluence of 16 J/cm2. Above this level no further change in surface chemistry was evident, but surfaces became rougher, suggesting the onset of etching.

  19. 980-nm diode laser and fiber optic resectoscope in endourological surgery

    NASA Astrophysics Data System (ADS)

    Cecchetti, Walter; Guazzieri, Stefano; Tasca, Andrea; Dal Bianco, M.; Zattoni, Filiberto; Pagano, Francesco

    1996-12-01

    The 980 nm Ceralas D50 diode laser, produces homogeneous lesions on tissues of different nature. In our endourological tests we used the Ceralas D50 coupled with Comeg 24 ch laser resectoscope, and we treated 22 patients: n.5 bladder cancers, n.3 uretero pelvic junction obstructions, with hydronephrosis, n.3 urethra stenosis, n1 ureter stenosis, n.4 multiple upper tract transitional cell carcinomas, n.6 BPH treatments with VLAP modalities. Using the 1000 micrometers delivery fibers with different shaped tips, we obtained a bloodless sharp cut and easily vaporizations with minimum carbonizations, with power output in the range of 8-12 W, and 18-24W for VLAP.

  20. Temperature-dependent 780-nm laser absorption by engineering grade aluminum, titanium, and steel alloy surfaces

    SciTech Connect

    Rubenchik, Alexander M.; Wu, Sheldon S. Q.; Kanz, V. Keith; LeBlanc, Mary M.; Lowdermilk, W. Howard; Rotter, Mark D.; Stanley, Joel R.

    2014-07-17

    When modeling laser interaction with metals for various applications it requires a knowledge of absorption coefficients for real, commercially available materials with engineering grade (unpolished, oxidized) surfaces. But, most currently available absorptivity data pertain to pure metals with polished surfaces or vacuum-deposited thin films in controlled atmospheres. A simple laboratory setup is developed for the direct calorimetric absorptivity measurements using a diode-array laser emitting at 780 nm. A scheme eliminating the effect of convective and radiative losses is implemented. Futhermore, the obtained absorptivity results differ considerably from existing data for polished pure metals and are essential for the development of predictive laser-material interaction models.

  1. Compact frequency-modulation Q-switched single-frequency fiber laser at 1083 nm

    NASA Astrophysics Data System (ADS)

    Zhang, Yuanfei; Feng, Zhouming; Xu, Shanhui; Mo, Shupei; Yang, Changsheng; Li, Can; Gan, Jiulin; Chen, Dongdan; Yang, Zhongmin

    2015-12-01

    A compact frequency-modulation Q-switched single-frequency fiber laser is demonstrated at 1083 nm. The short linear resonant cavity consists of a 12 mm long homemade Yb3+-doped phosphate fiber and a pair of fiber Bragg gratings (FBGs) in which the Q-switching and the frequency excursion is achieved by a tensile-induced period modulation. Over 375 MHz frequency-tuning range is achieved with a modulation frequency varying from tens to hundreds of kilohertz. The highest peak power of the output pulse reaching 6.93 W at the repetition rate of 10 kHz is obtained.

  2. Erroneous laboratory values obtained from central catheters.

    PubMed

    Johnston, J B; Messina, M

    1991-01-01

    Serious analytic errors in potassium measurements have been identified in blood specimens obtained from newly inserted central catheters. Erroneous elevated readings have been related to interactions of chemistry analyzer electrodes and substances fixed to external and intraluminal walls of the central catheter. Anecdotal summaries of this phenomenon are presented to enable the nurse to recognize potential problems when sampling blood from central catheters. Studies were performed to determine the amount of flush necessary to clear the catheter of interfering residue. To eliminate this potentially hazardous occurrence, recommended flush volumes, nursing implications, and actions are described.

  3. Obtaining growth hormone from calf blood

    NASA Technical Reports Server (NTRS)

    Kalchev, L. A.; Ralchev, K. K.; Nikolov, I. T.

    1979-01-01

    The preparation of a growth hormone from human serum was used for the isolation of the hormone from calf serum. The preparation was biologically active - it increased the quantity of the free fatty acids released in rat plasma by 36.4 percent. Electrophoresis in Veronal buffer, ph 8.6, showed the presence of a single fraction having mobility intermediate between that of alpha and beta globulins. Gel filtration through Sephadex G 100 showed an elutriation curve identical to that obtained by the growth hormone prepared from pituitary glands.

  4. Incisional effects of 1940 nm thulium fiber laser on oral soft tissues

    NASA Astrophysics Data System (ADS)

    Güney, Melike; Tunç, Burcu; Gülsoy, Murat

    2013-02-01

    Lasers of different wavelengths are being used in oral surgery for incision and excision purposes with minimal bleeding and pain. Among these wavelengths, those close to 2μ yield more desirable results on oral soft tissue due to their strong absorption by water. The emission of 1940 nm Thulium fiber laser is well absorbed by water which makes it a promising tool for oral soft tissue surgery. This study was conducted to investigate the potential of thulium fiber laser as an incisional and excisional oral surgical tool. Ovine tongue has been used as the target tissue due to its similarities to human oral tissues. Laser light obtained from a 1940 nm Thulium fiber laser was applied in contact mode onto ovine tongue completely submerged in saline solution in vitro, via a 600)μm fiber moved with a velocity of 0.5 mm /s to form incisions. There were a total of 9 groups determined by the power (2,5-3- 3,5 W), and number of passes (1-3-5). The samples were stained with HE for microscopic evaluation of depth of ablation and extent of coagulation. The depth of incisions produced with 1940 nm Thulium fiber laser increased with increasing power and number of passes, however an increase in the width of the coagulation zone was also observed.

  5. Double-exposure materials for pitch division with 193nm lithography: requirements, results

    NASA Astrophysics Data System (ADS)

    Bristol, Robert; Shykind, David; Kim, Sungwon; Borodovsky, Yan; Schwartz, Evan; Turner, Courtney; Masson, Georgeta; Min, Ke; Esswein, Katherine; Blackwell, James M.; Suetin, Nikolay

    2009-03-01

    We present the results of both theoretical and experimental investigations of materials for application either as a reversible Contrast Enhancement Layer (rCEL) or a Two-Stage PAG. The purpose of these materials is to enable Litho- Litho-Etch (LLE) patterning for Pitch Division (PD) at the 16nm logic node (2013 Manufacturing). For the rCEL, we find from modeling using an E-M solver that such a material must posses a bleaching capability equivalent to a Dill A parameter of greater than 100. This is at least a factor of ten greater than that achieved so far at 193nm by any usable organic material we have tested. In the case of the Two-Stage PAG, analytical and lithographic modeling yields a usable material process window, in terms of reversibility and two-photon vs. one-photon acid production rates (branching ratio). One class of materials, based on the cycloadduct of a tethered pair of anthracenes, has shown promise under testing at 193nm in acetonitrile. Sufficient reversibility without acid production, enabled by near-UV exposure, has been achieved. Acid production as a function of dose shows a clear quadratic component, consistent with a branching ratio greater than 1. The experimental data also supports a acid contrast value of approximately 0.05 that could in principle be obtained with this molecule under a pitch division double-exposure scenario.

  6. Characterization of AlInGaN-based 405nm distributed feedback laser diodes

    NASA Astrophysics Data System (ADS)

    Masui, S.; Tsukayama, K.; Yanamoto, T.; Kozaki, T.; Nagahama, S.; Mukai, T.

    2008-02-01

    The first-order AlInGaN 405 nm distributed feed-back (DFB) laser diodes were grown on the low dislocation freestanding GaN substrates by a metal organic chemical vapor deposition method. The first-order diffractive grating whose period was 80 nm was formed into an n-type cladding layer. The fine tooth shape grating was obtained by the EB lithography and the dry etching. No additional threading dislocation could be found at the regrowth interface. As a result, we succeeded in demonstrating the first-order AlInGaN based 405 nm DFB laser diodes under cw operation. The threshold current and the slope efficiency were 22 mA and 1.44 W/A under continuous wave operation at 25 °C, respectively. The single longitudinal mode emission was maintained up to an output power of 60 mW. The fundamental transverse mode operation with a single longitudinal mode was observed in the temperature range from 15 °C to 85 °C at an output power of 30 mW. The lifetime was estimated to be 4000 h by the lifetime test which was carried out under the condition of a constant output power of 30mW at 25 °C for 1000 h. The single longitudinal mode emission was maintained for the life tested DFB laser diodes.

  7. 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

    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 periods. However, these 193nm binary photomasks can be impacted by a phenomenon of chrome oxidation leading to critical dimensions uniformity (CDU) degradation with a pronounced radial signature. If not detected early enough, this CDU degradation may cause defectivity issues and lower yield on wafers. Fortunately, a standard cleaning and repellicle service at the mask shop has been demonstrated as efficient to remove the grown materials and get the photomask CD back on target.Some detection methods have been already described in literature, such as wafer CD intrafield monitoring (ACLV), giving reliable results but also consuming additional SEM time with less precision than direct photomask measurement. In this paper, we propose another approach, by monitoring the CDU directly on the photomask, concurrently with defect inspection for regular requalification to production for wafer fabs. For this study, we focused on a Metal layer in a 90nm technology node. Wafers have been exposed with production conditions and then measured by SEM-CD. Afterwards, this photomask has been measured with a SEM-CD in mask shop and also inspected on a KLA-Tencor X5.2 inspection system, with pixels 125 and 90nm, to evaluate the Intensity based Critical Dimension Uniformity (iCDU) option. iCDU was firstly developed to provide feed-forward CDU maps for scanner intrafield corrections, from arrayed dense structures on memory photomasks. Due to layout complexity and differing feature types, CDU monitoring on logic photomasks used to pose unique challenges.The selection of suitable feature types for CDU monitoring on logic photomasks is no longer an issue, since the transmitted intensity map gives all the needed information, as shown in this paper. In this study, the photomask was heavily degraded after more than 18,000 300

  8. KEY COMPARISON: Final report on CCPR K1-a: Spectral irradiance from 250 nm to 2500 nm

    NASA Astrophysics Data System (ADS)

    Woolliams, Emma R.; Fox, Nigel P.; Cox, Maurice G.; Harris, Peter M.; Harrison, Neil J.

    2006-01-01

    The CCPR K1-a key comparison of spectral irradiance (from 250 nm to 2500 nm) was carried out to meet the requirements of the Mutual Recognition Arrangement by 13 participating national metrology institutes (NMIs). Because of the fragile nature of the tungsten halogen lamps used as comparison artefacts, the comparison was arranged as a star comparison with three lamps per participant. NPL (United Kingdom) piloted the comparison and, by measuring all lamps, provided a link between participants' measurements. The other participants were BNM-INM (France), CENAM (Mexico), CSIRO (Australia), HUT (Finland), IFA-CSIC (Spain), MSL-IRL (New Zealand), NIM (China), NIST (United States of America), NMIJ (Japan), NRC (Canada), PTB (Germany) and VNIIOFI (Russian Federation). Before the analysis was completed and the results known, the pilot discussed with each participant which lamp measurements should be included as representative of their comparison. As a consequence of this check, at least one measurement was excluded from one third of the lamps because of changes due to transportations. The comparison thus highlighted the difficulty regarding the availability of suitable transfer standards for the dissemination of spectral irradiance. The use of multiple lamps and multiple measurements ensured sufficient redundancy that all participants were adequately represented. In addition, during this pre-draft A phase all participants had the opportunity to review the uncertainty budgets and methods of all other participants. This new process helped to ensure that all submitted results and their associated uncertainties were evaluated in a consistent manner. The comparison was analysed using a model-based method which regarded each lamp as having a stable spectral irradiance and the measurements made by an NMI as systematically influenced by a factor that applies to all that NMI's measurements. The aim of the analysis was to estimate the systematic factor for each NMI. Across the

  9. RELATIVISTIC CALCULATION OF TRANSITION PROBABILITIES FOR 557.7 nm AND 297.2 nm EMISSION LINES IN OXYGEN

    SciTech Connect

    Chantler, C. T.; Nguyen, T. V. B.; Lowe, J. A.; Grant, I. P.

    2013-05-20

    The 557.7 nm green line and the 297.2 nm ultraviolet line in oxygen have been studied extensively due to their importance in astrophysics and atmospheric science. Despite the enormous effort devoted to these two prominent transition lines over 30 years, and in fact going back to 1934, the ratio of their transition probabilities remains a subject of major discrepancies amongst various theoretical calculations for many decades. Moreover, theoretical results are inconsistent with available laboratory results, as well as recent spacecraft measurements of Earth's airglow. This work presents new relativistic theoretical calculations of the transition probabilities of these two photoemission lines from neutral oxygen using the multi-configuration Dirac-Hartree-Fock method. Our calculations were performed in both length and velocity gauges in order to check for accuracy and consistency, with agreement to 8%. Whilst remaining a challenging computation, these results directly bear upon interpretations of plasma processes and ionization regimes in the universe.

  10. Combined fractional resurfacing (10600 nm/1540 nm): Tridimensional imaging evaluation of a new device for skin rejuvenation.

    PubMed

    Mezzana, Paolo; Valeriani, Maurizio; Valeriani, Roberto

    2016-11-01

    In this study were described the results, by tridimensional imaging evaluation, of the new "Combined Fractional Resurfacing" technique with the first fractional laser that overtakes the limits of traditional ablative, nonablative fractional resurfacing by combining CO2 ablative and GaAs nonablative lasers. These two wavelengths can work separately or in a mixed modality to give the best treatment choice to all the patients. In this study, it is demonstrated that the simultaneous combination of the CO2 wavelength (10600 nm) and GaAs wavelength (1540 nm) reduced the downtime, reduced pain during the treatment, and produced better results on fine wrinkles reduction and almost the same results on pigmentation as seen with 3D analysis by Antera (Miravex).

  11. Sub-70 nm resolution tabletop microscopy at 13.8 nm using a compact laser-plasma EUV source.

    PubMed

    Wachulak, Przemyslaw W; Bartnik, Andrzej; Fiedorowicz, Henryk

    2010-07-15

    We report the first (to our knowledge) demonstration of a tabletop, extreme UV (EUV) transmission microscope at 13.8 nm wavelength with a spatial (half-pitch) resolution of 69 nm. In the experiment, a compact laser-plasma EUV source based on a gas puff target is applied to illuminate an object. A multilayer ellipsoidal mirror is used to focus quasi-monochromatic EUV radiation onto the object, while a Fresnel zone plate objective forms the image. The experiment and the spatial resolution measurements, based on a knife-edge test, are described. The results might be useful for the realization of a compact high-resolution tabletop imaging systems for actinic defect characterization.

  12. 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

    2003-06-01

    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 (~10 mW) devices all the way to high power extended cavity lasers. The latter have demonstrated ~1 W 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 (0.05% rms from dc-2 MHz), sub 10 mrad beam pointing stability combined with small size, low power consumption (<10 W) and high efficiency.

  13. 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.

  14. 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.

  15. Variation of the Mn I 539.4 nm line with the solar cycle

    NASA Astrophysics Data System (ADS)

    Danilovic, S.; Solanki, S. K.; Livingston, W.; Krivova, N.; Vince, I.

    2016-03-01

    Context. As a part of the long-term program at Kitt Peak National Observatory (KPNO), the Mn i 539.4 nm line has been observed for nearly three solar cycles using the McMath telescope and the 13.5 m spectrograph in double-pass mode. These full-disk spectrophotometric observations revealed an unusually strong change of this line's parameters over the solar cycle. Aims: Optical pumping by the Mg II k line was originally proposed to explain these variations. More recent studies have proposed that this is not required and that the magnetic variability (i.e., the changes in solar atmospheric structure due to faculae) might explain these changes. Magnetic variability is also the mechanism that drives the changes in total solar irradiance variations (TSI). With this work we investigate this proposition quantitatively by using the same model that was earlier successfully employed to reconstruct the irradiance. Methods: We reconstructed the changes in the line parameters using the model SATIRE-S, which takes only variations of the daily surface distribution of the magnetic field into account. We applied exactly the same model atmospheres and value of the free parameter as were used in previous solar irradiance reconstructions to now model the variation in the Mn i 539.4 nm line profile and in neighboring Fe i lines. We compared the results of the theoretical model with KPNO observations. Results: The changes in the Mn i 539.4 nm line and a neighbouring Fe i 539.52 nm line over approximately three solar cycles are reproduced well by the model without additionally tweaking the model parameters, if changes made to the instrument setup are taken into account. The model slightly overestimates the change for the strong Fe i 539.32 nm line. Conclusions: Our result confirms that optical pumping of the Mn ii 539.4 nm line by Mg II k is not the main cause of its solar cycle change. It also provides independent confirmation of solar irradiance models which are based on the assumption

  16. Obtaining optical properties using Representative Layer Theory

    NASA Astrophysics Data System (ADS)

    Razavi, Neema; Yust, Brain; Sardar, Dhiraj

    2011-03-01

    Reliable and minimally invasive methods for diagnosis of toxicity and onset of disease are important for advances in clinical practices. This is commonly achieved through the optical properties, such as a change in the absorption or scattering strength of the diseased tissue. Thus, being able to quantitatively characterize these changes is important to advancements in medical diagnostic methods. By adapting the Representative Layer Theory to the integrating sphere technique, very thin biological samples may be optically characterized, yielding a quick and easy method for monitoring optical changes as a function of disease progression. Samples, consisting of cells, dyes, and nanoparticles of known concentrations were optically characterized at multiple wavelengths. Optical properties obtained by the Representative Layer Theory are compared to those obtained through other methods, such as Kubelka-Munk and Inverse Adding Doubling which are known to have sample thickness limitations. This work is also supported in part by National Science Foundation PREM Grant No. DMR - 0934218 and UTSA Collaborative Research Seed Grant Program (CRSGP).

  17. Obtaining information by dynamic (effortful) touching

    PubMed Central

    Turvey, M. T.; Carello, Claudia

    2011-01-01

    Dynamic touching is effortful touching. It entails deformation of muscles and fascia and activation of the embedded mechanoreceptors, as when an object is supported and moved by the body. It is realized as exploratory activities that can vary widely in spatial and temporal extents (a momentary heft, an extended walk). Research has revealed the potential of dynamic touching for obtaining non-visual information about the body (e.g. limb orientation), attachments to the body (e.g. an object's height and width) and the relation of the body both to attachments (e.g. hand's location on a grasped object) and surrounding surfaces (e.g. places and their distances). Invariants over the exploratory activity (e.g. moments of a wielded object's mass distribution) seem to ground this ‘information about’. The conception of a haptic medium as a nested tensegrity structure has been proposed to express the obtained information realized by myofascia deformation, by its invariants and transformations. The tensegrity proposal rationalizes the relative indifference of dynamic touch to the site of mechanical contact (hand, foot, torso or probe) and the overtness of exploratory activity. It also provides a framework for dynamic touching's fractal nature, and the finding that its degree of fractality may matter to its accomplishments. PMID:21969694

  18. High reliability level on single-mode 980nm-1060 nm diode lasers for telecommunication and industrial applications

    NASA Astrophysics Data System (ADS)

    Van de Casteele, J.; Bettiati, M.; Laruelle, F.; Cargemel, V.; Pagnod-Rossiaux, P.; Garabedian, P.; Raymond, L.; Laffitte, D.; Fromy, S.; Chambonnet, D.; Hirtz, J. P.

    2008-02-01

    We demonstrate very high reliability level on 980-1060nm high-power single-mode lasers through multi-cell tests. First, we show how our chip design and technology enables high reliability levels. Then, we aged 758 devices during 9500 hours among 6 cells with high current (0.8A-1.2A) and high submount temperature (65°C-105°C) for the reliability demonstration. Sudden catastrophic failure is the main degradation mechanism observed. A statistical failure rate model gives an Arrhenius thermal activation energy of 0.51eV and a power law forward current acceleration factor of 5.9. For high-power submarine applications (360mW pump module output optical power), this model exhibits a failure rate as low as 9 FIT at 13°C, while ultra-high power terrestrial modules (600mW) lie below 220 FIT at 25°C. Wear-out phenomena is observed only for very high current level without any reliability impact under 1.1A. For the 1060nm chip, step-stress tests were performed and a set of devices were aged during more than 2000 hours in different stress conditions. First results are in accordance with 980nm product with more than 100khours estimated MTTF. These reliability and performance features of 980-1060nm laser diodes will make high-power single-mode emitters the best choice for a number of telecommunication and industrial applications in the next few years.

  19. Comparison of the photothermal effects of 808nm gold nanorod and indocyanine green solutions using an 805nm diode laser

    NASA Astrophysics Data System (ADS)

    Hasanjee, Aamr M.; Zhou, Feifan; West, Connor; Silk, Kegan; Doughty, Austin; Bahavar, Cody F.; Chen, Wei R.

    2016-03-01

    Non-invasive laser immunotherapy (NLIT) is a treatment method for metastatic cancer which combines noninvasive laser irradiation with immunologically modified nanostructures to ablate a primary tumor and induce a systemic anti-tumor response. To further expand the development of NLIT, two different photosensitizing agents were compared: gold nanorods (GNR) with an optical absorption peak of 808 nm and indocyanine green (ICG) with an optical absorption peak of ~800 nm. Various concentrations of GNR and ICG solutions were irradiated at different power densities using an 805 nm diode laser, and the temperature of the solutions was monitored during irradiation using a thermal camera. For comparison, dye balls made up of a 1:1 volume ratio of gel solution to GNR or ICG solution were placed in phantom gels and were then irradiated using the 805 nm diode laser to imitate the effect of laser irradiation on in vivo tumors. Non-invasive laser irradiation of GNR solution for 2 minutes resulted in a maximum increase in temperature by 31.8 °C. Additionally, similar irradiation of GNR solution dye ball within phantom gel for 10 minutes resulted in a maximum temperature increase of 8.2 °C. Comparatively, non-invasive laser irradiation of ICG solution for 2 minutes resulted in a maximum increase in temperature by 28.0 °C. Similar irradiation of ICG solution dye ball within phantom gel for 10 minutes yielded a maximum temperature increase of only 3.4 °C. Qualitatively, these studies showed that GNR solutions are more effective photosensitizing agents than ICG solution.

  20. Size and time-resolved growth rate measurements of 1 to 5 nm freshly formed atmospheric nuclei

    SciTech Connect

    Kuang C.; Chen, M.; Zhao, J.; Smith, J.; McMurry, P. H.; Wang, J.

    2012-04-12

    This study presents measurements of size and time-resolved particle diameter growth rates for freshly nucleated particles down to 1 nm geometric diameter. Novel data analysis methods were developed, de-coupling for the first time the size and time-dependence of particle growth rates by fitting the aerosol general dynamic equation to size distributions obtained at an instant in time. Size distributions of freshly nucleated total aerosol (neutral and charged) were measured during two intensive measurement campaigns in different environments (Atlanta, GA and Boulder, CO) using a recently developed electrical mobility spectrometer with a diethylene glycol-based ultrafine condensation particle counter as the particle detector. One new particle formation (NPF) event from each campaign was analyzed in detail. At a given instant in time during the NPF event, size-resolved growth rates were obtained directly from measured size distributions and were found to increase approximately linearly with particle size from {approx}1 to 3 nm geometric diameter, increasing from 5.5 {+-} 0.8 to 7.6 {+-} 0.6 nm h{sup -1} in Atlanta (13:00) and from 5.6 {+-} 2 to 27 {+-} 5 nm h{sup -1} in Boulder (13:00). The resulting growth rate enhancement {Lambda}, defined as the ratio of the observed growth rate to the growth rate due to the condensation of sulfuric acid only, was found to increase approximately linearly with size from {approx}1 to 3 nm geometric diameter. For the presented NPF events, values for {Lambda} had lower limits that approached {approx}1 at 1.2 nm geometric diameter in Atlanta and {approx}3 at 0.8 nm geometric diameter in Boulder, and had upper limits that reached 8.3 at 4.1 nm geometric diameter in Atlanta and 25 at 2.7 nm geometric diameter in Boulder. Nucleated particle survival probability calculations comparing the effects of constant and size-dependent growth indicate that neglecting the strong dependence of growth rate on size from 1 to 3 nm observed in this study

  1. High efficient photovoltaic power converter suitable for 920nm to 970nm InGaAs laser diodes

    NASA Astrophysics Data System (ADS)

    Liu, James; Wu, Ta-Chung; Cohen, Mort; Werthen, Jan G.

    2005-09-01

    In this work, we report a highly efficient Photovoltaic Power Converter (PPC) suitable for 920 nm to 970 nm InGaAs MQW lasers for the first time. The epitaxial layers were grown by low pressure MOCVD on the semi-insulting GaAs substrate. The epi layers consist of a p-n junction of In0.12Ga0.88As and the window layer of p+ AlInGaAs. The device is made of seven or eight pie-segments of equal area series-connected by means of air-bridges. Under 500mW of 940nm laser illumination, the open-circuit voltage of the eight-segment InGaAs chip is 6.7V. The short-circuit current is 29.7mA. Its maximum delivered electrical power is 171.2mW, equal to a 34.2% overall power conversion efficiency. We also demonstrate the high temperature characteristic and stability of the device.

  2. Writing time estimation of EB mask writer EBM-9000 for hp16nm/logic11nm node generation

    NASA Astrophysics Data System (ADS)

    Kamikubo, Takashi; Takekoshi, Hidekazu; Ogasawara, Munehiro; Yamada, Hirokazu; Hattori, Kiyoshi

    2014-10-01

    The scaling of semiconductor devices is slowing down because of the difficulty in establishing their functionality at the nano-size level and also because of the limitations in fabrications, mainly the delay of EUV lithography. While multigate devices (FinFET) are currently the main driver for scalability, other types of devices, such as 3D devices, are being realized to relax the scaling of the node. In lithography, double or multiple patterning using ArF immersion scanners is still a realistic solution offered for the hp16nm node fabrication. Other lithography candidates are those called NGL (Next Generation Lithography), such as DSA (Directed-Self-Assembling) or nanoimprint. In such situations, shot count for mask making by electron beam writers will not increase. Except for some layers, it is not increasing as previously predicted. On the other hand, there is another aspect that increases writing time. The exposure dose for mask writing is getting higher to meet tighter specifications of CD uniformity, in other words, reduce LER. To satisfy these requirements, a new electron beam mask writer, EBM-9000, has been developed for hp16nm/logic11nm generation. Electron optical system, which has the immersion lens system, was evolved from EBM-8000 to achieve higher current density of 800A/cm2. In this paper, recent shot count and dose trend are discussed. Also, writing time is estimated for the requirements in EBM-9000.

  3. Generation of coherent 19- and 38-nm radiation at a free-electron laser directly seeded at 38 nm.

    PubMed

    Ackermann, S; Azima, A; Bajt, S; Bödewadt, J; Curbis, F; Dachraoui, H; Delsim-Hashemi, H; Drescher, M; Düsterer, S; Faatz, B; Felber, M; Feldhaus, J; Hass, E; Hipp, U; Honkavaara, K; Ischebeck, R; Khan, S; Laarmann, T; Lechner, C; Maltezopoulos, Th; Miltchev, V; Mittenzwey, M; Rehders, M; Rönsch-Schulenburg, J; Rossbach, J; Schlarb, H; Schreiber, S; Schroedter, L; Schulz, M; Schulz, S; Tarkeshian, R; Tischer, M; Wacker, V; Wieland, M

    2013-09-13

    Initiating the gain process in a free-electron laser (FEL) from an external highly coherent source of radiation is a promising way to improve the pulse properties such as temporal coherence and synchronization performance in time-resolved pump-probe experiments at FEL facilities, but this so-called "seeding" suffers from the lack of adequate sources at short wavelengths. We report on the first successful seeding at a wavelength as short as 38.2 nm, resulting in GW-level, coherent FEL radiation pulses at this wavelength as well as significant second harmonic emission at 19.1 nm. The external seed pulses are about 1 order of magnitude shorter compared to previous experiments allowing an ultimate time resolution for the investigation of dynamic processes enabling breakthroughs in ultrafast science with FELs. The seeding pulse is the 21st harmonic of an 800-nm, 15-fs (rms) laser pulse generated in an argon medium. Methods for finding the overlap of seed pulses with electron bunches in spatial, longitudinal, and spectral dimensions are discussed and results are presented. The experiment was conducted at FLASH, the FEL user facility at DESY in Hamburg, Germany.

  4. 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.

  5. MAGNETIC FIELDS OF AN ACTIVE REGION FILAMENT FROM FULL STOKES ANALYSIS OF Si I 1082.7 nm AND He I 1083.0 nm

    SciTech Connect

    Xu, Z.; Liu, Y.

    2012-04-20

    Vector magnetic fields of an active region filament in the photosphere and upper chromosphere are obtained from spectro-polarimetric observations recorded with the Tenerife Infrared Polarimeter (TIP II) at the German Vacuum Tower Telescope. We apply Milne-Eddington inversions on full Stokes vectors of the photospheric Si I 1082.7 nm and the upper chromospheric He I triplet at 1083.0 nm to obtain the magnetic field vector and velocity maps in two atmosphere layers. We find that (1) a complete filament was already present in H{alpha} at the beginning of the TIP II data acquisition. Only a partially formed one, composed of multiple small threads, was present in He I. (2) The AR filament comprises two sections. One shows strong magnetic field intensities, about 600-800 G in the upper chromosphere and 800-1000 G in the photosphere. The other exhibits only comparatively weak magnetic field strengths in both layers. (3) The Stokes V signal is indicative of a dip in the magnetic field strength close to the chromospheric PIL. (4) In the chromosphere, consistent upflows are found along the PIL flanked by downflows. (5) The transversal magnetic field is nearly parallel to the PIL in the photosphere and inclined by 20 Degree-Sign -30 Degree-Sign in the chromosphere. (6) The chromospheric magnetic field around the filament is found to be in normal configuration, while the photospheric field presents a concave magnetic topology. The observations are consistent with the emergence of a flux rope with a subsequent formation of a filament.

  6. Up-conversion detectors at 1550 nm for quantum communication: review and recent advances

    NASA Astrophysics Data System (ADS)

    Tournier, M.; Alibart, O.; Doutre, F.; Tascu, S.; de Micheli, M. P.; Ostrowsky, D. B.; Thyagarajan, K.; Tanzilli, S.

    . The poled waveguides are designed to up-convert single photons at 1550 nm to 600 nm when a 980 nm diode laser is used as pump. We obtain an overall efficiency of about 0.6% for a noise level of about 8× 103 counts/s. This overall efficiency includes both insertion and propagation losses, and internal up-conversion and quantum detection (Si-APD) efficiencies. Despite a low efficiency value compared to what has been obtained so far by other groups, the efficiency/noise ratio is still comparable which still allows us investigating the noise issue. From the spectrum obtained in both poled and non-poled waveguides we conclude that the noise comes from an alternative phase-matching scheme which permits creating paired photons at 1550 and 2700 nm wavelength by down-conversion of the 980 nm pump laser. Knowing that 1550 nm corresponds to the input signal wavelength, up-conversion of actual signal or pump-induced photons at this particular wavelength cannot be discriminated, therefore contributing to the noise at the final wavelength of 600 nm. We believe that this process of down-conversion of the pump laser to the signal wavelength (plus complementary wavelength) is responsible for the unexpected noise level reported in all the up-conversion detector realizations.

  7. Complex patterns in fossilized stromatolites revealed by hyperspectral imaging (400-2496 nm).

    PubMed

    Murphy, R J; Van Kranendonk, M J; Kelloway, S J; Wainwright, I E

    2016-09-01

    Hyperspectral imaging (400-2496 nm) was used to quantitatively map surface textures and compositional variations in stromatolites to determine whether complexity of textures could be used as evidence to support biogenicity in the absence of preserved biomarkers. Four samples of 2.72-2.4 Ga stromatolites from a variety of settings, encompassing marine and lacustrine environments, were selected for hyperspectral imaging. Images of the sawn surfaces of samples were processed to identify reflectance and mineral absorption features and quantify their intensity (as an index of mineral abundance) using automated feature extraction. Amounts of ferrous iron were quantified using a ratio of reflectance at 1650 and 1299 nm. Visible near infrared imagery (400-970 nm) did not reveal additional textural patterns to those obtained from visual inspection. Shortwave infrared imagery (1000-2496 nm), however, revealed complex laminar and convoluted patterns, including a distinctive texture of sharp peaks and broad, low troughs in one sample, similar to living tufted microbial mats. Spectral analysis revealed another sample to be composed of dolomite. Two other samples were dominated by calcite or chlorite ± illite. Large variations in amounts of ferrous iron were found, but ferric iron was exclusively located in the oxidation crust. Hyperspectral imaging revealed large differences between parts of a sample of biogenic and non-biogenic origin. The former was characterized by calcite with varying amounts of ferrous iron, distributed in lenticular, convoluted patterns; the latter by Mg-Fe chlorite with large amounts of aluminium silicate, distributed as fine laminar layers. All minerals identified by hyperspectral imaging were confirmed by thin section petrography and XRD analyses. Spatial statistics generated from quantitative minerals maps showed different patterns between these different parts of the sample. Thus, hyperspectral imaging was shown to be a powerful tool for

  8. Temperature dependence of the dielectric function of laser deposited YBCO thin film at 3392nm

    SciTech Connect

    Walmsley, D.G.; Bade, T.; McCafferty, P.G.; Rea, C.; Dawson, P.; Wallace, R.J.; Bowman, R.M.

    1996-12-31

    The authors have excited surface plasmons in an YBCO thin film at different temperatures using attenuated total reflection of light. The 300nm thick c-axis film was fabricated using pulsed laser deposition onto an MgO (100) substrate with 248nm KrF excimer radiation. Critical temperature of the film was 89.6K and its roughness, as shown by atomic force microscopy, 20nm rms, without droplets over areas of 10 {micro}m x 10{micro}m. The sample was mounted in Otto geometry on a cooled stage which allowed the temperature to be varied between 300K and 70K. An infrared HeNe laser at 3,392nm was used to excite the surface plasmons. The dielectric function of the film was determined between room temperature and 80K. The imaginary part of the dielectric function decreased substantially with reduction in temperature. Results obtained were: {var_epsilon}{sub r} = {minus}24.1 + 0.0013T and {var_epsilon}{sub i} = 7.7 + 0.067T where T is the temperature in kelvin. The ratio {var_epsilon}{sub i}{sup 300}/{var_epsilon}{sub i}{sup 80} at 2.13 is less than the resistance ratio R{sup 300}/R{sup 80} at 2.81. An explanation is offered in terms of two temperature independent mechanisms operative at optical frequencies: enhanced Rayleigh scattering of surface plasmons at grain boundaries and intraband/interband transitions. The real part of the dielectric function, {var_epsilon}{sub r}, was found to be only slightly temperature dependent. It was, however, highly sample dependent when comparison was made with the results of other films, a feature attributed to surface and grain boundary contamination.

  9. Studies on 405nm blue-violet diode laser with external grating cavity

    NASA Astrophysics Data System (ADS)

    Li, Bin; Gao, Jun; Zhao, Jun; Yu, Anlan; Luo, Shiwen; Xiong, Dongsheng; Wang, Xinbing; Zuo, Duluo

    2016-03-01

    Spectroscopy applications of free-running laser diodes (LD) are greatly restricted as its broad band spectral emission. And the power of a single blue-violet LD is around several hundred milliwatts by far, it is of great importance to obtain stable and narrow line-width laser diodes with high efficiency. In this paper, a high efficiency external cavity diode laser (ECDL) with high output power and narrow band emission at 405 nm is presented. The ECDL is based on a commercially available LD with nominal output power of 110 mW at an injection current of 100 mA. The spectral width of the free-running LD is about 1 nm (FWHM). A reflective holographic grating which is installed on a home-made compact adjustable stage is utilized for optical feedback in Littrow configuration. In this configuration, narrow line-width operation is realized and the effects of grating groove density as well as the groove direction related to the beam polarization on the performances of the ECDL are experimentally investigated. In the case of grating with groove density of 3600 g/mm, the threshold is reduced from 21 mA to 18.3 mA or 15.6 mA and the tuning range is 3.95 nm or 6.01 nm respectively when the grating is orientated in TE or TM polarization. In addition, an output beam with a line-width of 30 pm and output power of 92.7 mW is achieved in TE polarization. With these narrow line-width and high efficiency, the ECDL is capable to serve as a light source for spectroscopy application such as Raman scattering and laser induced fluorescence.

  10. On Helium 1083 nm Line Polarization during the Impulsive Phase of an X1 Flare

    NASA Astrophysics Data System (ADS)

    Judge, Philip G.; Kleint, Lucia; Sainz Dalda, Alberto

    2015-12-01

    We analyze spectropolarimetric data of the He i 1083 nm multiplet (1s2s{}3{S}1-1s2p{}3{P}2,1,0o) during the X1 flare SOL2014-03-29T17:48, obtained with the Facility Infrared Spectrometer (FIRS) at the Dunn Solar Telescope. While scanning active region NOAA 12017, the FIRS slit crossed a flare ribbon during the impulsive phase, when the helium line intensities turned into emission at ≲twice the continuum intensity. Their linear polarization profiles are of the same sign across the multiplet including 1082.9 nm, intensity-like, at ≲5% of the continuum intensity. Weaker Zeeman-induced linear polarization is also observed. Only the strongest linear polarization coincides with hard X-ray (HXR) emission at 30-70 keV observed by RHESSI. The polarization is generally more extended and lasts longer than the HXR emission. The upper J = 0 level of the 1082.9 nm component is unpolarizable thus, lower-level polarization is the culprit. We make non-LTE radiative transfer calculations in thermal slabs optimized to fit only intensities. The linear polarizations are naturally reproduced, through a systematic change of sign with wavelength of the radiation anisotropy when slab optical depths of the 1082.9 component are ≲1. Neither are collisions with beams of particles needed, nor can they produce the same sign of polarization of the 1082.9 and 1083.0 nm components. The He i line polarization merely requires heating sufficient to produce slabs of the required thickness. Widely different polarizations of Hα, reported previously, are explained by different radiative anisotropies arising from slabs of different optical depths.

  11. New approach to obtain boron selective emitters

    SciTech Connect

    Moehlecke, A.; Luque, A.

    1994-12-31

    Selective emitters, used in high efficiency solar cells, need a series of oxidations and photolithographic steps that render the process more expensive. In this paper, a new way to make selective emitters using boron is presented. The main feature of this approach is to save oxide growths and photolithographic processes and it is based on the property of boron doped silicon surfaces to be resistant to anisotropic etchings like the one performed during the texturization. Using this characteristic of boron emitter surfaces, the authors can obtain a highly doped emitter under metal grid and simultaneously a shield to avoid texture on these surfaces. First cells were processed and short wavelength response of p{sup +}nn{sup +} solar cells was enhanced by using lightly doped boron emitters in the uncovered area.

  12. Obtaining the metric of our Universe

    NASA Astrophysics Data System (ADS)

    Jacobs, Mark W.; Linder, Eric V.; Wagoner, Robert V.

    1992-05-01

    We formulate a method for solving the gravitational field equations for perturbations to a Friedmann-Robertson-Walker metric, which does not depend on any kind of averaging procedure or make any a priori assumptions about the magnitude of fluctuations in the matter variables. We present a Green's function for obtaining the effective potential which characterizes the metric perturbations directly from the (possibly large) density fluctuations, and describe the application to astrophysical observations, for example, the angular-diameter distance-versus-redshift relation. The results do not assume a particular model for the formation of structure in the matter distribution, and are valid everywhere in our Universe outside of strong-field regions (e.g., black holes).

  13. A Method for Obtaining Integrable Couplings

    NASA Astrophysics Data System (ADS)

    Zhang, Yu-Sen; Chen, Wei; Liao, Bo; Gong, Xin-Bo

    2006-06-01

    By making use of the vector product in R3, a commuting operation is introduced so that R3 becomes a Lie algebra. The resulting loop algebra tilde R3 is presented, from which the well-known AKNS hierarchy is produced. Again via applying the superposition of the commuting operations of the Lie algebra, a commuting operation in R6 is constructed so that R6 becomes a Lie algebra. Thanks to the corresponding loop algebra tilde R3 of the Lie algebra R3, the integrable coupling of the AKNS system is obtained. The method presented in this paper is rather simple and can be used to work out integrable coupling systems of the other known integrable hierarchies of soliton equations.

  14. Where Manitoba children obtain their cigarettes.

    PubMed Central

    Stanwick, R S; Fish, D G; Manfreda, J; Gelskey, D; Skuba, A

    1987-01-01

    People who start to smoke as children put themselves at greater risk of dying prematurely or being disabled by tobacco-induced disease. One solution is to restrict children's access to cigarettes, thereby reducing consumption of the product and, ultimately, damage to health. This study found that in 1985 the majority of Manitoba public school children 8 to 15 years of age who smoked "regularly" (defined as usually every day) obtained their cigarettes from stores. This source could be reduced, if not eliminated, were a federal regulation passed in 1908 enforced. Under Canada's Tobacco Restraint Act it is illegal for merchants to sell tobacco to anyone under the age of 16 years. By implementing this existing law, authorities would not only be keeping the profit from almost a million dollars in cigarette sales in Manitoba alone out of tobacco company coffers but also be having an impact on the leading cause of preventable premature death and disability in Canada. PMID:3621098

  15. EBM-9000: EB mask writer for product mask fabrication of 16nm half-pitch generation and beyond

    NASA Astrophysics Data System (ADS)

    Takekoshi, Hidekazu; Nakayama, Takahito; Saito, Kenichi; Ando, Hiroyoshi; Inoue, Hideo; Nakayamada, Noriaki; Kamikubo, Takashi; Nishimura, Rieko; Kojima, Yoshinori; Yashima, Jun; Anpo, Akihito; Nakazawa, Seiichi; Iijima, Tomohiro; Ohtoshi, Kenji; Anze, Hirohito; Katsap, Victor; Golladay, Steven; Kendall, Rodney

    2014-07-01

    EBM-9000 equipped with new features such as new electron optics, high current density (800A/cm2) and high speed deflection control has been developed for the 11nm technology node(tn) (half pitch (hp) 16nm). Also in parallel of aggressive introduction of new technologies, EBM-9000 inherits the 50kV variable shaped electron beam / vector scan architecture, continuous stage motion and VSB-12 data format handling from the preceding EBM series to maintain high reliability accepted by many customers. This paper will report our technical challenges and results obtained through the development.

  16. Fixed Pattern Correction and Rapid Analysis Procedures for He I 1083 nm Imaging Spectroscopy with the NASA/NSO Spectromagnetograph

    NASA Technical Reports Server (NTRS)

    Jones, Harrison P.

    2003-01-01

    Imaging spectroscopy in the He 1083 nm lines is a powerful tool for probing the top of the chromosphere and bottom of the transition region. A method for spectral flat-fielding using a uniform solar exposure with spectral lines in place is presented and illustrated with 1083 nm data obtained with the NASA/NSO Spectromagnetograph at the National Solar Observatory Kitt Peak Vacuum Telescope. An efficient method for analysis of the data producing images in continuum intensity, line-of-sight velocity, equivalent width, central line depth, Doppler width, and line asymmetry is also presented and illustrated.

  17. Jupiter's Belt-Zone Boundary (Methane filter, 732 nm)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mosaic of a belt-zone boundary near Jupiter's equator. The images that make up the four quadrants of this mosaic were taken within a few minutes of each other and show Jupiter's appearance at 732 nanometers (nm). Sunlight at 732 nm is weakly absorbed by atmospheric methane. This absorption lowers the total amount of scattered light detected by the Galileo spacecraft while enhancing the fraction that comes from higher in Jupiter's atmosphere where less methane is present. The features of the lower ammonia cloud deck that are seen at 756 nm remain visible, but features in the higher, diffuse cloud are made more apparent.

    The bowed shape of the clouds in the center of the image is created by a combination of stretching in the eastward direction by strong winds and stretching in the north-south direction by weaker winds. The precise shape of the bow and the eastward wind speeds can be measured. The north-south wind speeds, too small to be directly measured, then can be calculated. These images may provide the first indirect measurement of Jupiter's north-south winds.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  18. 28nm node process optimization: a lithography centric view

    NASA Astrophysics Data System (ADS)

    Seltmann, Rolf

    2014-10-01

    Many experts claim that the 28nm technology node will be the most cost effective technology node forever. This results from primarily from the cost of manufacturing due to the fact that 28nm is the last true Single Patterning (SP) node. It is also affected by the dramatic increase of design costs and the limited shrink factor of the next following nodes. Thus, it is assumed that this technology still will be alive still for many years. To be cost competitive, high yields are mandatory. Meanwhile, leading edge foundries have optimized the yield of the 28nm node to such a level that that it is nearly exclusively defined by random defectivity. However, it was a long way to go to come to that level. In my talk I will concentrate on the contribution of lithography to this yield learning curve. I will choose a critical metal patterning application. I will show what was needed to optimize the process window to a level beyond the usual OPC model work that was common on previous nodes. Reducing the process (in particular focus) variability is a complementary need. It will be shown which improvements were needed in tooling, process control and design-mask-wafer interaction to remove all systematic yield detractors. Over the last couple of years new scanner platforms were introduced that were targeted for both better productivity and better parametric performance. But this was not a clear run-path. It needed some extra affords of the tool suppliers together with the Fab to bring the tool variability down to the necessary level. Another important topic to reduce variability is the interaction of wafer none-planarity and lithography optimization. Having an accurate knowledge of within die topography is essential for optimum patterning. By completing both the variability reduction work and the process window enhancement work we were able to transfer the original marginal process budget to a robust positive budget and thus ensuring high yield and low costs.

  19. Ocular safety limits for 1030nm femtosecond laser cataract surgery

    NASA Astrophysics Data System (ADS)

    Wang, Jenny; Sramek, Christopher; Paulus, Yannis M.; Lavinsky, Daniel; Schuele, Georg; Anderson, Dan; Dewey, David; Palanker, Daniel V.

    2013-03-01

    Application of femtosecond lasers to cataract surgery has added unprecedented precision and reproducibility but ocular safety limits for the procedure are not well-quantified. We present an analysis of safety during laser cataract surgery considering scanned patterns, reduced blood perfusion, and light scattering on residual bubbles formed during laser cutting. Experimental results for continuous-wave 1030 nm irradiation of the retina in rabbits are used to calibrate damage threshold temperatures and perfusion rate for our computational model of ocular heating. Using conservative estimates for each safety factor, we compute the limits of the laser settings for cataract surgery that optimize procedure speed within the limits of retinal safety.

  20. Allsky Airglow Imagery from Albuquerque, NM; TOMEX 2000

    NASA Astrophysics Data System (ADS)

    Swenson, G. R.

    2001-12-01

    Allsky imager of OH Meinel and O2 Atmospheric emission bands were observed for the TOMEX rocket campaign from Albuquerque, NM, along with the Na/wind temperature lidar. Motion analysis of imagery describes a main wave propagating from the NW but other secondary waves appear from the NE to present a quasi chaotic wave field. The main wave had a typical horizontal wavelength of a several 10s of km and a period of less than15 minutes. The instrinsic wave parameters of the high frequency waves will be presented.

  1. Investigation of electron beam stabilization of 193-nm photoresists

    NASA Astrophysics Data System (ADS)

    Kim, Myoung-Soo; Park, Jong-Woon; Kim, Hak-Joon; Jun, Bum-Jin; Gil, Myung-Goon; Kim, Bong-Ho; Ross, Matthew F.; Livesay, William R.

    2001-08-01

    193nm lithography is a promising candidate for the fabrication of microelectronic devices at the 130nm design rule and below. With smaller feature sizes, below 130nm, reduced resist thickness is essential because of the pattern collapse issues at high aspect ratios and the limited depth of focus with 193nm lithography tools. However, ArF resists have shown problems with etch selectivity, especially with the thin resist layers necessary. Additionally, pattern slimming during CD-SEM measurement, due to the nature of the resist chemistry, is an issue with feature stability after patterning. At present, many studies have been performed for improving the etch selectivity of resists and addressing line slimming issues. In this study, the electron beam stabilization process has been applied for improving the etch selectivity of resist patterns having an aspect ratio less than 3.0. The electron beam stabilization has been applied to two different ArF resist types; acrylate and cyclic-olefin- maleic-anhydride (COMA), which have been evaluated with respect to materials properties, etch selectivity, and line slimming performance as a function of electron beam dose and etch condition. Film shrinkage and the change in index of refraction were monitored as a function of stabilization condition. The chemical properties were characterized before and after electron beam stabilization using FTIR analysis. Blanket resist etch rate studies were performed as a function of stabilization condition for each resist type. Cross- sectional views of resist patterns after etch processing were also investigated to evaluate the improvement in etch resistance provided by the electron beam process. CD SEM measurements were performed to evaluate the impact of the stabilization process on the patterned features. The issue of line slimming has also been evaluated, with and without electron beam stabilization, for the different ArF resist materials considered. The results were compared with a Kr

  2. Novel high sensitivity EUV photoresist for sub-7nm node

    NASA Astrophysics Data System (ADS)

    Nagai, Tomoki; Nakagawa, Hisashi; Naruoka, Takehiko; Tagawa, Seiichi; Oshima, Akihiro; Nagahara, Seiji; Shiraishi, Gosuke; Yoshihara, Kosuke; Terashita, Yuichi; Minekawa, Yukie; Buitrago, Elizabeth; Ekinci, Yasin; Yildirim, Oktay; Meeuwissen, Marieke; Hoefnagels, Rik; Rispens, Gijsbert; Verspaget, Coen; Maas, Raymond

    2016-03-01

    Extreme ultraviolet lithography (EUVL) has been recognized as the most promising candidate for the manufacture of semiconductor devices for the 7 nm node and beyond. A key point in the successful introduction of EUV lithography in high volume manufacture (HVM) is the effective EUV dose utilization while simultaneously realizing ultra-high resolution and low line edge roughness (LER). Here we show EUV resist sensitivity improvement with the use of a photosensitized chemically amplified resist PSCARTM system. The evaluation of this new chemically amplified resist (CAR) as performed using EUV interference lithography (EUV-IL) is described and the fundamentals are discussed.

  3. Fast efficient Ca atomic resonance filter at 423 nm.

    PubMed

    Walther, F G

    1992-11-15

    An optically pumped active Ca atomic resonance filter is demonstrated, applicable to background-limited optical communications through scatter channels. In pump saturation, the filter should detect 50% of the incident 423-nm signal power with an internal photon gain of 6 and a response time of 10 micros, 2 orders of magnitude faster than a passive Ca filter. Response time of 100 micros has been demonstrated, limited by available pump power. The filter maintains the wide field of view and reduced solar background associated with atomic absorption at the Ca Fraunhofer line while permitting higher data rate communications.

  4. Megasonic cleaning strategy for sub-10nm photomasks

    NASA Astrophysics Data System (ADS)

    Hsu, Jyh-Wei; Samayoa, Martin; Dress, Peter; Dietze, Uwe; Ma, Ai-Jay; Lin, Chia-Shih; Lai, Rick; Chang, Peter; Tuo, Laurent

    2016-10-01

    One of the main challenges in photomask cleaning is balancing particle removal efficiency (PRE) with pattern damage control. To overcome this challenge, a high frequency megasonic cleaning strategy is implemented. Apart from megasonic frequency and power, photomask surface conditioning also influences cleaning performance. With improved wettability, cleanliness is enhanced while pattern damage risk is simultaneously reduced. Therefore, a particle removal process based on higher megasonic frequencies, combined with proper surface pre-treatment, provides improved cleanliness without the unintended side effects of pattern damage, thus supporting the extension of megasonic cleaning technology into 10nm half pitch (hp) device node and beyond.

  5. Novel EUV resist materials design for 14nm half pitch and below

    NASA Astrophysics Data System (ADS)

    Tsubaki, Hideaki; Tarutani, Shinji; Fujimori, Toru; Takizawa, Hiroo; Goto, Takahiro

    2014-04-01

    Polymers with a different Tg and activation energy were prepared to clarify influences of acid diffusion on resolution at 15 nm half-pitch (hp) and 14 nm hp using a EUV micro-field exposure tool (MET) at LBNL. Resolution on such a narrow pattern was limited by collapse and pinching. Clear relationship between pinching numbers and polymer Tg indicates that acid diffusion is one of major contributors on the pinching. In addition, polymers with a low thermal activation energy (Ea) on deprotection were effective for reducing pinching. This is probably originated from its high chemically amplification character even in low post-exposure bake (PEB) temperature to obtain both large chemical contrast and short acid diffusion. On the other hand, a good correlation between a cleanable outgassing amount and Ea indicates trade-off relationship between outgassing and resolution. Advantages of n-butyl acetate (nBA) developer have been investigated in viewpoint of dissolution uniformity. Surface roughness of a non-patterned resist film at half-exposed area, which was well correlated with LWR, was measured by AFM as indicator of uniformity in development process. To avoid any differences in resist chemistry other than development process, cross linking negative tone resist was applied for this study. The surface roughness obtained by nBA, which is conventional negative-tone imaging (NTI) developer, was 32 % lower than that obtained by 2.38 % TMAH solution. NTI resist system with a nBA developer and optimized resist reduced LWR from 4.8 nm to 3.0 nm in comparison with conventional positive tone resist with a 2.38 % TMAH developer. In addition, advantage on semi-dense trench patterning was well defined. New EUV sensitizer with 1.15 times higher EUV absorption resulted in 1.15 times higher acid yield by EUV exposure. Lithography performance of the new EUV sensitizer has been investigated by MET at SEMATECH Albany. Sensitivity was indeed improved from 20 mJ/cm2 to 17 mJ/cm2 according

  6. Simultaneous dual-wavelength lasing at 1047 and 1053 nm and wavelength tuning to 1072 nm in a diode-pumped a-cut Nd : LiYF4 laser

    NASA Astrophysics Data System (ADS)

    Lin, Zhi; Wang, Yi; Xu, Bin; Cheng, Yongjie; Xu, Huiying; Cai, Zhiping

    2015-12-01

    We report on diode-end-pumped a-cut Nd:YLF laser on F→I transition. In a free-running regime, using an output coupler with a radius of curvature of 1000 mm, we obtain dual-wavelength laser operation at both π-polarized 1047 nm and σ-polarized 1053 nm with maximum output power of about 1.25 W and the highest slope efficiency of about 50.9% at pump power of 5.77 W at room temperature, for the first time to our knowledge. Furthermore, using a 0.1-mm glass plate as a wavelength selector, a dual-wavelength laser at 1047 and 1072 nm can also be yielded with the maximum output power of 0.34 W, which has not been reported before.

  7. Tunable high-power narrow-spectrum external-cavity diode laser at 675 nm as a pump source for UV generation.

    PubMed

    Chi, Mingjun; Jensen, Ole Bjarlin; Erbert, Götz; Sumpf, Bernd; Petersen, Paul Michael

    2011-01-01

    High-power narrow-spectrum diode laser systems based on tapered gain media in an external cavity are demonstrated at 675 nm. Two 2 mm long amplifiers are used, one with a 500 μm long ridge-waveguide section (device A), the other with a 750 μm long ridge-waveguide section (device B). Laser system A based on device A is tunable from 663 to 684 nm with output power higher than 0.55 W in the tuning range; as high as 1.25 W output power is obtained at 675.34 nm. The emission spectral bandwidth is less than 0.05 nm throughout the tuning range, and the beam quality factor M(2) is 2.07 at an output power of 1.0 W. Laser system B based on device B is tunable from 666 to 685 nm. As high as 1.05 W output power is obtained around 675.67 nm. The emission spectral bandwidth is less than 0.07 nm throughout the tuning range, and the beam quality factor M(2) is 1.13 at an output power of 0.93 W. Laser system B is used as a pump source for the generation of 337.6 nm UV light by single-pass frequency doubling in a bismuth triborate (BIBO) crystal. An output power of 109 μW UV light, corresponding to a conversion efficiency of 0.026% W(-1), is attained.

  8. Thermal lensing characterization of a high-radiance 946nm planar waveguide laser

    NASA Astrophysics Data System (ADS)

    Ng, S. P.; Mackenzie, J. I.

    2012-06-01

    We present the characterization of the in-plane thermal lens in a quasi-four-level Nd:YAG planar waveguide (PW) laser configured for high-radiance operation with an external stable-cavity. Our approach utilises the measurement of the laser's output irradiance distribution at the near- and far-field positions concurrently in order to obtain the "real time" beam propagation parameter and thus beam quality factor, M2. Coupled with the knowledge of the intra-cavity-thermal-lens- dependent beam sizes at an intra-cavity beam waist, the power dependent effective thermal lens focal length was characterized. A thermal lens focal length of >450 mm was obtained at all incident pump powers up to the maximum level of 87 W. This characterization enabled the build of a 29 W 946 nm PW laser with a record output radiance of 4.3 TWm-2sr-1.

  9. Tribological performance of sub-100-nm femtosecond laser-induced periodic surface structures on titanium

    NASA Astrophysics Data System (ADS)

    Bonse, J.; Höhm, S.; Koter, R.; Hartelt, M.; Spaltmann, D.; Pentzien, S.; Rosenfeld, A.; Krüger, J.

    2016-06-01

    Sub-100-nm laser-induced periodic surface structures (LIPSS) were processed on bulk titanium (Ti) surfaces by femtosecond laser pulse irradiation in air (30 fs pulse duration, 790 nm wavelength). The laser peak fluence, the spatial spot overlap, and the number of overscans were optimized in a sample-scanning geometry in order to obtain large surface areas (5 mm × 5 mm) covered homogeneously by the LIPSS. The laser-processed regions were characterized by optical microscopy (OM), white light interference microscopy (WLIM) and scanning electron microscopy (SEM). The friction coefficient of the nanostructured surfaces was tested during 1000 cycles under reciprocal sliding conditions (1 Hz, 1.0 N normal load) against a 10-mm diameter ball of hardened 100Cr6 steel, both in paraffin oil and in engine oil used as lubricants. Subsequently, the corresponding wear tracks were qualified by OM, SEM, and energy dispersive X-ray analyses (EDX). The results of the tribological tests are discussed and compared to that obtained for near wavelength-sized fs-LIPSS, processed under somewhat different irradiation conditions. Some constraints for a beneficial effect of LIPSS on the tribological performance are provided.

  10. Pulsed 532 nm laser wirestripping: Removal of dye-doped polyurethane insulation

    NASA Astrophysics Data System (ADS)

    Brannon, J.; Snyder, C.

    1994-07-01

    Removal of rhodamine 6G doped polyurethane insulation coated onto 50 μm diameter wire is shown to proceed efficiently and cleanly by irradiation with 532 nm Q-switched pulses from a Nd:YAG laser. The stripping action produced by this method is similar in quality to excimer laser wirestripping. Several experimental parameters were explored including fluence, pulse duration, dye concentration, and the number of incident pulses. Acceptable stripping conditions were obtained for a 3 5 s exposure at 10 Hz, using a dye concentration of 10% by weight, and 12 n pulses at 650 mJ/cm2. Nearly 0.5 μm/pulse is removed at this fluence, which exceeds the threshold fluence of ≈600 mJ/cm2 by only 50 mJ/cm2. The measured 532 nm absorption coefficient of the 10% dye-doped polyurethane was ≈4×104 cm-1. Lower fluences and/or dye concentrations produced inadequate stripping, while shorter duration pulses caused unacceptable melting of the thin gold layer which covered the copper core of the wire. Pulse-by-pulse photographs of the stripping action clearly show melting of the dye/polymer insulation, and thermal “rollback” of the insulation near the stripped end. Regardless, excellent edge definition is obtained by this method.

  11. A Compact "Water Window" Microscope with 60 nm Spatial Resolution for Applications in Biology and Nanotechnology.

    PubMed

    Wachulak, Przemyslaw; Torrisi, Alfio; Nawaz, Muhammad F; Bartnik, Andrzej; Adjei, Daniel; Vondrová, Šárka; Turňová, Jana; Jančarek, Alexandr; Limpouch, Jiří; Vrbová, Miroslava; Fiedorowicz, Henryk

    2015-10-01

    Short illumination wavelength allows an extension of the diffraction limit toward nanometer scale; thus, improving spatial resolution in optical systems. Soft X-ray (SXR) radiation, from "water window" spectral range, λ=2.3-4.4 nm wavelength, which is particularly suitable for biological imaging due to natural optical contrast provides better spatial resolution than one obtained with visible light microscopes. The high contrast in the "water window" is obtained because of selective radiation absorption by carbon and water, which are constituents of the biological samples. The development of SXR microscopes permits the visualization of features on the nanometer scale, but often with a tradeoff, which can be seen between the exposure time and the size and complexity of the microscopes. Thus, herein, we present a desk-top system, which overcomes the already mentioned limitations and is capable of resolving 60 nm features with very short exposure time. Even though the system is in its initial stage of development, we present different applications of the system for biology and nanotechnology. Construction of the microscope with recently acquired images of various samples will be presented and discussed. Such a high resolution imaging system represents an interesting solution for biomedical, material science, and nanotechnology applications.

  12. Densification Kinetics and Structural Evolution During Microwave and Pressureless Sintering of 15 nm Titanium Nitride Powder

    NASA Astrophysics Data System (ADS)

    Zgalat-Lozynskyy, Ostap; Ragulya, Andrey

    2016-02-01

    Microwave sintering (MWS) of commercially available 15-nm-size nanocrystalline TiN powder was studied. Densification kinetics and grain growth mechanisms of nano-TiN were evaluated using non-isothermal heating up to 1500 °C with variable heating rates. A true nanocrystalline ceramic with ~80-nm-size grains and 94.5 % theoretical density was obtained via MWS consolidation at 1400 °C. At higher temperatures, however, an uncontrolled grain growth and a formation of bimodal microstructure were noticed. A temperature dependence of grain growth suggested grain boundary sliding as a primary mechanism of densification below 1100-1200 °C. An activation energy of nano-TiN densification under MWS varied from 26 ± 3 kJ/mol at the initial stage of sintering (900-1200 °C) to 162 ± 22 kJ/mol at higher temperatures. In addition, a relationship coupling microstructural characteristics (grain size, grain boundary) with mechanical properties of titanium nitride ceramics obtained via both microwave and pressureless sintering techniques was discussed.

  13. Coupling functions for NM total intensity and different multiplicities: Analytical approach

    NASA Astrophysics Data System (ADS)

    Lev, Dorman

    Coupling functions for NM total intensity and different multiplicities play important role when we by observed data of cosmic ray (CR) variations on the ground based detectors (mostly neutron monitors and muon telescopes) tried to determine the primary variations of CR energy spectrum out of the Earth’s atmosphere and magnetosphere, into interplanetary space. This is especially important for forecasting expected radiation hazards from solar CR, because by determined primary solar CR energy spectrum in the interplanetary space it is possible to determine effective time of solar CR ejection into solar wind, source function and the diffusion coefficient of solar CR propagation in space in dependence of particle energy and distance from the Sun. Coupling functions are important also for investigations of Forbush effect and precursory effects for forecasting dangerous interplanetary shock waves. We check obtained results for coupling functions by latitude expedition experimental data. We found how coupling functions depend from the level of solar activity and pressure on the level of observations. Obtained results are presented in the analytical forms that are convenient to use for any NM at any place on the Earth.

  14. New space value of the solar oblateness obtained with PICARD

    SciTech Connect

    Irbah, Abdanour; Meftah, Mustapha; Hauchecorne, Alain; Bocquier, Maxime; Cisse, E. Momar; Djafer, Djelloul; Corbard, Thierry

    2014-04-20

    The PICARD spacecraft was launched on 2010 June 15 with the scientific objective of studying the geometry of the Sun. It is difficult to measure solar oblateness because images are affected by optical distortion. Rolling the satellite, as done in previous space missions, determines the contribution of the telescope by assuming that the geometry of the Sun is constant during the observations. The optical response of the telescope is considered to be time-invariant during the roll operations. This is not the case for PICARD because an orbital signature is clearly observed in the solar radius computed from its images. We take this effect into account and provide the new space value of solar oblateness from PICARD images recorded in the solar continuum at 535.7 nm on 2011 July 4-5. The equator-pole radius difference is 8.4 ± 0.5 mas, which corresponds to an absolute radius difference of 6.1 km. This coincides with the mean value of all solar oblateness measurements obtained during the last two decades from the ground, balloons, and space. It is also consistent with values determined from models using helioseismology data.

  15. 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).

  16. 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.

  17. 1125-nm quantum dot laser for tonsil thermal therapy

    NASA Astrophysics Data System (ADS)

    McMillan, Kathleen

    2011-03-01

    Thermal therapy has the potential to provide a nonexcisional alternative to tonsillectomy. Clinical implementation requires that the lymphoid tissue of tonsils is heated homogeneously to produce an amount of primary thermal injury that corresponds to gradual postoperative tonsil shrinkage, with minimal risk of damage to underlying critical blood vessels. Optical constants are derived for tonsils from tissue components and used to calculate the depth of 1/e of irradiance. The 1125 nm wavelength is shown to correspond to both deep penetration and minimal absorption by blood. A probe for tonsil thermal therapy that comprises two opposing light emitting, temperature controlled surfaces is described. For ex vivo characterization of tonsil heating, a prototype 1125 nm diode laser is used in an experimental apparatus that splits the laser output into two components, and delivers the radiation to sapphire contact window surfaces of two temperature controlled cells arranged to irradiate human tonsil specimens from opposing directions. Temperatures are measured with thermocouple microprobes at located points within the tissue during and after irradiation. Primary thermal damage corresponding to the recorded thermal histories are calculated from Arrhenius parameters for human tonsils. Results indicate homogeneous heating to temperatures corresponding to the threshold of thermal injury and above can be achieved in advantageously short irradiation times.

  18. 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).

  19. Photofragment Translational Spectroscopy of Propargyl Radicals at 248 nm

    SciTech Connect

    Goncher, S.J.; Moore, D.T.; Sveum, N.E.; Neumark, D.M.

    2007-12-21

    The photodissociation of propargyl radical, C{sub 3}H{sub 3}, and its perdeuterated isotopolog was investigated using photofragment translational spectroscopy. Propargyl radicals were produced by 193 nm photolysis of allene entrained in a molecular beam expansion, and then photodissociated at 248 nm. photofragment time-of-flight spectra were measured at a series of laboratory angles using electron impact ionization coupled to a mass spectrometer. Data for ion masses corresponding to C{sub 3}H{sub 2}{sup +}, C{sub 3}H{sup +}, C{sub 3}{sup +}, and the analogous deuterated species show that both H and H{sub 2} loss occur. The translational energy distributions for these processes have average values = 5.7 and 15.9 kcal/mol, respectively, and are consistent with dissociation on the ground state following internal conversion, with no exit barrier for H loss but a tight transition state for H{sub 2} loss. The translational energy distribution for H atom loss is similar to that in previous work on propargyl in which the H atom, rather than the heavy fragment, was detected. The branching ratio for H loss/H{sub 2} loss was determined to be 97.6/2.4 {+-} 1.2, in good agreement with RRKM results.

  20. Spin-on organic hardmask materials in 70nm devices

    NASA Astrophysics Data System (ADS)

    Oh, Chang-Il; Uh, Dong-Seon; Kim, Do-Hyeon; Lee, Jin-Kuk; Yun, Hui-Chan; Nam, Irina; Kim, Min-Soo; Yoon, Kyong-Ho; Hyung, Kyung-Hee; Tokareva, Nataliya; Cheon, Hwan-Sung; Kim, Jong-Seob; Chang, Tu-Won

    2007-03-01

    In ArF lithography for < 90nm L/S, amorphous carbon layer (ACL) deposition becomes inevitable process because thin ArF resist itself can not provide suitable etch selectivity to sub-layers. One of the problems of ACL hardmask is surface particles which are more problematic in mass production. Limited capacity, high cost-of-ownership, and low process efficiency also make ACL hardmask a dilemma which can not be ignored by device makers. One of the answers to these problems is using a spin-on organic hardmask material instead of ACL hardmask. Therefore, several processes including bi-layer resist process (BLR), tri-layer resist process (TLR), and multi-layer resist process (MLR) have been investigated. In this paper, we have described spin-on organic hardmask materials applicable to 70nm memory devices. Applications to tri-layer resist process (TLR) were investigated in terms of photo property, etch property and process compatibility. Based on the test results described in this paper, our spin-on hardmask materials are expected to be used in mass production.

  1. Evaluation of fluorinated dissolution inhibitors for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Hamad, Alyssandrea H.; Houlihan, Francis M.; Seger, Larry; Chang, Chun; Ober, Christopher K.

    2003-06-01

    Fluorinated diesters were synthesized and evaluated as dissolution inhibitors (DIs) for 157 nm lithography. The results of dissolution rate measurements, exposure studies, and etching experiments on blends of fluorinated polymers containing these dissolution inhibitors are reported. It was shown that the DIs effectively slow the dissolution rate of the matrix polymer, poly(hexafluorohydroxyisopropyl styrene) (PHFHIPS). Etching studies show that they enhance the plasma etch resistance of poly(methyl methacrylate) using tetrafluoromethane plasma. Addition of the best performing dissolution inhibitor, cyclohexane-1,4-dicarboxylic acid bis-(1-cyclohexyl-2,2,2-trifluoro-1-methyl-ethyl) ester) (FCDE1) to candidate 157 nm photoresist polymers, Duvcor and poly(hexafluorohydroxyisopropyl styrene)-co-poly(t-butyl methacrylate) [pPHFHIPS-co-pt-BMA], improves the imaging behavior of these polymers. Our attempts to elucidate the mechanism of dissolution inhibition for this series of compounds will be discussed. Fourier Transform Infrared (FTIR) studies in conjunction with dissolution rate measurements performed on a series of DI analogues suggest a mechanism based on hydrogen bonding.

  2. High index fluoride materials for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Nawata, T.; Inui, Y.; Masada, I.; Nishijima, E.; Satoh, H.; Fukuda, T.

    2006-03-01

    We tried to investigate various kinds of metal fluoride materials which have higher gravity than CaF II and cubic crystal system, and we found out barium lithium fluoride (BaLiF 3) and potassium yttrium fluoride (KY 3F 10) as candidates for the last lens material. We have developed unique Czochralski (CZ) machines and techniques for the growth of large calcium fluoride single crystals. And we applied these technologies to the growth of fluoride high index materials. We have succeeded to grow the large BaLiF 3 single crystal with 120mm in diameter and a KY 3F 10 single crystal, and measured their basic properties such as refractive index, VUV transmittance, birefringence, and so on. As a result of our basic research, we found out that BaLiF 3 single crystal is transparent at VUV region, and the refractive index at 193nm is 1.64, and KY 3F 10 single crystal has the index of 1.59 at the wavelength of 193nm which is slightly higher than fused silica. We expect that these fluoride high index materials are useful for the last lens material of the next generation immersion lithography.

  3. Unknown Bands Observed in the 266 NM Photolysis of Iodomethanes

    NASA Astrophysics Data System (ADS)

    Du, Jia-Jen; Chen, Chia-Hsin; Chang, Bor-Chen

    2012-06-01

    Unknown bands that were not seen in the nascent emission spectra following the near-UV photolysis of bromomathanes (CHBr3-nCl_n, n= 0, 1, 2 and CH_2Br_2) were observed in the 520-820 nm region of the nascent emission spectra following the 266 nm photolysis of iodomethanes (CHI_3, CH_2I_2, and CH_3I) in a slow flow system at ambient temperature. We have dramatically improved the signal-to-noise (S/N) ratios of these unknown bands for further data analyses. Pressure dependence and temporal waveforms of the unknown bands were also recorded. The analyses show that these bands have the vibrational intervals of roughly 400 cm-1 and possibly originate from the same upper level with emission to different lower levels. Moreover, the nascent emission spectra of photolyzing the deuterated or 13C-substituted isotopomers (CD_2I_2, CD_3I, and 13CH_2I_2) were also acquired, and the results indicate that the carrier molecule probably does not contain any hydrogen or carbon atoms. Our current progress will be presented. S.-X. Yang, G.-Y. Hou, J.-H. Dai, C-.H. Chang, and B.-C. Chang, J. Phys. Chem. A 114, 4785 (2010) C.-N. Liu, H.-F. Liao, G.-Y. Hou, S-.X. Yang, and B.-C. Chang, 65 OSU International Symposium on Molecular Spectroscopy, MI10 (2010).

  4. 240 nm UV LEDs for LISA test mass charge control

    NASA Astrophysics Data System (ADS)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2015-05-01

    Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps.

  5. Optical gain at 1550 nm from colloidal solution of Er3+-Yb3+ codoped NaYF4 nanocubes.

    PubMed

    Liu, Xiaofeng; Chi, Yingzhi; Dong, Guoping; Wu, E; Qiao, Yanbo; Zeng, Heping; Qiu, Jianrong

    2009-03-30

    We demonstrated optical amplification at 1550 nm with a carbon tetrachloride solution of Er(3+)-Yb(3+) codoped NaYF(4) nanocubes synthesized with solvo-thermal route. Upon excitation with a 980 nm laser diode, the nanocube solution exhibited strong near-infrared emission by the (4)I(13/2)-->(4)I(15/2) transition of Er(3+) ions due to energy transfer from Yb(3+) ions. We obtained the highest optical gain coefficient at 1550 nm of 0.58 cm(-1) for the solution with the pumping power of 200 mW. This colloidal solution might be a promising candidate as a liquid medium for optical amplifier and laser at the optical communication wavelength.

  6. First Detection of Sign-reversed Linear Polarization from the Forbidden [O I] 630.03 nm Line

    NASA Astrophysics Data System (ADS)

    de Wijn, A. G.; Socas-Navarro, H.; Vitas, N.

    2017-02-01

    We report on the detection of linear polarization of the forbidden [O i] 630.03 nm spectral line. The observations were carried out in the broader context of the determination of the solar oxygen abundance, an important problem in astrophysics that still remains unresolved. We obtained spectro-polarimetric data of the forbidden [O i] line at 630.03 nm as well as other neighboring permitted lines with the Solar Optical Telescope of the Hinode satellite. A novel averaging technique was used, yielding very high signal-to-noise ratios in excess of 105. We confirm that the linear polarization is sign-reversed compared to permitted lines as a result of the line being dominated by a magnetic dipole transition. Our observations open a new window for solar oxygen abundance studies, offering an alternative method to disentangle the Ni i blend from the [O i] line at 630.03 nm that has the advantage of simple LTE formation physics.

  7. Note: deep ultraviolet Raman spectrograph with the laser excitation line down to 177.3 nm and its application.

    PubMed

    Jin, Shaoqing; Fan, Fengtao; Guo, Meiling; Zhang, Ying; Feng, Zhaochi; Li, Can

    2014-04-01

    Deep UV Raman spectrograph with the laser excitation line down to 177.3 nm was developed in this laboratory. An ellipsoidal mirror and a dispersed-subtractive triple monochromator were used to collect and disperse Raman light, respectively. The triple monochromator was arranged in a triangular configuration with only six mirrors used. 177.3 nm laser excited Raman spectrum with cut-off wavenumber down to 200 cm(-1) and spectral resolution of 8.0 cm(-1) can be obtained under the condition of high purity N2 purging. With the C-C σ bond in Teflon selectively excited by the 177.3 nm laser, resonance Raman spectrum of Teflon with good quality was recorded on the home-built instrument and the σ-σ(*) transition of C-C bond was studied. The result demonstrates that deep UV Raman spectrograph is powerful for studying the systems with electronic transition located in the deep UV region.

  8. Note: Deep ultraviolet Raman spectrograph with the laser excitation line down to 177.3 nm and its application

    NASA Astrophysics Data System (ADS)

    Jin, Shaoqing; Fan, Fengtao; Guo, Meiling; Zhang, Ying; Feng, Zhaochi; Li, Can

    2014-04-01

    Deep UV Raman spectrograph with the laser excitation line down to 177.3 nm was developed in this laboratory. An ellipsoidal mirror and a dispersed-subtractive triple monochromator were used to collect and disperse Raman light, respectively. The triple monochromator was arranged in a triangular configuration with only six mirrors used. 177.3 nm laser excited Raman spectrum with cut-off wavenumber down to 200 cm-1 and spectral resolution of 8.0 cm-1 can be obtained under the condition of high purity N2 purging. With the C-C σ bond in Teflon selectively excited by the 177.3 nm laser, resonance Raman spectrum of Teflon with good quality was recorded on the home-built instrument and the σ-σ* transition of C-C bond was studied. The result demonstrates that deep UV Raman spectrograph is powerful for studying the systems with electronic transition located in the deep UV region.

  9. Diode-pumped continuous wave self-sum-frequency mixing yellow Nd:YAB laser at 592 nm

    NASA Astrophysics Data System (ADS)

    Li, Y. L.; Jiang, H. L.; Ni, T. Y.; Zhang, T. Y.; Tao, Z. H.; Zeng, Y. H.

    2011-04-01

    A dual-wavelength continuous wave (CW) diode-pumped Nd:YAB laser that generates simultaneous laser action at the wavelengths 1062 and 1338 nm is demonstrated. A total output power of 278 mW at the two fundamental wavelengths was achieved at the absorbed pump power of 9.8 W. Furthermore, generation of yellow laser light at 592 nm produced by Type-I self-sum-frequency-mixing of both fundamental waves is observed under non-optimal phase matching conditions. With a diode pump power of 9.8 W, TEM00 mode yellow laser at 592 nm of 37 mW is obtained. The power stability in 4 h is better than 3.3%.

  10. Circular polarization switching and bistability in an optically injected 1300 nm spin-vertical cavity surface emitting laser

    SciTech Connect

    Alharthi, S. S. Henning, I. D.; Adams, M. J.; Hurtado, A.; Korpijarvi, V.-M.; Guina, M.

    2015-01-12

    We report the experimental observation of circular polarization switching (PS) and polarization bistability (PB) in a 1300 nm dilute nitride spin-vertical cavity surface emitting laser (VCSEL). We demonstrate that the circularly polarized optical signal at 1300 nm can gradually or abruptly switch the polarization ellipticity of the spin-VCSEL from right-to-left circular polarization and vice versa. Moreover, different forms of PS and PB between right- and left-circular polarizations are observed by controlling the injection strength and the initial wavelength detuning. These results obtained at the telecom wavelength of 1300 nm open the door for novel uses of spin-VCSELs in polarization sensitive applications in future optical systems.

  11. Squeezed light at 1550 nm with a quantum noise reduction of 12.3 dB.

    PubMed

    Mehmet, Moritz; Ast, Stefan; Eberle, Tobias; Steinlechner, Sebastian; Vahlbruch, Henning; Schnabel, Roman

    2011-12-05

    Continuous-wave squeezed states of light at the wavelength of 1550 nm have recently been demonstrated, but so far the obtained factors of noise suppression still lag behind today's best squeezing values demonstrated at 1064 nm. Here we report on the realization of a half-monolithic nonlinear resonator based on periodically-poled potassium titanyl phosphate which enabled the direct detection of up to 12.3 dB of squeezing at 5 MHz. Squeezing was observed down to a frequency of 2 kHz which is well within the detection band of gravitational wave interferometers. Our results suggest that a long-term stable 1550 nm squeezed light source can be realized with strong squeezing covering the entire detection band of a 3rd generation gravitational-wave detector such as the Einstein Telescope.

  12. Efficient white-light continuum generation in transparent solid media using ˜250 fs, 1053 nm laser pulses

    NASA Astrophysics Data System (ADS)

    Imran, T.; Figueira, G.

    2010-04-01

    We report white-light continuum generation in solid-state media (fused silica and sapphire) using seed pulses centered at 1053 nm and at a repetition rate of 10 Hz. We have investigated the influence of different parameters, such as changing the focal position and the energy of the incident pulse within the medium to obtain optimal white-light continuum. Preliminary results indicate that for intense laser pulses, waist position inside the media and input energy are crucial for high efficiency white-light continuum generation over the wavelength range 400-1100 nm. It was also found that pulses centered at 1053 nm generate a flatter spectrum, with higher white-light continuum efficiency. Such a flat response over a broad bandwidth in the continuum has the potential to be efficiently compressed to shorter durations.

  13. Polarized supercontinuum in birefringent photonic crystal fibre pumped at 1064 nm and application to tuneable visible/UV generation.

    PubMed

    Xiong, C; Wadsworth, W J

    2008-02-18

    We generate a flat, polarized and single mode supercontinuum (SC) spanning 450-1750 nm in a highly birefringent photonic crystal fibre (PCF) pumped by a 1064 nm microchip laser. More than 99% of the total power is kept in a single linear polarization. The measured power coupling penalty due to the elliptical core is less than 6% (0.25 dB). As one of its applications, we demonstrate tuneable visible/UV generation in the nonlinear crystal BIBO pumped by this polarized SC source. A tuneable range of 400-525 nm is obtained by critical phase matching in BIBO. We also show the results of visible/UV generation in BIBO pumped by the signal wavelength of polarized four-wave mixing (FWM) in PCF.

  14. 976-nm passively mode-locked ytterbium-doped fiber laser core-pumped by 915-nm semiconductor laser

    NASA Astrophysics Data System (ADS)

    Zhou, Yue

    2016-11-01

    In this paper, we demonstrate an all-normal dispersion (ANDi) femtosecond YDFL. The laser operates around 976 nm via single-clad single-mode core-pumped method, which could enhance the slope efficiency up to 19% compared to that of 14% via double-clad multi-mode pumped method. The pulse repetition rate is 44.3 MHz, and pulse energy is approximately 1 nJ. Through external cavity pulse compression by a pair of gratings, the pulse duration can be compressed to 250 fs, nearly transform-limited.

  15. Holistic overlay control for multi-patterning process layers at the 10nm and 7nm nodes

    NASA Astrophysics Data System (ADS)

    Verstappen, Leon; Mos, Evert; Wardenier, Peter; Megens, Henry; Schmitt-Weaver, Emil; Bhattacharyya, Kaustuve; Adam, Omer; Grzela, Grzegorz; van Heijst, Joost; Willems, Lotte; Wildenberg, Jochem; Ignatova, Velislava; Chen, Albert; Elich, Frank; Rajasekharan, Bijoy; Vergaij-Huizer, Lydia; Lewis, Brian; Kea, Marc; Mulkens, Jan

    2016-03-01

    Multi-patterning lithography at the 10-nm and 7-nm nodes is driving the allowed overlay error down to extreme low values. Advanced high order overlay correction schemes are needed to control the process variability. Additionally the increase of the number of split layers results in an exponential increase of metrology complexity of the total overlay and alignment tree. At the same time, the process stack includes more hard-mask steps and becomes more and more complex, with as consequence that the setup and verification of the overlay metrology recipe becomes more critical. All of the above require a holistic approach that addresses total overlay optimization from process design to process setup and control in volume manufacturing. In this paper we will present the holistic overlay control flow designed for 10-nm and 7-nm nodes and illustrate the achievable ultimate overlay performance for a logic and DRAM use case. As figure 1 illustrates we will explain the details of the steps in the holistic flow. Overlay accuracy is the driver for target design and metrology tool optimization like wavelength and polarization. We will show that it is essential to include processing effects like etching and CMP which can result in a physical asymmetry of the bottom grating of diffraction based overlay targets. We will introduce a new method to create a reference overlay map, based on metrology data using multiple wavelengths and polarization settings. A similar approach is developed for the wafer alignment step. The overlay fingerprint correction using linear or high order correction per exposure (CPE) has a large amount of parameters. It is critical to balance the metrology noise with the ultimate correction model and the related metrology sampling scheme. Similar approach is needed for the wafer align step. Both for overlay control as well as alignment we have developed methods which include efficient use of metrology time, available for an in the litho-cluster integrated

  16. Lead Oxychloride Borates Obtained under Extreme Conditions.

    PubMed

    Siidra, Oleg I; Kabbour, Houria; Mentre, Olivier; Nazarchuk, Evgeny V; Kegler, Philip; Zinyakhina, Diana O; Colmont, Marie; Depmeier, Wulf

    2016-09-06

    [Pb10O4]Pb2(B2O5)Cl12 (1) and [Pb18O12]Pb(BO2OH)2Cl10 (2) were obtained via high-temperature high-pressure experiments. [O12Pb18](12+) and [O4Pb10](12+) oxocentered structural units of different dimensionality are excised from the ideal [OPb] layer in tetragonal α-PbO. 2 is formed with an excess of lead oxide component, and 1 is formed with an excess of borate and halide reagents. The structure of 2 can be visualized as the incorporation of {Pb(10)Cl4(BO2OH)2} clusters into alternating PbO and chloride layers, with the existence of square vacancies in both. However, the structure of 1 is described as the intrusion of [O4Pb10](12+) tetramers linked by disordered Pb(B2O5) groups into a halogen three-dimensional matrix. The structure of 2 contains 10 symmetrically independent Pb positions. The 6s(2) lone electron pair is stereochemically active on Pb(1)-Pb(9) atoms, whereas it is inert on Pb(10). All of the Pb coordinations in the structure of 2, in accordance with ECCv (volume eccentricity) parameters and the density of states (DOS), can be subdivided into three groups. The current study is the first attempt to analyze this unusual behavior in structurally complex oxyhalide material with the rare case of Pb(2+) cations, demonstrating both stereochemically active and inactive behavior of the lone pair via charge and first-principle calculations.

  17. 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

  18. 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

  19. LD pumped high-repetition-rate high-power 532nm Nd:YAG/LBO solid state laser

    NASA Astrophysics Data System (ADS)

    Li, Pingxue; Liu, Dongyu; Chi, Junjie; Yang, Chun; Zhao, Ziqiang; Hu, Haowei; Zhang, Guangju; Yao, Yifei

    2013-09-01

    Diode pumped solid state 532 nm green laser is widely required for many industrial, medical and scientific applications. Among most of these applications, high power quasi-continuous-wave (QCW) green laser output is demanded. This can be efficiently achieved through a diode-side-pumped acoustic-optic Q-switched Nd:YAG laser with an intracavity second harmonic generation (SHG). In our experiment, LBO crystal is used for the second harmonic generation of high-average-power lasers of near infrared (NIR) range, though its effective NLO coefficient deff is relatively small. It is because of its high damage threshold (greater than 2.5 GW/cm2), large acceptance angle, small walk-off angle, and the nonhygroscopic characteristic. In this paper, we reported a high-repetition-rate high-power diode-side-pumped AO Q-switched Nd:YAG 532 nm laser. A plane-plane cavity with two rods, two AO Q-switches and the type II critical phase-matched LBO at room temperature were employed. Under the LD pump power of 480 W, 95.86 W at 1064 nm wavelength was achieved when the repetition rate was 15 kHz, and the 532 nm average output power of 44.77 W was obtained, with a pulse width of 111.7 ns, corresponding to an optical to optical conversion efficiency of 46.7% from 1064 nm to 532 nm. The 532 nm average output power was 40.10 W at a repetition rate of 10 kHz with a pulse width of 78.65 ns. The output characteristics of the SHG varying with the pumping current and the pulse repetition frequency (PRF) of the laser were also investigated. Further improvement of the SHG is under study.

  20. Component Repair Times Obtained from MSPI Data

    SciTech Connect

    Eide, Steven A.

    2015-05-01

    Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a “white” (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant’s insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of interest, only