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1

Feasibility of solar-pumped dye lasers  

NASA Technical Reports Server (NTRS)

Dye laser gains were measured at various pump-beam irradiances on a dye cell in order to evaluate the feasibility of solar pumping. Rhodamine 6G dye was considered as a candidate for the solar-pumped laser because of its high utilization of the solar spectrum and high quantum efficiency. Measurements show that a solar concentration of 20,000 is required to reach the threshold of the dye.

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1987-01-01

2

Electron Beam Pumping of Laser Dyes.  

National Technical Information Service (NTIS)

The report concerns the feasibility of electron beam pumped dye lasers. This work was undertaken because such lasers might be capable of producing powerful nanosecond pulse of visible light with a conversion efficiency as high as 5% from electrical energy...

R. T. Hodgson S. C. Wallace

1973-01-01

3

Excimer laser pumped dye laser for fluorescence decay time measurement  

SciTech Connect

A simple method is proposed for short fall-time dye laser pulse generation. The pulse tailoring is demonstrated by an excimer laser pumped double cavity dye laser. The achieved fall time is 280 ps with the use of a 7 ns long pump pulse.

Bor, Z.; Raksi, F.; Kovacs, G.; Racz, B.

1988-05-01

4

Threshold pump power of a solar-pumped dye laser  

NASA Technical Reports Server (NTRS)

Threshold solar power for dye laser pumping has been determined by measuring the gain of a rhodamine 6G dye laser amplifier at various solar-simulated irradiances on an amplifier cell. The measured threshold was 20,000 solar constants (2.7 kW/sq cm) for the dye volume of 2 x 5 x 40 cu mm and the optimum dye concentration of 0.001 M. The threshold is about one-third of that achievable with a high-intensity solar concentrator.

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1988-01-01

5

Limits on Efficiency of Optically Pumped Dye Lasers.  

National Technical Information Service (NTIS)

The efficiency of transferring energy from the pumping flux to the lasing flux in a dye laser is investigated. Useful relations are developed for quantum efficiency and loss from dye degradation, with nine key dimensionless parameters introduced to expres...

P. N. Everett

1989-01-01

6

A hybrid copper/gold laser pumped dye amplifier  

NASA Astrophysics Data System (ADS)

The design and operating characteristics of a high average power copper vapour laser pumped dye amplifier which is injected with the 627.8 nm output of a gold vapour laser are reported. In these experiments both the CVL pump and GVL injection signals are obtained from a modified CVL plasma tube. Amplifier gain and efficiency as functions of both the pump and injection power, for a number of dyes and dye mixtures, were investigated. Amplifier efficiencies of 25% are reported for CVL pump powers of 4 W and GVL injection powers of only 50 mW.

Ainsworth, M. D.; Piper, J. A.

1989-01-01

7

Preventing rapid decomposition of rhodamine dyes in excimer-pumped pulsed dye lasers  

SciTech Connect

A simple and effective method of preventing rapid decomposition of rhodamine dyes in Lambda-Physik excimer-pumped pulsed dye lasers is presented. Teflon coating the internal metal surfaces of the dye cell greatly increases the useful lifetime of the dye solution.

Arias, P.D.; Dai, H. (Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (US))

1990-01-01

8

A transversely pumped prismatic dye cell for high power dye lasers  

NASA Astrophysics Data System (ADS)

A new type of prismatic dye cell for transversely pumped pulsed dye lasers, which overcomes the shortcomings of the commonly used planar dye cell and is simple to construct, is described. The design of the cell ensures relatively uniform excitation of the dye which results in an output beam of circular cross-section and very good spatial quality.

Wright, W.; Falconer, I. S.

1988-07-01

9

Limits on efficiency of optically pumped dye lasers  

SciTech Connect

The efficiency of transferring energy from the pumping flux to the lasing flux in a dye laser is investigated. Useful relations are developed for quantum efficiency and loss from dye degradation, with nine key dimensionless parameters introduced to express the competing loss mechanisms. The modeling adds insight and helps optimize performance.

Everett, P.N.

1989-12-08

10

Design and Construction of Simple, Nitrogen-Laser-Pumped, Tunable Dye Lasers  

ERIC Educational Resources Information Center

The basic physical principles of dye lasers are discussed and used to analyze the design and operation of tunable dye lasers pumped by pulsed nitrogen lasers. Details of the design and construction of these dye lasers are presented. Some simple demonstration experiments are described. (BB)

Hilborn, Robert C.

1978-01-01

11

Comparative laser performances of pyrromethene 567 and rhodamine 6G dyes in copper vapour laser pumped dye lasers  

NASA Astrophysics Data System (ADS)

Narrowband laser performances and photochemical stability of alcoholic solutions of pyrromethene 567 and rhodamine 6G dyes, under high-repetition rate copper vapour laser (at 510 nm), as well as, high-peak intensity Nd:YAG laser (at 532 nm) excitation have been investigated. We have observed that pyrromethene 567 dye solutions offer higher efficiency, wider tuning range, but lower photochemical stability and higher lasing threshold than that of rhodamine 6G dye solutions. An addition of about 100 mM DABCO, as a singlet oxygen quencher, in pyrromethene 567 dye solutions improved its photochemical stability close to that of rhodamine 6G. The observation of higher slope efficiency, in spite of higher threshold pump energy for pyrromethene 567 dye than that of rhodamine 6G dye solutions, was explained by a predictive model on gain characteristics of both dye solutions as a function of pump energy.

Ray, A. K.; Kundu, S.; Sasikumar, S.; Rao, C. S.; Mula, S.; Sinha, S.; Dasgupta, K.

2007-05-01

12

High average power excimer laser-pumped dye oscillators  

SciTech Connect

The design, construction, and testing of a high-average-power excimer laser-pumped dye oscillator is described. The system is designed to produce up to 75 watts of average power in the near uv at a pulse repetition rate of 500 Hz. 8 figs.

Tennant, R.A.; Whitehead, M.C.; Tallman, C.R.; Basinger, R.W.

1988-01-01

13

Fast rise air spark pump for organic dye lasers  

Microsoft Academic Search

A specially constructed capacitor with low inductance is used to produce an air spark with short rise time, which is able to pump organic dye lasers with high efficiency. For Rhodamin 6 G we observed a threshold energy for stimulated emission of 3 Ws.

F. Aussenegg; J. Schubert

1969-01-01

14

LASERS AND LASER AMPLIFIERS: Synchronous pumping of jet organic dye lasers with sinusoidally modulated argon laser radiation  

NASA Astrophysics Data System (ADS)

A simple and convenient method of synchronous pumping of jet organic dye lasers is described. In this method a cw argon laser with sinusoidally modulated radiation is used as the pump source. The argon laser is modulated by a standing-wave acoustooptic modulator operating at the frequency of intermode beats of the dye laser. The results are given of an experimental investigation of the width of the mode locking range under synchronous pumping conditions and of the time and energy characteristics of the output radiation. The duration of the output pulses of the dye laser was ~ 350 ps under synchronous pumping conditions.

Ra?, G. I.; Ustinov, B. P.; Sharonov, G. V.

1988-09-01

15

A novel picosecond distributed feedback dye laser arrangement for excimer laser pumping  

NASA Astrophysics Data System (ADS)

A distributed feedback dye laser arrangement is described which can generate pulses at the subharmonic wavelengths of the main excimer laser lines (308 nm, 248 nm, 193 nm, etc.). The laser can be pumped with broadband lasers, such as the XeCl* laserpumped dye laser with competing cavities. The laser is designed to be used as a part of a femtosecond, terawatt excimer laser system.

Bor, Z.; Szabó, G.

1988-10-01

16

Ultraviolet dye lasers pumped by hypocycloidal pinch plasmas  

NASA Astrophysics Data System (ADS)

A hypocycloidal pinch (HCP) device was utilized to pump dye lasers in the near-UV. The spectral irradiance of the HCP light was found to be dependent on the input energy and the working gas (Ar) pressure. This paper reports on the optimum conditions for achieving lasing for the dyes p-terphenyl, BBQ, and POPOP. Specifically, for the case of p-terphenyl (which has an absorption maximum at 276 nm), an optimum pressure of 1 torr of Ar is determined. For electrical input energy of 900 J, a laser output of 8 mJ is obtained at 337 nm. These results with three dyes compare favorably with those obtained for a coaxial flashlamp system.

Yi, W. J.; Venable, D. D.; Lee, J. H.

17

Improving the output and liftime of flashlamp-pumped dye lasers  

Microsoft Academic Search

Techniques to improve the performance of a flashlamp-pumped dye laser are discussed, including the increasing of laser output by pumping it at a faster rate. For triaxial flashlamps, the output is shown to be optimized when the coolant is warmer than the dye solution by as much as 0.2 C. The optimum temperature difference may be bimodal, and is found

Aaron N. Fletcher; Dan E. Bliss; Michael E. Pietrak; George E. McManis III

1986-01-01

18

Laser dye stability, part 10. Effects of DABCO on flashlamp pumping of coumarin dyes  

NASA Astrophysics Data System (ADS)

1,4-Diazabicyclo[2.2.2]octane (DABCO) was tested as a flashlamp-pumped laser lifetime-extender with a variety of coumarin dyes and solvents under both air and argon. In a few cases, DABCO could be considered to have extended the lifetime as much as threefold; however, the selection of the appropriate cover gas and/or solvent could often yield a much greater improvement in the absence of DABCO. In general, DABCO was not found to be very valuable as a lifetime-extender. Furthermore, under some conditions DABCO was found to markedly reduce the laser lifetime and output.

Fletcher, A. N.; Pietrak, M. E.

1985-07-01

19

29-fsec pulse generation from a linear-cavity synchronously pumped dye laser  

NASA Astrophysics Data System (ADS)

29-fsec optical pulses at a center wavelength of 615 nm have been generated from a linear-cavity synchronously pumped dye laser without using the colliding-pulse mode-locking technique. The laser consists of two dye jets (a gain jet and a saturable absorber jet) and a sequence of four Brewster-angled prisms. Kiton Red S is used as the laser dye instead of the conventional Rhodamine 6G.

Kubota, Hirokazu; Kurokawa, Kenji; Nakazawa, Masataka

1988-09-01

20

Diode-pumped polymeric dye lasers operating at a pump power level of 10 mW  

Microsoft Academic Search

We present a low-threshold vertical-cavity dye laser that is pumped by an InGaN laser diode. This vertical-cavity laser has a 1.2-mum-thick poly-N-vinylcarbazole active layer doped with coumarin 540A. The threshold pump power depended on the dye concentration and showed the minimum value of 16 mW\\/pulse with the dye concentration of 4.0%. Single-mode laser action is attained at around 550 nm

Hajime Sakata; Hideki Takeuchi

2008-01-01

21

Investigation of dye lasers pumped by high-power KrF laser radiation  

NASA Astrophysics Data System (ADS)

The lasing characteristics of ethanol solutions of rhodamine R6Zh, coumarin K47, PTP and POPOP dyes excited by radiation from a KrF laser at approximately 10 J with pulse lengths of approximately 80 nsec were investigated. Lasing energy of approximately 1.1 J with efficiency of approximately 14% was obtained for R6Zh and K47 solutions; the energy for PTP was 0.65 J, with efficiency of approximately 8%; the respective figures for POPOP were 0.3 J and 5%. The advantages and disadvantages of a number of dye laser cells designed to be pumped by high power excimer lasers were investigated experimentally.

Klementov, A. D.; Morozov, N. V.; Sergeyev, P. B.

1985-01-01

22

Laser-Pumped Stimulated Emission from Organic Dyes: Experimental Studies and Analytic Comparisons.  

National Technical Information Service (NTIS)

Stimulated emission spectra of two organic dyes, chloro-aluminum phthalocyanine (CAP) and 3,3'-diethylthiatricarbocyanine iodide (DTTC) are compared. Giant-pulse ruby laser excitation was used in both cases. An end pumping configuration employed with DTTC...

P. P. Sorokin J. R. Lankard E. C. Hammond V. L. Moruzzi

1966-01-01

23

Performance of a prototype module of a 300-watt flashlamp-pumped dye laser  

SciTech Connect

Recent performance measurements on a prototype module of a multi-beam, flashlamp-pumped dye-laser system are discussed. Measurements of the total output energy of the dye laser and its distribution in the far field are presented for operation at a 5-Hz repetition rate. The implementation of a real-time dye-regeneration system and the choice of an optimum dye solvent are addressed. A large, multi-beam, flashlamp-pumped dye-laser system is being constructed for a field experiment. Performance measurements made on a prototype module of this laser system are presented. A test bed was assembled at the Laboratory that has the capability of supporting two of these dye-laser modules, and implements many of the unique features of the final system, such as on-line laser-performance diagnostics and the capability to overcome the detrimental effects of finite dye lifetime during operation of the system. The laser system test bed has fluid control, cooling, and electrical support for two separate laser beams working at full output power. There is also a provision for operating three laser beams at a reduced power level. This system has yielded valuable data on both laser performance and engineering aspects. Among the innovative features of the dye-laser system is the ability to run the lasers for extended periods of time without suffering the deleterious effects of dye degradation. Instruments monitor the level of photodegradation products in the dye process stream and direct a fraction of the dye into a carbon absorber, where the degradation products are removed.

Zollars, B.G.; Everett, P.N.

1987-12-11

24

48 fs, 190 kW pulse generation from a cavity dumped, synchronously pumped dye laser  

NASA Astrophysics Data System (ADS)

Optical pulses as short as 48 fs have been successfully generated from a cavity dumped, synchronously pumped dye laser. The laser has a linear cavity with a group velocity dispersion controller and Kiton Red S as the laser dye. Utilizing a single-mode fiber and a pair of Brewster-angled, single-crystal Paratellurite prisms, the pulses are compressed to 30 fs duration with a peak power of 130 kW at a repetition rate of 3.8 MHz.

Kurokawa, Kenji; Kubota, Hirokazu; Nakazawa, Masataka

1988-10-01

25

Dual picosecond dye lasers pumped by synchronized mode-locked and Q-switched Cw Nd:YAG lasers  

NASA Astrophysics Data System (ADS)

We have constructed a picosecond laser system with two Q-switched, mode-locked Nd:YAG lasers synchronously pumping two dye lasers. The Nd:YAG lasers are driven from the same rf source, and therefore produce synchronized pulse trains. Cross-correlation measurements of the two Nd:YAG lasers and of the two dye lasers are described, and the mode-locked pulses are found to be correlated to a high degree. Timing jitter between dye-laser pulses was determined to be ca. 50 ps. The phase relationship between the Nd:YAG lasers is found to be sensitive to cavity length detuning. The phase varies linearly with cavity length in a region ±0.02 mm about the optimum length. The laser system generates time-delays between pump and probe dye-laser pulses of up to milliseconds with picosecond resolution.

Bostick, James M.; Mounter, Sarah A.; Johnson, Carey K.

1988-12-01

26

Generation of high-power tunable picosecond pulses in a synchronously pumped dye laser  

SciTech Connect

This paper reports the study of synchronous mode-locking of a dye laser which consists of a concave spherical grating with a radius of curvature R = 2 m and is pumped by the second-harmonic pulse train from an actively passively mode-locked, repetitively pulsed Nd:YAG laser. A broadly tunable, high-power mode-locked dye laser source has been achieved. Real-time experimental investigation was made on the output characteristics of the dye laser with a BWS-5K high-resolution streak camera. Brief analysis and discussion are given concerning the experimental results.

Lin Jingu; Li Ran; Yao Yuqiu

1986-07-01

27

300 Femtosecond pulses at 497 nanometer generated by an excimer laser pumped cascade of distributed feedback dye lasers  

NASA Astrophysics Data System (ADS)

The setup is a cascade of 3 lasers: A competing cavity dye laser pumped by a XeCl excimer laser, followed by two distributed feedback dye lasers. The typical durations of the pulses from the lasers are 100 ps, 5 ps, and 300 fs, respectively. The output pulses at 497 nm are amplified up to 500 MW. The shortest pulse duration obtained was 198 fs.

Szabó, G.; Bor, Z.

1988-12-01

28

Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser  

NASA Technical Reports Server (NTRS)

The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

Williams, M. D.

1984-01-01

29

Improving the output and liftime of flashlamp-pumped dye lasers  

NASA Astrophysics Data System (ADS)

Techniques to improve the performance of a flashlamp-pumped dye laser are discussed, including the increasing of laser output by pumping it at a faster rate. For triaxial flashlamps, the output is shown to be optimized when the coolant is warmer than the dye solution by as much as 0.2 C. The optimum temperature difference may be bimodal, and is found to depend on the dye, solvent, and to a lesser extent upon the input energy. By increasing the viscosity and/or heat capacity of the dye solution, the triaxial system can be made to lase over a wider temperature difference without employing regulated temperature control or flowing the dye or coolant solutions.

Fletcher, Aaron N.; Bliss, Dan E.; Pietrak, Michael E.; McManis, George E., III

30

Spectral characteristics of a ternary-mixture of dyes in a dye laser pumped by copper vapor laser  

NASA Astrophysics Data System (ADS)

The spectral characteristics of a ternary-mixture, composed of Rhodamine 640, Rhodamine 6G and DCM in ethanol and excited by copper vapor laser, are reported. The concentration of each dye in the ternary-mixture was optimized to provide peak emission at 633 nm and absorb both wavelengths of copper vapor laser, i.e. 510.6 and 578.2 nm. A fluorescence range of 612-679 nm with a relatively broad peak at 631-634 nm was obtained when concentrations of Rhodamine 640, Rhodamine 6G and DCM in the ternary-mixture were 0.90 mM, 0.30 mM and 0.90 mM respectively. This ternary-mixture of dyes in ethanol, when used as a gain medium in a narrowband, tunable dye laser oscillator, transversely pumped by both wavelengths of a copper vapor laser, provided a spectral tuning range of 620-665 nm with an almost flat peak at 630-634 nm.

Khare, R.; Shukla, P. K.; Shrivastava, V. K.; Nakhe, S. V.

2014-02-01

31

Recent progress in the development of electrically and optically pumped dye vapor lasers  

NASA Astrophysics Data System (ADS)

This paper reviews new results in the field of organic dye vapor lasers. Gain studies of the scintillator dye POPOP in liquid solution and in the vapor phase show that a dye vapor exhibits optical gain nearly as high as in the solution case under excitation by a N2 laser. Superradiant emission has been observed from both optically excited POPOP vapor and electron-beam excited vapor. The optimum operating conditions of an electron-beam pumped dye vapor-buffer gas system with high purity argon as buffer are reported. Potential energy transfer processes from the rare-gas buffer to the dye vapor are discussed. The metastable ionic species Ar2(+) has been identified as the most likely POPOP excitation source after intense electron pumping of the dense Ar buffer gas at typically 4-5 atm. An estimate of the conversion efficiency from electronic energy deposited in the Ar buffer to stimulated emission of the dye yields 5 percent. These results suggest that an efficient tunable electron beam pumped dye vapor laser is feasible.

Marowsky, G.

1980-01-01

32

Comparison of the treatment of vascular lesions with the copper-vapor laser and flashlamp-pumped dye laser  

NASA Astrophysics Data System (ADS)

Vascular lesions such as port-wine stains and telangiectases are sometimes treated with carbon-dioxide lasers, argon lasers or argon-pumped dye lasers; however these lasers are non- specific in their thermal effect on tissues and as a result often cause significant scarring. Recently, evidence has accumulated that the flashlamp-pumped dye (585 nm) and copper- vapor (578 nm) lasers, which produce pulsed light that is efficiently absorbed by hemoglobin, are more selective in coagulating abnormal vascular tissue and as a result give a superior clinical result. It is not yet clear what the most important physical and biological mechanisms are during the light-tissue interaction mediated by these two lasers. The post-treatment sequence of events is different for tissue irradiated by each laser; most significantly, the flashlamp-pumped dye laser causes significant transient purpura, whereas the copper vapor laser causes blanching and eschar formation. The clinical outcome, that is regression of the lesion, is equally successful with either laser although some evidence has accumulated showing that the flashlamp-pumped dye laser is best suited to the treatment of small vessel disease while the copper-vapor laser is better for the treatment of large vessel disease. In this paper, we will discuss our observations of the treatment of vascular lesions on humans with the copper-vapor and flashlamp-pumped dye lasers using empirically derived efficacious treatment parameters. Mathematical models of light and heat propagation and in vivo experiments involving mice ears and rat skin flaps will be used to elucidate what we feel are the important underlying mechanisms of this vascular lesion laser therapy.

Flock, Stephen T.; Waner, Milton; McGrew, Ben; Colvin, G. B.; Montague, Donna

1992-08-01

33

Generation of subpicosecond pulses in a dye laser synchronously pumped by a limited train of ultrashort pulses  

NASA Astrophysics Data System (ADS)

Experimental results are presented on a high-power, high-efficiency subpicosecond tunable dye laser synchronously pumped by ultrashort pulses from a solid-state laser. Dye-laser pulses shorter than 0.3 ps were obtained with a peak power up to 1 GW.

Okishev, A. V.

1988-06-01

34

20 ps pulse generation by an excimer laser pumped double self-q-switched distributed feedback dye laser  

NASA Astrophysics Data System (ADS)

The mixing of a saturable absorber into the dye solution of a distributed feedback dye laser, such as the excimer laser-pumped system presently treated, leads to advantageous changes in the pulse-duration, dynamic range, and energy fluctuation characteristics. The results of calculations based on a simple rate equation model have been qualitatively verified by experiments in which stable, 20 psec-long single pulses were obtained; the mixing of a saturable absorber into the dye solution may be useful even in the case of an N2 or Cu-vapor laser.

Hebling, J.

1988-11-01

35

20 ps pulse generation by an excimer laser pumped double self-Q-switched distributed feedback dye laser  

NASA Astrophysics Data System (ADS)

The behaviour of an excimer-laser-pumped distributed feedback dye laser (ELP DFDL) using a mixture of saturable absorber and laser dye as an active medium was studied. In a DFDL self-Q-switching occurs because of the population inversion dependence of the feedback. If the DFDL contains absorber saturation of the absorption by the leading edge of the created laser pulse also causes Q-switching. As a result of this double self-Q-switching, mixing a saturable absorber into the laser dye, the laser pulses become shorter and more stable. This was demonstrated experimentally. Mixing Rhodamine B into the dye solution of a Coumarin 153 ELP DFDL, a six-fold reduction in the pulse duration and a more than two-fold reduction in the pulse energy instability were observed. The experimental results were in good qualitative agreement with the predictions of a simple rate equation model.

Hebling, J.

1988-11-01

36

Anomalous dependence of the lasing parameters of dye solutions on the spectrum of microsecond pump laser pulses  

SciTech Connect

The anomalous dependence of the lasing parameters of ethanol solutions of coumarin, rhodamine, oxazine, and laser dyes of other classes on the spectrum of microsecond pump laser pulses is found. The dependence is determined by the shape of the induced singlet - singlet absorption spectra and absorption spectra of short-lived photoproducts. The elucidation of the influence of these factors makes it possible to choose optimal pump spectra and to enhance the efficiency and stability of microsecond dye lasers. (active media)

Tarkovsky, V V; Kurstak, V Yu; Anufrik, S S [Yanka Kupala State University of Grodno, Grodno (Belarus)

2003-10-31

37

High-repetition-rate polymeric solid-state dye lasers pumped by a copper-vapor laser  

Microsoft Academic Search

We report on the laser action of pyrromethene 567 incorporated into polymeric matrices and pumped longitudinally with the green line of a copper-vapor laser. When the dye was dissolved in a copolymer of methyl methacrylate and pentaerythritol triacrylate, 290 mW average power at 1 kHz (37% lasing efficiency) was obtained. The laser output decreased to 150 mW after 30 min

A. Costela; I. Garc?´a-Moreno; R. Sastre; D. W. Coutts; C. E. Webb

2001-01-01

38

A high power dye laser pumped by a crowbar mode flashlamp  

NASA Astrophysics Data System (ADS)

A flashlamp pumped dye laser system is described. The flashlamp works in the crowbar mode and was especially developed for this laser system. The laser has been operated with rhodamine 6G (? ? 600 nm) and coumarine 1H (? ? 470 nm) with an output energy of up to 1 J per pulse. With a single etalon a linewidth of 0.2 nm was achieved in a pulse of 3-6 ?s length. The maximum repetition rate is 2 pps, limited by the high voltage power supply.

Gassen, J.; Müller, D.; Von Brentano, P.; Georgiadis, A. P.

1990-04-01

39

Spectral and spatial-angular characteristics of pulse-periodic flashlamp-pumped dye laser  

NASA Astrophysics Data System (ADS)

The spectral-energy characteristics and the spatial-angular distribution (SAD) of the radiation from a pulse-periodic flashlamp-pumped dye laser with a polarizing interference filter (PIF) was studied experimentally. The laser radiation SADs were measured for alcohol, aqueous and combined solutions. We showed that aqueous solutions, in particular, that of the coumarin 120 inclusion complex with (beta) - cyclodextrin provide a high directivity, a rather uniform distribution of the radiation across the beam, and a comparatively high laser efficiency for both the nonselective cavity and for those with the PIF. This is why these solutions may be used for the pulse-periodic operating modes. Relatively small radiation divergence is obtained for the small dye concentrations only when an alcohol or combined solutions is used, and the achieved laser efficiency is not high though. A system with the polarizing interference filters had been examined demonstrating a smooth tuning of the laser wavelength over the whole visible range (the laser dye had been changed).

Dzyubenko, M. I.; Maslov, Vyacheslav V.; Pelipenko, Viktor P.; Shevchenko, Valeriy V.

1998-06-01

40

Generation of picosecond pulses in monopulse-pumped dye lasers  

NASA Astrophysics Data System (ADS)

Stimulated emission of radiation by thin cavity cuvettes and laser systems consisting of such a cuvette and an external dispersion cavity is investigated. Four different stages are identified in the development of stimulated emission: the formation of inverse population, linear amplification of spontaneous noise, nonlinear amplification with the formation of a time pulse envelope, and decay of the residual inverse population. An experimental setup employing a YAG passive Q-locked laser with a repetition frequency less than 3 Hz is described. The dynamics of stimulated emission was shown to agree exactly with the results of the numerical experiment. Spectrally limited pulses 3.5 picoseconds long are produced.

Yegorov, K. D.; Petnikova, V. M.; Pleshanov, S. A.; Shuvalov, V. V.

1986-02-01

41

Subnanosecond single photon counting fluorescence spectroscopy using synchronously pumped tunable dye laser excitation.  

PubMed

A synchronously pumped tunable dye laser has been constructed and interfaced with a modified Ortec 9200 photon counting system for the purpose of measuring subnanosecond relaxation phenomena. The dye laser excitation pulse, which has an intrinsic 35-ps FWHM for Rhodamine 6G, is 350 ps when measured by time-correlated single photon counting. This value appears to be characteristic of the transit time jitter in the RCA 8850 photomultiplier tube. Subnanosecond fluorescence lifetimes of Rhodamine B with KI as a quencher have been determined by deconvolution of photons counted versus elapsed time using the method of moments; the shortest lifetime measured was 68 ps. Various technical aspects of the system are discussed with emphasis on applications to biophysical problems. PMID:18699278

Koester, V J; Dowben, R M

1978-08-01

42

Update on flashlamp pumped pulsed dye laser treatment for port wine stains (capillary malformation) patients  

PubMed Central

Background and Aims: Currently, the method of choice for the treatment of port-wine stains is laser photocoagulation. Because of evolving treatment options, it is no longer enough for port-wine stains merely to be lightened through laser treatment. The best course of management consists of the most appropriate laser that will produce the most complete clearing of a lesion in the fewest treatment sessions with the least morbidity. The goal is generally accomplished with the use of yellow-light lasers. Materials (Subjects) and Methods: Absorption of laser energy by melanin causes localized heating in the epidermis, which may, if not controlled, produce permanent complications such as hypertrophic scarring or dyspigmentation. Refinements of the results can be achieved by using the flashlamp-pumped pulsed dye laser (FLPDL) in conjunction with the cryogen spray cooling (CSC) system. In our related studies, the infrared thermal image instrument is used for doctors in determining the optimum laser light dosage and preventing the side effects caused by FLPDL. Topic application of angiogenesis inhibitor (Imiquimod) in conjunction with pulsed dye laser treatment for the PWS patients has been assessed for improvement of FLPDL treatment. Results: We present the clinical effect of FLPDL, and the efficacy and safety of cooled laser treatment of PWS birthmarks. Our clinical outcome in the laser treatment of patients with PWS has been achieved to maximize thermal impact on targeted vessels, while minimizing adverse complications. Conclusions: CSC in conjunction with FLPDL can improve the treatment of PWS. The infrared image instrument is helpful for doctors in determining the optimum laser light dosage. Topic application of angiogenesis inhibitor (Imiquimod) in conjunction with laser treatment for the PWS patients is promising in the near future.

Hsiao, Yen-Chang; Chang, Cheng-Jen

2011-01-01

43

Injection-locked flashlamp-pumped dye lasers of very narrow linewidth in the 570--720 nm range  

SciTech Connect

Tunable and very narrow bandwidth flashlamp-pumped dye lasers are presented, in which spectral narrowing is achieved by injection locking of the pulsed lasers to the radiation of tunable single-mode cw dye lasers. We describe the electronic feedback stabilization of the amplifying ring cavity allowing a complete injection. Peak powers up to 10 kW at a bandwidth of 6 MHz were obtained over a 200-nm tuning range with three different dyes between 572 and 720 nm. The repetition rate is 10 Hz, limited by the dye circulating pumps. The emphasis of this work relates to the two following points: efficient injection locking over a broad frequency range, and special electronic design for accurate synchronization of several amplifying lasers. An example of application for high-resolution coherent anti-Stokes Raman spectroscopy is given.

Boquillon, J.P.; Ouazzany, Y.; Chaux, R.

1987-07-01

44

Oxazine laser dyes  

DOEpatents

New oxazine compounds useful as dye laser media in solution, are superiior to prior art materials. The oxazine dyes useful when pumped by the 578.2 nm copper line to operate in the 700-800 nm range are described by formula I ##STR1##

Hammond, Peter R. (Livermore, CA); Field, George F. (Danville, CA)

1992-01-01

45

Dye lasers  

SciTech Connect

This patent describes a dye laser. It consists of a composite composition of an inorganic oxide glass monolith with a microporous structure containing an incorporated solution comprising a solvent component and a lasable dye component. Wherein the glass monolith has sealed outer surfaces.

Kuder, J.E.; McGinnis, J.L.; Goldberg, H.A.; Hart, T.R.; Che, T.M.

1989-10-31

46

Anomalous dependence of the lasing parameters of dye solutions on the spectrum of microsecond pump laser pulses  

Microsoft Academic Search

The anomalous dependence of the lasing parameters of ethanol solutions of coumarin, rhodamine, oxazine, and laser dyes of other classes on the spectrum of microsecond pump laser pulses is found. The dependence is determined by the shape of the induced singlet - singlet absorption spectra and absorption spectra of short-lived photoproducts. The elucidation of the influence of these factors makes

V V Tarkovsky; V Yu Kurstak; S S Anufrik

2003-01-01

47

ACTIVE MEDIA: Anomalous dependence of the lasing parameters of dye solutions on the spectrum of microsecond pump laser pulses  

Microsoft Academic Search

The anomalous dependence of the lasing parameters of ethanol solutions of coumarin, rhodamine, oxazine, and laser dyes of other classes on the spectrum of microsecond pump laser pulses is found. The dependence is determined by the shape of the induced singlet --- singlet absorption spectra and absorption spectra of short-lived photoproducts. The elucidation of the influence of these factors makes

V. V. Tarkovsky; V. Yu Kurstak; S. S. Anufrik

2003-01-01

48

Monolithic dye laser amplifier  

DOEpatents

A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Kuklo, T.C.

1993-03-30

49

Monolithic dye laser amplifier  

DOEpatents

A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Kuklo, Thomas C. (Ripon, CA)

1993-01-01

50

Infrared Dye Laser Study.  

National Technical Information Service (NTIS)

The feasibility of a flash lamp pumped, near infrared dye laser operating at a moderate repetition rate was shown. The laser produced output pulses of 17 kw peak power at a rate of 4 pulses per minute. The flow system that is essential for multiflash oper...

1973-01-01

51

A high power picosecond dye oscillator synchronously pumped by a Q-switched, mode-locked Nd:YAG laser  

Microsoft Academic Search

The design and performance of a tunable pulsed rhodamine-6G dye laser synchronously pumped by 750-microJ trains of 26 10-ns-spaced 532-nm pulses from a frequency-doubled Q-switched CW Nd:YAG laser to produce single Fourier-transform-limited 20-microJ pulses of linewidth 1\\/cm and duration 20 ps at repetition rate 500 Hz (using an output coupler) are reported. The operating principle of the laser is explained,

P. J. K. Wisoff; R. G. Caro; G. Mitchell

1985-01-01

52

Compact femtosecond system based on dye amplifiers pumped by a multichannel N2 longitudinal discharge laser  

NASA Astrophysics Data System (ADS)

New approach to construction of the compact femtosecond system is proposed. This system can provide less than 50 fs light pulses with up to 100 (mu) J energy and more than 500 Hz repetition rate in visible, near UV and IR spectral regions. There are some essential advantages of this system in comparison with traditional solid state amplifiers schemes. First of them is a possibility of self-selection of incident femtosecond pulses, second is a self isolation of amplifier from master oscillator. Than, weak self phase modulation and chirp broadening of pulses in thin dye cells which promise us to use simple prism pulse compressor, and finely is an amplification second harmonic radiation (violet-blue radiation). Amplified violet-blue femtosecond pulses can be used than for pumping of optical parametric oscillators (OPO) and amplifiers (OPA) on the base of LBO, BBO or LiJO3 crystals. Femtosecond pulses at the signal frequency from that OPO can be also amplified in multipass dye cells, pumped by the same N2 laser. Because beams in channels are simultaneously, it not need to use in this scheme start discharge electronic synchronization systems. Amplifiers parameters estimates give reason to expect that this version of femtosecond system will have smaller sizes and price in comparison with well known existing now on the market femtosecond systems, which provide femtosecond pulses less than 50 fs, with energy up to 100 (mu) J and repetition rate more than 500 Hz in visible, near UV and IR spectral regions.

Bondarev, B. V.; Ishchenko, V. N.; Kochubei, S. A.; Kukarin, S. V.; Sorokin, V. B.

1998-10-01

53

Multi-terrawatt, 100 fsec laser system using flashlamp-pumped, dye- converted Ti:Sapphire as an amplifier  

SciTech Connect

We report on amplification of 100 fsec laser pulses to 250 mJ using flashlamp-pumped, dye converted Ti:Sapphire. The resulting 5 Hz beam is focused to irradiances in excess of 5 {times} 10{sup 18} W/cm{sup 2}.

White, W.E.; Reitize, D.H.; Price, D.F.; Shepherd, R.L.; Bonlie, J.D.; Hunter, J.R.; Patterson, F.G. [Lawrence Livermore National Lab., CA (United States); Perressini, D.L. [Union Carbide Corp., Washougal, WA (United States)

1993-04-14

54

Efficacy of flashlamp-pumped pulsed dye laser therapy for port wine stains: clinical assessment and histopathological characteristics  

Microsoft Academic Search

Clinicopathological evaluation of flashlamp-pumped dye laser therapy for port wine stains was conducted on 474 subjects (135 male and 339 female) ranging in age from less than a year to 85 years (median = 17; lower quartile = 7 and upper quartile = 28). There was a significant variation in the rate of favourable response among lesion sites but the

Keiko Onizuka; Katsumi Tsuneda; Yoshisada Shibata; Masahiro Ito; Ichiro Sekine

1995-01-01

55

Synchronously pumped mode-locked dye laser pumped by a frequency-doubled mode-locked and Q-switched diode laser pumped Nd:YAG laser  

Microsoft Academic Search

We have developed a powerful and efficient mode-locked and Q-switched diode laser pumped Nd:YAG laser. Mode locking has been accomplished using intracavity frequency modulation (FM) to produce continuous-wave mode-locked pulses of 12 ps duration. Acousto-optic pre-lase Q switching has produced a train of pulses of about 25 ps average duration at a repetition rate of 360 MHz in an envelope

G. T. Maker; A. I. Ferguson

1989-01-01

56

Synchronously pumped mode-locked dye laser pumped by a frequency-doubled mode-locked and \\/ital Q\\/-switched diode laser pumped Nd:YAG laser  

Microsoft Academic Search

We have developed a powerful and efficient mode-locked and \\/ital Q\\/-switched diode laser pumped Nd:YAG laser. Mode locking has been accomplished using intracavity frequency modulation (FM) to produce continuous-wave mode-locked pulses of 12 ps duration. Acousto-optic pre-lase \\/ital Q\\/ switching has produced a train of pulses of about 25 ps average duration at a repetition rate of 360 MHz in

G. T. Maker; A. I. Ferguson

1989-01-01

57

Anisotropic fluorescence emission of a dye-doped fibre ring that is pumped by a ring laser beam  

NASA Astrophysics Data System (ADS)

The fluorescence characteristics of a dye-doped polymer fibre were studied by exciting the fibre ring with a ring laser beam. An efficient excitation was achieved from the fibre side owing to the high absorbance of the organic dye. The pump-laser power could be raised to over 400 kW (pulse duration: 5 ns), which was unattainable by the conventional fibre-end pumping method because of the poor laser power durability of the dye-doped polymers. The fibre ends, which were polished obliquely (45°) to pick up the circulating fluorescence, were coupled to each other with an index-matching oil. When the pump power density exceeded 0.2 kW mm-2 (total power: 40 kW), the circulating beam exhibited both a nonlinear peak-growth and a spectral narrowing that were caused by the stimulated emission. By contrast, the fluorescence in the radial direction became weaker as the pump power increased, indicating that the stimulated emission in the axial direction suppressed the fluorescence in the radial direction.

Saito, M.; Ishiguro, H.

2006-02-01

58

A air-bearing based, random orbital drive system for a longitudinally pumped solid state dye laser  

NASA Astrophysics Data System (ADS)

We present our results of an investigation of organic dye doped plastics as a lasing medium. The host materials we have examined are poly(methyl methacrylate) [acrylic], epoxy, polyester and polyurethane. Various solvents have been used to improve dye dispersion within the material. We produce plastic doped disks which are contained in a Littman configuration cavity. Longitudinal pumping with a frequency doubled pulsed Nd:YAG laser is used. To improve the lifetime of the doped disks we have incorporated the disk into an air-bearing assembly. By introducing translational motion with a solenoid, the disk undergoes random orbital motion with respect to the pump laser beam. Lifetime of the disk, lasing quality parameters (bandwidth, tunability, power) are examined.

de Armond, Fredrik; Dill, Robert; Suelzer, Joseph; Masters, Mark

2008-05-01

59

Subpicosecond-pulse development in a colliding-pulse mode-locking dye laser pumped by a pulsed xenon laser  

SciTech Connect

We obtain 0.34-psec optical pulses by using a long-pulse xenon-ion laser as a pump source in a colliding-pulse mode-locking (CPM) configuration. The pump shape is an important parameter affecting the development of short pulses. Some characteristics of xenon- and argon-laser-pumped CPM systems are compared.

Ansari, H.; Dienes, A.; Whinnery, J.R.

1985-01-01

60

Dye system for dye laser applications  

DOEpatents

A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

Hammond, Peter R. (Livermore, CA)

1991-01-01

61

Dye laser amplifier  

DOEpatents

An improved dye laser amplifier is disclosed. The efficiency of the dye laser amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant. 3 figs.

Moses, E.I.

1992-12-01

62

Diode pumped fiber laser  

Microsoft Academic Search

Q-switching in Nd:YAG fibers was investigated as a particularly interesting technique to generate narrow pulses in miniature solid state lasers. Laboratory models of both mechanically and passively Q-switched Nd:YAG fiber lasers were developed and characterized. The devices were made of a short length of end polished fiber placed between two miniature laser mirrors and optically end-pumped with a dye laser.

A. C. Cordova-Plaza; M. J. Digonnet; K. A. Fesler; C. J. Gaeta; S. Ping

1987-01-01

63

Modulation mixing in a multimode dye laser  

SciTech Connect

An argon-ion laser, modulated at two or more frequencies is used to pump a multimode dye laser. Time series of the modulated pump and the output of the dye laser are collected simultaneously. The dye-laser response is analyzed for the presence of chaotic and quasi-periodic attractors. One can estimate and compare the correlation dimension and the order-2 Renyi entropy of both the modulated-pump and dye-laser output signals using an embedding-space technique. Fourier transforms of the time series are also compared.

Koch, K.; Chakmakjian, S.H.; Papademetriou, S.; Stroud, C.R.

1989-06-01

64

Simple picosecond dye laser system pumped by a frequency doubled, optically compressed Q-switched mode-locked Nd:YAG laser  

Microsoft Academic Search

Using the frequency doubled output of the 3 ps pulses from a temporally compressed cw Q-switched and mode-locked Nd:YAG laser, a simple synchronously pumped dye laser was constructed to give frequency tunable operation with short pulses in the 5-10 ps range and peak powers of ~ 15 kW. A circularly scanning streak camera operating in stroboscopic mode was also used

A. S. L. Gomes; J. R. Taylor

1985-01-01

65

Optofluidic dye lasers  

Microsoft Academic Search

Optofluidic dye lasers are microfabricated liquid dye lasers enabled by the microfluidics technology. The integration of dye\\u000a lasers with microfluidics not only facilitates the implementation of complete “lab-on-a-chip” systems, but also allows the\\u000a dynamical control of the laser properties which is not achievable with solid-state optical components. We review the recent\\u000a demonstrations of on-chip liquid dye lasers and some of

Zhenyu Li; Demetri Psaltis

2008-01-01

66

Photothermal analysis of polymeric dye laser materials excited at different pump rates  

NASA Astrophysics Data System (ADS)

The photothermal properties and heat diffusion of polymeric lasers, made up from solutions of Rhodamine 6G in solid matrices of poly(2-hydroxyethyl methacrylate) with different amounts of the cross-linking monomer ethylene glycol dimethacrylate and copolymers of 2-hydroxyethyl methacrylate and methyl methacrylate have been studied through photothermal deflection spectroscopy. The heat load that is due to the pumping process was quantified as a function of the pump excitation repetition frequency (0.25-10 Hz), determining the time-dependent temperature changes at different locations within the laser matrix. A theoretical model, which reproduces these changes with high accuracy, was developed on the basis of the heat-diffusion equation of optically dense fluids. The observed thermal effects became important for impairing the laser stability at pump repetition frequencies higher than 1 Hz. In addition, the irreversible optical changes produced in the laser matrices at high pump fluence values (>1 J/cm2) were also analyzed. These effects originate, most likely, from a two-step photothermal mechanism.

Duchowic, Ricardo; Scaffardi, Lucía B.; Costela, Angel; García-Moreno, Inmaculada; Sastre, Roberto; Acun~A, Alberto Ulises

2003-02-01

67

Picosecond transient backward stimulated Raman scattering and pumping of femtosecond dye lasers  

Microsoft Academic Search

We report studies of transient, backward stimulated, Raman scattering (TBSRS) in solvents with a 10 Hz, 27 ps, 532 nm pump laser. The TBSRS effect was used to create pulses at 545 nm and 630 nm with durations of 2–3 ps and 5–10 ?J of energy. The duration, energy and fluctuations of the Raman pulse were studied as a function

Steven M Arrivo; Kenneth G Spears; Jeffrey Sipior

1995-01-01

68

Photothermal analysis of polymeric dye laser materials excited at different pump rates  

Microsoft Academic Search

The photothermal properties and heat diffusion of polymeric lasers, made up from solutions of Rhodamine 6G in solid matrices of poly(2-hydroxyethyl methacrylate) with different amounts of the cross-linking monomer ethylene glycol dimethacrylate and copolymers of 2-hydroxyethyl methacrylate and methyl methacrylate have been studied through photothermal deflection spectroscopy. The heat load that is due to the pumping process was quantified as

Ricardo Duchowic; Lucía B. Scaffardi; Angel Costela; Inmaculada García-Moreno; Roberto Sastre

2003-01-01

69

Infrared Dye Laser Study.  

National Technical Information Service (NTIS)

Building on work done in Phase I of this study (See AD-748 863), research on near-infrared dye lasers continued along several lines. Eighteen more Kodak organic dyes were screened for laser action using a linear flash lamp for excitation. Six dyes lased b...

B. E. Plourde J. P. Webb

1973-01-01

70

Characteristics of a multicolor dye laser  

Microsoft Academic Search

An experimental investigation on the possibility of obtaining tunable, multiple wavelength output in mixture of dyes pumped by a nitrogen laser has been carried out. A great number of binary dye mixtures have been tested. Simultaneous two wavelength operation is generally possible provided the gain profiles of both dyes are neither strongly overlapped nor too widely separated. Three color emission

P. Burlamacchi; H. F. Ranea Sandoval

1979-01-01

71

Hybrid Titanium-Sapphire: Dye laser  

NASA Astrophysics Data System (ADS)

On this work we present a Titanium:Sapphire laser with an intracavity dye amplifier. The system was pumped with 5 W of 532 nm laser radiation from an intracavity doubled Nd: YVO4 laser. The dye used was styryl 14 dye dissolved in a 15%:85% combination of ethylene glycol and propylene carbonate solvents inside a flow cell. The laser was tuned using a three-stage birefringent filter. We observe the behavior of the system in which the intracavity amplifier, depending on the pump power, behaved as an amplifier, hybrid laser or saturable absorber.

Gerardo Treviño-Palacios, Carlos; Zapata-Nava, Oscar Javier; Iturbe-Castillo, M. David

2011-01-01

72

Direct solar pumped laser  

SciTech Connect

A direct solar pumped laser operates on emission from the phosphorescent T1 -> SO transition of a suitable dye molecule used in liquid or solid solution. The first excited singlet electronic state s1 is excited from the ground state so by light from solar concentrators absorbed in the absorption bands of the strong spin-allowed transitions sp <- so, P > or = 1, where the primary absorption band is usually P 1. Excitation of dye molecules to the first triplet state t1 occurs via intersystem crossing from s1 to the triplet state manifold.

Volkin, H.C.

1981-07-28

73

Chemical Stabilization of Laser Dyes.  

National Technical Information Service (NTIS)

Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. This results in attenuation of dye laser output. Modes of degradation of coumarin dye lasers under both anaerobic and aerobic conditions were determined...

T. H. Koch

1984-01-01

74

Laser ablation of dyes  

NASA Astrophysics Data System (ADS)

High density 50 ?s pulses of the UV dyes PPF, POPOP and BBO and of two dyes in the visible region, Xanthen N92 and Fluorol 7GA were generated by laser ablation. Dye powders were pressed with 7800 kp/cm 2 in round pellets which were ablated by exposure to KrF excimer laser radiation (248 nm) at a fluence of 100 mJ/cm 2. The ablation cloud was optically activated with a XeCl excimer laser. Its fluorescence spectrum was measured and was identified as a dye vapour fluorescence spectrum by comparison to conventional dye solution and dye vapour spectra. The dye cloud is not deflected in an electric field (10 6 V/m). By changing the delay time between the ablation laser and the focused activation laser, the velocity distribution of the ablated dye was measured. Its maximum is at 600 m/s for PPF. Knowing the thickness of the ablated dye layer per shot (300 Å) and the size of the ablation cloud (pictures of a video camera), one can estimate the maximum density of the dye in the gas pulse to be 10 -5 mol/ l in the range of concentration of lasing dyes. However, no lasing was observed up to now.

Späth, M.; Stuke, M.

1992-01-01

75

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its good utilization of the solar spectrum and high quantum efficiency. The measurement shows that a solar concentration of 20,000 is required to reach the threshold of the dye. The work to construct a kinetic model algorithm which predicts the output parameter of laser was progressed. The kinetic model was improved such that there is good agreement between the theoretical model and experimental data for the systems defined previously as flashlamp pumped laser oscillator, and the long path length solar pumped laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1986-01-01

76

Photoacoustic analysis of stimulated emission in pulsed dye lasers  

Microsoft Academic Search

Stimulated emission in pulsed dye lasers was characterized in several experimental conditions by analyzing the changes in the acoustic signals generated in a dye solution, with the dye laser cavity either active or inhibited (i.e., by blocking the optical path or misaligning of the optical components). Pump energy threshold, optimum dye concentration, tuning range and maximum-emission wavelength of a rhodamine

M. Villagrán-Muniz; C. Garcia-Segundo; H. F. Ranea-Sandoval; C. Gogorza; G. M. Bilmes

1995-01-01

77

Investigation of the temperature dependence of the lasing characteristics of a dye laser with lamp pumping  

Microsoft Academic Search

In the present paper the results are presented of experimental investigations into the determination of the dependence of the lasing characteristics of ethanolic solutions of four dyes as the temperature of the solutions was varied from 15 to 60~ The four dyes which were studied are 4-methylumbelliferone (4-MU), unsubstituted rhodamine (UR), Rhodamine 6G (R6G), and Rhodamine C (RC). In these

V. A. Alekseev; L. K. Denisov; V. I. Kozintsev; N. A. Kozlov; A. I. Sopin

1979-01-01

78

Argon-pumped tunable dye laser therapy for facial port-wine stain hemangiomas in adults--a new technique using small spot size and minimal power  

Microsoft Academic Search

A low power, argon-pumped tunable dye laser was used to deliver yellow light of 577 nm. Individual blood vessels within port-wine stain hemangiomas were treated with a 0.1-mm beam of light using 8 X magnification. This technique permits excellent resolution of facial and nuchal port-wine stain hemangiomas in adults without the adverse complications of textural change, permanent pigmentation abnormality, or

A. Scheibner; R. G. Wheeland

1989-01-01

79

Argon-pumped tunable dye laser therapy for facial port-wine stain hemangiomas in adults--a new technique using small spot size and minimal power  

SciTech Connect

A low power, argon-pumped tunable dye laser was used to deliver yellow light of 577 nm. Individual blood vessels within port-wine stain hemangiomas were treated with a 0.1-mm beam of light using 8 X magnification. This technique permits excellent resolution of facial and nuchal port-wine stain hemangiomas in adults without the adverse complications of textural change, permanent pigmentation abnormality, or hypertrophic scarring.

Scheibner, A.; Wheeland, R.G.

1989-03-01

80

Low-threshold self-pumped phase conjugation of an Ar+-laser beam by using a dye-doped nematic liquid crystal  

NASA Astrophysics Data System (ADS)

Investigations of self-pumped phase conjugation (SPPC) of a low power cw-Ar-laser by using a dye-doped nematic liquid crystal are reported. The phase conjugated signal was generated by stimulated thermal scattering. The threshold power at a wavelength of 514.5 nm was about 30 mW and the maximum power-reflectivity was up to 1%. The ability to compensate phase aberrations has been demonstrated.

Antipov, O. L.; Eichler, Hans J.; MacDonald, R.; Meindl, P.

1996-04-01

81

[Berlin dye laser].  

PubMed

The conditions for an optimal ophthalmic coagulating system are derived from the absorption spectra of xanthophyll, melanin and hemoglobin. Coagulation is effected by a dye laser with two dyes. The continuously tunable range of 570 nm to 680 nm opens up new horizons in photocoagulation of the retina. PMID:6543236

Wollensak, J; Seiler, T

1984-12-01

82

Infrared Dye Laser Study.  

National Technical Information Service (NTIS)

Near infrared laser action has been demonstrated for 9 Kodak organic dyes, using a linear flash lamp for excitation. The spectral region covered by these 9 dyes extends from 850 nm to at least 960 nm, with no tuning attempted so far. Output is in the kilo...

B. E. Plourde J. P. Webb

1972-01-01

83

Optofluidic circular grating distributed feedback dye laser  

NASA Astrophysics Data System (ADS)

We demonstrate an optically pumped surface emitting optofluidic dye laser using a second-order circular grating distributed feedback resonator. We present a composite bilayer soft lithography technique specifically developed for the fabrication of our dye laser and investigate a hybrid polymer material system [poly(dimethylsiloxane)/perfluoropolyether] to construct high-resolution Bragg gratings. Our lasers emit single frequency light at low lasing thresholds of 6 ?J/mm2. These optofluidic dye lasers can serve as low-cost and compact coherent light sources that are fully integrated within microfluidic analysis chips and provide an efficient approach to construct compact spectroscopy systems.

Chen, Yan; Li, Zhenyu; Henry, M. David; Scherer, Axel

2009-07-01

84

Dabco stabilization of coumarin dye lasers  

NASA Astrophysics Data System (ADS)

1.4-diazabicyclo [2.2.2] octane (DABCO) has been shown to extend the lifetime of several coumarin dyes in nitrogen-laser-pumped and flash-lamp-pumped dye lasers. With 0.010 M DABCO average power output remains at better than 907 of initial power at least three times longer than without DABCO.DABCO is effective in stabilizing dye solutions which are not oxygen degassed and to a lesser extent, in stabilizing oxygen degassed dye solutions. Average power output, pulse duration, and spectral linewidth are not significantly affected. Stabilization is proposed to occur through a combination of dye triplet excited state quenching and quenching of singlet oxygen which results from oxygen quenching of dye triplet states.

Von Trebra, Robert; Koch, Tad H.

1982-12-01

85

Fiber optics interface for a dye laser oscillator and method  

DOEpatents

A dye laser oscillator in which one light beam is used to pump a continuous stream of dye within a cooperating dye chamber for producing a second, different beam is generally disclosed herein along with a specific arrangement including an optical fiber and a fiber optics interface for directing the pumping beam into the dye chamber. The specific fiber optics interface illustrated includes three cooperating lenses which together image one particular dimension of the pumping beam into the dye chamber from the output end of the optical fiber in order to insure that the dye chamber is properly illuminated by the pumping beam.

Johnson, S.A.; Seppala, L.G.

1984-06-13

86

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from April 1, 1985 to Sept. 30, 1985 under NASA grant NAS1-441 entitled direct solar pumped iodine laser amplifier. During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) the radiation characteristics of solar simulator and the parametric characteristics of photodissociation iodine laser continuously pumped by a Vortek solar simulator; (2) kinetic modeling of a solar pumped iodine laser amplifier; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K. S.

1985-01-01

87

Characteristics of a Broadband Dye Laser Using Pyrromethene and Rhodamine Dyes  

NASA Technical Reports Server (NTRS)

A broadband dye laser pumped by a frequency-doubled Nd:YAG laser with a full-width half-maximum (FWHM) from 592 to 610 nm was created for the use in a dual-pump broadband CARS system called WIDECARS. The desired broadband dye laser was generated with a mixture of Pyrromethene dyes as an oscillator gain medium and a spectral selective optic in the oscillator cavity. A mixture of Rhodamine dyes were used in the amplifier dye cell. To create this laser a study was performed to characterize the spectral behavior of broadband dye lasers created with Rhodamine dyes 590, 610, and 640, Pyrromethene dyes 597 and 650 as well as mixture of these dyes.

Tedder, Sarah A.; Danehy, Paul M.; Wheeler, Jeffrey L.

2011-01-01

88

Dye film leaky waveguide laser  

NASA Astrophysics Data System (ADS)

Based on a dye-doped polymer film with a refractive index less than that of the glass substrate, a leaky waveguide laser device has been investigated. The film is made from a polyurethane based commercial epoxy which is doped with a newly synthesized dye material: trans-4-[P-(N-ethyl-N-hydroxylethylamino) styryl]-N-methylpyridinium tetraphenylborate. The key element of the laser device is a flint-glass made equilateral prism on one surface of which the dye doped film forms a leaky waveguide structure. By combining this prism with a lateral linear pump source and two cavity mirrors, the quasiwaveguide lasing can be obtained. The absorption and fluorescence spectra of the new dye doped film, and the spatial, spectral and temporal behavior of the lasing output from the device are presented. Under pump conditions of 532 nm wavelength, 10 ns pulsewidth and 5 Hz repetition rate, this device provides the peak lasing wavelength at ˜ 590nm, a lasing efficiency of ˜ 12%, and a lasing lifetime ? 3 X 10 4 pulses.

He, Guang S.; Zhao, Chan F.; Park, Chi-Kyun; Prasad, Paras N.; Burzynski, Ryszard

1994-09-01

89

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

Injection locking was applied to a cavity-dumped coaxial flashlamp pumped dye laser in an effort to obtain nanosecond duration pulses which have both high energy and narrow-linewidth. In the absence of an injected laser pulse, the cavity-dumped dye laser was capable of generating high energy (approx. 60mJ) nanosecond duration output pulses. These pulses, however, had a fixed center wavelength and were extremely broadband (approx. 6nm FWHM). Experimental investigations were performed to determine if the spectral properties of these outputs could be improved through the use of injection-locking techniques. A parametric study to determine the specific conditions under which the laser could be injection-locked was also carried out. Significant linewidth reduction to 0.0015nm) of the outputs was obtained through injection-locking but only at wavelengths near the peak lasing wavelength of the dye. It was found, however; that by inserting weakly dispersive tuning elements in the laser cavity, these narrow-linewidth outputs could be obtained over a wide (24nm) tuning range. Since the tuning elements had low insertion losses, the tunability of the output was obtained without sacrificing output pulse energy.

Davidson, F.; Hohman, J.

1985-01-01

90

Investigation of picosecond chlorophyll dye lasers  

NASA Astrophysics Data System (ADS)

The experimental setup of a red psec pulse output from an ultrashort-cavity dye laser pumped by the third harmonic from a colliding-pulse mode-locked Nd:YAG laser is reported, and experimental results are presented. The dependence of the output laser wavelength of chl a and b in different aggregations in solutions on the dye concentration is studied. In an ethanol solution of chl a with a concentration of 2 mM and for a laser cavity less than 36 microns long, a single mode-tunable psec pulse train was obtained. The divergence angle of the laser beam was about 60 mrad.

Liu, Yixian; Wang, Yagang; Zhu, Wei; Li, Fuming; Yang, Shanyuan

1988-09-01

91

Dye laser tuner  

SciTech Connect

A laser of the kind in which the lasing medium is a free flowing dye stream incorporates a means of tuning the output wave length of the laser, this means being in the form of a wedged birefringent plate which is driven in a linear mode by a linear translator so that the thickness of the birefringent plate traversed by the intracavity beam of laser light may be varied.

Arthurs, E.G.; Purdie, A.F.

1980-11-11

92

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator were carried out before amplifier studies. The amplifier studies are postponed to the extended period after completing the parametric studies. In addition, the kinetic modeling of a solar-pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) a 10 W CW iodine laser pumped by a Vortek solar simulator; (2) kinetic modeling to predict the time to lasing threshold, lasing time, and energy output of solar-pumped iodine laser; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K. S.

1986-01-01

93

Chemical stabilization of laser dyes  

NASA Astrophysics Data System (ADS)

Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. This results in attenuation of dye laser output through interference of stimulated emission. The roles of singlet oxygen and excitation intensity on dye degradation were explored. Singlet oxygen is formed but its reactions with the dye do not appear to be a major cause of dye laser output deterioration. High light intensity results in dye sensitized, solvent oligomerization to yield materials which interfere with dye stimulated emission. 1, 4-Diazabicyclo2,2,2octane (DABCO)inhibits this oligomerization.

Koch, Tad H.

1987-05-01

94

Treatment of Port-Wine Stains with Flash Lamp Pumped Pulsed Dye Laser on Indian Skin: A Six Year Study  

PubMed Central

Context: Port-wine stain (PWS) is one of the commonly encountered congenital cutaneous vascular lesions, with an equal sex distribution. Pulsed dye lasers (PDL) have revolutionized the treatment of both congential and acquired cutaneous vascular lesions. The pulsed dye lasers owing to its superior efficacy and safety profile have become the gold standard for the management of port-wine stains. Aims: To evaluate the efficacy and side effects of pulsed dye laser for the management of Port-wine stain on Indian skin. Materials and Methods: Seventy five patients of Fitzpatrick skin types IV&V with PWS underwent multiple treatments with PDL (V beam-Candela) over a period of six years at monthly intervals. Laser parameters were wavelength 595nm, spot sizes 7-10mm, fluence 6-12 j/cm2, pulse duration 0.45-10ms, along with cryogen cooling. Serial photographs were taken before and after every session. Clinical improvement scores of comparable photographs using a quartile grading (o=<20%, 1=21-40%, 2=41-60%, 3=61-80%, 4=>80%) were judged independently by two dermatologists after the series of treatment. Minimum number of treatments was 6 and maximum 17. They were followed up at six monthly intervals to observe re darkening of PWS. Results: No patient showed total clearance.Grade3 improvement was observed in 70 % of children and 50% of adults after 8-10 sessions. Children showed better and faster response than adults. Thirty percent of patients developed post inflammatory hyper pigmentation which resolved over a period of six to eight weeks. Two patients had superficial scarring due to stacking of pulses. None of the patients showed re darkening of PWS till now. Conclusion: Pulsed dye laser is an effective and safe treatment for port-wine stain in Indian skin.

Thajudheen, Chandroth Ponnambath; Jyothy, Kannangath; Priyadarshini, Arul

2014-01-01

95

Pyranoquinoline Laser Dyes.  

National Technical Information Service (NTIS)

The patent application pertains to 2-keto-6,7,8,9-tetrahydro-2H-pyrano(3,2-g)-quinoline and 2-keto-9-methyl-6,7,8,9-tetrahydro-2H-pyrano(3,2-g)-quinoline, compounds useful as laser dyes, which are prepared from 7-hydroxy-1,2,3,4-tetrahydroquinoline.

P. R. Hammond E. J. Schimitschek J. Trias

1976-01-01

96

Multiwavelength dye laser  

SciTech Connect

The problems of collimating, synchronizing and combining a plurality of laser beams to generate a composite beam are substantially reduced by the use of one or more lasers especially adapted to lase in two or more separate wavelengths. Specifically , a composite beam generating system comprises at least one multiwavelength laser for emitting a multiwavelength beam having at least two separated wavelength components, one or more additional lasers for generating respective additional beams, and means for combining the multiwavelength beam with one or more additional beams. In a preferred embodiment, a four-component multiwavelength composite beam is generated by polarization combination of the outputs of a pair of orthogonally polarized two-component multiwavelength lasers. The preferred embodiment of a multiwavelength laser is a liquid dye laser having, as one of the reflecting means defining the resonant cavity, an optical reflector having a reflectivity versus wavelength characteristic with a local minimum of reflectivity between two regions of substantially greater reflectivity.

Draggoo, V.; Mcallister, G.L.

1981-10-06

97

Photochemistry of coumarin laser dyes  

SciTech Connect

Coumarin laser dyes are widely used in dye lasers for the generation of tunable laser light in the blue-green spectral region. As in the case with most laser dyes, coumarin dyes undergo photochemical reactions that interfere with simulated emission and result in loss of laser power output. This thesis describes the photochemistry of coumarin laser dyes under both anaerobic and aerobic conditions and some attempts to extend the useful lifetime of several dyes in dye lasers. Irradiation of Coumarin 311, 7-dimethylamino-4-methyl-coumarin (15), in oxygen-free ethanol solution results in the inefficient dye destruction. Products formed absorb light at the lasing wavelength of the dye, interfere with stimulated emission, and decrease the power output of the dye laser. Addition of the sulfur free radical chain transfer agents ethanethiol and ethyl disulfide retard the rate of formation of photoproducts absorbing at the lasing wavelengths. Deuterium incorporation, from the irradiation of Coumarin 311 in the presence of ethanethiol-S-d and ethyl disulfide, indicates that photoproducts most likely result from the reactions of free radicals which are generated in a bimolecular reaction between excited Coumarin 311 and ground state Coumarin 311. Ethanethiol and ethyl disulfide are shown to decrease the rate of power loss from a Coumarin 1 (3) dye laser. The naturally occurring amino acid cysteine acts similarly.

von Trebra, R.J.

1984-01-01

98

Water soluble laser dyes  

DOEpatents

Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

Hammond, Peter R. (Livermore, CA); Feeman, James F. (Wyomissing, PA); Field, George F. (Santa Ana, CA)

1998-01-01

99

Partially Pumped Random Lasers  

NASA Astrophysics Data System (ADS)

Conventional lasers consist of two components: a gain material that is pumped in order to provide amplification of light and a cavity to provide feedback. Random lasers replace the traditional laser cavity with a random, multiple-scattering medium. This can give rise to complex lasing behavior, such as unpredictable multidirectional and multifrequency output. Controlling these systems has proved difficult and, until now, has consisted of material and structural manipulations. In random lasers, the most common pumping mechanism is an optical field, which can be applied uniformly or partially across the scattering medium. Partial pumping, referring to the restricted spatial extent of the pump applied to the gain material, is therefore quite ubiquitous in such systems. In contrast to conventional lasers, however, the impact of partial pumping can be significant in random lasers as a subset of the scattering medium is probed. In this review, we discuss state-of-the-art investigations of partially pumped random lasers. Numerical and experimental investigations of how even a simple spot profile of the pump can dramatically alter random laser output are presented. First, the simple case of partial pumping in strongly scattering systems where laser modes are spatially confined is described. Then the most common but more difficult case of weakly scattering random lasers is considered. Here, modes are spatially extended, forcing greater mode interaction and making the random laser output more difficult to predict. Finally, we review recent works that show how the pumping degree of freedom allows a general increase in control over random lasers.

Andreasen, Jonathan; Bachelard, Nicolas; Bhaktha, Shivakiran B. N.; Cao, Hui; Sebbah, Patrick; Vanneste, Christian

2014-02-01

100

Green pumped Alexandrite lasers  

NASA Astrophysics Data System (ADS)

Initial experiments with pulsed and CW pumping an alexandrite laser rod at 532 nm are presented. This pumping architecture holds promise for the production of scalable diode-pumped, tunable alexandrite laser systems operating in the near infrared (750 nm), and the ultraviolet (375 and 250 nm) spectral regions.

Kuper, Jerry W.; Brown, David C.

2005-04-01

101

Characteristics of LKI-501 Tunable Dye Laser with Dyes in Solid Matrix (Abstract Only).  

National Technical Information Service (NTIS)

An experimental study of the LKI-501 tunable dye laser was made with dyes in a solid matrix of polymethyl methacrylate and with pumping by second harmonic radiation from a YAG:Nd (3+) laser in pulses of 11 ns duration at a repetition rate of 25 Hz. The ch...

A. I. Zhiltsov A. G. Klimashina V. Y. Mnuskin V. G. Nikiforov A. N. Tokareva

1987-01-01

102

Active-Passively Mode-Locked Dye Laser for Diagnosis of Laser-Produced Plasmas.  

National Technical Information Service (NTIS)

In this report an active-passively mode-locked, flashlamp-pumped dye laser for diagnosis of laser-produced plasmas is described. This dye laser system used as a pulsed light source for high-speed photography of laser-target experiments was synchronized to...

Y. L. Teng R. Fedosejevs R. Sigel

1981-01-01

103

Diode pumped alkali lasers  

Microsoft Academic Search

Diode pumped alkali lasers attract growing attention during the past several years because they have demonstrated potential to compete and, possibly, replace the best existing high power laser systems. In spite of the fact that an optically pumped alkali (potassium) vapor laser was first proposed by A.L. Schawlow and C.H. Townes in 1958, the intensive research and development of alkali

B. V. Zhdanov; R. J. Knize

2011-01-01

104

Statistical properties of pulsed dye laser radiation  

NASA Astrophysics Data System (ADS)

Single-shot spectral measurements of the radiation of an excimer-laser-pumped dye laser were performed with a high-resolution multichannel recording system in order to determine the influence of mode fluctuations and spectral instabilities of the cavity on an average laser linewidth. It is shown for a 3-15X10 -3nm linewidth, which is typical of commercial lasers in multimode lasing regime, that the standard deviation of the laser linewidth makes up 15 percent of the average amount. The conditions were determined under which the contribution of spectral instabilities of the cavity transmission band becomes essential.

Berik, E.; Davidenko, V.

1988-06-01

105

Variables affecting clinical response to treatment of facial port-wine stains by flash lamp-pumped pulsed dye laser: the importance of looking beyond the skin.  

PubMed

The response of port-wine stains (PWS) to conventional laser treatment in adults is difficult to predict. To assess the influence of local or systemic hemodynamic variables on the clearance of PWS by using flash lamp-pumped pulsed (FLPP) dye laser. All consecutive patients ages 18 years or older undergoing laser treatment for a facial PWS were eligible. Laser sessions were scheduled every 8 weeks. All patients were evaluated based on a standard scale with four evaluation categories, from no or minimal improvement to total or almost total clearance. Clearance was achieved by 50.1 % (95 % confidence interval 35.6-64.7) of patients after a maximum of 15 treatment sessions. In multivariate analysis, increased age, a newly described Type III capillaroscopic pattern, and presence of lesions in dermatome V2 were all associated with a reduced clinical response to treatment. In a model restricted to demographic pattern and patient characteristics, arterial hypertension was also associated with a lower clinical response. A strong association was found between arterial hypertension and the Type III capillaroscopic pattern. Age, arterial hypertension, capillaroscopic pattern, and body location should be considered when planning laser treatment of PWS. PMID:24487956

Bencini, Pier Luca; Cazzaniga, Simone; Galimberti, Michela Gianna; Zane, Cristina; Naldi, Luigi

2014-07-01

106

Optofluidic Distributed Feedback Dye Lasers  

Microsoft Academic Search

We review our recent work on poly(dimethylsiloxane) (PDMS)-based optofluidic dye lasers using a guided wave distributed feedback (DFB) cavity. We show experimental results of single-mode operation, an integrated laser array, multiple color dye lasing, mechanical and fluidic tuning, and monolithic integration with microfluidic circuits. Potential applications and future directions are discussed

Zhenyu Li; Demetri Psaltis

2007-01-01

107

Study of a 1-watt repetitive dye laser.  

PubMed

A repetitive flashtube pumped dye laser (pulse rate up to 30 Hz) is described. The untuned laser output average power with rhodamine 6G is 1 W. When tuned by a Perot-Fabry etalon, 0.36 W is obtained in a bandwidth of 3 A. Output power is given for several dyes emitting between 440 nm and 680 nm. The behavior of flashtubes and dye solutions after long use is discussed. PMID:20125242

Loth, C; Meyer, Y H

1973-01-01

108

SU8 BASED SOLID STATE DYE LASERS FOR LAB-ON-A-CHIP MICROSYSTEMS  

Microsoft Academic Search

We present a new type of optically pumped solid polymer dye lasers, which can easily be integrated with polymer based microsystems. The widely used photoresist SU-8 has been functionalized with optical gain, by doping it with Rhodamine 6G laser dye. The laterally emitting lasers can be fabricated on any suitable substrate in a single photo lithographic step on the dye

S. Kragh; S. Balslev; A. Kristensen

109

Bichromatic emission in a ring dye laser  

NASA Technical Reports Server (NTRS)

An experimental study of a high-Q Rhodamine 6G ring dye laser has been performed, and bichromatic emission (BE) with wavelength spacings as large as 110 A when the laser operated bidirectionally has been measured. The BE vanished at all excitations when the laser was forced into unidirectional operation using a Faraday isolator. However, when a weak reflected beam was allowed to make a single pass in the direction opposite to that allowed by the Faraday device, BE is recovered at the higher pump powers.

Lawandy, N. M.; Sohrab Afzal, R.; Rabinovich, W. S.

1987-01-01

110

Theory and Operation of High-Power CW and Long-Pulse Dye Lasers.  

National Technical Information Service (NTIS)

A complete theoretical model for CW and long-pulse dye lasers is developed. The effects of excited singlet-state absorption of pump and laser light and triplet absorption of pump and laser light are included. Expressions are derived for gain, actual dye t...

O. Teschke A. Dienes J. R. Whinnery

1975-01-01

111

Analysis of dye degradation effects on output energy of the pulsed organic dye laser. Master's thesis  

SciTech Connect

The dominant excitation and relaxation mechanisms found in dye molecules are discussed and then incorporated into a model for the xanthene dye laser. Rate equations for this model are presented which include terms that account for excited state singlet absorption and triplet absorption. The system of rate equations are solved using the steady-rate approximation to derive equations for the threshold pump power and output power of the laser. The output power and threshold pump power equations are modified to include variables that allow the following effects of dye degradation to be examined: dye concentration reduction, reaction product absorption of pump radiation, reaction product absorption of lasing radiation, and singlet quenching by the reaction products. Theoretical values based on available experimental data are derived for these variables. A computer program is used to integrate the output power of the laser over the duration of a flashlamp pulse to compute the pulse energy.

Bridging, A.J.

1980-12-01

112

Photoacoustic testing of gain regions in dye laser amplifiers  

Microsoft Academic Search

Summary form only given. Measurement of the gain regions and characterization of a one-stage Rhodamine 6G pulsed dye laser were performed using amplitude changes in the acoustic signals generated in an amplifier media by a pulsed-pump laser, when the oscillator laser beam is blocked or not.

G. Ramos-Ortiz; M. Villagran-Muniz; H. F. Ranea-Sandoval

1996-01-01

113

Fusion reactor pumped laser  

DOEpatents

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

Jassby, Daniel L. (Princeton, NJ)

1988-01-01

114

Diode pumped alkali lasers  

NASA Astrophysics Data System (ADS)

Diode pumped alkali lasers attract growing attention during the past several years because they have demonstrated potential to compete and, possibly, replace the best existing high power laser systems. In spite of the fact that an optically pumped alkali (potassium) vapor laser was first proposed by A.L. Schawlow and C.H. Townes in 1958, the intensive research and development of alkali vapor started only in 2003, when really efficient lasing in Rb and Cs vapors was demonstrated. The interest to this research was stimulated by the possibility of using efficient diode lasers for optical pumping of the alkali gain medium that promises high overall efficiency of the device. A variety of experiments on alkali lasers, including the demonstration of efficient Rb, Cs and K vapor lasers, power scaling experiments with multiple diode laser pumping sources and experiments on diode pumped alkali vapor amplifiers were performed during the past several years. In this paper we present a review of the most important achievements in high power alkali lasers research and development, discuss some problems existing in this field and future perspectives in DPAL development.

Zhdanov, B. V.; Knize, R. J.

2011-10-01

115

Picosecond distributed feedback dye lasers  

SciTech Connect

The distributed feedback dye laser is a source of single picosecond pulses tunable in a very wide wavelength range. Operational principles, experimental arrangements, and recent applications are reviewed in this paper.

Bor, Z.; Muller, A.

1986-08-01

116

A tunable dual frequency dye laser - dual frequency oscillator design  

NASA Technical Reports Server (NTRS)

The pulsed dye laser offers a tunable oscillator, followed by three amplifiers. It is pumped by a dual frequency Nd:YAG laser. Tuning and spectral width are controlled by a holographic network connected to a high power telescope. The modified two wavelength dye laser allows for absorption lidar techniques for remote sensing of the atmosphere. Line switching is achieved by electrooptical commutation. A feasibility experiment was performed with the original oscillator. A model was then built, and tested with different dyes. After a few modifications were made to improve the conversion efficiency, this oscillator was inserted in the laser to check whether the amplifier stages were correctly adjusted.

Abury, Y.

1983-01-01

117

Generation of ultrashort dye laser pulses by transient oscillations and its applications  

NASA Astrophysics Data System (ADS)

By applying the Controlled Transient Oscillation (CTO) twice in a N2-laser-pumped dye laser system, a compact 10 ps cascade pumped dye laser was built. System performance was examined both in time and in frequency. A simple theoretical model is used to calculate the output pulse duration and power. A N2-laser side-pumped dye laser was then evaluated to improve the spatial fluctuation of the cascade pumped dye laser. A detailed study has also shown that CTO can be used to generate shorter pulses from such an oscillator. A modified cascade pumped dye laser was built and a narrower output pulse duration was measured. Higher power was achieved with a 3-stage dye amplifier chain pumped by the second harmonic of a Q-switched Nd:YAG dye amplifier chain pumped by the Q-switched Nd:YAG laser output. Two different experiments were performed with pulses from the amplified output of the modified cascade pumped CTO dye laser system. With 1.5 mJ at 566.5 nm, a laser induced plasma shutter was induced in air. Truncation speed of such a plasma shutter was further compared with results from 632.8 and 532 nm. Computer simulation appeared to be very close to the experimental results. Possibility of generating ultrashort visible laser pulses was also discussed.

Hsu, Jon Shaochung

118

Single mode pulsed dye laser oscillator  

DOEpatents

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability. 6 figs.

Hackel, R.P.

1992-11-24

119

Thermally induced refractive index gradients in a dye-laser cell  

NASA Astrophysics Data System (ADS)

The program GABI calculates refractive index gradients generated in a dye solution, flowing in a planar cell, and pumped by a repetitively pulsed copper vapor laser beam. The calculation results serve for design evaluation and selection of optimal pump geometry, dye solvent and dye solution flow velocity.

Burshtein, Z.; Levron, D.; Bialolenker, G.

1988-11-01

120

Diode pumped fiber laser  

Microsoft Academic Search

The objective of this program was the study and exploratory development of a miniature solid state laser source as a potential signal source in a variety of fiber optic sensors and systems. The specific source to be studied was composed of a single-crystal Neodymium-YAG optical fiber end-pumped with a single semiconductor laser diode.

M. J. F. Digonnet; H. J. Shaw

1983-01-01

121

Pumped up Lasers  

NASA Technical Reports Server (NTRS)

Cutting Edge Optronics released the first of potentially three products to result from an SBIR contract with Goddard Space Flight Center. The first commercial result is the WhisperMiniSlab, a diode pump for high performance laser systems. The slab uses a zig-zag path through the laser crystal which eliminates the need for thermal lensing. The result is smaller lasers with better beam quality for use in medical and industrial applications.

2000-01-01

122

Progress in solid state dye laser development  

SciTech Connect

A triaxial flashlamp (15 cm) was used to optically pump laser rods prepared from an acrylate based copolymer (0.95 cm O.D. {times} 10.0 cm L.). The performance of 13 laser dyes incorporated into this polymeric solid host is reported. The best lasing performance was obtained with sulforhodamine-B, with a calculated slope efficiency of 0.52% and a maximum single pulse output energy of 580 mJ. A commercially available fluorescent polymeric material was also evaluated. 12 refs., 2 figs.

Hermes, R.E.

1990-01-01

123

Multi-Wavelength Dye Laser System.  

National Technical Information Service (NTIS)

A four-wavelength dye laser system consisted of four dye lasers is developed. Its laser parameters and time characteristic after mixing four beams have been measured. The factors which have an effect on efficient dye laser power are discussed briefly. The...

T. Xingli S. G. Cheng

1995-01-01

124

Cladding-pumped fiber laser  

Microsoft Academic Search

Laser emission at 1.06 ?m, pump light absorption, laser threshold, slope efficiency, and alignment tolerance as a function of the fiber length have been measured for a cladding-pumped double-clad Nd:glass fiber laser. The fiber laser was pumped with a laser diode emitting at 810 nm. It produced an output power of 15.9 mW at an absorbed pump power of 55.1

T. Weber; W. Luthy; H. P. Weber; V. Neuman; H. Berthou; G. Kotrotsios; J. P. Dan; H. E. Hintermann

1995-01-01

125

ARTICLES: Investigation of dye lasers excited by high-power KrF laser radiation  

NASA Astrophysics Data System (ADS)

An investigation was made of the lasing characteristics of ethanol solutions of the dyes rhodamine 6G (R6G), coumarin 47 (C47), p-terphenyl (PTP), and POPOP pumped by high-power KrF laser radiation (? = 248 nm) pulses of up to 10 J energy and 80 nsec duration. A laser output energy of 1.1 J at an efficiency of 14% was obtained from the R6G and C47 solutions. The optical strength of the R6G and C 47 solutions at the pump radiation wavelength was determined. The construction of dye lasers pumped by high-power excimer laser radiation was considered.

Klementov, A. D.; Morozov, Nikolai V.; Sergeev, P. B.

1984-07-01

126

BRIEF COMMUNICATIONS: Excitation of dye solutions and their mixtures by copper vapor laser radiation  

Microsoft Academic Search

Laser action is reported from ethanol solutions of uranin, rhodamine 6G, rhodamine B, cresyl violet, and their mixtures pumped by copper vapor laser radiation. The energy and spectral characteristics of the dye lasers are presented. The characteristics of excitation of individual dyes by two-frequency copper laser radiation are noted.

L. V. Masarnovskii; A. N. Soldatov; V. B. Sukhanov

1979-01-01

127

Energy transfer distributed feedback dye laser using Rhodamine B-Acid blue 7 dye mixture.  

PubMed

The characteristics of energy transfer distributed feedback dye laser (ETDFDL) are studied both theoretically and experimentally in a mixture of Rhodamine B and Acid blue 7 dyes pumped by 532 nm Nd:YAG laser. The behaviour of donor and acceptor DFDL, the dependence of their pulse width and output power on pump power and donor-acceptor concentrations are studied. Experimentally, the tunability is achieved over the spectral range 565-680 nm using a prism dye cell arrangement. The output energy of DFDL is measured at the emission peaks of donor and acceptor for different pump powers and donor-acceptor concentrations. The output pulse of DFDL is found to be as narrow as 40-ps duration, which is nearly 100-fold shorter than the pump pulse. The pulse linewidth is of the order of 0.1 A. PMID:12695029

Ahamed, M Basheer; Palanisamy, P K

2003-03-01

128

Laser diode pumped fiber lasers with pump cavity  

Microsoft Academic Search

A fiber laser is described comprising: a laser optical fiber comprising a single mode fiber core of laser material and a multi-mode fiber surrounding the single mode fiber core and forming a pump cavity around the single mode core; a high power coherent laser diode source operatively associated with the laser optical fiber to provide coherent pumping radiation into the

Kafka

1989-01-01

129

On the design of pulsed dye laser amplifiers  

SciTech Connect

The authors apply a formula for the small signal gain of a dye laser amplifier (obtained and verified in a previous work) to the case of a transverse pumped R6G amplifier. They trace a set of curves as a function of dimensionless parameters which give the gain for any combination of the parameters characterizing the amplifier (dye concentration, active length, etc.) The curves can be applied to design dye laser amplifiers for ultrashort pulses, both with saturated or unsaturated gain. They give numerical examples of the use of those curves that suggest that the new designs would require much lower pumping energies than the previous ones. Similar sets of curves can be easily obtained for other dyes or pumping configurations.

Hnilo, A.A.; Martinez, O.E.

1987-05-01

130

The time-resolved spectrum of a pulsed dye laser  

Microsoft Academic Search

The spectral evolution in a xenon ion-pumped open dye stream laser was measured and analysed in terms of a theoretical spectro-temporal relation previously derived. Sweep occurs in a 200 ns time scale and simultaneous oscillations of several wavelengths can be achieved by varying laser cavity parameters. Experiments were completely reproduced by assuming that the phenomena can be ascribed to the

J. O. Tocho; H. F. Ranea-Sandoval; R. Duchowicz; M. Garavaglia

1984-01-01

131

Fusion reactor pumped laser  

DOEpatents

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

Jassby, D.L.

1987-09-04

132

Side-pumped fiber laser  

Microsoft Academic Search

A neodymium-doped side-pumped double-clad fiber laser operating at 1.06 µm is described. We report here, what is, to our knowledge, the first exclusively repetitive side-pumping scheme with two monomode laser diodes. Side-pumping has been realized by prism-fiber couplers. A pump-light-loss analysis at the pump positions has been performed. An output power of 13.5 mW is obtained with both diode lasers.

Th. Weber; W. Lüthy; H. P. Weber

1996-01-01

133

Nuclear pumped laser modeling  

Microsoft Academic Search

A model for an indirectly nuclear pumped laser experiment was developed. The apparatus consists of the usual cylindrical neutron moderator enclosing a gas filled quartz cell. The quartz cell in this case has two concentric compartments; the larger output compartment is filled with He-3 and fluorescent gases which are coupled radiatively to the inner compartment which is filled with a

J. W. Wilson; A. Shapiro

1979-01-01

134

A Pumped Atom Laser  

Microsoft Academic Search

We have experimentally demonstrated simultaneous pumping and out-coupling of an atom laser via Bose enhanced (by the condensate) spontaneous photon emission. Source atoms in the |F = 2, MF = 0> hyperfine state of ^87Rb are coupled by a light field to the |F ' = 1, MF = 0> excited state and are then stimulated to emit a photon

John Close; Nick Robins; Cristina Figl; Matthew Jeppesen; Graham Dennis

2008-01-01

135

Nuclear pumped laser II  

NASA Technical Reports Server (NTRS)

The first direct nuclear pumped laser using the He-2-(n,p) H-3 reaction is reported. Lasing took place on the 1.79 microns Ar I transition in a mixture of He-3-Ar at approximately 600 Torr total pressure. It was found that the electrically pulsed afterglow He-Ar laser had the same concentration profile as the nuclear pumped laser. As a result, nuclear lasing was also achieved in He-3-Xe (2.027 micron) and He-3-Kr (2.52 micron). Scaling of laser output with both thermal flux and total pressure as well as minority concentration has been completed. A peak output (He-3-Ar) of 3.7 watts has been achieved at a total pressure of 4 atm. Direct nuclear pumping of He-3-Ne has also been achieved. Nuclear pumping of a He-3-NF3 mixture was attempted, lasing in FI at approximately 7000 A, without success, although the potential lasing transitions appeared in spontaneous emission. Both NF3 and 238UF6 appear to quench spontaneous emission when they constitute more than 1% of the gas mixture.

Deyoung, R. J.; Lee, J. H.; Pinkston, W. T.

1977-01-01

136

Analysis of a dye-laser model including quantum noise  

SciTech Connect

An analytical study of a dye-laser model which includes quantum white noise and nonwhite pump fluctuations is presented. The extension of an earlier approximation to include quantum noise gives a unified picture of the statistical properties of the laser light for negative pump parameters. These include intensity fluctuations and discontinuous changes of the most probable intensity. An alternative approximation (obtained within the same scheme) is discussed for situations above threshold.

Aguado, M.; San Miguel, M.

1988-01-15

137

Influence of surfactants on a nonflowing dye laser  

NASA Astrophysics Data System (ADS)

The effect of surfactants on the performance of pulsed, laser-pumped, flowing dye lasers has been reported. The use of surfactants in a nonflowing dye cell permits remarkably improved performance in a laser that is much simpler and more compact. The characteristics of such a system are reported here. Solutions of the laser dye rhodamine 590 perchlorate in various solvents were studied. Up to 300-percent improvement in conversion efficiency was observed for solutions with surfactants. Operation of the laser with the ethylene glycol/sodium dodecyl sulfate solution demonstrated a consistent output of around 8.0 mJ at a repetition rate of 5 Hz. Preliminary results on the laser bandwidth, pulse width, energy stability, and conversion efficiency will be presented.

Moran, M. B.; Marrs, C. D.

1988-05-01

138

Nuclear pumped laser modeling  

NASA Technical Reports Server (NTRS)

A model for an indirectly nuclear pumped laser experiment was developed. The apparatus consists of the usual cylindrical neutron moderator enclosing a gas filled quartz cell. The quartz cell in this case has two concentric compartments; the larger output compartment is filled with He-3 and fluorescent gases which are coupled radiatively to the inner compartment which is filled with a lasing gas for efficient optical pumping. The fluorescent gas in this study was a mixture of Ar, Kr and F2. Perfluoroalkyliodide was chosen as the lasant material of the inner compartment. The degree of photoabsorption in the lasant gas was calculated. The kinetic efficiencies of various gas combinations in the outer fluorescence tube were then evaluated in order to maximize the fluorescence output in the iodine pump band.

Wilson, J. W.; Shapiro, A.

1979-01-01

139

Laser dye toxicity, hazards, and recommended controls  

SciTech Connect

Laser dyes are complex fluorescent organic compounds which, when in solution with organic solvents, form a lasing medium. The wavelength of a dye laser's output beam can vary with different dyes, concentrations, and solvents, giving it a tunable feature capable of emitting ultraviolet, visible, or infrared radiation. Toxicity information on the approximately 100 commercially available laser dyes is very scarce. Limited animal experimentation has been performed with only a few dyes. This paper summarizes what is known about laser dye toxicity, and offers recommendations for controlling dye hazards. The laser dyes investigated have been categorized according to their central chemical structures. These include the xanthenes (rhodamines and fluoresceins), polymethines (cyanines and carbocyanines), coumarins, and stilbenes. A few other miscellaneous dyes that do not fall into one of these categories have also been investigated. Prepared laser dye solutions usually contain very small quantities of dye--typical dye concentrations are 10/sup -2/ to 10/sup -5/ molar. For this reason, the solvent in which the dye is dissolved plays an important role when defining potential hazards. Practically all the solvents used are flammable and toxic by inhalation and skin absorption, and therefore must be controlled properly.

Mosovsky, J.A.

1983-05-06

140

Solar Pumped Laser Microthruster  

SciTech Connect

The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

Rubenchik, A. M.; Beach, R.; Dawson, J.; Siders, C. W. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore CA 94550 (United States)

2010-10-08

141

Diode pumped solid-state laser oscillators for spectroscopic applications  

NASA Technical Reports Server (NTRS)

The rapid improvement in diode laser pump sources has led to the recent progress in diode laser pumped solid state lasers. To date, electrical efficiencies of greater than 10 percent were demonstrated. As diode laser costs decrease with increased production volume, diode laser and diode laser array pumped solid state lasers will replace the traditional flashlamp pumped Nd:YAG laser sources. The use of laser diode array pumping of slab geometry lasers will allow efficient, high peak and average power solid state laser sources to be developed. Perhaps the greatest impact of diode laser pumped solid state lasers will be in spectroscopic applications of miniature, monolithic devices. Single-stripe diode-pumped operation of a continuous-wave 946 nm Nd:YAG laser with less than 10 m/w threshold was demonstrated. A slope efficiency of 16 percent near threshold was shown with a projected slope efficiency well above a threshold of 34 percent based on results under Rhodamine 6G dye-laser pumping. Nonlinear crystals for second-harmonic generation of this source were evaluated. The KNbO3 and periodically poled LiNbO3 appear to be the most promising.

Byer, R. L.; Basu, S.; Fan, T. Y.; Kozlovsky, W. J.; Nabors, C. D.; Nilsson, A.; Huber, G.

1987-01-01

142

Photothermal Characterization and Stability Analysis of Polymeric Dye Lasers  

Microsoft Academic Search

The millisecond heat dissipation of pump energy in polymeric, solid-state dye lasers has been studied with photothermal deflection spectroscopy (PTDS) to determine the contribution of that process to photodegradation of the active material. The samples were solutions of Rhodamine 6G in 2-hydroxyethyl methacrylate copolymerized with various amounts of methyl methacrylate or ethylene glycol dimethylacrylate to change the microstructure properties of

Ricardo Duchowicz; Lucía B. Scaffardi; Angel Costela; Inmaculada García-Moreno; Roberto Sastre; A. Ulises Acuña

2000-01-01

143

Two-photon pumped lasing dyes and their sol-gel glass/polymer composites  

NASA Astrophysics Data System (ADS)

A newly synthesized laser dye, trans-4-[P-(N-ethyl-N-hydroxyethylamino)styryl]- N-methylpyridinium tetraphenylborate (dye I), has high thermal- and photo-stability as well as strong two-photon-induced upconversion emission. Utilizing dye I doped bulk polymer rods, two-photo pumped frequency unconverted cavity lacing has been accomplished using a Q- switched Nd:YAG laser as the pump source. The upconversion lacing efficiency was 3.5%, and the cavity lacing lifetime, in terms of pulse numbers, was more than 4 by 104 pulses at 2 Hz repetition rate. By impregnating these dyes into a silica-gel:polymethylmethacrylate (PMMA) and Vycor-PMMA composite glasses, two-photon cavity lacing properties have also been studied.

Zhao, Chanfeng; He, Guang S.; Bhawalkar, Jayant D.; Park, Chi-Kyun; Prasad, Paras N.

1996-03-01

144

Polarization properties of dye-based random lasers  

NASA Astrophysics Data System (ADS)

We present the first systematic study on the emission polarization of coherent random lasing (RL). Employing a single-shot spectro-polarimeter the complete polarization state and the degree of polarization could be recovered for individual RL modes. It turned out that the polarization of RL modes is strongly dependent on the pump polarization, which can be explained with the dipolar nature of the dye molecules. Furthermore, by using a highly viscous solvent for the laser-dye and a linear pump polarization, it was possible to force all random-lasing modes into just the same linear polarization.

Knitter, Sebastian; Kues, Michael; Fallnich, Carsten

2013-03-01

145

Optical Pumps for Erbium Lasers.  

National Technical Information Service (NTIS)

The overall objective is to produce more efficient pulsed optical pumps for erbium lasers. Both xenon and alkali-metal vapor lamps are being studied. Laser materials both glass and YAG were selected and their absorption and excitation spectra determined. ...

L. Noble

1971-01-01

146

A Model of the Para-Terphenyl Dye Laser (Un Modele du Laser a Colorant Para-Terphenyl).  

National Technical Information Service (NTIS)

A theoretical model for a Para-Terphenyl dye laser pumped by an excimer laser has been developed. A new set of reaction-rate coefficients for Para-Terphenyl has been established. The problem of spontaneous emission in a dye has been solved analytically. T...

G. Fournier

1981-01-01

147

Triplet-extinction coefficients of some laser dyes. 1  

SciTech Connect

For flashlamp-pumped dye lasers, the negative effect of triplet-state losses on laser action efficiency is well known. Oscilloscope traces of laser pulses showed that laser action diminishes much sooner than the flashlamp excitation pulse. This effect was attributed to the buildup of triplet-state dye molecules during the excitation from the flashlamp pulse. Triplet-extinction coefficients epsilon(T) were measured over the laser-action spectral region of Rhodamine 6G; Rhodamine B; Rhodamine 110; Fluorol-7GA; Coumarin 540A; Coumarin 522; Coumarin 1; Coumarin 120; 4,4'-diphenyl stilbene; and 2,7-bis(4-methoxy-phenyl)-9,9-dipropylfluorene. The different lines from an argon-ion cw laser were employed for excitation. McClure's method was used to obtain the triplet extinction coefficients Epsilon(T). The method requires the measurement of triplet optical densities OD(T) as a function of different cw laser-excitation intensities (powers) I(ex). The importance of triplet-state losses on dye-laser efficiency is reviewed. The laser action properties of the laser dyes studied are briefly discussed as they relate to the measured epsilon=(T) values.

Pavlopoulos, T.G.; Golich, D.J.

1989-03-01

148

Efficiency and photostability of dye-doped solid-state lasers in different hosts  

Microsoft Academic Search

We survey the preparation procedures of pyrromethene (PM) and rhodamine dyes in silica, silica–zirconia, organically modified silicate (ormosil) and organic polymer matrices. Absorption and luminescence spectra, as well as decay time fluorescence of pyrromethene dyes are given. The solid-state laser samples were tested and their efficiencies and photostabilities at transversal pumping configuration, are given. Pyrromethene 597 had the best laser

Eli Yariv; Silke Schultheiss; Tsiala Saraidarov; Renata Reisfeld

2001-01-01

149

Raman-shifted dye laser for water vapor DIAL measurements  

Microsoft Academic Search

For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, we have generated narrowband (--0.03-cm⁻¹) laser radiation at 720- and 940-nm wavelengths by stimulated Raman scattering (SRS) using the narrow linewidth (--0.02-cm⁻¹) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20% and

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

1987-01-01

150

Raman-shifted dye laser for water vapor DIAL measurements  

Microsoft Academic Search

For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, narrowband (about 0.03\\/cm) laser radiation at 720- and 940-nm wavelengths was generated by stimulated Raman scattering (SRS), using the narrow linewidth (about 0.02\\/cm) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20

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

1987-01-01

151

Industrial hygiene concerns of laser dyes  

SciTech Connect

A variety of materials are used as dyes in laser systems, but often very little is known about each dye`s toxicity or mutagenicity/carcinogenicity. As a precaution, we have devised guidelines for handling these materials. We studied the literature to determine the hazards associated with various common laser dye solutions, taking into account the possible toxicity and mutagenicity/carcinogenicity of the solvent used. Working from this information, we have proposed three control classes -- limited, moderate, and strict -- for work performed with dyes in each class. This paper describes the considerations that went into preparing our guidelines and summarizes the precautions themselves.

Miller, G.

1990-11-01

152

Solid hosts for dye laser rods: Part 1, Criteria for choosing a host material  

SciTech Connect

This paper will attempt to provide selection criteria for polymers as hosts for flashlamp-pumped dye laser rods. The properties of transparent polymer materials are compared with typical inorganic crystal and glass hosts. 2 figs., 1 tab.

Erickson, G.F.

1987-01-01

153

Incident angle and polarization effects on the dye-doped cholesteric liquid crystal laser  

Microsoft Academic Search

Polarization effect of the pulsed pumping laser on the lasing characteristics of the dye-doped right-handed cholesteric liquid crystal (CLC) is studied at different incident angles. At a small incident angle (

Yuhua Huang; Ying Zhou; Qi Hong; Alexandra Rapaport; Michael Bass; Shin-Tson Wu

2006-01-01

154

Spectral broadening in a microdroplet dye laser  

NASA Astrophysics Data System (ADS)

We have observed broadening of the lasing spectrum of 60-?m diameter micrdroplet dye lasers. The spectral width of microdroplet dye lasers consisting of Rhodamine 6G or Pyrromethene 597 is essentially constant when water is used as a solvent but broaden by >30% at high input-laser intensities when ethanol is used as solvent. Spectral broadening is preceded by stimulated Raman scattering of ethanol in the microdroplets as the input-laser intensity increases.

Knospe, Anders G.; Kwok, Alfred S.

2004-05-01

155

Self-pulsing in a band model for dye lasers  

SciTech Connect

We study the self-pulsing stemming from the Risken-Nummedal-Graham-Haken-type multimode instability in the dye laser described by a band model. Analytical self-pulsing solutions for arbitrary pumping are presented. A distinct feature of the pulsation is that it corresponds to a very low pumping threshold and the required cavity-mode condition can be satisfied in a conventional ring dye laser. Another distinct feature is that the phase velocity of the pulsation may be smaller than the light velocity in the medium. The simple rule, which tells us whether the pulsation is a super- or subcritical one and was found for the two-level model in a previous paper, has been extended to the band model. The results are relevant for experimental investigation of the Risken-Nummedal-Graham-Haken-type multimode instabilities, which are intrinsic to multimode lasers, but have not yet been identified in experiment.

Fu, H.; Haken, H. (Institut fuer Theoretische Physik und Synergetik, Universitaet Stuttgart, 7000 Stuttgart (Federal Republic of Germany))

1990-10-01

156

Adaptive holographic pumping of thin-film organic lasers.  

PubMed

In this Letter, we use a reconfigurable hologram to dynamically control the position of incidence of the pump beam onto a liquid-crystal dye-based laser. The results show that there is an increase in the stability of the laser output with time and the average power when compared with the output of the same laser when it is optically excited using a static pump beam. This technique also provides additional functionality, such as wavelength tuning and spatial shaping of the pump beam, both of which are demonstrated here. PMID:24177125

Wood, Simon M; Mavrogordatos, Themistoklis K; Morris, Stephen M; Hands, Philip J W; Castles, Flynn; Gardiner, Damian J; Atkinson, Katie L; Coles, Harry J; Wilkinson, Timothy D

2013-11-01

157

Lasers pumped by ion beams  

NASA Astrophysics Data System (ADS)

Eleven rare-gas laser lines in the near-IR and a 1.45-micron line in carbon were pumped with continuous beams of 3.5-MeV He(+) and Ar(+) ions. Laser action was demonstrated in gas mixtures (He-Ar, He-Ne, Ar-Xe, He-Ar-Xe, He-O2-N2O, He-N2-N2O, and He-CO2), using the laser cell and the optical resonator described by Ulrich et al. (1983). The 12 IR laser lines observed in these experiments are closely related to nuclear-pumped lasers known from literature (e.g., a maximum output power of 170 mW was observed from He-Ar laser lines), and can be used to study the mechanisms of nuclear-pumped lasers and nuclear-induced plasmas.

Ulrich, A.; Hammer, J. W.; Biermayer, W.

1988-04-01

158

Microfluidic dye laser integration in a lab-on-a-chip device  

NASA Astrophysics Data System (ADS)

We report on an original design and fabrication of microfluidic dye laser integrated into a functional poly-dimethylsiloxane (PDMS) lab-on-a-chip system. Soft lithography has been used for the fabrication of the microfluidic channels allowing the liquid dye circulation. The laser cavity, formed by two cleaved optical fibers with end face metallization, is directly integrated into a microfluidic channel. The active dye molecules are optically pumped by a pulsed and frequency-doubled Nd:Yag laser at 532 nm wavelength. Finally, the output laser beam is extracted and coupled into the optical fiber. As a result, the characteristics of the laser output power as a function of pumping energy density is presented. We also show that the micro dye laser we fabricated can work steadily with an average output power up to 0.35 mW. The wavelength tunability is also demonstrated with the laser system.

Kou, Qingli; Yesilyurt, Ilker; Escalier, Guilhem; Galas, Jean Christophe; Coureau, Laurent; Chen, Yong

2004-12-01

159

Industrial hygiene concerns of laser dyes  

SciTech Connect

A variety of materials are used as dyes in laser systems, but often very little is known about each dye's toxicity or mutagenicity/carcinogenicity. As a precaution, we have devised guidelines for handling these materials. We studied the literature to determine the hazards associated with various common laser dye solutions, taking into account the possible toxicity and mutagenicity/carcinogenicity of the solvent used. Working from this information, we have proposed three control classes -- limited, moderate, and strict -- for work performed with dyes in each class. This paper describes the considerations that went into preparing our guidelines and summarizes the precautions themselves.

Miller, G.

1990-11-01

160

Multi-wavelength laser from dye-doped cholesteric polymer films.  

PubMed

A multi-wavelength laser is demonstrated using a dye-doped cholesteric polymer film whose reflection bandwidth is broadened with several oscillations. Due to the abrupt change of the density of state between oscillation peak and valley, each oscillation functions as a photonic band gap for generating a laser wavelength under the excitation of a pumping laser. As a result, a multiple wavelength laser is generated. Results indicate that the dye-doped cholesteric liquid crystal polymer film is a good candidate for fabricating broadband lasers such as white light lasers. Potential applications include experimental testing of laser materials, identification markers, information displays, and inertial confinement laser fusion. PMID:21197044

Huang, Yuhua; Wu, Shin-Tson

2010-12-20

161

Investigation of dye lasers excited by high-power KrF laser radiation  

NASA Astrophysics Data System (ADS)

An investigation was made of the lasing characteristics of ethanol solutions of the dyes rhodamine 6G (R6G), coumarin 47 (C47), p-terphenyl (PTP), and POPOP pumped by high-power 248-nm KrF-laser pulses of up to 10-J energy and 80-nsec duration. A laser output energy of 1.1 J at an efficiency of 14 percent was obtained from the R6G and C47 solutions. The optical strength of the R6G and C47 solutions at the pump-radiation wavelength was determined. The construction of dye lasers pumped by high-power excimer-lasers radiation was considered.

Klementov, A. D.; Morozov, N. V.; Sergeev, P. B.

1984-07-01

162

A new diolefinic laser dye: 2,5-bis-2-(2-naphthyl) vinyl pyrazine (B2NVP)  

Microsoft Academic Search

The title dye acts as a laser dye upon pumping with nitrogen laser (?ex=337.1). B2NVP in N,N-dimethylformamide (DMF) gives amplified spontaneous emission (ASE) with a maximum at about 470nm, but only low laser activity upon nitrogen laser pumping. The difference between ?E (emission cross-section) and ??E (from ASE calculated effective emission cross-section) is interpreted as S1–Sn absorption, the maximum of

Sadiq M. Al-Hazmy; A. S. Babaqi; E. Daltrozzo; M. Klink; J. Sauter; E. M. Ebeid

1999-01-01

163

Effect of pump efficiency on lasing in dye-doped chiral nematic liquid crystals  

NASA Astrophysics Data System (ADS)

The purpose of this study was to investigate the effect of varying the pump efficiency of dye-doped chiral nematic liquid crystal lasers, through the dependence on absorption efficiency. Two dyes from the rhodamine subset of the xanthene family (rhodamine B and rhodamine 6G) with similar chemical properties but different absorption and emission spectra have been compared for a fixed pumping wavelength (532nm). Each dye was dissolved in E49 (a commercial nematic mixture from Merck NB-C) and the resulting mixtures characterised in terms of their absorption and laser induced fluorescence spectra. A high twisting power chiral dopant (BDH1281, also from Merck NB-C) was used to induce 1-D photonic band gaps with the high and low energy edges corresponding to the fluorescence maximum for each dye. Laser action was induced in the resulting four mixtures and typical laser parameters such as slope efficiency and threshold energy were examined for each one. The results indicate that the mixtures doped with rhodamine 6G had an absolute absorption ~ 57% greater than those doped with rhodamine B. Rhodamine 6G-doped mixtures therefore had the highest pump efficiency and lased more than 6 times more efficiently then those doped with rhodamine B. We believe that the performance of rhodamine 6G is also influenced by its greater degree of alignment with the liquid crystal host and a possible input energy dependence of the quantum efficiency of the dyes (indicated by the fluorescence characteristics of the achiral dye-doped mixtures). Further experimentation is needed to determine exactly which parameters are responsible for the superior performance of rhodamine 6G in chiral nematic lasers.

Gillespie, Carrie; Morris, Stephen M.; Coles, Harry J.

2005-04-01

164

Flash-Pumped Titanium Laser.  

National Technical Information Service (NTIS)

A flashlamp pumped titanium sapphire laser has been operated with efficiencies approaching 1% using a fluorescent converter. Performance of specific fluorescent converters is described, and ways to further increase the efficiency at the titanium sapphire ...

L. Esterowitz P. Lacovara R. Allen

1989-01-01

165

Dye lasing arrangement including an optical assembly for altering the cross-section of its pumping beam and method  

DOEpatents

An optical assembly is disclosed herein along with a method of operation for use in a dye lasing arrangement, for example a dye laser oscillator or a dye amplifier, in which a continuous stream of dye is caused to flow through a given zone in a cooperating dye chamber while the zone is being illuminated by light from a pumping beam which is directed into the given zone. This in turn causes the dye therein to lase and thereby produce a new dye beam in the case of a dye laser oscillator or amplify a dye beam in the case of a dye amplifier. The optical assembly so disclosed is designed to alter the pump beam such that the beam enters the dye chamber with a different cross-sectional configuration, preferably one having a more uniform intensity profile, than its initially produced cross-sectional configuration. To this end, the assembly includes a network of optical components which first act on the beam while the latter retains its initially produced cross-sectional configuration for separating it into a plurality of predetermined segments and then recombines the separated components in a predetermined way which causes the recombined beam to have the different cross-sectional configuration.

O'Neil, Richard W. (Pleasanton, CA); Sweatt, William C. (Alburquerque, NM)

1992-01-01

166

Study of excitation transfer in flowing helium afterglow pumped with a tuneable dye laser. 2: Measurement of the rate coefficient for the rotational relaxation of He2(3p (3 Pi g))  

NASA Technical Reports Server (NTRS)

The rotational relaxation of the He2(3p(3pi g)) state is examined by optically pumping a flowing helium afterglow with a tuneable dye laser. The population of the J = 8 rotational state is enhanced by optically saturating the R sub 7 component of the transition connecting this state with the metastable He2(2s (3 Sigma u +)) molecular state. From the lifetime and yield of the Q sub 7 component, the rate coefficient for the rotational relaxation via the forbidden delta J = 1 channel is determined to be of the order of 2 x 10 to the minus 11th power cm3/sec. It is found that this represents about half of the total rate of rotational relaxation in this state.

Collins, C. B.; Johnson, B. W.

1972-01-01

167

Theoretical studies of solar pumped lasers  

NASA Technical Reports Server (NTRS)

One concept for collecting solar energy is to use large solar collectors and then use lasers as energy converters whose output beams act as transmission lines to deliver the energy to a destination. The efficiency of the process would be improved if the conversion could be done directly using solar pumped lasers, and the possibility of making such lasers is studied. There are many applications for such lasers, and these are examined. By including the applications first, the requirements for the lasers will be more evident. They are especially applicable to the Space program, and include cases where no other methods of delivering power seem possible. Using the lasers for conveying information and surveillance is also discussed. Many difficulties confront the designer of an efficient system for power conversion. These involve the nature of the solar spectrum, the method of absorbing the energy, the transfer of power into laser beams, and finally, the far field patterns of the beams. The requirements of the lasers are discussed. Specific laser configurations are discussed. The thrust is into gas laser systems, because for space applications, the laser could be large, and also the medium would be uniform and not subject to thermal stresses. Dye and solid lasers are treated briefly. For gas lasers, a chart of the various possibilities is shown, and the various families of gas lasers divided according to the mechanisms of absorbing solar radiation and of lasing. Several specific models are analyzed and evaluated. Overall conclusions for the program are summarized, and the performances of the lasers related to the requirements of various applications.

Harries, Wynford L.

1990-01-01

168

Water-Soluble Fluorescing and Laser Dyes.  

National Technical Information Service (NTIS)

This invention relates to water-soluble lasing dyes. When dyes are used in lasers, they are usually dissolved in organic solvents. One widely used solvent is ethanol. As a solvent, water offers advantages over organic compounds in that it is more readily ...

R. A. Henry

1978-01-01

169

New active media based on bifluorophormic compounds for dye lasers  

NASA Astrophysics Data System (ADS)

The photophysical properties (photostability, spectral-luminescent and generation properties) of eight new organic compounds have been studied, in which the molecular composition of two flurophores -- 1,3,5-triphenylpyrazoline and 2,5-diphenylzoxazole-1,3 (or 2,5- diphenyloxazole-1,3,4) -- were included. The effect of the structure of the investigated molecules and the polar properties of solvents on the spectral position of absorption and fluorescence bands was analyzed. The dyes have been found to have a fluorescence quantum efficiency (gamma) between 0.40 and 0.82 in these solvents. The dye laser performance using these dyes has also been investigated using the same solvents under nitrogen-laser pumping to compare them with the commercially available standard dye POPOP, which generates radiation in the violet spectrum region and allows the extension of the range of the active media used in liquid lasers in this spectrum region. A tuning range of nearly 60 nm was obtained in the blue region with efficiency up to 85% in comparison to the standard dye POPOP.

Neyra Bueno, O. L.; Gruzinskiy, V. V.; Seniuk, M. A.; Afanasiady, L. S.

1996-02-01

170

Diode pumped fiber laser  

Microsoft Academic Search

Work conducted in the area of single crystal fiber optical devices is described. Miniature Nd:YAG 1.32 micron lasers were fabricated using both free space (unguided) and single crystal fiber configurations. Bulk lasers with thresholds as low as 19 mw and near optimum slope efficiencies of 36% were demonstrated. Several guided fiber lasers were also successfully brought to oscillation. The best

C. Gaeta; M. Digonnet

1984-01-01

171

Transverse pumped laser amplifier architecture  

DOEpatents

An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

2013-07-09

172

Approximate analytic solutions for the optical pumping of fluorescent dyes  

NASA Technical Reports Server (NTRS)

A general technique for solving a system of rate equations describing the interaction of an electromagnetic field and a molecular system is presented. The method is used to obtain approximate time-dependent solutions for the upper-level population of fluorescent dyes in the presence of a pump field.

Lawandy, N. M.

1978-01-01

173

Approximate analytic solutions for the optical pumping of fluorescent dyes  

NASA Technical Reports Server (NTRS)

A general technique for solving a system of rate equations describing the interaction of an electromagnetic field and a molecular system is presented. The method is used to obtain approximate time-dependent solutions for the upper-level populations of fluorescent dyes in the presence of a pump field.

Lawandy, N. M.

1979-01-01

174

Cavity dumped operation of a CW pumped Q-switched and mode-locked YLF laser  

NASA Astrophysics Data System (ADS)

A CW pumped Nd3+:LiYF4 (Nd3+:YLF) laser is demonstrated in Q-switched, mode locked, and cavity dumped operation to provide stable pulse energies in excess of 2 mJ (30 MW peak power). In operation as a dye laser pump source (noncavity dumped operation), the shorter pulses and larger number of pump pulses in the Q-switched pulse envelope, relative to the analogous YAG system, enable a factor of about 3 reduction in dye pulse durations. The system represents a simple source for dye pulses in the 10 ps range with MW peak powers.

Min, L.; Bao, Q.; Miller, R. J. Dwayne

1988-11-01

175

New laser materials for laser diode pumping  

NASA Technical Reports Server (NTRS)

The potential advantages of laser diode pumped solid state lasers are many with high overall efficiency being the most important. In order to realize these advantages, the solid state laser material needs to be optimized for diode laser pumping and for the particular application. In the case of the Nd laser, materials with a longer upper level radiative lifetime are desirable. This is because the laser diode is fundamentally a cw source, and to obtain high energy storage, a long integration time is necessary. Fluoride crystals are investigated as host materials for the Nd laser and also for IR laser transitions in other rare earths, such as the 2 micron Ho laser and the 3 micron Er laser. The approach is to investigate both known crystals, such as BaY2F8, as well as new crystals such as NaYF8. Emphasis is on the growth and spectroscopy of BaY2F8. These two efforts are parallel efforts. The growth effort is aimed at establishing conditions for obtaining large, high quality boules for laser samples. This requires numerous experimental growth runs; however, from these runs, samples suitable for spectroscopy become available.

Jenssen, H. P.

1990-01-01

176

Electron beam pumped semiconductor laser  

NASA Technical Reports Server (NTRS)

Electron-beam-pumped semiconductor ultra-violet optical sources (ESUVOSs) are disclosed that use ballistic electron pumped wide bandgap semiconductor materials. The sources may produce incoherent radiation and take the form of electron-beam-pumped light emitting triodes (ELETs). The sources may produce coherent radiation and take the form of electron-beam-pumped laser triodes (ELTs). The ELTs may take the form of electron-beam-pumped vertical cavity surface emitting lasers (EVCSEL) or edge emitting electron-beam-pumped lasers (EEELs). The semiconductor medium may take the form of an aluminum gallium nitride alloy that has a mole fraction of aluminum selected to give a desired emission wavelength, diamond, or diamond-like carbon (DLC). The sources may be produced from discrete components that are assembled after their individual formation or they may be produced using batch MEMS-type or semiconductor-type processing techniques to build them up in a whole or partial monolithic manner, or combination thereof.

Hug, William F. (Inventor); Reid, Ray D. (Inventor)

2009-01-01

177

Dye lasers: Design, operation, and performance. March 1975-October 1989 (Citations from the Searchable Physics Information Notices data base). Report for Mar 75-Oct 89  

SciTech Connect

This bibliography contains citations concerning the design, operation, and performance of dye lasers. Dye materials, pulse techniques, laser pumping systems, experimental applications, design of dye laser systems, and performance evaluations are considered. Modeling of dye laser operation is also discussed. Descriptions of system components and experimental variables, and their effects on laser output are included. References to other laser systems such as carbon dioxide lasers, x-ray lasers, and UV lasers are included in related bibliographies. (Contains 264 citations fully indexed and including a title list.)

Not Available

1989-11-01

178

Raman-shifted dye laser for water vapor DIAL measurements  

NASA Astrophysics Data System (ADS)

For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, narrowband (about 0.03/cm) laser radiation at 720- and 940-nm wavelengths was generated by stimulated Raman scattering (SRS), using the narrow linewidth (about 0.02/cm) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20 percent and 35 percent, when using a conventional and waveguide Raman cell, respectively. The linewidth of the first Stokes line at high cell pressures, and the inferred collisional broadening coefficients, agree well with those previously measured in spontaneous Raman scattering.

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

1987-05-01

179

Raman-shifted dye laser for water vapor DIAL measurements.  

PubMed

For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, we have generated narrowband (~0.03-cm(-1)) laser radiation at 720- and 940-nm wavelengths by stimulated Raman scattering (SRS) using the narrow linewidth (~0.02-cm(-1)) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20% and 35% when using a conventional and waveguide Raman cell, respectively. We measured the linewidth of the first Stokes line at high cell pressures and inferred collisional broadening coefficients that agree well with those previously measured in spontaneous Raman scattering. PMID:20454378

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

1987-05-01

180

Raman-shifted dye laser for water vapor DIAL measurements  

NASA Technical Reports Server (NTRS)

For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, narrowband (about 0.03/cm) laser radiation at 720- and 940-nm wavelengths was generated by stimulated Raman scattering (SRS), using the narrow linewidth (about 0.02/cm) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20 percent and 35 percent, when using a conventional and waveguide Raman cell, respectively. The linewidth of the first Stokes line at high cell pressures, and the inferred collisional broadening coefficients, agree well with those previously measured in spontaneous Raman scattering.

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

1987-01-01

181

Confinement of pyridinium hemicyanine dye within an anionic metal-organic framework for two-photon-pumped lasing  

NASA Astrophysics Data System (ADS)

Two-photon-pumped dye lasers are very important because of their applications in wavelength up-conversion, optical data storage, biological imaging and photodynamic therapy. Such lasers are very difficult to realize in the solid state because of the aggregation-caused quenching. Here we demonstrate a new two-photon-pumped micro-laser by encapsulating the cationic pyridinium hemicyanine dye into an anionic metal-organic framework (MOF). The resultant MOF?dye composite exhibits significant two-photon fluorescence because of the large absorption cross-section and the encapsulation-enhanced luminescent efficiency of the dye. Furthermore, the well-faceted MOF crystal serves as a natural Fabry-Perot resonance cavity, leading to lasing around 640?nm when pumped with a 1064-nm pulse laser. This strategy not only combines the crystalline benefit of MOFs and luminescent behaviour of organic dyes but also creates a new synergistic two-photon-pumped lasing functionality, opening a new avenue for the future creation of solid-state photonic materials and devices.

Yu, Jiancan; Cui, Yuanjing; Xu, Hui; Yang, Yu; Wang, Zhiyu; Chen, Banglin; Qian, Guodong

2013-10-01

182

Confinement of pyridinium hemicyanine dye within an anionic metal-organic framework for two-photon-pumped lasing.  

PubMed

Two-photon-pumped dye lasers are very important because of their applications in wavelength up-conversion, optical data storage, biological imaging and photodynamic therapy. Such lasers are very difficult to realize in the solid state because of the aggregation-caused quenching. Here we demonstrate a new two-photon-pumped micro-laser by encapsulating the cationic pyridinium hemicyanine dye into an anionic metal-organic framework (MOF). The resultant MOF [symbol: see text] dye composite exhibits significant two-photon fluorescence because of the large absorption cross-section and the encapsulation-enhanced luminescent efficiency of the dye. Furthermore, the well-faceted MOF crystal serves as a natural Fabry-Perot resonance cavity, leading to lasing around 640 nm when pumped with a 1064-nm pulse laser. This strategy not only combines the crystalline benefit of MOFs and luminescent behaviour of organic dyes but also creates a new synergistic two-photon-pumped lasing functionality, opening a new avenue for the future creation of solid-state photonic materials and devices. PMID:24173352

Yu, Jiancan; Cui, Yuanjing; Xu, Hui; Yang, Yu; Wang, Zhiyu; Chen, Banglin; Qian, Guodong

2013-01-01

183

Computer simulation of CPM dye lasers  

SciTech Connect

Quantative analysis of the laser pulses of various intracavity elements in a CPM dye laser is carried out in this study. The pulse formation is simulated with a computer, resulting in an asymmetric numerical solution for the pulse shape. The mechanisms of pulse formation are also discussed based on the results of computer simulation.

Wang Qingyue; Zhao Xingjun (Department of Precision Instruments, Tianjin University, Tianjin (CN))

1990-01-01

184

Dye laser remote sensing of marine plankton  

NASA Technical Reports Server (NTRS)

Dye laser, emitting four wavelengths sequentially in time, has been incorporated into helicopter-borne lidar flight package, for performing studies of laser-induced fluorescence of chlorophyll A in algae. Data obtained by multicolor lidar technique can provide water-resource management with rapid-access wide-area coverage of the impact of various environmental factors for any body of water.

Mumola, P. B.; Jarrett, O., Jr.; Brown, C. A., Jr.

1973-01-01

185

Volume-pumped nuclear lasers  

NASA Technical Reports Server (NTRS)

A summary is given to experimental results on volume-pumped nuclear lasers obtained at the Langley Research Center. The first volume-pumped nuclear laser was achieved in 1976 using the He-3(n, p)H-3 reaction. Since that time laser output has increased by more than a factor of 1000 (from mW to W). Lasing has been demonstrated in He-3-Ar (1.27 and 1.79 micron), He-3-Xe (2.027, 3.5, and 3.65 microns), He-3-Kr (2.19 and 2.52 microns), and He-3-Cl (1.587 micron). Pressures of the lasing mixture range from 300 torr to 4 atm with a peak power output of 26 W were achieved in a He-3-Ar mixture with a multiple-pass laser configuration.

Hohl, F.; Jalufka, N. W.; Williams, M. D.; Deyoung, R. J.

1979-01-01

186

Compact and highly efficient laser pump cavity  

DOEpatents

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, Jim J. (Dublin, CA); Bass, Isaac L. (Castro Valley, CA); Zapata, Luis E. (Livermore, CA)

1999-01-01

187

Efficient distributed feedback solid state dye laser with a dynamic grating  

Microsoft Academic Search

.   We present the first operation of a distributed feedback solid state dye laser with a dynamic, pump-induced grating. Broadly\\u000a tunable, narrow band operation in the region of 616 nm (604–649 nm) has been demonstrated with perylene red laser dye doped\\u000a in poly(methyl methacrylate) (PMMA), when pumped with a frequency doubled Nd:YAG laser. Conversion efficiencies of 20%, corresponding\\u000a to 35% optical-to-optical efficiency,

W. J. Wadsworth; I. T. McKinnie; A. D. Woolhouse; T. G. Haskell

1999-01-01

188

Diffusion driven optofluidic dye lasers encapsulated into polymer chips.  

PubMed

Lab-on-a-chip systems made of polymers are promising for the integration of active optical elements, enabling e.g. on-chip excitation of fluorescent markers or spectroscopy. In this work we present diffusion operation of tunable optofluidic dye lasers in a polymer foil. We demonstrate that these first order distributed feedback lasers can be operated for more than 90 min at a pulse repetition rate of 2 Hz without fluidic pumping. Ultra-high output pulse energies of more than 10 ?J and laser thresholds of 2 ?J are achieved for resonator lengths of 3 mm. By introducing comparatively large on-chip dye solution reservoirs, the required exchange of dye molecules is accomplished solely by diffusion. Polymer chips the size of a microscope cover slip (18 × 18 mm(2)) were fabricated in batches on a wafer using a commercially available polymer (TOPAS(®) Cyclic Olefin Copolymer). Thermal imprinting of micro- and nanoscale structures into 100 ?m foils simultaneously defines photonic resonators, liquid-core waveguides, and fluidic reservoirs. Subsequently, the fluidic structures are sealed with another 220 ?m foil by thermal bonding. Tunability of laser output wavelengths over a spectral range of 24 nm on a single chip is accomplished by varying the laser grating period in steps of 2 nm. Low-cost manufacturing suitable for mass production, wide laser tunability, ultra-high output pulse energies, and long operation times without external fluidic pumping make these on-chip lasers suitable for a wide range of lab-on-a-chip applications, e.g. on-chip spectroscopy, biosensing, excitation of fluorescent markers, or surface enhanced Raman spectroscopy (SERS). PMID:22820609

Wienhold, Tobias; Breithaupt, Felix; Vannahme, Christoph; Christiansen, Mads Brøkner; Dörfler, Willy; Kristensen, Anders; Mappes, Timo

2012-10-01

189

Dye laser amplifier including a dye cell contained within a support vessel  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell. 6 figs.

Davin, J.

1992-12-01

190

Dye laser amplifier including a dye cell contained within a support vessel  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell.

Davin, James (Gilroy, CA)

1992-01-01

191

A laser induced cavitation pump  

Microsoft Academic Search

We demonstrate and discuss a liquid pumping effect based on the interaction between periodically generated cavitation microbubbles and a millimeter diameter tube. The bubbles are generated by the heat of laser adsorption at the tip of an optical fiber immersed in liquid. When the bubbles are generated well away from the tube, a steady streaming flow with a relatively large

G. R. Wang; J. G. Santiago; M. G. Mungal; B. Young; S. Papademetriou

2004-01-01

192

Far-red polyurethane-host solid-state dye laser  

SciTech Connect

The output energy and emission spectrum of a solid-state dye laser using Oxazine 1 in polyurethane as the gain medium have been measured. Under microsecond pumping, efficient lasing has been obtained in the range 700-745 nm. The highest conversion efficiency and output energy achieved are 23% and 127 mJ, respectively. (lasers)

Nikolaev, S V; Pozhar, V V; Dzyubenko, M I [A.Ya. Usikov Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine, Khar'kov (Ukraine); Doroshenko, A O [Research Institute of Chemistry, V. N. Karazin Kharkiv National University, Kharkov (Ukraine)

2009-09-30

193

Spatially-hole-burned distributed feedback dye laser produced tunable single picosecond pulses  

NASA Astrophysics Data System (ADS)

A new type of distributed feedback dye laser is described in which the Bragg grating is formed by spatial hole-burning. With a simple excimer laser pumped arrangement, single high stability 6 ps pulses were generated. The pulses were nearly transformlimited and were 33 times shorter than the rise time of the pulse which created the Bragg grating.

Ráksi, F.

1988-09-01

194

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

NASA Technical Reports Server (NTRS)

Existing DIAL systems for water vapor measurements in the troposphere operate at wavelengths near 720 nm. The use of stronger water vapor absorption lines in the range 930 to 960 nm will significantly improve DIAL measurements in the upper troposphere and lower stratosphere where water vapor concentrations are low. The generation of light at 940 nm using a frequency doubled Nd:YAG pumped dye laser is inefficient due to the small absorption if infrared dyes at the pump wavelength. However, 940 nm generation utilizing stimulated Raman scattering of dye lasers is attractive because of a potentially high conversion efficiency plus the possibility of retaining the narrow linewidth available from some dye lasers. The Raman conversion efficiency and line broadening are presented for first Stokes operation at 720 and 940 nm using hydrogen and deuterium as the Raman media.

Grossmann, B. E.; Higdon, N. S.; Higdon, N. S.; Higdon, N. S.; Higdon, N. S.; Higdon, N. S.; Higdon, N. S.

1986-01-01

195

Fusion Pumped Laser.  

National Technical Information Service (NTIS)

The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic fi...

D. S. Pappas

1987-01-01

196

Pulsed dye laser therapy for pediatric warts.  

PubMed

Viral wart infections constitute one of the most common pediatric skin diseases, and various modalities have been used to manage them. Although pulsed dye laser therapy is known to be a safe and efficacious modality, the reported cure rates for this method have varied, and no studies have reported treatment of pediatric patients alone. This prospective, nonblinded, nonrandomized study was performed to evaluate the efficacy and safety of pulsed dye laser therapy for pediatric warts. We found that this method is safe, relatively effective, and worth considering as an additional therapeutic option for viral warts in children, although not as a first-line therapy. PMID:17461819

Park, Hyun Su; Kim, Jee Woong; Jang, Sang Jai; Choi, Jung Chul

2007-01-01

197

Laser dyes III: Concepts to increase the photostability of laser dyes  

NASA Astrophysics Data System (ADS)

Two approaches of increasing the photostability of the laser dye POPOP are reported. Desensibilisation against singlet oxygen was accomplished either by substitution with electron acceptor groups or by linking the dye molecule with a suitable quencher unit, e.g. tertiary amines. To test the efficiency of the modifications of the dye molecules the rate of their continuous UV-bleaching ( ? = 366 nm) was investigated.

Liphardt, Bodo; Liphardt, Bernd; Lüttke, W.

1983-11-01

198

CONTROL OF LASER RADIATION PARAMETERS: Phase-polarization control of the emission spectra of ring dye lasers  

NASA Astrophysics Data System (ADS)

A ring dye laser with a three-mirror resonator and phase-polarization control of the emission spectrum was constructed and investigated. A resonator mirror performed the function of a nonresonant rotator of the plane of polarization of the light wave. Such a system subjected to single-pulse laser pumping was capable of generating narrow-band radiation with a spectral width 2-4 pm and a high signal/noise ratio in a fairly wide range of pump energies.

Smirnov, A. Ya; Teplyashin, L. L.

1988-05-01

199

Fusion pumped laser  

DOEpatents

Apparatus is provided for generating energy in the form of laser radiation. A tokamak fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The tokamak design provides a temperature and a magnetic field which is effective to generate a neutron flux of at least 10.sup.15 neutrons/cm.sup.2.s. A conversion medium receives neutrons from the tokamak and converts the high-energy neutrons to an energy source with an intensity and an energy effective to excite a preselected lasing medium. The energy source typically comprises fission fragments, alpha particles, and radiation from a fission event. A lasing medium is provided which is responsive to the energy source to generate a population inversion which is effective to support laser oscillations for generating output radiation.

Pappas, Daniel S. (Los Alamos, NM)

1989-01-01

200

Fusion pumped laser  

DOEpatents

The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

Pappas, D.S.

1987-07-31

201

Multi-lamp laser pumping cavity  

Microsoft Academic Search

An optically pumped laser comprises: A. a cylindrical laser rod having a longitudinal central rod axis; B. cylindrical lamps for optically pumping the laser rod. The lamps have longitudinal central lamp axes parallel to the rod axis. The lamps being so located with respect to each other and to the laser rod as to define in cross section a base

Kuppenheimer; J. D. Jr

1987-01-01

202

Fusion pumped laser  

Microsoft Academic Search

The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10¹⁵ neutrons\\/cm²\\/center dot\\/s. Conversion means are provided adjacent the fusion reactor

1987-01-01

203

Gas laser chemical pump fluidization  

SciTech Connect

An improvement to the chemical pump as currently used to pump a gas laser cavity is achieved by employing a chemical pump with a fluidized bed, i.e., a bed of particles of a reactive material wherein the particles are suspended in a column by an inert driving fluid. The driving fluid which is nonreactive with the particles of reactive material can be selected from the group consisting of helium and argon. In addition to its function to fluidize the particles of reactive material, the driving fluid can function for some designs to load or unload the particle bed material. The reactive material is selected from the materials consisting of lithium, sodium, potassium, rubidium, cesium, calcium, strontium, barium, titanium, zirconium, hafnium, and alloys of the same which are reactive with the laser effluent gases which include various mixtures of hydrogen, deuterium, nitrogen, hydrogen fluoride, deuterium fluoride, and other combustion products. The reactive materials form solids or liquids from the effluent gases which are brought into intimate contact with the fluidized bed. Fluidization of the bed results from flow of the laser effluent gases as augmented by the driving fluid to maintain the proper fluidization and particle motion to maintain the reaction required for retention of the low pressure necessary for efficient operation of the laser. The particle motion also serves to reduce the temperature gradients in the bed and increases the heat transfer from the bed to the container walls.

Martin, W.D.

1980-04-01

204

Spatially resolved spectra of resonantly pumped laser produced plasmas of lithium  

Microsoft Academic Search

Spatially resolved visible spectra emitted from a plasma formed by focusing the output of a flashlamp pumped dye laser onto solid targets of lithium have been recorded. The effects of laser wavelength on plasma formation have been analyzed by tuning the laser to the first resonance transition in lithium at 6708 Å and comparing the results with those obtained at

Tom McCormack; Gerry O'Sullivan

1999-01-01

205

Monochromatic End-Pumped Operation of an Alexandrite Laser. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Operation of an alexandrite laser pumped by short wavelength visible laser diodes is described. Two polarization-combined 640 nm diodes produced 25 mW output at 753 nm. Characterization measurements were performed with a dye laser. The best slope efficien...

R. Scheps J. Myers T. Glesne H. Serreze

1993-01-01

206

Diode-pumped laser altimeter  

NASA Technical Reports Server (NTRS)

TEM(sub 00)-mode output energies up to 22.5 mJ with 23 percent slope efficiencies were generated at 1.064 microns in a diode-laser pumped Nd:YAG laser using a transverse-pumping geometry. 1.32-micron performance was equally impressive at 10.2 mJ output energy with 15 percent slope efficiency. The same pumping geometry was successfully carried forward to several complex Q-switched laser resonator designs with no noticeable degradation of beam quality. Output beam profiles were consistently shown to have greater than 90 percent correlation with the ideal TEM(sub 00)-order Gaussian profile. A comparison study on pulse-reflection-mode (PRM), pulse-transmission-mode (PTM), and passive Q-switching techniques was undertaken. The PRM Q-switched laser generated 8.3 mJ pulses with durations as short as 10 ns. The PTM Q-switch laser generated 5 mJ pulses with durations as short as 5 ns. The passively Q-switched laser generated 5 mJ pulses with durations as short as 2.4 ns. Frequency doubling of both 1.064 microns and 1.32 microns with conversion efficiencies of 56 percent in lithium triborate and 10 percent in rubidium titanyl arsenate, respectively, was shown. Sum-frequency generation of the 1.064 microns and 1.32 microns radiations was demonstrated in KTP to generate 1.1 mJ of 0.589 micron output with 11.5 percent conversion efficiency.

Welford, D.; Isyanova, Y.

1993-01-01

207

Cavity dumped operation of a CW pumped Q-switched and mode-locked YLF laser  

Microsoft Academic Search

A CW pumped Nd3+:LiYF4 (Nd3+:YLF) laser is demonstrated in Q-switched, mode locked, and cavity dumped operation to provide stable pulse energies in excess of 2 mJ (30 MW peak power). In operation as a dye laser pump source (noncavity dumped operation), the shorter pulses and larger number of pump pulses in the Q-switched pulse envelope, relative to the analogous YAG

L. Min; Q. Bao; R. J. Dwayne Miller

1988-01-01

208

Visible solar-pumped lasers  

NASA Astrophysics Data System (ADS)

We report on two visible solar pumped lasers; a red alexandrite laser with a potential tunability range between 700 and 818 nm, and a frequency doubled Nd:YAG laser operating at 532 nm. Highly concentrated solar energy was obtained by a 3-stage concentrator. An output power of up to 12 W was obtained from the alexandrite laser. The Q-switched Nd:YAG laser employed a type II KTP crystal for intracavity frequency doubling. Q-switching was obtained either passively or actively. In the passive Q-switching version, a water cooled Cr +4:YAG crystal was introduced into the laser cavity acting as both saturable absorber and laser rear mirror, and enforcing high repetition rate operation between 10 and 50 kHz. The average output power at 532 nm was 4.1 W. With an active acousto-optic modulator introduced between the laser rod and the high reflection rear mirror, the average output power at 532 nm and 7.3 kHz repetition rate was 8.7 W.

Lando, Mordechai; Shimony, Yehoshua; Benmair, Roth M. J.; Abramovich, Dov; Krupkin, Vladimir; Yogev, Amnon

1999-10-01

209

Efficiency and photostability of dye-doped solid-state lasers in different hosts  

NASA Astrophysics Data System (ADS)

We survey the preparation procedures of pyrromethene (PM) and rhodamine dyes in silica, silica-zirconia, organically modified silicate (ormosil) and organic polymer matrices. Absorption and luminescence spectra, as well as decay time fluorescence of pyrromethene dyes are given. The solid-state laser samples were tested and their efficiencies and photostabilities at transversal pumping configuration, are given. Pyrromethene 597 had the best laser dye performance with slope efficiency of 43.3% when doped in ormosil glass and high photostability when doped in poly(methyl methacrylate) (PMMA) . Analysis and explanations for the results are given.

Yariv, Eli; Schultheiss, Silke; Saraidarov, Tsiala; Reisfeld, Renata

2001-02-01

210

Diode pumped solid-state laser oscillators for spectroscopic applications  

Microsoft Academic Search

The rapid improvement in diode laser pump sources has led to the recent progress in diode laser pumped solid state lasers. To date, electrical efficiencies of greater than 10 percent were demonstrated. As diode laser costs decrease with increased production volume, diode laser and diode laser array pumped solid state lasers will replace the traditional flashlamp pumped Nd:YAG laser sources.

R. L. Byer; S. Basu; T. Y. Fan; W. J. Kozlovsky; C. D. Nabors; A. Nilsson; G. Huber

1987-01-01

211

Blackbody-pumped CO2 laser experiment  

NASA Astrophysics Data System (ADS)

Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping. Previously announced in STAR as N83-10420

Christiansen, W. H.; Insuik, R. J.

1983-07-01

212

Modeling laser performance of scalable side pumped alkali laser  

Microsoft Academic Search

Diode pumped alkali lasers (DPAL) offer the potential for high power and efficient operation. The extremely low quantum defect of the alkali system minimizes thermal management requirements. At the same time DPALs keep advantages of gas lasers (no thermal stresses, high intrinsic beam quality). Side pumped geometry simplifies system design, separating laser and pump light and providing physical space for

Aleksey M. Komashko; Jason Zweiback

2010-01-01

213

Dye laser amplifier including a low turbulence, stagnation-free dye flow configuration  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of for example 30 gallons/minute, a specifically designed support vessel for containing the dye cell and a screen device for insuring that the dye stream passes into the dye cell in a substantially turbulent free, stagnation-free manner. 9 figs.

Davin, J.

1992-12-01

214

Dye laser amplifier including a low turbulence, stagnation-free dye flow configuration  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of for example 30 gallons/minute, a specifically designed support vessel for containing the dye cell and a screen device for insuring that the dye stream passes into the dye cell in a substantially turbulent free, stagnation-free manner.

Davin, James (Gilroy, CA)

1992-01-01

215

Lasing behavior of sol-gel silica doped with UV laser dyes  

NASA Astrophysics Data System (ADS)

Doped and undoped silica samples were fabricated using the sol-gel method. Extended UV transmission down to 200 nm was observed for the undoped sol-gel silica. Three UV dyes (PTP, Exalite 351, and PBD) were used to dope sol-gel silica by diffusion. Lasing and fluorescence properties of these UV laser dyes in the silica matrices were studied. Laser emissions for PTP-, Exalite 351-, and PBD-doped silica samples peaked at 342 nm, 352 nm, and 364 nm. The laser output at 342 nm was the shortest wavelength yet achieved in solid-state dye lasers. The slope efficiency of the PTP-doped sol-gel silica laser was up to 17%. The output energy of the laser emission decreased to 50% of its initial value after 700 shots with a pump repetition rate of 5 Hz.

Lam, K. S.; Lo, D.

1998-04-01

216

Analysis of Dye Degradation Effects on Output Energy of the Pulsed Organic Dye Laser.  

National Technical Information Service (NTIS)

The dominant excitation and relaxation mechanisms found in dye molecules are discussed and then incorporated into a model for the xanthene dye laser. Rate equations for this model are presented which include terms that account for excited state singlet ab...

A. J. Bridging

1980-01-01

217

Studies of two-photon pumped frequency-upconverted lasing properties of a new dye material  

SciTech Connect

The two-photon absorption (TPA), TPA-induced frequency upconversion emission, and two-photon-pumped (TPP) lasing properties of a new dye, {ital trans}-4[{ital p}-(N-hydroxyethylN-methylamino)stryryl]-N-methylpyridinium iodide (abbreviated as ASPI) were experimentally investigated. This new dye has a moderate TPA cross section ({sigma}{sub 2}{approx}3.9{times}20{sup {minus}20} cm{sup 4}/GW in benzyl alcohol), but exhibits a low lasing threshold and high lasing efficiency when pumped with a 1064 nm pulsed laser beam. Furthermore, the TPA-induced fluorescence yield is strongly dependent on the polarity of the solvent, making it a promising dye for sensing applications. The spectral, temporal, and spatial structures as well as the output/input characteristics of the TPP cavity lasing and the superradiant (cavityless) lasing are systematically measured using a 1 cm path quartz cuvette filled with the ASPI solution or a doped polymer rod. The net conversion efficiency from the absorbed 1064 nm pump pulse energy to the {approximately}615 nm upconverted cavity lasing energy was found to be as high as {approximately}17{percent}. {copyright} {ital 1997 American Institute of Physics.}

He, G.S.; Yuan, L.; Cui, Y.; Li, M.; Prasad, P.N. [Photonics Research Laboratory, Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000 (United States)] [Photonics Research Laboratory, Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000 (United States)

1997-03-01

218

Lasant Materials for Blackbody-Pumped Lasers  

NASA Technical Reports Server (NTRS)

Blackbody-pumped solar lasers are proposed to convert sunlight into laser power to provide future space power and propulsion needs. There are two classes of blackbody-pumped lasers. The direct cavity-pumped system in which the lasant molecule is vibrationally excited by the absorption of blackbody radiation and laser, all within the blackbody cavity. The other system is the transfer blackbody-pumped laser in which an absorbing molecule is first excited within the blackbody cavity, then transferred into a laser cavity when an appropriate lasant molecule is mixed. Collisional transfer of vibrational excitation from the absorbing to the lasing molecule results in laser emission. A workshop was held at NASA Langley Research Center to investigate new lasant materials for both of these blackbody systems. Emphasis was placed on the physics of molecular systems which would be appropriate for blackbody-pumped lasers.

Deyoung, R. J. (editor); Chen, K. Y. (editor)

1985-01-01

219

High power diode pumped solid state lasers  

NASA Astrophysics Data System (ADS)

Although operational for over twenty years, diode pumped solid state lasers have, for most of their existence, been limited to individual diodes pumping a tiny volume of active medium in an end pumped configuration. More recent years have witnessed the appearance of diode bars, packing around 100 diodes in a 1 cm bar which have enabled end and side pumped small solid state lasers at the few Watt level of output. This paper describes the subsequent development of how proper cooling and stacking of bars enables the fabrication of multi kill average power diode pump arrays with irradiances of 1 kw/cm peak and 250 W/cm(exp 2) average pump power. Since typical conversion efficiencies from the diode light to the pumped laser output light are of order 30 percent or more, kW average power diode pumped solid state lasers now are possible.

Solarz, R.; Albrecht, G.; Beach, R.; Comaskey, B.

1992-11-01

220

Effect of solvent viscosity on the anisotropy of distribution of excited centers in an active medium of a dye laser at a pump power near the threshold value  

SciTech Connect

Dependences of the anisotropy of the distribution of excited centers (A) in rhodamine 6G and 6-aminophenolenon solutions in organic solvents of different viscosity are studied. Relying on the character of the dependence of A on the viscosity, the conclusion is made that it is possible to employ a relation similar to the Levshin-Perrin formula for polarized luminescence in the threshold excitation mode. Experimental data are used to calculate angles between absorption and emission dipoles of electron auxochrome groups of molecules for the dyes under investigation and to estimate the effective volume of activator molecules for the ethanol solution of rhodamine 6G. 6 refs., 1 fig.

Yartsev, A.I.; Sechkarev, A.V. [Vavilov State Optical Inst., St. Petersburg (Russian Federation)

1995-03-01

221

Position-Sensitive Cholesteric Liquid Crystal Dye Laser Covering a Full Visible Range  

Microsoft Academic Search

We fabricated a cholesteric-liquid-crystal distributed-feedback laser cell with spatial gradient structures not only of the helical pitch but also of the concentrations of two dyes. By utilizing the energy transfer between two dyes, lasing was achieved covering a full visible range from 470 to 670 nm continuously by translating the cell with respect to a pumping beam without changing the

Koji Sonoyama; Yoichi Takanishi; Ken Ishikawa; Hideo Takezoe

2007-01-01

222

Photophysics of Laser Dye-Doped Polymer Membranes for Laser-Induced Fluorescence Photogrammetry  

NASA Technical Reports Server (NTRS)

Laser-induced fluorescence target generation in dye-doped polymer films has recently been introduced as a promising alternative to more traditional photogrammetric targeting techniques for surface profiling of highly transparent or reflective membrane structures. We investigate the photophysics of these dye-doped polymers to help determine their long-term durability and suitability for laser-induced fluorescence photogrammetric targeting. These investigations included experimental analysis of the fluorescence emission pattern, spectral content, temporal lifetime, linearity, and half-life. Results are presented that reveal an emission pattern wider than normal Lambertian diffuse surface scatter, a fluorescence time constant of 6.6 ns, a pump saturation level of approximately 20 micro J/mm(exp 2), and a useful lifetime of more than 300,000 measurements. Furthermore, two demonstrations of photogrammetric measurements by laser-induced fluorescence targeting are presented, showing agreement between photogrammetric and physically measured dimensions within the measurement scatter of 100 micron.

Dorrington, Adrian A.; Jones, Thomas W.; Danehy, Paul M.

2004-01-01

223

A miniature electron beam pumped laser  

NASA Astrophysics Data System (ADS)

The 1.73 ?m XeI laser has been operated in a fully continuous mode using a table-top electron beam pumped laser setup. A 12 keV electron beam sent through a 300 nm thick silicon nitride membrane into a laser gas mixture of typically 600 mbar gas pressure was used for pumping. A low loss cavity was installed, resulting in a very low pumping power of 37 mW to reach laser threshold. The geometrical conditions for the laser setup such as the shape of the beam pumped volume and its overlap with the optical mode volume are discussed. The laser scheme has been clearly identified as a recombination laser scheme by operating the laser in pulsed mode and observing the time structure of the laser pulse.

Skrobol, C.; Heindl, T.; Krücken, R.; Morozov, A.; Steinhübl, R.; Wieser, J.; Ulrich, A.

2009-07-01

224

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1987-01-01

225

Solar powered blackbody-pumped lasers  

NASA Astrophysics Data System (ADS)

A concept for a solar-powered laser is presented which utilizes an intermediate blackbody cavity to provide a uniform optical pumping environment for the lasant, typically CO or CO2 or possibly a solid state laser medium. High power cw blackbody- pumped lasers with efficiencies on the order of 20 percent or more are feasible. The physical basis of this idea is reviewed. Small scale experiments using a high temperature oven as the optical pump have been carried out with gas laser mixtures. Detailed calculations showing a potential efficiency of 35 percent for blackbody pumped Nd:YAG system are discussed.

Christiansen, Walter H.; Sirota, J. M.

226

Lasers with sub-Poissonian pump  

SciTech Connect

It is shown that, introducing quantum-mechanical degrees of freedom for the pump field, one can model optical-pumping processes of a laser with sub-Poissonian statistics. For a class of pump models containing regular pumping at one end of the range and Poissonian pumping at the other, the exact stationary moments for the pump-field-averaged laser field are calculated in the strong-saturation limit of the lasing transition. It is demonstrated that, in a photodetection experiment of the laser output, complete noise suppression in the photocurrent fluctuation spectrum is, at least in principle, achievable. Finally, an approximate Fokker-Planck equation for photon distribution of the laser field with explicit appearance of the pump-light intensity correlation function in the diffusion term is derived and solved in the stationary limit.

Marte, M.A.M.; Zoller, P. (Institut fuer Theoretische Physik, Universitaet Innsbruck, Innsbruck, Austria (AT))

1989-11-15

227

Suitability of Polymeric Media In Solid State Dye Lasers  

NASA Astrophysics Data System (ADS)

Solid hosts doped with organic dyes are suitable for tunable solid state lasers because of large band width in visible region. Moreover they also overcome the problems of toxicity and limited tunability due to liquid solutions of the dyes. We report fluorescence spectra of different rhodamine dyes in different solid hosts which can be quite helpful in choosing the proper solid host for solid state dye lasers.

Sharma, Amit; Saini, G. S. S.

2011-12-01

228

Generation of microsecond laser pulses in polyurethane matrices doped with dyes  

SciTech Connect

Active laser elements based on polyurethane matrices doped with rhodamine 6G and oxazine 17 dyes are fabricated and tested. Lasing in the yellow-green and red spectral regions is obtained upon excitation of these matrices by a dye laser at 532 nm. The spectral and spatial-angular parameters of emission are studied. It is shown that these parameters are similar for polymer and liquid dye lasers. It is confirmed that pump radiation causes strong thermal distortions of active polymer media and the degree of influence of these distortions on lasing is demonstrated in experiments. The tuning of a laser based on a rhodamine 6G-doped polymer matrix is demonstrated in the range between 579 and 601 nm. (lasers)

Nikolaev, S V; Pozhar, V V; Dzyubenko, M I [A.Ya. Usikov Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine, Khar'kov (Ukraine)

2006-08-31

229

Mid-Infrared Optically Pumped Lasers.  

National Technical Information Service (NTIS)

Optically pumped lasers emitting in the middle-infrared spectral region are reviewed. General features of these lasers are discussed, and published data on them are summarized. Approximate lasing wavelengths are indicated, and a few of the more important ...

C. R. Jones

1978-01-01

230

Pulsed dye laser therapy for viral warts  

Microsoft Academic Search

Twenty-eight patients with 103 recalcitrant and 20 simple viral warts were treated with the Cynosure PhotoGenica V pulsed dye laser at 585 nm, and fluencies of 6.0–9.0 J\\/cm2. An eradication rate of 92% for recalcitrant warts after an average of 2.1 (range 1–7) treatments and 75% for simple warts after an average of 1.6 (range 1–2) treatments was achieved with

J. Kenton-Smith; S. T. Tan

1999-01-01

231

The effect of triplet quenchers on vapor-phase dye-laser performance  

NASA Astrophysics Data System (ADS)

An XeF pumped vapor phase POPOP dye laser with a pulse duration of 300 ns was obtained when trans-stilbene was used as triplet quencher. An energy conversion efficiency of 7,5% with a peak power efficiency of 12% was measured.

Klimek, D. E.

1984-06-01

232

Optofluidic microcavities: Dye-lasers and biosensors  

PubMed Central

Optofluidic microcavities are integrated elements of microfluidics that can be explored for a large variety of applications. In this review, we first introduce the physics basis of optical microcavities and microflow control. Then, we describe four types of optofluidic dye lasers developed so far based on both simple and advanced device fabrication technologies. To illustrate the application potential of such devices, we present two types of laser intracavity measurements for chemical solution and single cell analyses. In addition, the possibility of single molecule detection is discussed. All these recent achievements demonstrated the great importance of the topics in biology and several other disciplines.

Chen, Y.; Lei, L.; Zhang, K.; Shi, J.; Wang, L.; Li, H.; Zhang, X. M.; Wang, Y.; Chan, H. L. W.

2010-01-01

233

Effects of resonant pumping on the temporal and spatial evolution of a laser produced lithium plasma  

Microsoft Academic Search

The spatial and temporal distribution of neutral and singly ionized lithium atoms has been investigated when slab targets are irradiated by ~1 mus pulses of both resonant and nonresonant radiation from a flashlamp pumped dye laser. The ion population is enhanced when the laser is tuned to resonance with the 2s-2p line of neutral lithium and there is evidence for

Paul Bowe; Jim Conway; Padraig Dunne; Thomas McCormack; Gerry O'Sullivan

1999-01-01

234

Raman-shifted dye laser for water vapor DIAL measurements  

SciTech Connect

For improved DIAL measurements of water vapor in the upper troposphere or lower stratosphere, we have generated narrowband (--0.03-cm/sup -1/) laser radiation at 720- and 940-nm wavelengths by stimulated Raman scattering (SRS) using the narrow linewidth (--0.02-cm/sup -1/) output of a Nd:YAG-pumped dye laser. For a hydrogen pressure of 350 psi, the first Stokes conversion efficiencies to 940 nm were 20% and 35% when using a conventional and waveguide Raman cell, respectively. We measured the linewidth of the first Stokes line at high cell pressures and inferred collisional broadening coefficients that agree well with those previously measured in spontaneous Raman scattering.

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

1987-05-01

235

Preliminary investigation of the effects of dye concentration on the output of a multiwavelength dye laser  

NASA Technical Reports Server (NTRS)

The effects of dye concentration on the output wavelength and energy of a multiwavelength dye laser were investigated. The dyes tested were Coumarin 2 in methyl alcohol and Rhodomine 6G, Acridine Red, and 7-diethylamino-4-methyl Coumarin (7DA 4MC) in ethyl alcohol.

Clark, I. O.; Burney, L. G.

1974-01-01

236

FALCON reactor-pumped laser technology for space power applications.  

National Technical Information Service (NTIS)

The FALCON reactor-pumped laser program is investigating concepts for high power laser systems pumped directly by fission energy from a nuclear reactor. The direct pumping of laser media with fission energy offers the potential system advantages of scalin...

D. A. McArthur G. N. Hays P. S. Pickard

1991-01-01

237

Polarization of dye laser radiation. I. Theory of the steady-state approximation  

SciTech Connect

A theory is given of dye solution lasers in which an allowance is made for the optical anisotropy of dye molecules. The calculated dependences of the degree of polarization of generated radiation on the azimuth of linearly polarized transverse pump radiation (polarization diagrams) and on the degree of excess above the threshold are shown to agree well with the experimental results. The anisotropy of absorption and stimulated emission is described using the antiheuristic part of the polarizability tensor (spatial coherent oscillator model). Specific calculations are made for models of parallel and orthogonal linear absorption and emission oscillators. A dye solution is regarded as a nonlinear amplifying quasicrystal.

Yaroshenko, O.I.

1983-11-01

238

Mechanism for pumping lasers with squeezed light  

SciTech Connect

In this paper we demonstrate how the squeezed-pump-laser model of Marte and Walls (Phys. Rev. A 37, 1235 (1988)) may be realized in practice. We consider a three-level atomic medium interacting with two cavity modes pumped with squeezed light. We show that this pumping mechanism both achieves atomic inversion and squeezes the fluctuations on the lasing transition.

Haake, F.; Walls, D.F.; Collett, M.J.

1989-03-15

239

Diode-pumped alkali laser-bleached wave dynamics  

NASA Astrophysics Data System (ADS)

A three level analytic model for optically pumped alkali metal vapor lasers is developed by considering the steady state rate equations for the longitudinally averaged number densities of the ground 2S 1/2 and first excited 2P3/2, and 2P1/2 states. The threshold pump intensity includes both the requirements to fully bleach the pump transition and exceed optical losses, typically about 200 Watts/cm2. Slope efficiency depends critically on the fraction of incident photons absorbed. For efficient operation, the collisional relaxation between the two upper levels should be fast to prevent bottle-necking. By assuming a statistical distribution between the upper two levels, the limiting analytic solution for the quasi-two level system is achieved. The highly saturated pump limit of the recently developed three-level model for Diode Pumped Alkali Lasers (DPAL) is also developed. The model is anchored to several recent laser demonstrations. A rubidium laser pumped on the 5 2S1/2 - 5 2P3/2 D2 transition by a pulsed dye laser at pump intensities exceeding 3.5 MW/cm2 (< 1000 times threshold) has been demonstrated. Output energies as high as 12 ?J/pulse are limited by the rate for collision relaxation of the pumped 2P3/2 state to the upper laser 2P1/2 state. More than 250 photons are available for every rubidium atom in the pumped volume during each pulse. For modest alkali atom and ethane spin-orbit relaxer concentrations, the gain medium can only process about 50 photons/atom during the 2 - 8 ns pump pulse. At 110° C and 550 Torr of ethane, the system is bottlenecked. The system efficiency based on absorbed photons approaches 36% even for these extreme pump conditions. Furthermore, at 320°C with 2500 torr of helium, a pulsed potassium laser with 1.15 MW/cm2 peak intensity and 9.3% slope efficiency has been demonstrated.

Perram, Glen P.; Miller, Wooddy; Hurd, Ed

2012-11-01

240

Diode-pumped fiber laser. Final report, September 1984December 1986  

Microsoft Academic Search

Q-switching in Nd:YAG fibers was investigated as a particularly interesting technique to generate narrow pulses in miniature solid-state lasers. Laboratory models of both mechanically and passively Q-switched Nd:YAG fiber lasers were developed and characterized. The devices were made of a short length of end polished fiber placed between two miniature laser mirrors and optically end-pumped with a dye laser. Mechanical

A. C. Cordova-Plaza; M. J. Digonnet; K. A. Fesler; C. J. Gaeta; S. Ping

1987-01-01

241

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

Han, Kwang S.; Hwang, In Heon

1990-01-01

242

ARTICLES: Molecular infrared lasers using resonant laser pumping (review)  

Microsoft Academic Search

A review is given of investigations of the properties and characteristics of middle-infrared pulsed molecular gas lasers using resonant laser pumping. The physical basis and general operating principles of these lasers are presented. Attention is focused on lasers emitting in the 600-900 cm-1 range using TEA CO2 lasers as pump sources. The conditions for formation of the population inversion and

Arkadii Z. Grasyuk; V. S. Letokhov; V. V. Lobko

1980-01-01

243

Molecular infrared lasers using resonant laser pumping (review)  

Microsoft Academic Search

A review is given of investigations of the properties and characteristics of middle-infrared pulsed molecular gas lasers using resonant laser pumping. The physical basis and general operating principles of these lasers are presented. Attention is focused on lasers emitting in the 600–900 cm?1 range using TEA CO2 lasers as pump sources. The conditions for formation of the population inversion and

Arkadii Z Grasyuk; V. S. Letokhov; V. V. Lobko

1980-01-01

244

Diode pumped alkali vapor fiber laser  

DOEpatents

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2006-07-26

245

Diode pumped alkali vapor fiber laser  

DOEpatents

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2007-10-23

246

Single mode solid state distributed feedback dye laser fabricated by gray scale electron beam lithography on a dye doped SU8 resist  

Microsoft Academic Search

We demonstrate gray scale electron beam lithography on a functionalized SU-8 resist for fabrication of single mode solid state dye laser devices. The resist is doped with Rhodamine 6G perchlorate and the lasers are based on a first-order Bragg grating distributed feedback resonator. The lasers are optically pumped at 532 nm, and exhibit low lasing threshold from 530 nJ mm-2

S. Balslev; T. Rasmussen; P. Shi; A. Kristensen

2005-01-01

247

Diode laser--pumped solid-state lasers.  

PubMed

Diode laser-pumped solid-state lasers are efficient, compact, all solid-state sources of coherent optical radiation. Major advances in solid-state laser technology have historically been preceded by advances in pumping technology. The helical flash lamps used to pump early ruby lasers were superseded by the linear flash lamp and arc lamp now used to pump neodymium-doped yttrium-aluminum-garnet lasers. The latest advance in pumping technology is the diode laser. Diode laser-pumped neodymium lasers have operated at greater than 10 percent electrical to optical efficiency in a single spatial mode and with linewidths of less than 10 kilohertz. The high spectral power brightness of these lasers has allowed frequency extension by harmonic generation in nonlinear crystals, which has led to green and blue sources of coherent radiation. Diode laser pumping has also been used with ions other than neodymium to produce wavelengths from 946 to 2010 nanometers. In addition, Q-switched operation with kilowatt peak powers and mode-locked operation with 10-picosecond pulse widths have been demonstrated. Progress in diode lasers and diode laser arrays promises all solid-state lasers in which the flash lamp is replaced by diode lasers for average power levels in excess of tens of watts and at a price that is competitive with flash lamp-pumped laser systems. Power levels exceeding 1 kilowatt appear possible within the next 5 years. Potential applications of diode laser-pumped solid-state lasers include coherent radar, global sensing from satellites, medical uses, micromachining, and miniature visible sources for digital optical storage. PMID:17832940

Byer, R L

1988-02-12

248

Synchronous and hybrid mode-locking of a Styryl 13 dye laser  

NASA Astrophysics Data System (ADS)

We report synchronous and hybrid mode-locking of a Styryl 13 cw dye. Pulses ? ps were obtained tunable from 870 to 1040 nm, when the laser was synchronously pumped by a frequency-doubled mode-locked cw Nd:YAG laser. Hybrid mode-locking using the saturable absorber IR 143 produced 830 fs pulses near 926 nm in a simple linear cavity.

Stark, Thomas S.; Dawson, Martin D.; Smirl, Arthur L.

1988-11-01

249

CCMR: Analysis of Surface Dyes: Preparation for Laser Spectroscopy  

NSDL National Science Digital Library

Preliminary work for laser spectroscopy with surface-adsorbed dyes is presented. Prussian blue dye is characterized and future sum-frequency generation experiments are described. Ultrafast surface-specific laser spectroscopy is utilized as an effective way of directly studying electron transfer between dye and semiconductor in dye-sensitized solar cells. Previous studies and theories have not allowed these electron transfer mechanisms to be fully understood. Future work will utilize infrared analysis to observe vibrational modes in dye and form a picture of electron transfer.

Souva, Matthew

2010-08-15

250

Molecular reorientation-based grating diffraction in dye-doped nematic liquid crystals with red pumping source  

NASA Astrophysics Data System (ADS)

We report the results of a grating diffraction experiment in which a blue anthraquinone dye, Disperse blue 14, is doped to nematic liquid crystal host and the sample is employed as a nonlinear media. The change of refractive index, caused by the photoinduced molecular reorientation, brings about the promising grating diffraction capability of a novel liquid crystal system. This system contains an anthraquinone dye in the absorbance band of red He-Ne laser, which is used as a pumping source. Accessible diffraction efficiency is 20% under optimum circumstances and analyzed results are in consistency with the expectations reinforced by the literature information of the other resembling liquid crystal systems.

San, S. E.; Köysal, O.; Ecevit, F. N.

2002-11-01

251

Pulse-width fluctuations of a cascade transient oscillation dye laser  

NASA Astrophysics Data System (ADS)

Most of the common high-energy laser systems have output pulse widths in the 1-15-ns region, and it is desirable to develop a reliable scheme in which these high-energy laser pulses can be employed to pump a dye laser and produce ultrashort laser pulses directly. In connection with efforts to produce picosecond dye laser pulses, this letter is concerned with the Roess-Lin transient oscillation scheme used in cascade. The optical arrangement of the cascade transient oscillation (CTO) dye laser is modified with the objective to produce shorter pulses. A study of the output pulse duration stability of this laser system is conducted, and a rms fluctuation of + or - 11 percent is observed. It is pointed out that this value compares very favorably with that of other picosecond laser systems. On the basis of the observed fluctuation, it can be stated that picosecond time-resolved measurements can be performed with the CTO dye laser with a resolution of 8 ps.

Hsu, S. C.; Kwok, H. S.

1986-02-01

252

Limitations of an optically pumped rubidium laser imposed by atom recycle rate  

Microsoft Academic Search

A rubidium laser pumped on the 52S1\\/2–52P3\\/2 D2 transition by a pulsed dye laser at pump intensities exceeding 3.5 MW\\/cm2 (>1000 times threshold) has been demonstrated. Output energies as high as 12 ?J\\/pulse are limited by the rate for collision\\u000a relaxation of the pumped 2P3\\/2 state to the upper laser 2P1\\/2 state. More than 250 photons are available for every rubidium

W. S. Miller; C. V. Sulham; J. C. Holtgrave; G. P. Perram

2011-01-01

253

Limitations of an optically pumped rubidium laser imposed by atom recycle rate  

Microsoft Academic Search

A rubidium laser pumped on the 52S1\\/2-52P3\\/2 D2 transition by a pulsed dye laser at pump intensities exceeding 3.5 MW\\/cm2 (>1000 times threshold) has been demonstrated. Output energies as high as 12 muJ\\/pulse are limited by the rate for collision relaxation of the pumped 2P3\\/2 state to the upper laser 2P1\\/2 state. More than 250 photons are available for every

W. S. Miller; C. V. Sulham; J. C. Holtgrave; G. P. Perram

2011-01-01

254

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled 'Direct solar-pumped iodine laser amplifier'. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.

Han, Kwang S.

1987-01-01

255

Vapour phase dye lasers of the visible range  

NASA Astrophysics Data System (ADS)

Laser action is reported, in tmitrin 3(470 nm), imitrin 9(525 nm), coumarin 153 (C153(480 nm), C7(522 nm), C30 (526 nm), C6(520 nm) and 7 diethylamino-3(2'-benzoxazplyl)-eoumarin dyes in vapour phase with buffer gases (36 atm). Third harmonic of neodymium laser (355 nm, 100 mJ, 20 ns) was used for the excitation. Laser conversion efficiency for some coumarins exceeds 12%. POPOP vapour phase dye laser (395 am) efficiency exceeds 22%. Prospects of vapour phase dye laser development are discussed.

Basov, N. G.; Logunov, O. A.; Startsev, A. V.; Stoilov, Yu. Yu.; Zuev, V. S.

256

Diode laser-pumped solid-state lasers  

NASA Technical Reports Server (NTRS)

Recently, interest in diode laser-pumped solid-state lasers has increased due to their advantages over flashlamp-pumped solid-state lasers. A historical overview is presented of semiconductor diode-pumped solid-state lasers beginning with work in the early 1960s and continuing through recent work on wavelength extension of these devices by laser operation on new transitions. Modeling of these devices by rate equations to obtain expressions for threshold, slope efficiency, and figures of merit is also given.

Fan, Tso Yee; Byer, Robert L.

1988-01-01

257

Scaling studies of blackbody pumped lasers  

NASA Technical Reports Server (NTRS)

The scaling of blackbody pumped lasers to large powers is being studied. The computational results show the possibility of high pressure transverse flow blackbody pumped lasers. A nonsteady technique with metal shims heated rapidly to 1500 K as the blackbody pumping source is being used to carry out the experiment. Fast temperature rise of the shims creates pressure waves inside the laser cavity which destroy the resonance of the cavity. A new design with rectangular quartz tubing inside the cavity to prevent the waves from reaching the lasing region is under construction.

Chang, Jim; Christiansen, Walter H.

1986-01-01

258

Exploding conducting film laser pumping apparatus  

DOEpatents

Exploding conducting film laser optical pumping apparatus. The 342-nm molecular iodine and the 1.315-.mu.m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

Ware, Kenneth D. (San Diego, CA); Jones, Claude R. (Los Alamos, NM)

1986-01-01

259

Modeling laser performance of scalable side pumped alkali laser  

NASA Astrophysics Data System (ADS)

Diode pumped alkali lasers (DPAL) offer the potential for high power and efficient operation. The extremely low quantum defect of the alkali system minimizes thermal management requirements. At the same time DPALs keep advantages of gas lasers (no thermal stresses, high intrinsic beam quality). Side pumped geometry simplifies system design, separating laser and pump light and providing physical space for a large number of diode stacks needed for power scaling. The three-level nature of these lasers complicates modeling, making numerical simulation the most viable option for system studies in this geometry. We have built a simplified numerical code for simulation of CW laser performance in different side pumped geometries and studied performance of a rubidium DPAL with helium and methane buffer gases at high pump power. We observed dramatic differences in pump absorption with the laser turned off compared to an operating laser. Cell temperature is a key parameter that controls effective absorption length. If pump density is sufficiently high, we can find an operating point with optical to optical efficiency above 60% with reasonably homogenous spatial laser output profile even for a single side pumped laser cell.

Komashko, Aleksey M.; Zweiback, Jason

2010-02-01

260

Pyrromethene-BF2 complexes as laser dyes  

Microsoft Academic Search

In 1984, less than two decades after its discovery, a review described the dye laser as one of the most useful and practical of tunable coherent sources. Laser dye activity was presumed to reflect a casual relationship with various ancillary properties including photostability, solubility and other interactions with solvent, fluorescence quantum yield, molar extinction of absorption, and minimal overlap of

Mayur Shah; Kannappan Thangaraj; Mou-Ling Soong; Lionel T. Wolford; Joseph H. Boyer; Ieva R. Politzer; Theodore G. Pavlopoulos

1990-01-01

261

Energy transfer processes in two different bifluorophoric laser dyes  

NASA Astrophysics Data System (ADS)

The mechanism of intramolecular energy transfer in two bifluorophoric laser dyes has been investigated by measurements of laser parameters, excited state absorption and phosphorescence spectra. The new value found for the dimethyl-POPOP triplet energy (48.0 kcal/mole) accounts for the different behaviour of the two classes of bifluorophoric dyes used in this investigation.

Liphardt, Bodo; Liphardt, Bernd; Lüttke, W.; Ouw, D.

1982-10-01

262

Vapor dye lasers with multiplate reflectors  

NASA Astrophysics Data System (ADS)

The specific nature of a multiplate reflector and refractive index changes of an active medium under optical pumping result in Q-switching of longitudinal modes. Time dependence of the emission spectra are obtained for TOPOT vapors and POPOP solutions in toluene to estimate rates of refractive index changes in the course of generation. It is shown that under certain conditions, a laser with such a resonator can be used to determine the wavelength tuning range.

Borisevich, N. A.; Povedailo, V. A.; Tolkachev, V. A.

1980-05-01

263

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

Han, Kwang S.; Hwang, In Heon; Stock, Larry V.

1989-01-01

264

A review of laser-pumped infrared lasers  

NASA Technical Reports Server (NTRS)

The lasing mechanisms are reviewed of molecules that have demonstrated laser action in the laboratories with laser emissions in the spectral range from 3 to 35 microns. A list of lasants and laser mechanisms are defined. The pumping sources for these lasers are mainly infrared lasers; however, the case in which excitation of bromine atoms at 2.71 microns by a flashlamp as energy input is also included in the review. A conceptual drawing of lasing mechanisms is shown. Three pumping mechanisms are shown, the first being the direct-pumped system in which the lasant molecule absorbs the infrared radiation from pump laser directly, and it is excited into the upper laser level from the ground state. The second system is the indirect-pumped system where the infrared-pump laser first excites an absorbing molecule which stores its vibrational energy. Through collision this energy is transferred to the lasant molecule, populating the upper laser level. In the third system, i.e., in a Br2-CO2 mixture, a flashlamp replaces the infrared laser as the pump source for the absorbing molecule.

Chen, K. Y.

1985-01-01

265

Tunable organic thin-film laser pumped by an inorganic violet diode laser  

NASA Astrophysics Data System (ADS)

We demonstrate an organic thin-film distributed feedback (DFB) laser pumped by an inorganic violet laser diode (?=406 nm). The active organic medium consists of a highly efficient, modified poly(9,9-dioctylfluorene) derivative containing 12% of statistical intrachain 6,6'-(2,2'-octyloxy-1,1'-binaphthalene) binaphthyl spacer groups. The polymer is doped with 4 wt % of the stilbene dye 1,4-bis(2-(4-(N,N-di(p-tolyl)amino)phenyl)vinylbenzene). This guest-host system features minimum lasing threshold energy densities below 1 ?J/cm2 for second order DFB resonator geometries and significant absorption (7.3×104 cm-1) at the wavelength of the pumping diode laser. The entire setup states an extremely compact and cost effective, laser source tunable between 496 and 516 nm.

Riedl, T.; Rabe, T.; Johannes, H.-H.; Kowalsky, W.; Wang, J.; Weimann, T.; Hinze, P.; Nehls, B.; Farrell, T.; Scherf, U.

2006-06-01

266

High-repetition-rate amplification of tunable femtosecond pulses with a q-switched CW Nd:YAG pumping laser  

NASA Astrophysics Data System (ADS)

Frequency-tunable femtosecond pulses from a hybridly mode-locked dye laser system are amplified 10 3 times using a compact CW Nd:YAG pumping laser Q-switched at 1 kHz repetition rate. This practical laser system produces amplified tunable 14 fs pulses with a fiber compressor.

Ishida, Yuzo; Tokizaki, Takashi; Yajima, Tatsuo

1988-10-01

267

Alternative wavelengths for optically pumped alkali lasers  

NASA Astrophysics Data System (ADS)

As pump intensity in Diode Pumped Alkali Lasers (DPAL) is scaled to more than 100 times threshold, several nonlinear optical processes are encountered including two photon absorption and stimulated Raman scattering. A pulsed, optically pumped potassium laser with pump intensities exceeding 1 MW/cm2 has been demonstrated with output intensities exceeding 100 kW/cm2, requiring helium buffer gas pressures above 3 atm. At low pressure Stimulated Electronic Raman Scattering (SERS) has been observed in the same system. Indeed, second and third order SERS has been observed from the DPAL upper laser level. Two-photon absorption at wavelengths near then DPAL pump transition has also been observed and used to demonstrate lasing in the blue and mid infrared. Lasing in the blue has also been achieved by direct excitation of the second excited 2P3/2 level in Cs.

Perram, Glen P.

2012-05-01

268

Solid-state dye laser with modified poly(methyl methacrylate)-doped active elements  

NASA Astrophysics Data System (ADS)

Laser generation with modified poly(methyl methacrylate) (MPMMA)-doped matrices with several different types of Rhodamine-based dyes was obtained. Pumping with a frequency-doubled Q-switched Nd:YAG laser was used. During the experiments, high conversion efficiency was achieved. The strong nonlinear dependence of the operating lifetime and the conversion efficiency of material tested on the pump-pulse-repetition rate was observed. Possible mechanisms responsible for the conversion-efficiency drop and the useful lifetime of the material are discussed.

Maslyukov, A.; Sokolov, S.; Kaivola, M.; Nyholm, K.; Popov, S.

1995-03-01

269

Double Pulse Pumping of Ruby Lasers.  

National Technical Information Service (NTIS)

Laser performance in double pulse mode of pumping was studied. The xenon flash lamp was energized by two condenser banks discharged in sequence with a time delay between both discharges. Theoretical analysis of discharge characteristics and of experimenta...

P. Shajenko

1966-01-01

270

Applications for reactor-pumped lasers.  

National Technical Information Service (NTIS)

Nuclear reactor-pumped lasers (RPLs) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experime...

R. J. Lipinski D. A. McArthur

1994-01-01

271

20 Hz lamp pumped erbium glass laser  

NASA Astrophysics Data System (ADS)

Q-switched laser behavior of the new IRE RAS developed Yb-Er phosphate glass LGS-KhCh2 was studied using FTIR and water-cooled chamber with lamp pumping. Laser rod near 3 mm in diameter and 80 mm long was investigated. Laser output of 5-10 mJ was achieved at 1535 nm at 20 Hz repetition rate. For the first time, to our best knowledge, the CW operation of the erbium glass laser under lamp pumping is demonstrated.

Alekseev, N. E.; Byshevskaya-Konopko, L. O.; Izyneev, Anatoly A.; Kravchenko, Victor; Sadovski, P. I.

2004-04-01

272

Fission reactor pumped lasers: History and prospects  

NASA Astrophysics Data System (ADS)

A historical account is given of work at Sandia since 1979, beginning with initial experiments on reactor ionized electrical excitation of CO2 lasers. An account of recent work at Sandia is also given centering on the Pulsed Reactor III for experiments at high excitation rates with small laser volumes, and the Sandia Annular Core Research Reactor for experiments at lower excitation rates with larger laser volume. Prospects are given for future reactor pumped laser work.

McArthur, David A.

273

DOE reactor-pumped laser program.  

National Technical Information Service (NTIS)

FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and h...

J. R. Felty R. J. Lipinski D. A. McArthur P. S. Pickard

1993-01-01

274

Laser-induced quantum pumping in graphene  

NASA Astrophysics Data System (ADS)

We investigate non-adiabatic electron pumping in graphene generated by laser irradiation with linear polarization parallel or perpendicular to the transport direction. Transport is dominated by the spatially asymmetric excitation of electrons from evanescent into propagating modes. For a laser with parallel polarization, the pumping response exhibits a subharmonic resonant enhancement which directly probes the Fermi energy; no such enhancement occurs for perpendicular polarization. The resonance mechanism relies on the chirality of charge carriers in graphene.

San-Jose, Pablo; Prada, Elsa; Schomerus, Henning; Kohler, Sigmund

2012-10-01

275

Exploding conducting film laser pumping apparatus  

DOEpatents

The 342-nm molecular iodine and the 1.315-..mu..m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

Ware, K.D.; Jones, C.R.

1984-04-27

276

Efficient Optically Pumped Cesium Vapor Laser  

NASA Astrophysics Data System (ADS)

We have demonstrated a cesium laser with 81% slope efficiency relative to the input pump power. The maximum output power at 894 nm was 0.36 W with a pump power of 0.57 W (the overall optical efficiency was 63%). Optically pumped alkali lasers have a number of desirable features as compared to solid state or fiber lasers: the quantum efficiency is high (95.3% for Cs as compared to 76% for a 1.06 ?m Nd:YAG laser); the gain medium is a gas with excellent optical quality; thermal problems are reduced since the gas gain medium can be flowed to remove heat. We used the three-level pump scheme to create the population inversion on the D1 transition (6P1/2 to 6S1/2) in the Cs atomic vapor. A narrowband pump laser operating at 852 nm pumps the atoms to the 6P3/2 state (D2 line) which is then rapidly quenched to the 6P1/2 state by an ethane buffer gas. This creates a population inversion between the 6P1/2 and 6S1/2 states and lasing at 894 nm. The experimental set-up consisted of a Coherent MBR 110 Ti:Sapphire laser used as a pump source and a 2 cm long Cs vapor cell with AR coated windows positioned in the center of a 16 cm long stable laser cavity. The cell was filled with metallic cesium and 500 Torr of ethane at 20^oC and was placed inside a temperature controlled oven. The laser cavity was longitudinally pumped through the input cavity mirror.

Zhdanov, B.; Ehrenreich, T.; Knize, R. J.

2006-05-01

277

Simple solid state polymeric dye laser for scientific research and biomedical applications  

NASA Astrophysics Data System (ADS)

Simple dye laser with the solid state polymeric active medium pumped by the second harmonic of Nd:YAG laser (532 nm) is presented. Active medium is made of dye-doped polyurethane acrylate (PUA) prepared by radical photopolymerization. Laser dyes in PUA are characterized by some peculiarities in spectral and photochemical properties which are important for lasing. To attain high laser efficiency, the hemispherical resonator with total length of 12 cm was used. In this case laser efficiency exceeds 30% with tuning range of 545-750 nm and spectral linewidth 0.4 nm. For removing the thermo-optical distortions in active polymeric medium and increasing its operational lifetime the original scanning system of active element has been constructed. It provides a possibility to realize the repetition rate up to 25 Hz (at peak intensity up to 80 MW/cm2) and to obtain the operational lifetime more than one million pulses for the proposed dyes. The elaborated laser has the certain advantages as compared to solid state Ti:Sapphire laser in relation to the peak power output and optical damage of active medium.

Bondar, Mikhail V.; Przhonska, Olga V.; Tikhonov, Evgeny A.

1995-04-01

278

High power semiconductor disk laser with monolithically integrated pump lasers  

NASA Astrophysics Data System (ADS)

Semiconductor disk lasers have attracted a lot of interest in the last few years due to high output power combined with good beam quality and possible wavelength engineering. One of the disadvantages is the need for external optical pumping by edge-emitting semiconductor lasers that increase packaging effort and cost. Therefore, semiconductor disk lasers with monolithically integrated pump lasers would be of high interest. We report on a novel design and experimental realization to monolithically integrate pump lasers with a semiconductor disk laser in a one-step epitaxial design. By careful design of integrated pump lasers and stacking sequence, it is possible to efficiently excite vertical emitter areas with different mesa sizes. First results are shown at 1060 nm emission wavelength with high output power out of mesa diameters of 100 ?m to 400 ?m. The devices can be conveniently characterized on a wafer level using dry-etched pump laser facets. In pulsed operation 1.7W out of a 100 ?m diameter mesa and 2.5W out of a 200 ?m diameter mesa are demonstrated. Additionally, more than 0.6W in cw operation using a 400 ?m structure were achieved. In summary, an innovative approach for truly monolithic integration of a semiconductor disk laser with pump lasers has been pioneered.

Diehl, Wolfgang; Albrecht, Tony; Brick, Peter; Furitsch, Michael; Illek, Stefan; Lutgen, Stephan; Pietzonka, Ines; Luft, Johann; Stolz, Wolfgang

2008-05-01

279

Pulsed pumping of semiconductor disk lasers.  

PubMed

Efficient operation of semiconductor disk lasers is demonstrated using uncooled and inexpensive 905nm high-power pulsed semiconductor pump lasers. Laser emission, with a peak power of 1.7W, is obtained from a 2.3mum semiconductor disk laser. This is seven times the power achieved under continuous pumping. Analysis of the time-dependent spectral characteristics of the laser demonstrate that significant device heating occurs over the 100-200ns duration of the pumping pulse - finite element modelling of the thermal processes is undertaken in support of these data. Spectral narrowing to below 0.8nm is obtained by using an intra-cavity birefringent filter. PMID:19532565

Hempler, Nils; Hopkins, John-Mark; Kemp, Alan J; Schulz, Nico; Rattunde, Marcel; Wagner, Joachim; Dawson, Martin D; Burns, David

2007-03-19

280

Passive mode locking of lasers with a tunable dye cell  

SciTech Connect

A laminar-flow dye cell with continuously variable thickness (tunable without removal of the dye solution) provides an excellent way of optimizing passively mode-locked lasers. Varying the cell thickness adjusts low-light-level transmittance to match the total cavity and excitation energy conditions and also varies pulse duration. Acceptable cell thicknesses and dye concentrations can be calculated theoretically using well-known parameters. The cell can be conveniently retuned to compensate for dye degradation or to provide conditions for Q switching. Experimental evidence is presented for a Nd:YAG laser.

Baumann, G.Z.; Goldstein, R.L.

1982-11-01

281

Picosecond DPSS laser technology for OPCPA pumping  

NASA Astrophysics Data System (ADS)

We present the design and challenges of a diode-pumped solid-state (DPSS) system to amplify picosecond pulses to high pulse energies and high average powers. We discuss our implemented solutions to mitigate thermal effects and present the obtained performance of the picosecond pulse amplification at the multi-10-MW level. Our here presented picosecond DPSS laser is well suited for pumping an optical parametric chirped-pulse amplification (OPCPA) system. Several laser technologies have been employed to pump OPCPA systems and we show how our DPSS system compares in performance to the other approaches.

Vaupel, Andreas; Bodnar, Nathan; Webb, Benjamin; Shah, Lawrence; Richardson, Martin

2014-02-01

282

Self-Sustaining Nuclear Pumped Laser-Fusion Reactor Experiment.  

National Technical Information Service (NTIS)

The features of a neutron feedback nuclear pumped (NFNP) laser-fusion reactor equipment were studied with the intention of establishing the feasibility of the concept. The NFNP laser-fusion concept is compared schematically to electrically pumped laser fu...

F. P. Boody C. K. Choi G. H. Miley

1977-01-01

283

Complete optical analysis of an UV laser dye using saturation techniques  

SciTech Connect

The saturation properties of an UV laser dye, 3,5,3,5-tetra-t-butyl-p-sexiphenyl (TBS), pumped by a XeCl laser were studied. The experimental data included measurements of the optical saturation of transmission and amplifier gain. The data were fit directly to photon propagation differential equations to obtain the saturation intensities for absorption and emission. From the measured saturation parameters a complete determination was made of the optical constants of the singlet states in TBS. The results presented include the absorption spectrum, fluorescence spectrum, fluorescence lifetime, excited-state absorption cross sections at the pump laser and dye laser wavelengths, quantum yield, wavelength dependence of the stimulated emission cross section, and an upper bound for the intersystem crossing rate. The saturation analysis method provides a rapid experimental evaluation of a laser dye with high accuracy. A two-photon excited transition at the long wavelengths of the laser oscillator tuning range of TBS produces photochemical degradation. The photochemical degradation rate increases with increasing wavelength.

Jensen, C.C. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Schroeder, H. (Max-Planck Institute fuer Quantenoptik, 8046 Garching (Germany))

1992-11-20

284

Chemical stabilization of laser dyes. Final report, 1 July 1981-1 October 1984  

SciTech Connect

Coumarin laser dyes upon excitation degrade to produce products which absorb at the lasing wavelength. This results in attenuation of dye laser output. Modes of degradation of coumarin dye lasers under both anaerobic and aerobic conditions were determined and methods of stabilization of dye lasers were established.

Koch, T.H.

1984-11-01

285

Frequency stabilization of diode-laser-pumped solid state lasers  

NASA Technical Reports Server (NTRS)

The goal of the NASA Sunlite program is to fly two diode-laser-pumped solid-state lasers on the space shuttle and while doing so to perform a measurement of their frequency stability and temporal coherence. These measurements will be made by combining the outputs of the two lasers on an optical radiation detector and spectrally analyzing the beat note. Diode-laser-pumped solid-state lasers have several characteristics that will make them useful in space borne experiments. First, this laser has high electrical efficiency. Second, it is of a technology that enables scaling to higher powers in the future. Third, the laser can be made extremely reliable, which is crucial for many space based applications. Fourth, they are frequency and amplitude stable and have high temporal coherence. Diode-laser-pumped solid-state lasers are inherently efficient. Recent results have shown 59 percent slope efficiency for a diode-laser-pumped solid-state laser. As for reliability, the laser proposed should be capable of continuous operation. This is possible because the diode lasers can be remote from the solid state gain medium by coupling through optical fibers. Diode lasers are constructed with optical detectors for monitoring their output power built into their mounting case. A computer can actively monitor the output of each diode laser. If it sees any variation in the output power that might indicate a problem, the computer can turn off that diode laser and turn on a backup diode laser. As for stability requirements, it is now generally believed that any laser can be stabilized if the laser has a frequency actuator capable of tuning the laser frequency as far as it is likely to drift in a measurement time.

Byer, Robert L.

1988-01-01

286

High pulse energy flashlamp pumpable laser dyes  

NASA Astrophysics Data System (ADS)

The class of laser dye known as 4PyMPO was given an expanded fluorophor by substitution of a biphenylene for the phenylene group. Neither the derived quaternary salt or zwitterion had a higher extinction coefficient, quantum yield, or bathochromic shift of absorption from that of the parent compound. Replacement of the methoxy M by julolidino was not achieved. In 2-(4'-methoxy 4-biphenyl) 1-propylbenzimidazole, the methanesulfonate acid salt was no higher in quantum yield than the methanesulfonate quat., indicating no steric hindrance to planarity in the excited state. Addition of a phenylene group, again, did not improve the fluorescence properties. A symmetrical version with benzimidazolium ions at both ends is being prepared. Synthesis of a bridged quaterphenyl with stilbenylmethyl groups as potential intramolecular triplet state quenchers is one step from the target molecule. Synthesis of a high-energy dye related to the most effective bridged sexiphenyls known by replacement of benzene rings 2 and 5 by furan rings is one step from the target molecule.

Kauffman, Joel M.; Novinski, John

1990-04-01

287

Cryosorption-pumped CW chemical laser  

Microsoft Academic Search

A miniature CW chemical laser is described which can serve as a convenient multiline source in the IR. It employs condensible carrier gases with cryosorption pumping only (thus no moving parts) to deliver 300 and 200 mW, respectively, of HF and HCl radiation. Five laser reactions with a total of nine lines each of HCl and HF in the regions

K. R. Newton; R. B. Bernstein

1978-01-01

288

Solar-pumped photodissociation iodine laser  

NASA Technical Reports Server (NTRS)

The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-W CW output for more than one hour was achieved using n-C3F7I vapor as the laser material and a vortex-stabilized argon arc as the light source.

Lee, J. H.; Weaver, W. R.; Humes, D. H.; Williams, M. D.; Lee, M. H.

1986-01-01

289

Scaling of diode-pumped Cs laser: transverse pump, unstable cavity, MOPA  

Microsoft Academic Search

There has been recent interest in Diode Pumped Alkali Lasers (DPALs) and their scaling to higher powers. Scaling of DPALs to high powers requires using multiple pump sources such as laser diode arrays or stacks of arrays. Coupling of multiple pump beams into the laser gain medium can be realized using a transverse pumping scheme that is most efficient for

B. V. Zhdanov; M. K. Shaffer; R. J. Knize

2010-01-01

290

Semiconductor disk laser-pumped subpicosecond holmium fibre laser  

SciTech Connect

The first passively mode-locked holmium fibre laser has been demonstrated, with a semiconductor saturable absorber mirror (SESAM) as a mode locker. Semiconductor disk lasers have been used for the first time to pump holmium fibre lasers. We obtained 830-fs pulses at a repetition rate of 34 MHz with an average output power of 6.6 mW.

Chamorovskiy, A Yu; Marakulin, A V; Leinonen, T; Kurkov, Andrei S; Okhotnikov, Oleg G

2012-01-31

291

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of rate equations was improved to increase the accuracy and the efficiency of the calculation. The improved algorithm was applied to explain the existing experimental data taken from a flashlamp pumped iodine laser for three kinds of lasants, i-C3F7I, n-C4F9I, and t-C4F9I. Various solid laser materials were evaluated for solar-pumping. The materials studied were Nd:YAG, Nd:YLF, and Cr:Nd:GSGG crystals. The slope efficiency of 0.17 percent was measured for the Nd:YLF near the threshold pump intensity which was 211 solar constants (29W/sq cm). The threshold pump intensity of the Nd:YAG was measured to be 236 solar constants (32W/sq cm) and the near-threshold slope efficiency was 0.12 percent. True CW laser operation of Cr:Nd:GSGG was possible only at pump intensities less than or equal to 1,500 solar constants (203 W/sq cm). This fact was attributed to the high thermal focusing effect of the Cr:Nd:GSGG rod.

Han, Kwang S.; Hwang, In Heon; Kim, Khong Hon; Stock, Larry V.

1988-01-01

292

Dye energy transfer in xerogel matrices and application to solid-state dye lasers  

Microsoft Academic Search

Laser dyes Rhodamine B and Perylene Red were incorporated at different relative concentrations into hybrid matrices synthesized using the sol–gel process. Energy transfer from Rhodamine B-donor to Perylene Red-acceptor molecules was observed. Using the different co-doped samples, solid-state dye laser systems were achieved with tuning band position control and increased efficiency with respect to the materials using solely one type

Tran Hong Nhung; Michael Canva; Frédéric Chaput; Hélène Goudket; Gisèle Roger; Alain Brun; Dang Duc Manh; Nguyen Dai Hung; Jean-Pierre Boilot

2004-01-01

293

Semiconductor disk laser pumped Cr2+:Znse lasers.  

PubMed

A new flexible pump source, the optically-pumped semiconductor disk laser (SDL), for the Cr(2+):ZnSe laser is reported. The SDL provides up to 6W output power at a free running central wavelength of 1.98 microm. The Cr(2+):ZnSe laser operated at an output power of 1.8W and a slope efficiency of approximately 50% with respect to absorbed pump power whilst maintaining a low output intensity noise figure of <0.14% RMS. The system required no optical isolation even under the situation of significant optical feedback. PMID:19907603

Hempler, Nils; Hopkins, John-Mark; Rösener, Benno; Rattunde, Marcel; Wagner, Joachim; Fedorov, Vladimir V; Moskalev, Igor S; Mirov, Sergey B; Burns, David

2009-09-28

294

Stable, red laser pumped, multi-kilohertz Alexandrite laser  

NASA Astrophysics Data System (ADS)

Operation of a miniature Alexandrite laser pulse-pumped at 671 nm by a Q-switched, frequency-doubled, diode-pumped Nd:GdVO 4 laser is reported. Average power output ˜150 mW at 765 nm with optical-to-optical slope efficiencies of 28% has been demonstrated for gain-switched operation of the Alexandrite laser at 80 kHz. Q-switched pump-pulse stacking has been used to reduce output pulse width by a factor of 6 and increase peak power by a factor of 38 over gain-switched operation.

Ogilvy, Hamish; Withford, Michael J.; Piper, James A.

2006-04-01

295

Design and operation of a tunable continuous dye laser.  

PubMed

Design considerations and performance are discussed for the previously reported continuous dye solution laser. Output power was 1 W untuned and up to 320 mW when tuned by a prism. Tuning range was 525-680 nm, obtained with the use of several dye solutions. Theoretical predictions. of output power as a function of input power and of dye concentration were in good agreement with measurements. PMID:20111458

Tuccio, S A; Strome, F C

1972-01-01

296

Multicolor diode-pumped upconversion fiber laser.  

PubMed

We present a new method to control the power of individual spectral components of a multicolor laser by mirrors with variable air gaps and by a composite resonator configuration. We demonstrate a Pr/Yb-ZBLAN fiber laser with arbitrary spectral composition of three simultaneously emitted components at 492 nm, 520 nm, and 635 nm. With 100 mW pump power at 850 nm launched into the fiber, the total laser output exceeds 10 mW. PMID:20596214

Hellmig, Ortwin; Salewski, Stefan; Stark, Arnold; Schwenke, Jörg; Toschek, Peter E; Sengstock, Klaus; Baev, Valery M

2010-07-01

297

Diode pumped alkali vapor fiber laser  

Microsoft Academic Search

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into

Stephen A. Payne; Raymond J. Beach; Jay W. Dawson; William F. Krupke

2007-01-01

298

Diode pumped alkali vapor fiber laser  

Microsoft Academic Search

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into

Stephen A. Payne; Raymond J. Beach; Jay W. Dawson; William F. Krupke

2006-01-01

299

Investigation of the pump wavelength influence on pulsed laser pumped Alexandrite lasers  

NASA Astrophysics Data System (ADS)

Recent theoretical modelling and experimental results have shown that excess lattice phonon energy created dur ing the non-radiative energy transfer from the 4T2 pump manifold to the 2E storage level in Alexandrite when pumped with wavelengths shorter than ˜645 nm causes chaotic lasing output. Shorter pump wavelengths have also been associated with increased non-radiative energy decay and reduced laser efficiency. We report studies of fluorescence emission spectra of Alexandrite illuminated at a range of wavelengths from green to red, which demonstrate reduced fluorescence yield for shorter pump wavelengths at elevated crystal temperatures. Investigations of pulsed laser pumping of Alexandrite over the same spectral range demonstrated reduced pump threshold energy for longer pump wavelengths. High repetition rate pulsed pumping of Alexandrite at 532, 578 and 671 nm showed stable and efficient laser performance was only achieved for red pumping at 671 nm. These results support the theoretical model and demonstrate the potential for scalable, red laser pumped, all-solid-state Alexandrite lasers.

Ogilvy, H.; Withford, M. J.; Mildren, R. P.; Piper, J. A.

2005-09-01

300

5-J 1.8-microsec pulse 10-pps dye laser for combustion applications.  

PubMed

A 5-J/pulse 1.8-microsec pulse width 10-Hz flashlamp-pumped tunable dye laser system has been built for performing spontaneous Raman scattering experiments in combusting media at the Combustion Research Facility, Sandia National Laboratories, Livermore. Details of construction, including a microprocessor-based diagnostic and control system, are described, and performance of the system in terms of various operating parameters is noted. PMID:20389936

Miller, C K; Lavasek, J W; Jones, E D

1982-05-15

301

AFRL Advanced Electric Lasers Branch - Construction and Upgrade of a 50-watt Facility-Class Sodium Guidestar Pump Laser  

Microsoft Academic Search

The development of a reliable and effective laser source for pumping mesospheric sodium to generate an artificial guidestar has been well documented. From the early achievements with 589nm high-power dye lasers at the Keck and Lick observatories to the ground-breaking 50W CW FASOR (Frequency Addition Source of Optical Radiation) Guidestar at the Air Forces Starfire Optical Range (SOR), there has

T. Justin Bronder; Harold Miller; Jonathan Stohs; C. Lu; J. Baker; A. Lucero

2009-01-01

302

Single mode solid state distributed feedback dye laser fabricated by gray scale electron beam lithography on a dye doped SU-8 resist  

NASA Astrophysics Data System (ADS)

We demonstrate gray scale electron beam lithography on a functionalized SU-8 resist for fabrication of single mode solid state dye laser devices. The resist is doped with Rhodamine 6G perchlorate and the lasers are based on a first-order Bragg grating distributed feedback resonator. The lasers are optically pumped at 532 nm, and exhibit low lasing threshold from 530 nJ mm-2 and single mode output at selectable wavelengths from 580 to 630 nm, determined by the grating pitch. The lasers are well suited for integration into polymer based lab-on-chip circuits for interference based sensing.

Balslev, S.; Rasmussen, T.; Shi, P.; Kristensen, A.

2005-12-01

303

Progress in discharge-pumped excimer lasers  

NASA Astrophysics Data System (ADS)

This paper describes recent results achieved in the development of discharge pumped excimer lasers at the Textron Defense Systems organization (formerly the Avco Research Laboratory). Included is a description of a KrF laser with more than one Joule output at 2.4% efficiency, a 200 mJ XeCl laser operating with a 500 nsec wide pulse, and a several Joule, discharge pumped, KrCl laser operating at 222 nm. All of these devices are switched using thyratrons and are therefore capable of repetitive performance. The KrF and XeCl experiments were conducted with the same laser device operating with a conventional capacitor transfer excitation circuit for the KrF experiments but modified to operate with a pulser-sustainer discharge circuit using magnetic switching for the XeCl tests. The KrCl device is a 40 liter volume system built by Northrop and also operates with a magnetically switched discharge.

Pike, Charles T.

1993-04-01

304

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

A XeCl laser which was developed earlier for an iodine laser oscillator was modified in order to increase the output pulse energy of XeCl laser so that the iodine laser output energy could be increased. The electrical circuit of the XeCl laser was changed from a simple capacitor discharge circuit of the XeCl laser to a Marx system. Because of this improvement the output energy from the XeCl laser was increased from 60 mj to 80 mj. Subsequently, iodine laser output energy was increased from 100 mj to 3 mj. On the other hand, the energy storage capability and amplification characteristics of the Vortek solar simulator-pumped amplifier was calculated expecting the calculated amplification factor is about 2 and the energy extraction efficiency is 26 percent due to the very low input energy density to the amplifier. As a result of an improved kinetic modeling for the iodine solar simulator pumped power amplifier, it is found that the I-2 along the axis of the tube affects seriously the gain profile. For the gas i-C3F7I at the higher pressures, the gain will decrease due to the I-2 as the pumping intensity increases, and at these higher pressures an increase in flow velocity will increase the gain.

Han, Kwang S.; Hwang, In H.; Stock, Larry V.

1988-01-01

305

Solar pumped lasers and their applications  

NASA Astrophysics Data System (ADS)

Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

Lee, Ja H.

306

Solar pumped continuous wave carbon dioxide laser  

NASA Technical Reports Server (NTRS)

In an effort to demonstrate the feasibility of a solar pumped laser concept, gain has been measured in a CO2-He laser medium optically pumped by blackbody radiation. Various gas mixtures of CO2 and He have been pumped by blackbody radiation emitted from an electrically heated oven. Using a CO2 laser as a probe, an optical gain coefficient of 1.8 x 10 to the -3rd/cm has been measured at 10.6 microns for a 9:1 CO2-He mixture at an oven temperature of about 1500 K, a gas temperature of about 400 K and a pressure of about 1 torr. This corresponds to a small signal gain coefficient when allowance is made for saturation effects due to the probe beam, in reasonable agreement with a theoretical value.

Yesil, O.; Christiansen, W. H.

1978-01-01

307

High power LD-end-pumped Nd:YVO4 laser as a pump source for Raman fiber laser  

Microsoft Academic Search

A LD-single-end-pumped Nd:YVO4 CW all-solid-state laser with maximum output power 12.5W at 1064nm was designed to pump the cascaded phosphosilicate fiber Raman laser. The Nd:YVO4 laser is lower in cost than Yb-doped cladding fiber laser which is usually used as a pump for Raman fiber laser. However, it is inefficient to couple pump beam into single mode fiber (SMF). The

Chaohong Huang; Wencai Huang; Zhengqian Luo; Guoyong Sun; Zhiping Cai

2007-01-01

308

Scaling studies of solar pumped lasers  

NASA Technical Reports Server (NTRS)

A progress report of scaling studies of solar pumped lasers is presented. Conversion of blackbody radiation into laser light has been demonstrated in this study. Parametric studies of the variation of laser mixture composition and laser gas temperature were carried out for CO2 and N2O gases. Theoretical analysis and modeling of the system have been performed. Reasonable agreement between predictions in the parameter variation and the experimental results have been obtained. Almost 200 mW of laser output at 10.6 micron was achieved by placing a small sapphire laser tube inside an oven at 1500 K the tube was filled with CO2 laser gas mixture and cooled by longitudinal nitrogen gas flow.

Christiansen, W. H.; Chang, J.

1985-01-01

309

Scaling studies of solar pumped lasers  

NASA Astrophysics Data System (ADS)

A progress report of scaling studies of solar pumped lasers is presented. Conversion of blackbody radiation into laser light has been demonstrated in this study. Parametric studies of the variation of laser mixture composition and laser gas temperature were carried out for CO2 and N2O gases. Theoretical analysis and modeling of the system have been performed. Reasonable agreement between predictions in the parameter variation and the experimental results have been obtained. Almost 200 mW of laser output at 10.6 micron was achieved by placing a small sapphire laser tube inside an oven at 1500 K the tube was filled with CO2 laser gas mixture and cooled by longitudinal nitrogen gas flow.

Christiansen, W. H.; Chang, J.

1985-08-01

310

Flashlamp-pumped iodine monobromide laser characteristics  

NASA Technical Reports Server (NTRS)

The operating characteristics of a flashlamp-pumped IBr laser were investigated to evaluate its suitability for solar-pumped laser applications. A peak power of 350 W/sq cm at 2.7 microns was achieved at 12-torr IBr pressure. At 500-J flashlamp energy, the IBr output saturated; a gain of 0.17% per cm was measured for IBr. Neon was found to be effective for enhancing the recombination of the photodissociation products. With neon as a buffer gas, the laser pulse length was extended to 53 microsec. The termination of the laser pulse, within the flashlamp pulse, is thought to be due to the temperature rise in the gas. Increasing the IBr initial temperature decreased the lasing output. At 300 C, output dropped to approximately one-half the room temperature value. The dominant quencher is thought to be atomic iodine. IBr was found to couple better to the flashlamp energy than C3F7I.

Zapata, L. E.; De Young, R. J.

1983-01-01

311

Solar-pumped CO laser  

Microsoft Academic Search

This paper describes a method of converting thermal radiation directly into laser radiation at a wavelength of about 5 micrometers. The working fluid for the laser operation is a mixture of carbon monoxide and argon. The source of thermal radiation is assumed to be a solar oven or electrical oven operating in the range of 2000 to 2500 K. The

Charles E. Treanor

1986-01-01

312

Resonance coherent anti-Stokes Raman scattering in nitrogen dioxide using a broadband dye laser  

NASA Astrophysics Data System (ADS)

We have applied electronically resonant coherent anti-Stokes Raman scattering (CARS) to the detection of nitrogen dioxide. The resonance CARS spectrum of NO2 in a sample cell was recorded around a Raman shift of 1500 cm-1 using a frequency-doubled injection-seeded single-mode Nd:YAG laser and a tunable dye laser. In particular, we demonstrate the use of a broadband Stokes laser to measure resonance CARS spectra of NO2. Recordings at various pump laser frequencies were made by temperature tuning of the Nd:YAG master laser. The pressure dependence of the signal was also investigated. The resonance CARS results are compared with laser-induced fluorescence measurements. The work shows the high resolution achievable in complex molecular spectra using resonance CARS.

Oikarinen, L.; Nyholm, K.; Kaivola, Matti; Aminoff, C. G.

1995-09-01

313

Modelling end-pumped solid state lasers  

Microsoft Academic Search

The operation dynamics of end-pumped solid-state lasers are investigated by means of a spatially resolved numerical rate-equation model and a time-dependent analytical thermal model. The rate-equation model allows the optimization of parameters such as the output coupler transmission and gain medium length, with the aim of improving the laser output performance. The time-dependent analytical thermal model is able to predict

E. H. Bernhardi; C. Bollig; A. Forbes; M. J. D. Esser; K. Wörhoff; L. Agazzi; N. Ismail; X. Leijtens

2008-01-01

314

Diode-bar-pumped planar waveguide lasers  

Microsoft Academic Search

Diode-bar lasers have been used with great success to pump high power solid state lasers in numerous different geometries; nevertheless it remains a challenge to use the highly asymmetric diode-bar output efficiently. We describe an approach to this problem in which the solid-state gain medium is fabricated as a planar waveguide, into which the high-aspect-ratio emission from the diode-bar can

A. C. Tropper; C. L. Bonner; C. T. A. Brown; D. P. Shepherd; W. A. Clarkson; D. C. Hanna

1998-01-01

315

A Modular Control Platform for a Diode Pumped Alkali Laser  

Microsoft Academic Search

Many of the difficulties of creating compact, high power laser systems can be overcome if the heat dissipating properties of chemical lasers can be combined with the efficiency of diode lasers. Recently, the novel idea of using solid state diode lasers to pump gaseous gain media, such as is done in diode pumped alkali lasers (DPALs), has been proposed and

J. Shapiro; S. Teare

2008-01-01

316

Dye-enhanced selective laser ablation for surgical mucosectomy.  

PubMed

The diode laser operates at a wavelength of 805 nm; indocyanine green (ICG) has a maximum energy absorption of a wavelength of approximately 800 nm. The effect of the diode laser as a laser knife can be significantly enhanced with an injection of ICG. In the present study, this dye-enhanced photothermal effect was investigated in the field of surgical endoscopy. A 9-cm2 region of the canine gastric mucosa was removed by the laser after injection of 5 ml of ICG solution at a concentration of 0.5 mg/mL into the submucosal space. The diode laser was used at a power output of 10 watts. The canine stomach was removed 10 days after the operation to investigate the site histologically. Clinical application using transanal endoscopic microsurgery (TEM) was employed using a dye-enhanced laser in five patients with a rectal adenoma. The pathological changes in the canine gastric wall resected 10 days after the operation showed that the low-power laser enhanced by ICG produced less fibrosis in the submucosal space than electrocautery. Mucosal resection using a dye-enhanced laser was easily performed in these five patients. It was concluded that this easy removal of the mucosa by a dye-enhanced laser was due to its ability to produce hemostasis of the vessels and its excellent tissue-cutting effect. PMID:10872619

Yamashita, Y; Sakai, T; Watanabe, K; Maekawa, T; Shirakusa, T

1999-12-01

317

Solar-pumped CO laser  

NASA Astrophysics Data System (ADS)

This paper describes a method of converting thermal radiation directly into laser radiation at a wavelength of about 5 micrometers. The working fluid for the laser operation is a mixture of carbon monoxide and argon. The source of thermal radiation is assumed to be a solar oven or electrical oven operating in the range of 2000 to 2500 K. The use of carbon monoxide as the lasing material presents the advantage that the absorbing lines can be pressure broadened to permit efficient absorption of the thermal radiation without unacceptable increases in vibrational relaxation. Estimates of the efficiency, size, and power loading of such a laser are discussed.

Treanor, Charles E.

318

Light-emitting diode pumped polymer lasers  

NASA Astrophysics Data System (ADS)

Semiconducting polymers are very promising optoelectronic materials enabling the simple fabrication of devices such as light-emitting diodes, lasers and solar cells. However, the development of polymer lasers has been hampered by the low charge mobility of these materials preventing electrically driven lasers. We find that this problem can be overcome by taking advantage of the complementary properties of inorganic semiconductors. We show that by separating the charge transporting and lasing regions in a structure combining an indium gallium nitride light-emitting diode with a semiconducting polymer distributed feedback laser, an electrically pumped hybrid polymer laser can be made. This provides a new route to simple, convenient, compact and low-cost visible lasers with the potential for applications in security, sensing, spectroscopy, and medical diagnostics.

Turnbull, G. A.; Yang, Y.; Shaw, P.; Ruseckas, A.; Samuel, I. D. W.

2008-08-01

319

Theory of an Optically Pumped Gas Laser.  

National Technical Information Service (NTIS)

A theoretical description of the steady-state operation of an optically-pumped gas laser is presented. The three-level gas is described by a suitably modified form of the Boltzmann equation. This formulation is intermediate between the rate equation and s...

J. J. Healy T. F. Morse

1972-01-01

320

Non-linear fluorescence in dye solutions induced by a low power laser  

NASA Astrophysics Data System (ADS)

Measurements of the fluorescence intensity IF, excited by two-photon pumping, have been carried out in different dye solutions by utilizing a low power cw laser ( IL ? 12 mW) and a particular experimental technique. A considerable departure from the quadratic law IF ? I2L with the varying of 2 h? - ?Ei quantity has been detected. This behaviour has bee n accounted for by considering the dependence of the non-linear and linear cross sections relative to the S 0 ? S 1 and S 0 ? S 2 transitions on the laser frequency.

Catalano, I. M.; Cingolani, A.

1980-01-01

321

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

Solar-pumped lasers were investigated by comparing experimental results from pulse experiments with steady state calculations. The time varying behavior of an IBr laser is studied. The analysis is only approximate, but indicates that conditions occurring in a pulsed experiment are quite different from those at steady state. The possibility of steady-state lasing in an IBr laser is determined. The effects of high temperatures on the quenching and recombination rates are examined. Although uncertainties in the values of the rate coefficients make it difficult to draw firm conclusions, it seems steady state running may be possible at high temperatures.

Harries, W. L.

1982-01-01

322

Laser photolysis of fluorone dyes in a chitosan matrix  

SciTech Connect

Kinetics of laser-induced photobleaching of fluorone dyes (fluorescein, dibromofluorescein, eosin Y, erythrosin B, Rose Bengal) is studied in a chitosan matrix. For all dyes the bleaching kinetics at the intensities of laser radiation 0.7 - 11.9 W cm{sup -2} demonstrates quasi-monomolecular behaviour. The results are analysed using a kinetic model, based on the four-level (S{sub 0}, S{sub 1}, T{sub 1}, T{sub n}) scheme of the dye with chemically active triplet states taken into account. It is shown that the rate constants of the chemical reaction involving higher triplet states in the dyes studied amount to (3.9 - 18.6) Multiplication-Sign 10{sup 6} s{sup -1} and exceed the analogous values for the reaction involving the first lower triplet states by nine orders of magnitude. The rate of reaction involving the first triplet states appeared to be higher by one - two orders of magnitude than that in the case of higher triplet states involved because of low population of the latter. The possible mechanism of dye bleaching with participation of chitosan that consists in reduction of the dye to the leuco form by transfer of hydrogen from the chitosan matrix is discussed. (interaction of laser radiation with matter. laser plasmas)

Slyusareva, E A; Sizykh, A G; Gerasimova, M A; Slabko, V V; Myslivets, S A

2012-08-31

323

Investigation of the dye concentration influence on the lasing wavelength and threshold for a micro-fluidic dye laser  

Microsoft Academic Search

We investigate a micro-fluidic dye laser, which can be integrated with polymer-based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the lasing threshold. The laser device is characterised using the laser dye Rhodamine 6G dissolved in ethanol, and the influence of dye concentration on the lasing wavelength and threshold is investigated. The experiments confirm

B. Helbo; S. Kragh; B. G. Kjeldsen; J. L. Reimers; A. Kristensen

2004-01-01

324

Microwave accelerator E-beam pumped laser  

DOEpatents

A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

Brau, Charles A. (Los Alamos, NM) [Los Alamos, NM; Stein, William E. (Los Alamos, NM) [Los Alamos, NM; Rockwood, Stephen D. (Los Alamos, NM) [Los Alamos, NM

1980-01-01

325

High power diode lasers for solid-state laser pumps  

NASA Technical Reports Server (NTRS)

The development and commercial application of high power diode laser arrays for use as solid-state laser pumps is described. Such solid-state laser pumps are significantly more efficient and reliable than conventional flash-lamps. This paper describes the design and fabrication of diode lasers emitting in the 780 - 900 nm spectral region, and discusses their performance and reliability. Typical measured performance parameters include electrical-to-optical power conversion efficiencies of 50 percent, narrow-band spectral emission of 2 to 3 nm FWHM, pulsed output power levels of 50 watts/bar with reliability values of over 2 billion shots to date (tests to be terminated after 10 billion shots), and reliable operation to pulse lengths of 1 ms. Pulse lengths up to 5 ms have been demonstrated at derated power levels, and CW performance at various power levels has been evaluated in a 'bar-in-groove' laser package. These high-power 1-cm stacked-bar arrays are now being manufactured for OEM use. Individual diode laser bars, ready for package-mounting by OEM customers, are being sold as commodity items. Commercial and medical applications of these laser arrays include solid-state laser pumping for metal-working, cutting, industrial measurement and control, ranging, wind-shear/atmospheric turbulence detection, X-ray generation, materials surface cleaning, microsurgery, ophthalmology, dermatology, and dental procedures.

Linden, Kurt J.; Mcdonnell, Patrick N.

1994-01-01

326

High power diode lasers for solid-state laser pumps  

NASA Astrophysics Data System (ADS)

The development and commercial application of high power diode laser arrays for use as solid-state laser pumps is described. Such solid-state laser pumps are significantly more efficient and reliable than conventional flash-lamps. This paper describes the design and fabrication of diode lasers emitting in the 780 - 900 nm spectral region, and discusses their performance and reliability. Typical measured performance parameters include electrical-to-optical power conversion efficiencies of 50 percent, narrow-band spectral emission of 2 to 3 nm FWHM, pulsed output power levels of 50 watts/bar with reliability values of over 2 billion shots to date (tests to be terminated after 10 billion shots), and reliable operation to pulse lengths of 1 ms. Pulse lengths up to 5 ms have been demonstrated at derated power levels, and CW performance at various power levels has been evaluated in a 'bar-in-groove' laser package. These high-power 1-cm stacked-bar arrays are now being manufactured for OEM use. Individual diode laser bars, ready for package-mounting by OEM customers, are being sold as commodity items. Commercial and medical applications of these laser arrays include solid-state laser pumping for metal-working, cutting, industrial measurement and control, ranging, wind-shear/atmospheric turbulence detection, X-ray generation, materials surface cleaning, microsurgery, ophthalmology, dermatology, and dental procedures.

Linden, Kurt J.; McDonnell, Patrick N.

1994-02-01

327

A modified pump laser system to pump the titanium sapphire laser  

NASA Technical Reports Server (NTRS)

As a result of the wide tunability of the titanium sapphire laser NASA has sited it to be used to perform differential absorption lidar (DIAL) measurements of H2O vapor in the upper and lower troposphere. The titanium sapphire laser can provide a spectrally narrow (0.3 to 1.0 pm), high energy (0.5 to 1.0 J) output at 727, 762, and 940 nm which are needed in the DIAL experiments. This laser performance can be obtained by addressing the line-narrowing issues in a master oscillator and the high energy requirement in a fundamental mode oscillator. By injection seeding, the single frequency property of the master oscillator can produce a line narrow high energy power oscillator. A breadboard model of the titanium sapphire laser that will ultimately be used in NASA lidar atmospheric sensing experiment is being designed. The task was to identify and solve any problem that would arise in the actual laser system. One such problem was encountered in the pump laser system. The pump laser that is designed to pump both the master oscillator and power oscillator is a Nd:YLF laser. Nd:YLF exhibits a number of properties which renders this material an attractive option to be used in the laser system. The Nd:YLF crystal is effectively athermal; it produces essentially no thermal lensing and thermally induced birefringence is generally insignificant in comparison to the material birefringence resulting from the uniaxial crystal structure. However, in application repeated fracturing of these laser rods was experience. Because Nd:YLF rods are not commercially available at the sizes needed for this application a modified pump laser system to replace the Nd:YLF laser rod was designed to include the more durable Nd:YAG laser rods. In this design, compensation for the thermal lensing effect that is introduced because of the Nd:YAG laser rods is included.

Petway, Larry B.

1990-01-01

328

Preparation of 6-hydroxyindolines and their use for preparation of novel laser dyes  

DOEpatents

A novel method is described for the synthesis of 6-hydroxyindolines and new fluorescent dyes produced therefrom, which dyes are ring-constrained indoline-based rhodamine class dyes. These dyes have absorption and emission spectra which make them particularly useful in certain dye laser applications.

Field, G.F.; Hammond, P.R.

1993-10-26

329

Preparation of 6-hydroxyindolines and their use for preparation of novel laser dyes  

DOEpatents

A novel method for the synthesis of 6-hydroxyindolines and new fluorescent dyes produced therefrom, which dyes are ring-constrained indoline-based rhodamine class dyes. These dyes have absorption and emission spectra which make them particularly useful in certain dye laser applications.

Field, George F. (Danville, CA); Hammond, Peter R. (Livermore, CA)

1993-01-01

330

Simultaneously tunable two-wavelength dye laser using two dielectric multilayer filters  

NASA Astrophysics Data System (ADS)

A nitrogen-laser-pumped tunable dye laser using a single dielectric multilayer filter as the tuning element has been reported by Nomura et al. (1982). A description is given here of a simultaneous tunable two-wavelength dye laser pumped by a nitrogen laser using a second dielectric multilayer filter to extend the first. The first dielectric multilayer filter (1-nm FWHM at 467.9 nm; 50 percent peak transmittance), which is inserted between two mirrors having reflectivities of 70 percent and 100 percent, tunes at one wavelength. The light is reflected by the layer over nearly the whole of the wavelength region, except the transmitted wavelength, which is tuned by the two mirrors. Another wavelength is selected by the second dielectric multilayer filter (1-nm FWHM at 468.9 nm; 50 percent peak transmittance), which is inserted between the first filter and a third mirror, whose reflectivity is 100 percent. It is pointed out that this laser can be used in a differential absorption lidar system because of the perfect collinearity of the tuning spectra.

Saito, Y.; Teramura, T.; Nomura, A.; Kano, T.

1983-06-01

331

Triplet extinction coefficients of some laser dyes I  

SciTech Connect

We measured the triplet extinction coefficients epsilon/sub T/ over the laser action spectral region of Rhodamine 6G; Rhodamine B; Rhodamine 110; Fluorol-7GA; Coumarin 540A; Coumarin 522; Coumarin 1; Coumarin 120; 4,4'-diphenyl stilbene; and 2,7-bis-(4-methoxy-phenyl)-9,9-dipropylfluorene. We employed the different lines from an argon ion cw laser for excitation. McClure's method was used to obtain the triplet extinction coefficients epsilon/sub T/. The method requires the measurement of triplet optical densities OD/sub T/ as a function of different cw laser excitation intensities (powers) I/sub ex/ . The importance of triplet-state losses on dye laser efficiency is reviewed. The laser action properties of the laser dyes we studied are briefly discussed as they relate to the measured epsilon/sub T/ values.

Pavlopoulos, T.G.; Golich, D.J.

1988-07-15

332

Conversion of the luminescence of laser dyes in opal matrices to stimulated emission  

SciTech Connect

The luminescence and laser characteristics of a synthetic opal matrix filled with organic dyes are studied upon excitation by nanosecond laser pulses. The appearance of stimulated emission in a partially ordered scattering medium is investigated. It is shown that if the luminescence spectrum of a dye (oxazine-17) is located far outside the photonic bandgap of the opal matrix, stimulated emission along a preferential direction in the (111) plane is observed when pumping exceeds a threshold even without an external optical cavity. The stimulated emission spectrum is considerably narrower than the luminescence spectrum and consists of several narrow lines located within the dye luminescence band. If the luminescence spectrum of a dye (rhodamine 6G) overlaps with the photonic bandgap of the opal matrix, a different picture is observed. The loss of radiation in the matrix leads to the red shift of the luminescence spectrum, while the stimulated emission as in the case of oxazine-17 lies is observed within the luminescence band. (active media, lasers, and amplifiers)

Alimov, O K [Institute of Nuclear Physics, Academy of Sciences of Uzbekistan, Tashkent (Uzbekistan); Basiev, T T; Orlovskii, Yu V; Osiko, V V [Laser Materials and Technology Research Center, A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Samoilovich, M I [Tekhnomash Central Research Technological Institute, Moscow (Russian Federation)

2008-07-31

333

Polymer photonic crystal dye lasers as label free evanescent cell sensors  

NASA Astrophysics Data System (ADS)

Dye doped polymer photonic crystal band edge lasers are applied for evanescent wave sensing of cells. The lasers are rectangular shaped slab waveguides of dye doped polymer on a glass substrate, where a photonic crystal is formed by 100 nm deep air-holes in the surface of the 375 nm high waveguides. The lasers are fabricated by combined nanoimprint and photolithography (CNP) in Ormocore hybrid polymer doped with the laser dye Pyrromethene 597. The lasers emit in the chip plane at a wavelength around 595 nm when pumped with 5 ns pulses from a compact frequency doubled Nd:YAG laser. We investigate the sensitivity of photonic crystal band-edge lasers to partial coverage with HeLa cells. The lasers are chemically activated with a flexible UV activated anthraquinone based linker molecule, which enables selective binding of cells and molecules. When measuring in Phosphate Buffered Saline (PBS), which has a refractive index close to that of the cells, the emission wavelength depends linearly on the cell density on the sensor surface. Our results demonstrate that nanostructured hybrid polymer lasers, which are cheap to fabricate and very simple to operate, can be selectively chemically activated with UV sensitive photolinkers for further bioanalytical applications. This opens the possibility to functionalize arrays of optofluidic laser sensors with different bio-recognition molecules for multiplexed sensing. The linear relationship between cell coverage and wavelength indicates that the slight refractive index perturbation from the partial coverage of the sensor influences the entire optical mode, rather than breaking down the photonic crystal feedback.

Christiansen, Mads B.; Lopacinska, Joanna M.; Jakobsen, Mogens H.; Mortensen, Niels A.; Dufva, Martin; Kristensen, Anders

2009-08-01

334

Efficient pumping of inertial fusion energy lasers  

NASA Astrophysics Data System (ADS)

Solid-state lasers have been demonstrated as attractive drivers for laser-plasma interaction and have presently been developed for various applications like inertial confinement fusion (ICF) [1], particle acceleration and intense X-ray generation [3]. Viable real world applications like power production at industrial scale will require high laser system efficiency, repetition rate and lifetime which are only possible with semiconductor diode pumping. The paper describes the work conducted with two 20 kW diode laser sources pumping an ytterbium:YAG laser amplifier. The set-up acts as a small scale prototype for the DiPOLE project [2]. This project aims to develop scalable gas cooled cryogenic multi-slab diode pumped solid state lasers capable of producing KJ pulse energy. A scale-down prototype is currently under development at the Central Laser Facility (CLF) designed to generate 10 J at 10 Hz. To secure an efficient pumping process the sources have to fulfill aside power requirement in the spectral and time domain, the claim for high homogenization and low divergence of the spatial and angular beam distribution as well as a minimization of losses within the optical path. The existing diode laser sources designed and built by INGENERIC deliver 20 kW pulsed power, concentrated on a plateau of FWHM dimension of 20 x 20 mm² with a homogeneity of more than 90 %. The center wavelength of 939.5 nm is controlled in a range of ± 0.1 nm. The time and area integrated spectrum of at least 76 % of the total energy is contained within a 6 nm wide wavelength band around the center wavelength. Repetition rates can be adjusted between 0.1 Hz up to 10 Hz with rise and fall times less than 50 ?s and pulse durations from 0.2 ms to 1.2 ms. The paper describes the impact of different designs on the performance of pump sources and puts special emphasis on the influence of the optical components on efficiency and performance. In addition the influence of the measuring principle is discussed.

Wessling, C.; Rübenach, O.; Hambücker, S.; Sinhoff, V.; Banerjeea, S.; Ertel, K.; Mason, P.

2013-02-01

335

Photophysical and laser emission studies of 8-polyphenylene-substituted BODIPY dyes in liquid solution and in solid polymeric matrices.  

PubMed

In our search for efficient and photostable laser dyes, four new dyes with the basic structure of the commercial BODIPY laser dye PM567, with either an 8-diphenylene or an 8-p-triphenylene group, both substituted at the terminal polyphenylene position with an acetoxymethyl (dyes P2Ar1Ac and P3Ar1Ac, respectively) or a methacryloyloxymethyl group (dyes P2Ar1MA and P3Ar1MA, respectively), have been synthesized. The photophysical and lasing properties of the dyes have been studied both dissolved in liquid solvents (acetoxymethyl dyes) and incorporated into solid polymeric matrices, in the latter case as solutions (acetoxymethyl dyes) or as copolymers with methyl methacrylate (methacryloyloxymethyl dyes). In liquid solution, the photophysics of P2Ar1Ac and P3Ar1Ac is scarcely affected by the number (two or three) of p-phenylene units. Quantum mechanical calculations reveal that the p-phenylene units in these dyes are twisted ca. 37 degrees each other, an that the first 8-p-phenylene group stands nearly perpendicular to the aromatic BODIPY plane, resulting in electronic decoupling of the two chromophores. P2Ar1Ac exhibits a somewhat lower photodegradation quantum yield under UV and visible irradiation, if compared with P3Ar1Ac or with PM567, likely because of its also lower rate constant for the reaction with in situ-generated singlet molecular oxygen. Both acetoxymethyl dyes emit laser radiation in solution in all the solvents tried, under transversal pumping at 532 nm. In ethyl acetate, with a dye concentration of 0.80 x 10(-3) M, laser efficiencies as high as 80% have been observed. When the 8-polyphenylene dyes were incorporated into solid poly(methyl methacrylate) (PMMA) matrices, as solutions or as copolymers, the fluorescence emission increased with respect to that of the parent PM567 dye dissolved in the same matrix, and lasing efficiencies in the range 18-31% were obtained, with good photostability. The dye P2Ar1Ac dissolved in PMMA was found to exhibit the best overall laser behavior, with a good balance between efficiency and photostability. PMID:18597028

Alvarez, M; Costela, A; García-Moreno, I; Amat-Guerri, F; Liras, M; Sastre, R; López Arbeloa, F; Bañuelos Prieto, J; López Arbeloa, I

2008-07-01

336

A Coupled Cavity Micro Fluidic Dye Ring Laser  

Microsoft Academic Search

We present a laterally emitting, coupled cavity micro fluidic dye ring laser, suitable for integration into lab-on-a-chip micro systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10 microns thick SU-8 polymer on

M. Gersborg-Hansen; S. Balslev; N. A. Mortensen; A. Kristensen

2004-01-01

337

A coupled cavity micro-fluidic dye ring laser  

Microsoft Academic Search

We present a laterally emitting, coupled cavity micro-fluidic dye ring laser, suitable for integration into lab-on-a-chip micro-systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10?m thick SU-8 polymer on a glass substrate.

M. Gersborg-Hansen; S. Balslev; N. A. Mortensen; A. Kristensen

2005-01-01

338

Dye-sensitized solar cells using laser processing techniques  

Microsoft Academic Search

Laser processing techniques, such as laser direct-write (LDW) and laser sintering, have been used to deposit mesoporous nanocrystalline TiO2 (nc-TiO2) films for use in dye-sensitized solar cells. LDW enables the fabrication of conformal structures containing metals, ceramics, polymers and composites on rigid and flexible substrates without the use of masks or additional patterning techniques. The transferred material maintains a porous,

Heungsoo Kim; Alberto Pique; Gary P. Kushto; Raymond C. Y. Auyeung; S. H. Lee; Craig B. Arnold; Zakia H. Kafafi

2004-01-01

339

Dye-sensitized solar cells using laser processing techniques  

Microsoft Academic Search

Laser processing techniques, such as laser direct-write (LDW) and laser sintering, have been used to deposit mesoporous nanocrystalline TiO2 (nc-TiO2) films for use in dye-sensitized solar cells. LDW enables the fabrication of conformal structures containing metals, ceramics, polymers and composites on rigid and flexible substrates without the use of masks or additional patterning techniques. The transferred material maintains a porous,

H. Kim; R. C. Y. Auyeung; S. H. Lee; C. B. Arnold; Z. H. Kafafi

340

Solid-state dye lasers based on polymethyl methacrylate modified with methanol  

NASA Astrophysics Data System (ADS)

Solid-state dye samples based on modified polymethyl methacrylate with methanol (MPMMA) doped with pyrromethene 567 (PM567) were first prepared. The effects of volume percentage of methanol on the laser performances of the samples, including spectra properties, slope efficiency and photostability were studied. The highest slope efficiency 66.39% was obtained in the sample (MMA:methanol = 16:4). Pumping the samples at a repetition rate of 5 Hz with a pulse energy as high as 100 mJ (the fluence was 0.26 J/cm2), the output energy dropped to half of its initial value after approximate 156720 shots and the corresponding normalized photostability reached 101.86 GJ/mol in the sample (MMA:methanol = 17:3). Our results indicate that it can obtain a high slope efficiency and good photostability for a solid-state dye laser using MPMMA as solid hosts.

Jiang, Y. G.; Fan, R. W.; Xia, Y. Q.; Chen, D. Y.

2011-02-01

341

Angioma serpiginosum: dermoscopy for diagnosis, pulsed dye laser for treatment.  

PubMed

Angioma serpiginosum is a rare benign vascular disorder, characterized clinically by multiple minute, red to purple, grouped macules in serpiginous and gyrate patterns and histopathologically by ectatic dilatation of capillaries. Patients can undergo unnecessary hematological tests, because the condition can be confused with chronic purpuric dermatoses. An 18-year-old man with angioma serpiginosum of his left arm was evaluated by dermoscopy and treated with pulsed dye laser. Numerous small, relatively well-demarcated, round to oval red lagoons were determined with dermoscopy, and approximately 75% of the area of his lesion disappeared after four sessions of pulsed dye laser. Our case supports the hypothesis that dermoscopy is beneficial in the diagnosis of angioma serpiginosum and that pulsed dye laser is effective in the treatment of this disorder. PMID:16674788

Ilknur, Turna; Fetil, Emel; Akarsu, Sevgi; Altiner, Didem Didar; Uluku?, Ca?nur; Güne?, Ali Tahsin

2006-04-01

342

Physics of fusion pumped lasers  

NASA Astrophysics Data System (ADS)

A novel concept is described which utilizes a liquified rare gas as both an energy converter and high-density lasing media. The concept allows the advantage of the large mean-free path of high energy fusion neutrons together with a highly-efficient mechanism for volumetric production of 1 MeV electrons which causes ionization and excitation throughout the medium. This scheme coupled together with the high efficiency for light production of liquid excimers may provide the possibilities for a new dimension in high power lasers.

Pappas, D. S.

1989-08-01

343

Terahertz graphene lasers: Injection versus optical pumping  

NASA Astrophysics Data System (ADS)

We analyze the formation of nonequilibrium states in optically pumped graphene layers and in forward-biased graphene structures with lateral p-i-n junctions and consider the conditions of population inversion and lasing. The model used accounts for intraband and interband relaxation processes as well as deviation of the optical phonon system from equilibrium. As shown, optical pumping suffers from a significant heating of both the electron-hole plasma and the optical phonon system, which can suppress the formation of population inversion. In the graphene structures with p-i-n junction, the injected electrons and holes have relatively low energies, so that the effect of cooling can be rather pronounced, providing a significant advantage of the injection pumping in realization of graphene terahertz lasers.

Ryzhii, Victor; Otsuji, Taiichi; Ryzhii, Maxim; Mitin, Vladimir

2013-12-01

344

Solar-pumped gas laser development  

NASA Technical Reports Server (NTRS)

A survey of gas properties through detailed kinetic models led to the identification of critical gas parameters for use in choosing appropriate gas combinations for solar pumped lasers. Broadband photoabsorption in the visible or near UV range is required to excite large volumes of gas and to insure good solar absorption efficiency. The photoexcitation density is independent of the absorption bandwidth. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than 10 A to insure lasing threshold over reasonable gain lengths. The system should show a high degree of chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. Although photoexcitation of electronic vibrational transitions is considered as a possible system if the emission bands sufficiently narrow, it appears that photodissociation into atomic metastables is more likely to result in a successful solar pumped laser system.

Wilson, J. W.

1980-01-01

345

Chemical stabilization of laser dyes. Final report, 1 December 1984-28 February 1987  

SciTech Connect

Coumarin laser dyes upon excitation degrade to produce products that absorb at the lasing wavelength. This results in attenuation of dye laser output through interference of stimulated emission. The roles of singlet oxygen and excitation intensity on dye degradation were explored. Singlet oxygen is formed but its reactions with the dye do not appear to be a major cause of dye laser output deterioration. High light intensity results in dye-sensitized, solvent oligomerization to yield materials that interfere with dye-stimulated emission. 1, 4-Diazabicyclo2,2,2octane (DABCO)inhibits this oligomerization.

Koch, T.H.

1987-05-07

346

Feasibility study: Monodisperse polymer particles containing laser-excitable dyes  

NASA Technical Reports Server (NTRS)

The objective was to determine the feasibility of the preparation of monodisperse spherical poly(methyl methacrylate) and polystyrene particles that contain laser-excitable dyes in the size range 0.1 microns to 1 cm. Poly(methyl methacrylate) and polystyrene were chosen because of their excellent optical properties. The sphericity was required for uniformity of spectral output of re-irradiated light from the dye-containing particles. The monodispersity was required to give each particle the same optical properties when exposed to laser light.

Vanderhoff, John W.; Chen, Jing-Hong

1993-01-01

347

Solar-pumped laser for free space power transmission  

NASA Technical Reports Server (NTRS)

Laser power transmission; laser systems; space-borne and available lasers; 2-D and 1 MW laser diode array systems; technical issues; iodine solar pumped laser system; and laser power transmission applications are presented. This presentation is represented by viewgraphs only.

Lee, Ja H.

1989-01-01

348

IMPROVED MICROFLUIDIC DESIGN OF AN ON-CHIP TUNABLE DYE LASER  

Microsoft Academic Search

We present a new improved microfluidic design of a tunable micro fluidic dye laser. The tunability relies on control of the dye (Rhodamine 6G) concentration in the laser cavity by means of a microfluidic diffusion mixer. This has been realized by integrating a new improved diffusion mixer design with an existing microfluidic dye laser design. By integration of high and

B. Bilenberg; J. P. Kutter; A. Kristensen

349

Grating THz laser with optical pumping  

NASA Astrophysics Data System (ADS)

In this paper, we present a design for a widely tunable solid-state optically and electrically pumped THz laser based on the Smith-Purcell free-electron laser. In the free-electron laser, an energetic electron beam pumps a metallic grating to generate surface plasmons. Our solid-state optically pumped design consists of a thin layer of dielectic, such as SiNx, sandwiched between a corrugated structure and a thin metal or semiconductor layer. The lower layer is for current streaming, and replaces the electron beam in the original design. The upper layer consists of one micro-grating for coupling the electromagnetic field in, another for coupling out, and a nano-grating for coupling with the current in the lower layer for electromagnetic field generation. The surface plasmon waves generated from the upper layer by an external electromagnetic field, and the lower layer by the applied current, are coupled. Emission enhancement occurs when the plasmonic waves in both layers are resonantly coupled.

Khoury, Jed; Haji-Saeed, Bahareh; Woods, Charles; Kierstead, John

2010-04-01

350

Efficient flashlamp-pumped IBr laser  

NASA Technical Reports Server (NTRS)

The operating characteristics and scaling parameters of a flashlamp-pumped, 4-m-long IBr laser were investigated to further evaluate its potential as a solar-pumped laser. A peak power of 3 kW/sq cm at 2.7 microns was achieved at 4-Torr IBr pressure. A gain of 0.07 per m was measured at a maximum capacitor discharge energy of 4 kJ. The threshold input power necessary for lasing was found to decrease by a factor of 4 and the laser pulse width increased fourfold as the active gain length was increased from 1 to 4 m. A maximum pulse width of 120 microseconds was achieved with 10-Torr argon diluent added to 4-Torr IBr. Quenching of the excited state by the parent molecule was shown to be unimportant for pressures less than 4-Torr IBr. An intrinsic efficiency in the range of 12 percent has been measured for flashlamp-pumped IBr.

Zapata, L. E.; De Young, R. J.

1985-01-01

351

Scalable pump source for diode pumped alkali laser  

NASA Astrophysics Data System (ADS)

External cavity diode laser systems are well-suited for diode pumped alkali laser (DPAL) systems due to their high power efficiency and excellent wavelength control under changing thermal loads. By conditioning the characteristics of feedback power, external cavities can narrow the spectral bandwidth and limit transverse modes of diode laser bars. Existing configurations typically use low-efficiency diffraction gratings at the Littrow angle to send back to the diodes a small fraction of the power, while directing the majority of the power forward in the output beam. We previously reported that a stepped mirror allows a single external cavity to condition the output beams of a stack of diode array bars. In this report, we describe a new approach that could use a single external cavity to condition the output beams of several hundred diode array bars. A high efficiency grating is used to feedback essentially all the power in the external cavity, and power splitters then distribute the power to multiple diode array stacks. A 384 bar module capable of 20 kW power output into a modelimited slowly diverging beam with a spectral width below 0.050 nm has been designed and proposed for use in a DPAL. A 50 bar 3 kW prototype is currently being assembled.

Hersman, F. W.; Distelbrink, J. H.; Ketel, J.; Sargent, D.; Watt, D. W.

2014-02-01

352

Role of pumping statistics in laser dynamics: Quantum Langevin approach  

Microsoft Academic Search

We study in detail the influence of pumping statistics on the laser dynamics. We apply the technique of quantum Langevin operators and generalize the corresponding noise operators to incorporate the statistical properties of the pump mechanism. These equations are then used to derive expressions for the phase and intensity fluctuations of lasers with various pump statistics. We find that a

Claus Benkert; M. O. Scully; J. Bergou; L. Davidovich; M. Hillery; M. Orszag

1990-01-01

353

A blackbody radiation-pumped CO2 laser experiment  

NASA Astrophysics Data System (ADS)

Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping.

Christiansen, W. H.; Insuik, R. J.; Deyoung, R. J.

1982-09-01

354

Laser Field Induced Azimuthal Anchoring Gliding in Dye Doped Nematic Liquid Crystals  

NASA Astrophysics Data System (ADS)

We have analyzed the rotating effect of an Ar+ linearly polarized laser beam on a dye-doped nematic liquid crystal (DDNLC) in a pump-probe experiment. An asymmetric capillary cell with two polymer coated glasses was used. An easy axis was induced by rubbing one surface, the other one remained non-oriented. The exciting laser beam entering the orienting surface has the polarization direction perpendicular to the easy axis. The time dependent transmitted intensity of a probe He-Ne laser beam (polarization direction parallel to the easy axis) has been measured. For large enough Ar+ laser power a non-monotonous curve (having one or even two maxima) has been observed. We develop a model which explains our experimental data by taking into account the gliding of the easy axis on the orienting surface. The azimuthal anchoring gliding angle has been estimated.

P?l?rie, Ion; E?eanu, Nicoleta

355

The influence of the easy axis on laser-induced ripple structures in dye-doped liquid crystal films  

NASA Astrophysics Data System (ADS)

We have investigated the role of the easy axis in the photoalignment effect induced by an Ar+ linearly polarized laser beam on a dye-doped nematic liquid crystal cell in a pump-probe experiment. The induced permanent structure in the irradiated zones was studied using a polarizing optical microscope, and the laser-induced surface morphology was studied by atomic force microscopy. The depth of the ripple structure depends on both the pump power and the irradiated surfaces. The azimuthal anchoring energy provided by the ripple structure was evaluated and it was concluded that it varies with the cell's symmetry.

Palarie, I.; Dascalu, C.; Iacobescu, G. E.

2010-12-01

356

Laser photolysis of fluorone dyes in a chitosan matrix  

NASA Astrophysics Data System (ADS)

Kinetics of laser-induced photobleaching of fluorone dyes (fluorescein, dibromofluorescein, eosin Y, erythrosin B, Rose Bengal) is studied in a chitosan matrix. For all dyes the bleaching kinetics at the intensities of laser radiation 0.7 — 11.9 W cm-2 demonstrates quasi-monomolecular behaviour. The results are analysed using a kinetic model, based on the four-level (S0, S1, T1, Tn) scheme of the dye with chemically active triplet states taken into account. It is shown that the rate constants of the chemical reaction involving higher triplet states in the dyes studied amount to (3.9 — 18.6) × 106 s-1 and exceed the analogous values for the reaction involving the first lower triplet states by nine orders of magnitude. The rate of reaction involving the first triplet states appeared to be higher by one — two orders of magnitude than that in the case of higher triplet states involved because of low population of the latter. The possible mechanism of dye bleaching with participation of chitosan that consists in reduction of the dye to the leuco form by transfer of hydrogen from the chitosan matrix is discussed.

Slyusareva, E. A.; Sizykh, A. G.; Gerasimova, M. A.; Slabko, V. V.; Myslivets, S. A.

2012-08-01

357

Advanced solar energy conversion. [solar pumped gas lasers  

NASA Technical Reports Server (NTRS)

An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

Lee, J. H.

1981-01-01

358

Efficiency of Nd laser materials with laser diode pumping  

NASA Technical Reports Server (NTRS)

For pulsed laser-diode-pumped lasers, where efficiency is the most important issue, the choice of the Nd laser material makes a significant difference. The absorption efficiency, storage efficiency, and extraction efficiency for Nd:YAG, Nd:YLF, Nd:GSGG, Nd:BEL, Nd:YVO4, and Nd:glass are calculated. The materials are then compared under the assumption of equal quantum efficiency and damage threshold. Nd:YLF is found to be the best candidate for the application discussed here.

Barnes, Norman P.; Cross, Patricia L.; Skolaut, Milton W., Jr.; Storm, Mark E.

1990-01-01

359

Comparison of the performance of photonic band-edge liquid crystal lasers using different dyes as the gain medium  

NASA Astrophysics Data System (ADS)

The primary concern of this work is to study the emission characteristics of a series of chiral nematic liquid crystal lasers doped with different laser dyes (DCM, pyrromethene 580, and pyrromethene 597) at varying concentrations by weight (0.5-2 wt %) when optically pumped at 532 nm. Long-wavelength photonic band-edge laser emission is characterized in terms of threshold energy and slope efficiency. At every dye concentration investigated, the pyrromethene 597-doped lasers exhibit the highest slope efficiency (ranging from 15% to 32%) and the DCM-doped lasers the lowest (ranging from 5% to 13%). Similarly, the threshold was found to be, in general, higher for the DCM-doped laser samples in comparison to the pyrromethene-doped laser samples. These results are then compared with the spectral properties, quantum efficiencies and, where possible, fluorescence lifetimes of the dyes dispersed in a common nematic host. In accordance with the low thresholds and high slope efficiencies, the results show that the molar extinction coefficients and quantum efficiencies are considerably larger for the pyrromethene dyes in comparison to DCM, when dispersed in the liquid crystal host.

Mowatt, Carrie; Morris, Stephen M.; Song, Myoung Hoon; Wilkinson, Timothy D.; Friend, Richard H.; Coles, Harry J.

2010-02-01

360

Optically pumped mid-infrared vibrational hydrogen chloride laser  

NASA Astrophysics Data System (ADS)

The results of an experimental investigation of an optically pumped vibrational laser in HCl are reported. Two different excitation sources were used: a Nd:yttrium-aluminum-garnet laser pumped optical parametric oscillator and a Raman shifted alexandrite laser. Overtone pumping on the (2,0) and (3,0) bands was employed to produce laser oscillation on the (3,2) and (2,1) bands near 3.8 ?m. We also developed a model for the optically pumped laser and compare predictions of the model to the observed behavior of the laser. The photon efficiency of the HCl laser was found to be approximately 60%, consistent with model predictions and with previous optically pumped hydrogen halide lasers.

Miller, Harold C.; McCord, John; Hager, Gordon D.; Davis, Steven J.; Kessler, William J.; Oakes, David B.

1998-10-01

361

Diode-pumped 10 W continuous wave cesium laser  

Microsoft Academic Search

An efficient cesium vapor laser pumped with a continuous wave laser diode array has been demonstrated. The linewidth of the pump source was narrowed using the external cavity to match it to the cesium absorption line. The output power of the continuous wave cesium laser was 10 W, which exceeds previous results by more than a factor of 10, and

Boris Zhdanov; R. J. Knize

2007-01-01

362

Amplified spontaneous emission in solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

The amplified spontaneous emission (ASE) from a long pulse, solar-simulating radiation pumped iodine laser amplifier is studied. The ASE threshold pump intensity is almost proportional to the inverse of the laser gain length when the gas pressure is constant in the laser tube.

Cho, Yong S.; Hwang, In H.; Han, Kwang S.; Lee, Ja H.

1992-01-01

363

Optical properties of a nuclear reactor pumped gas laser  

Microsoft Academic Search

Ray paths and focal lengths are derived to fourth order for a nuclear-reactor wall-pumped gas laser. Ray paths in the laser gain cell are shown to be nearly random for a long gain region. Focal lengths calculated from the ray paths exiting the laser are shown to oscillate between + or - infinity during pumping. The use of stimulated Brillouin

A. Corvo

1991-01-01

364

High-power diode-pumped solid state lasers  

NASA Astrophysics Data System (ADS)

Although operational for over twenty years, diode pumped solid state lasers have, for most of their existence, been limited to individual diodes pumping a tiny volume of active medium in an end pumped configuration. More recent years have witnessed the appearance of diode bars, packing around 100 diodes in a 1 cm bar which have enabled end and side pumped small solid state lasers at the few watt level of output. This paper describes the subsequent development of how proper cooling and stacking of bars enables the fabrication of multi kW average power diode pump arrays with irradiances of 1 kW/cm peak and 250 W/cm2 average pump power. Since typical conversion efficiencies from the diode light to the pumped laser output light are of order 30% or more, kW average power diode pumped solid state lasers now are possible.

Solarz, Richard W.; Albrecht, Georg F.; Beach, Raymond J.; Comaskey, Brian J.

1993-05-01

365

a Blackbody-Pumped Carbon Dioxide Laser  

NASA Astrophysics Data System (ADS)

A proof of concept experiment has been carried out to demonstrate the feasibility of using blackbody radiation to pump a gas laser. Building on earlier experiments in which optical gain was measured in a CO(,2) laser mixture exposed to blackbody radiation at a temperature of 1500(DEGREES)K, continuous wave oscillation of CO(,2) has been achieved, for the first time, using radiation from a blackbody cavity as the pump source. This was made possible by actively cooling the laser mixture as it was exposed to the radiation field of an electrically heated oven. Output power measurements are presented from a series of experiments using mixtures of CO(,2), He, and Ar. Maximum output power was obtained with a 20%CO(,2) - 15%He- 65%Ar mixture at pressures around 6-10 Torr. The output power was found to vary greatly with the gas temperature and the blackbody temperature. By varying these parameters output powers up to 8 mW have been achieved. The effects of the buffer gas are also shown to be important. Based on the experimental results, it is believed that the buffer gas is needed to inhibit diffusion of the excited species out of the laser mode volume. This diffusion leads to deactivation at the walls. Adding more CO(,2) results in a decrease in output power, indicating that the gas has a finite optical depth and the mode volume is not pumped if too much CO(,2) is present. A model which incorporates these effects is presented. The predicted small signal gains and powers based on this model adequately match the trends observed experimentally.

Insuik, Robin Joy

366

Nuclear-pumped CO2 laser  

NASA Technical Reports Server (NTRS)

The He-3 (n,p)T reaction was examined as an energy source for a CO2 laser. For this purpose He-3 was added to a functioning CO2 electrically excited laser. Initially the laser was run electrically with 12 torr total pressure. The gas mixture was 1:1:8, CO2:N2:He. At zero reactor power, the laser was tested in place next to the core of the Georgia Tech. Research Reactor. After verification of laser action He-3 was added to the system. The He-3 partial pressures of 10 torr, 50 torr, and 300 torr were added in three separate reactor runs. Reactor power ranged from zero to 5 million watts, which corresponds to a peak flux of 10 to the 14th power/sq cm. At reactor powers greater than 10 kW, gain of up to 30 percent was shown. However, indications are this may be due to gamma excitation rather than caused by the He-3 (n,p)T reaction. These results do agree with the data of past CO2 nuclear pumped laser experiments.

Rowe, M.

1979-01-01

367

Solid-state laser pumping by light guides  

SciTech Connect

What we believe to be novel pumping schemes for lamp-pumped solid-state lasers are proposed. Based on the refractive and total internal reflection principles, curved fused-silica light guides of rectangular cross sections are used to couple the pump radiation from an arc lamp into a laser crystal. The performances of light-guide pumping schemes are analyzed through a nonsequential ray-trace program and are compared to that of a single elliptical cavity. Improved pump radiation distribution around the laser crystal was registered. The light-guide cavities also permit tailoring the pump flux distribution within the active medium. A lamp-pumped Nd:YAG laser by alight-guide cavity was built and tested. An overall laser efficiency of 1.1% was measured.

Bernardes, Pedro H.; Liang Dawei

2006-06-01

368

Feasibility Study: Monodisperse Polymer Particles Containing Laser-Excitable Dyes.  

National Technical Information Service (NTIS)

The objective was to determine the feasibility of the preparation of monodisperse spherical poly(methyl methacrylate) and polystyrene particles that contain laser-excitable dyes in the size range 0.1 microns to 1 cm. Poly(methyl methacrylate) and polystyr...

J. W. Vanderhoff J. Chen

1993-01-01

369

Laser sintering of photoelectrode layers for Dye Solar Cell technology  

Microsoft Academic Search

Scanning laser processing has become a useful and often used tool in thin film solar cell industries, since it enables precise, low cost, non-contact and highly automated fabrication processes such as scribing, patterning, marking, edge deletion, local melting and sintering. Dye solar cells (DSCs) are electrochemical photovoltaic devices representing an attractive technology for large area solar energy conversion since they

G. Mincuzzi; L. Vesce; R. Riccitelli; A. Reale; A. Di Carlo; T. M. Brown

2009-01-01

370

Distortion Tolerance against Geometry Imperfections in Polymeric Microcavity Dye Laser  

Microsoft Academic Search

A polymeric solid-state microcavity dye laser of the size comparable to a lasing wavelength is modeled by means of the finite element method (FEM). Lasing modes are calculated taking into account the gain material properties, such as absorption, dispersion and fluorescence. Study of the microcavity tolerance against possible geometrical imperfections demonstrates good robustness of the chosen shape and stability of

Rui Zhang; Sergei Popov; Sebastien Ricciardi; Ari T. Friberg; Sergey Sergeyev

2008-01-01

371

Convenient Microscale Synthesis of a Coumarin Laser Dye Analog  

ERIC Educational Resources Information Center

Coumarin (2H-1-benzopyran-2-one) and its derivatives constitute a fascinating class of organic substances that are utilized industrially in areas such as cosmetics, food preservatives, insecticides and fluorescent laser dyes. The product can be synthesized, purified, and characterized within two hours with benefits of microscale reactivity being…

Aktoudianakis, Evangelos; Dicks, Andrew P.

2006-01-01

372

The passively mode locked coumarin 6H ring dye laser  

NASA Astrophysics Data System (ADS)

A colliding pulse mode locked ring dye laser is described in which Coumarin 6H was passively mode locked using 3, 3'-diethyl oxacarbocyanine iodide (DOCI). Pulses of less than 500 fs duration were obtained from 492 to 507 nm, the shortest pulses being of 110 fs at 497 nm.

French, P. M. W.; Taylor, J. R.

1988-06-01

373

Multi-wavelength oscillation DFB solid-state dye laser with cascade-arranged gratings  

Microsoft Academic Search

Solid-state dye lasers have been developed as compact and easy-to-handle coherent light sources. In particular, distributed feedback (DFB) solid-state dye lasers are able to emit narrow-banded single-mode laser beams. In DFB lasers, the diffraction grating is a key device for selecting the laser oscillation wavelength from a fluorescent band of organic dye. We adopted an \\

N. Nakai; M. Fukuda

2007-01-01

374

Recycle Rate in a Pulsed, Optically Pumped Rubidium Laser  

Microsoft Academic Search

A pulsed, optically pumped rubidium laser operating in analogy to the diode pumped alkali laser (DPAL) system at pump intensities as high as 750 kW\\/cm2 has been demonstrated with output energies of up to 13 muJ\\/pulse. Output energy is dramatically limited by spin-orbit relaxation rates under these high intensity pump conditions. More than 250 photons are available for every rubidium

Wooddy S. Miller; Clifford V. Sulham; Jeremy C. Holtgrave; Glen P. Perram

2010-01-01

375

Recycle Rate in a Pulsed, Optically Pumped Rubidium Laser  

Microsoft Academic Search

A pulsed, optically pumped rubidium laser operating in analogy to the diode pumped alkali laser (DPAL) system at pump intensities as high as 750 kW?cm2 has been demonstrated with output energies of up to 13 ?J?pulse. Output energy is dramatically limited by spin-orbit relaxation rates under these high intensity pump conditions. More than 250 photons are available for every rubidium

Wooddy S. Miller; Clifford V. Sulham; Jeremy C. Holtgrave; Glen P. Perram

2010-01-01

376

A diode-pumped Rb laser at 398 nm  

Microsoft Academic Search

The CW diode-pumped alkali laser (DPAL) based on the rubidium resonance transition at 794.8 nm has been investigated. The pump sources for these experiments are commercially available 780 nm fiber-coupled diode modules, incorporating volume holographic gratings for wavelength control. Operating characteristics, pump architecture, power scaling and lifetime limitations have been studied. To date, lasers pumped by single 20 W diode

A. B. Petersen

2008-01-01

377

FALCON reactor-pumped laser technology for space power applications  

NASA Astrophysics Data System (ADS)

The FALCON reactor-pumped laser program is investigating concepts for high power laser systems pumped directly by fission energy from a nuclear reactor. The direct pumping of laser media with fission energy offers the potential system advantages of scaling to very high laser powers with long run times, extremely compact and low-mass energy storage, and relatively simple gain generator design. Reactor pumping has been studied in the ACRR and SPR research reactor facilities at Sandia National Laboratories. Based on these experiments and extensive system analysis, large reactor-pumped laser systems have been evaluated for extraction efficiency, beam quality, and practically (considering auxiliary power needs, radiation damage to optical components, rejection of waste heat, and expected imperfections in excitation structures). It appears that high-power reactor-pumped lasers can be developed in the near term to provide important capabilities for the exploration and utilization of space.

McArthur, D. A.; Hays, G. N.; Pickard, P. S.

378

Dye-laser fluctuations: Comparison of colored loss-noise and white gain-noise models  

SciTech Connect

A single-mode dye-laser model incorporating pump white noise through gain-parameter fluctuations is analyzed. It includes a fluctuating saturation term. Intensity fluctuations, a first-order-like transition, and intensity correlation functions are calculated and discussed. It is found that effects previously claimed to be a consequence of the presence of colored noise in the context of loss-noise models can be also explained by white gain noise, except for the existence of two time regimes in the early decay of intensity correlation functions.

Aguado, M.; Hernandez-Garcia, E.; San Miguel, M.

1988-12-01

379

Polarization and polarization control of random lasers from dye-doped nematic liquid crystals.  

PubMed

A polarimetric study of random laser (RL) emitted from dye-doped nematic liquid crystals (NLCs) is presented. We observed linearly polarized light, the orientation of which is in proximity to the bisection between the polarization direction at the maximal scattering in NLCs and the nematic director. Any arbitrary linear polarization of RLs can be obtained by rotating the NLC sample. The efficiency and output uniformity over the complete direction angle of 2? can be optimized by choosing a proper pump polarization. PMID:23632550

Yao, Fengfeng; Zhou, Wenlong; Bian, Huanting; Zhang, Yu; Pei, Yanbo; Sun, Xiudong; Lv, Zhiwei

2013-05-01

380

A diode-pumped Rb laser at 398 nm  

NASA Astrophysics Data System (ADS)

The CW diode-pumped alkali laser (DPAL) based on the rubidium resonance transition at 794.8 nm has been investigated. The pump sources for these experiments are commercially available 780 nm fiber-coupled diode modules, incorporating volume holographic gratings for wavelength control. Operating characteristics, pump architecture, power scaling and lifetime limitations have been studied. To date, lasers pumped by single 20 W diode bars have produced over 1 W output at 794.8 nm and 100 mW at the 397.4 nm harmonic. Lasers pumped by two 40 W diodes generate almost 8 W at 794.8 nm.

Petersen, A. B.; Lane, R. L.

2008-03-01

381

High-energy transversely pumped alkali vapor laser  

NASA Astrophysics Data System (ADS)

We report on the results from our transversely pumped alkali laser. This system uses an Alexandrite laser to pump a stainless steel laser head. The system uses methane and helium as buffer gasses. Using rubidium, the system produced up to 40 mJ of output energy when pumped with 63 mJ. Slope efficiency was 75%. Using potassium as the lasing species the system produced 32 mJ and a 53% slope efficiency.

Zweiback, J.; Komashko, A.

2011-02-01

382

High-power fiber-laser-pumped mid-infrared laser sources  

Microsoft Academic Search

We present an efficient, high-power mid-infrared laser source using a Thulium fiber laser as pump source. The CW fiber laser pumps a Q-switched Ho:YAG laser which in turn pumps a ZnGeP2-based OPO. We have built a semi-ruggedized version of the laser for countermeasure field trials, and using a 15 W fiber laser we obtained 5.2 W output power in the

Espen Lippert; Stephane Nicolas; Gunnar Arisholm; Knut Stenersen; Asta S. Villanger; Gunnar Rustad

2006-01-01

383

Nuclear-Pumped Laser Concepts for Laser Fusion or Laser-Heated Solenoid Reactors.  

National Technical Information Service (NTIS)

The combination of a nuclear-pumped laser with a fusion reactor, using some of the neutrons emitted from the fusion reactor to pump the laser, is described. This paper describes several concepts which might be used, points out potential advantages of usin...

D. A. McArthur J. V. Walker

1976-01-01

384

High efficiency CW green-pumped alexandrite lasers  

NASA Astrophysics Data System (ADS)

High power, CW and pulsed alexandrite lasers were produced by pumping the laser rod with a high quality diode pumped 532 nm laser sources. This pumping architecture provides stable performance with output power > 1.4 W at 767nm in the free running mode and 0.78W at 1000 Hz. An output of 80 mW at 375.5 nm was achieved at 500 Hz. This approach holds promise for the production of a scalable diode-pumped, tunable alexandrite laser systems operating in the near infrared (750 nm), and the ultraviolet (375 and 250 nm) spectral regions.

Kuper, J. W.; Brown, D. C.

2006-03-01

385

DOE reactor-pumped laser program  

SciTech Connect

FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. A ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night. The compact size and self-contained power also makes an RPL very suitable for ship basing so that power-beaming activities could be situated around the globe. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, wide-area deposition of diamond-like coatings, and 3-D ceramic lithography.

Felty, J.R. [USDOE, Germantown, MD (United States). Defense Programs; Lipinski, R.J.; McArthur, D.A.; Pickard, P.S. [Sandia National Labs., Albuquerque, NM (United States)

1993-12-31

386

Laser demonstration and performance characterization of optically pumped Alkali Laser systems  

Microsoft Academic Search

Diode Pumped Alkali Lasers (DPALs) offer a promising approach for high power lasers in military applications that will not suffer from the long logistical trails of chemical lasers or the thermal management issues of diode pumped solid state lasers. This research focuses on characterizing a DPAL-type system to gain a better understanding of using this type of laser as a

Clifford V. Sulham

2010-01-01

387

Photostability enhancement of Pyrromethene 567 and Perylene Orange in oxygen-free liquid and solid dye lasers  

SciTech Connect

We investigated the effect of oxygen on the photostability of the laser dyes Pyrromethene 567, Perylene Orange, and Rhodamine 590 by determining their longevity of laser operation when pumped by the second harmonic of a Q-switched Nd:YAG laser. In solution, dissolved oxygen accelerated the photodegradation of Pyrromethene 567 and Perylene Orange but not Rhodamine 590. The photostability of Pyrromethene 567 was also found to be dependent on the solvent and on the lifetime of singlet oxygen. Deoxygenated Pyrromethene 567 doped polycom glass and modified poly(methyl methacrylate) (MPMMA) samples were tested for longevity of laser operation. A factor of 6 improvement in photostability was found for Pyrromethene 567 in MPMMA upon deoxygenation, and the total absorbed energy per mole of dye molecules to one-half output pulse energy was 36 GJ mol{sup {minus}1}. {copyright} 1997 Optical Society of America

Rahn, Mark D.; King, Terence A. [Laser Photonics Group, Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Hamblett, Ian [Department of Chemistry, University of Manchester, Manchester M13 9PL (United Kingdom)

1997-08-01

388

Interface module for transverse energy input to dye laser modules  

DOEpatents

An interface module for transverse energy input to dye laser modules is provided particularly for the purpose of delivering enhancing transverse energy beams in the form of illumination bar to the lasing zone of a dye laser device, in particular to a dye laser amplifier. The preferred interface module includes an optical fiber array having a plurality of optical fibers arrayed in a co-planar fashion with their distal ends receiving coherent laser energy from an enhancing laser source, and their proximal ends delivered into a relay structure. The proximal ends of the optical fibers are arrayed so as to be coplanar and to be aimed generally at a common point. The transverse energy beam array delivered from the optical fiber array is acted upon by an optical element array to produce an illumination bar which has a cross section in the form of a elongated rectangle at the position of the lasing window. The illumination bar is selected to have substantially uniform intensity throughout. 5 figs.

English, R.E. Jr.; Johnson, S.A.

1994-10-11

389

Interface module for transverse energy input to dye laser modules  

DOEpatents

An interface module (10) for transverse energy input to dye laser modules is provided particularly for the purpose of delivering enhancing transverse energy beams (36) in the form of illumination bar (54) to the lasing zone (18) of a dye laser device, in particular to a dye laser amplifier (12). The preferred interface module (10) includes an optical fiber array (30) having a plurality of optical fibers (38) arrayed in a co-planar fashion with their distal ends (44) receiving coherent laser energy from an enhancing laser source (46), and their proximal ends (4) delivered into a relay structure (3). The proximal ends (42) of the optical fibers (38) are arrayed so as to be coplanar and to be aimed generally at a common point. The transverse energy beam array (36) delivered from the optical fiber array (30) is acted upon by an optical element array (34) to produce an illumination bar (54) which has a cross section in the form of a elongated rectangle at the position of the lasing window (18). The illumination bar (54) is selected to have substantially uniform intensity throughout.

English, Jr., Ronald E. (Tracy, CA); Johnson, Steve A. (Tracy, CA) [Tracy, CA

1994-01-01

390

LASERS: Generation of microsecond laser pulses in polyurethane matrices doped with dyes  

Microsoft Academic Search

Active laser elements based on polyurethane matrices doped with rhodamine 6G and oxazine 17 dyes are fabricated and tested. Lasing in the yellow---green and red spectral regions is obtained upon excitation of these matrices by a dye laser at 532 nm. The spectral and spatial---angular parameters of emission are studied. It is shown that these parameters are similar for polymer

S. V. Nikolaev; V. V. Pozhar; M. I. Dzyubenko

2006-01-01

391

High-repetition-rate TEM00-mode diode-laser-pumped solid state lasers  

Microsoft Academic Search

A diode-laser side-pumped E-O Q-switched TEM00 Nd:YAG slab laser that uses a large N.A. cylindrical lens and a thin slab pumping geometry has been investigated. The pumping scheme has the ability to match well the pump beam to the laser's fundamental transverse mode in two axes. Approximately 1.1 times diffraction limited laser beam is obtained. The slope efficiency is 31%

Chun Tang; Chenglong Yang; Weimin Wang; Senlin Yang; Jingyan Chen

1998-01-01

392

Study of photoproducts of Rhodamine 6G in ethanol upon powerful laser pumping  

SciTech Connect

Absorption spectra of rhodamine 6G in ethanol solution are measured using, the technique of laser probing upon pumping by a doubled Nd {sup 3+}:YAG laser with pulse length{tau}{sub 01}{approx_equal}16ns. It is shown that, at the pumping energy density {ge}1.5 J/cm{sup 2}, short-lived ({tau} < 25 ns) and long-lived photoproducts formed in the dye solution, which absorbed in a wide spectral range, including the lasing region. The estimates show that the probability of rhodamine 6G transformation to the photoproduct upon three-step excitation at 532 nm achieves {approximately}2.5 X 10{sup -3}. It is noted that, in order to obtain reliable spectroscopic information using this technique, one should take into account the intense scattering of probing radiation by thermal noise gratings, which are formed due to self-diffraction of the pumping radiation into noise components.

Batishche, S.A.; Malevich, N.A.; Mostovnikov, V.A. [Stepanov Institute of Physics, Minsk (Russian Federation)

1995-04-01

393

Pumping scheme dependent multimode laser emission from free-standing cylindrical microcavity  

NASA Astrophysics Data System (ADS)

We report the observation of multimode laser emission from a free-standing microring cavity based on rhodamine 6G dye doped hollow poly(methyl methacrylate) optical fiber (DDHPOF) obtained by pulsed photo-excitation. Two different pumping schemes were employed to characterize DDHPOF; the stripe illumination and the spot illumination. By using spot illumination, the slope efficiency of system is enhanced by more than 3 times than that of the stripe illumination and also a red-shift in emission spectrum is observed with the pump power. When the pump power is increased beyond the threshold value, laser emission occurs with a multimode structure. From the relation between mode spacing and diameter of cylindrical cavity, the lasing action is considered to be formed by whispering gallery modes (WGMs).

Peter, Jaison; Saleem, Rasool; Sebastian, Ananthu; Radhakkrishnan, P.; Nampoori, V. P. N.; Girijavallabhan, C. P.; Kailasnath, M.

2014-06-01

394

Study of the Correlation between Degradation of Kiton Red S Laser Dye and Degradation of Laser Energy under Flash Conditions.  

National Technical Information Service (NTIS)

The laser dye Kiton Red S dissolved in ethanol was degraded under flashlamp excitation in a dye laser. Data obtained with infrared spectral analysis were used to construct plots of dye concentration versus shot number. From these plots the degradation rea...

J. M. Rabins

1978-01-01

395

Two-photon-pumped optical gain in dye-polymer composite materials  

NASA Astrophysics Data System (ADS)

Optical gain with two-photon pumping has been quantitatively characterized in the energy-transfer-coupled dye-polymer composite materials. Using femtosecond transient absorption spectroscopy, we observed frequency up-converted optical amplification in the dye-doped polymer films. Net optical gain coefficient in the polymer films with optimized doping is evaluated to be about 25 cm-1 by the variable-stripe-length measurements, which induces spectral narrowing of emission with linewidth changing from 42 nm to 9 nm. The intrinsic mechanisms for the optical gain in such composite system have been assigned to the amplified spontaneous emission and superfluorescence at relatively low and high excitation regimes, respectively.

Li, Wei; Zhang, Chunfeng; Chen, Qi; Wang, Xiaoyong; Xiao, Min

2012-03-01

396

Squeezed light from conventionally pumped multi-level lasers  

NASA Technical Reports Server (NTRS)

We have calculated the amplitude squeezing in the output of several conventionally pumped multi-level lasers. We present results which show that standard laser models can produce significantly squeezed outputs in certain parameter ranges.

Ralph, T. C.; Savage, C. M.

1992-01-01

397

Micro-optics for laser-diode bar collimation for pumping solid-state lasers  

Microsoft Academic Search

A longitudinally pumped Nd:YAG laser using a 1-cm long CW laser diode bar as a pump source is reported. Two microoptic arrays were developed to collimate the laser diode bar output prior to pumping the Nd:YAG crystal. One configuration produced 600 mW output power at 16 percent slope efficiency.

J. W. Pierce; G. Golob; G. Rolens

1991-01-01

398

Solid-state polymeric dye lasers  

Microsoft Academic Search

This paper presents a review of the organic solid-state polymer materials, which have become established as a new laser media. The photostability of these materials is discussed. Different types of solid-state lasers built around these materials are also reviewed.

Sunita Singh; V. R. Kanetkar; G. Sridhar; V. Muthuswamy; K. Raja

2003-01-01

399

Nuclear pumped laser research at the Jet Propulsion Laboratory  

NASA Technical Reports Server (NTRS)

Using a partially nuclear excited xenon flashlamp to pump an iodine laser, laser pulse shapes were analyzed with and without nuclear flashlamp augmentation. The pulse shapes indicate that the deposition of nuclear energy is equally as effective as electrical energy deposition in producing laser pulse energy output. The amplification of the E-beam pumped CF3I was measured at pressures of several atmospheres. Preliminary data shows that, for a part of the iodine laser pulse, amplification of almost a factor of two is measured. This measurement indicates that the gain in an E-beam pumped CF3I is an order of magnitude greater than in the coaxial laser tube.

Russell, G. R.

1979-01-01

400

Single-Mode Operation of Electrotunable Laser in a Dye-Doped Nematic Liquid-Crystal Waveguide under Holographic Excitation  

NASA Astrophysics Data System (ADS)

Optically pumped distributed feedback (DFB) lasing has been demonstrated in a dye-doped nematic liquid-crystal (NLC) waveguide by holographic excitation. Utilizing NLC with a low refractive index, the single-mode operation of a laser action was realized. With an applied electric field, continuous tuning of the single-mode lasing wavelength was realized due to the change in the effective refractive index of the NLC core layer caused by the reorientation of NLC molecules.

Matsui, Tatsunosuke; Ozaki, Masanori; Yoshino, Katsumi

2003-12-01

401

Recycle Rate in a Pulsed, Optically Pumped Rubidium Laser  

SciTech Connect

A pulsed, optically pumped rubidium laser operating in analogy to the diode pumped alkali laser (DPAL) system at pump intensities as high as 750 kW/cm{sup 2} has been demonstrated with output energies of up to 13 {mu}J/pulse. Output energy is dramatically limited by spin-orbit relaxation rates under these high intensity pump conditions. More than 250 photons are available for every rubidium atom in the pumped volume, requiring a high number of cycles per atom during the 2-8 ns duration of the pump pulse. At 550 Torr of ethane, the spin-orbit relaxation rate is too slow to effectively utilize all the incident pump photons. Indeed, a linear dependence of output energy on pump pulse duration for fixed pump energy is demonstrated.

Miller, Wooddy S.; Sulham, Clifford V.; Holtgrave, Jeremy C.; Perram, Glen P. [Department of Engineering Physics, Air Force Institute of Technology, 2950 Hobson Way, Wright-Patterson Air Force Base, Ohio 45433-7765 (United States)

2010-10-08

402

Recycle Rate in a Pulsed, Optically Pumped Rubidium Laser  

NASA Astrophysics Data System (ADS)

A pulsed, optically pumped rubidium laser operating in analogy to the diode pumped alkali laser (DPAL) system at pump intensities as high as 750 kW/cm2 has been demonstrated with output energies of up to 13 ?J/pulse. Output energy is dramatically limited by spin-orbit relaxation rates under these high intensity pump conditions. More than 250 photons are available for every rubidium atom in the pumped volume, requiring a high number of cycles per atom during the 2-8 ns duration of the pump pulse. At 550 Torr of ethane, the spin-orbit relaxation rate is too slow to effectively utilize all the incident pump photons. Indeed, a linear dependence of output energy on pump pulse duration for fixed pump energy is demonstrated.

Miller, Wooddy S.; Sulham, Clifford V.; Holtgrave, Jeremy C.; Perram, Glen P.

2010-10-01

403

Quantum theory of a squeezed-pump laser  

SciTech Connect

We analyze a model of a laser pumped by an incoherent source in a squeezed vacuum state. The squeezed pump introduces an anisotropy of phase in the laser output. Above threshold two stable solutions are found, with phases corresponding to the directions along which the noise of the bath is quenched. These solutions are illustrated by the potential function of the laser field. An analysis of fluctuations shows that the laser field has reduced phase fluctuations but not below the quantum limit.

Marte, M.A.M.; Walls, D.F.

1988-02-15

404

A new optical system for three-dimensional laser-Doppler-anemometry using an Argon-Ion and a dye laser  

NASA Astrophysics Data System (ADS)

A new optical system is described which allows three components of a fluid flow velocity vector to be measured simultaneously by means of laser Doppler anemometry. It is based on the use of an Argon-Ion laser which serves at the same time as the light source in a conventional two-component, two-color arrangement and as the pump source for a dye laser. With the dye laser a third interference fringe pattern is produced at an angle of 90 degrees with respect to the other two ones. The most important advantage as compared with competitive optics are the wide color separation and the nearly identical high power in all three fringe systems.

Pfeifer, H. J.

405

Grating formation in bi-layered DNA-complex devices: application to thin-film tunable dye lasers  

NASA Astrophysics Data System (ADS)

Interaction of some organic dyes with DNA induces fluorescence enhancement through intercalation or groove binding, stimulating the development of compact tunable thin-film dye lasers. We have demonstrated amplified spontaneous emission (ASE), laser emission and its tuning via distributed feedback (DFB) with a dynamic grating formed in DNA-surfactant complexes doped with cyanine or hemicyanine dyes. The formation of semi-persistent (or quasi-dynamic) grating is more preferable in order to realize stable and easily tunable laser sources, so we fabricated bi-layered devices composed of a DNA-CTMA layer doped with pyridine 1 (Py1) and an PMMA layer including an azo dye, Disperse Red 1 (DR1). Under simultaneous excitation of the azo layer with interfering two beams for grating formation and the emission layer with another beam as pumping, we observed laser emission from the device. The oscillation wavelength was controlled by varying the incident beam angles allowing the fast tuning suitable to applications. Furthermore, monolithic DNA device having two functions of lasing and grating formation would be more promising. DNA-CTMA complex had been considered to be a poor matrix for grating inscription, but we found that doping of an azo-carbazole compound made it possible to inscribe gratings with relatively high diffraction efficiency and with fast response which could be applicable to monolithic tunable laser system.

Kawabe, Yutaka; Chida, Toshifumi; Matsuoka, Toshinori; Fukuzawa, Kodai; Tada, Kazuhiro

2013-10-01

406

Development of distributed feedback dye lasers for generation of high-power 193 nm excimer laser short pulses  

NASA Astrophysics Data System (ADS)

The combination of picosecond dye lasers, nonlinear mixing in crystals, and excimer amplifiers offers an attractive way to generate intense diffraction-limited pulses throughout the ultraviolet region. However, it is difficult to generate 193 nm seed pulses because this wavelength cannot be obtained by second harmonic generation method in any known crystals. The thesis will describe a laser system which efficiently generates short, relatively stable high power 193 nm pulses. A new type of distributed feedback dye laser which has a grating on a thin substrate was also developed. It is reliable and easy to use. Two such DFDL's are used in the laser system to generate 10 ps pulses at two selected wavelengths of 266 nm and 706 nm that are frequency up-converted in a BBO crystal to generate nearly transform-limited 193 nm seed pulse about 10 ps in duration. The entire cascading dye laser system is pumped by a 350 mJ, 15 ns pulse at 308 nm generated by a XeCl excimer laser. The 193 nm seed pulse from BBO crystal is amplified in an ArF* excimer laser amplifier to 10 mJ in a nearly diffraction-limited beam. The system routinely produces 193 nm pulses of about 10 picosecond duration which can be focused to intensities of 10(exp 14) W/cm(exp 2). One application of this system is investigation of the interaction of intense radiation fields with diatomic molecules. A DFDL model which included non-sinusoidal profile of the modulated gain was developed. The model is used to study theoretically the fluctuation in pulse duration due to the pump variation and intrinsic fluctuation in spontaneous emission which leads the laser pulse. A two-grating DFDL was also developed, tested experimentally, and analyzed theoretically. It allows wavelength tuning and generation of shorter pulses. This type of system should be able to reach the subpicosecond regime with comparable pulse energies and beam divergences by using two-grating DFDL and thin BBO crystal.

Cui, Yifeng

1993-01-01

407

Photophysical and Photochemical Properties of Coumarin Laser Dyes in Amphiphilic Media.  

National Technical Information Service (NTIS)

Photophysical properties of coumarin laser dyes solubilized in aqueous detergent or cyclodextrin solutions have been investigated. Dyes appear to be incorporated in hydrated (hydrogen bonded) sites within detergent micelles. Photodegradation is inhibited ...

G. Jones W. R. Jackson S. Kanoktanaporn W. R. Bergmark

1983-01-01

408

Preparation of Certain M-Aminophenols and the Use Thereof for Preparation of Laser Dyes.  

National Technical Information Service (NTIS)

Methods are provided for making certain m-aminophenols using a sulfonation/alkali fusion procedure. The aminophenols are key intermediates in the synthesis of dyes, particularly efficient, stable dyes for laser application. Preparations of some rhodamine ...

P. R. Hammond

1983-01-01

409

Solar-pumped lasers for space power transmission  

NASA Technical Reports Server (NTRS)

Multi-Megawatt CW solar-pumped lasers appear to be technologically feasible for space power transmission in the 1990s time frame. A new concept for a solar-pumped laser is presented which utilizes an intermediate black body cavity to provide a uniform optical pumping environment for the lasant, either CO or CO2. Reradiation losses are minimized with resulting high efficiency operation. A 1 MW output laser may weigh as little as 8000 kg including solar collector, black body cavity, laser cavity and ducts, pumps, power systems and waste heat radiator. The efficiency of such a system will be on the order of 10 to 20%. Details of the new concept, laser design, comparison to competing solar-powered lasers and applications to a laser solar power satellite (SPS) concept are presented.

Taussig, R.; Bruzzone, C.; Nelson, L.; Quimby, D.; Christiansen, W.

1979-01-01

410

Treatment of facial skin using combinations of CO2, Q-switched alexandrite, and/or flashlamp-pumped dye and/or erbium lasers in the same treatment session  

NASA Astrophysics Data System (ADS)

Skin aging caused from chronological and photodamage processes results in many alterations in skin appearance. In many circumstances, patients who pursue CO2 laser resurfacing for facial rejuvenation are also concerned with other photoaging alternations that are beyond the efficacy of the CO2 laser. We demonstrated an approach to aged facial skin by using combined treatments of appropriate lasers.

Fitzpatrick, Richard E.; Manuskiatti, Woraphong; Goldman, Mitchel P.

1998-07-01

411

Vanadium-pumped titanium x-ray laser  

DOEpatents

A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions. 4 figs.

Nilsen, J.

1992-05-26

412

Vanadium-pumped titanium x-ray laser  

DOEpatents

A resonantly photo-pumped x-ray laser (10) is formed of a vanadium (12) and titanium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state neon-like titanium ions (34) are resonantly photo-pumped by line emission from fluorine-like vanadium ions (32).

Nilsen, Joseph (Livermore, CA)

1992-01-01

413

Optically Pumped 15.90 Micrometers SF6 Laser.  

National Technical Information Service (NTIS)

Optically pumped vibrational transition lasing has been achieved for the first time in a nonlinear molecule. Laser radiation at 628.74 + or - 0.02/cm was generated from SF6 using CO2 TEA laser excitation. The SF6 pumping is shown to be via absorption of t...

W. E. Barch H. R. Schlossberg H. R. Fetterman

1975-01-01

414

Scanning laser pulses driven microfluidic peristaltic membrane pump.  

PubMed

We reported a pulsed laser driven peristaltic pump for driving fluid in multilayer polydimethylsiloxane (PDMS) microchannels. By synchronizing the dynamics of deforming membrane valves with pulsed laser generated bubbles, a maximum pumping rate of 460 pl s(-1) has been achieved. PMID:22453871

Chen, Yue; Wu, Ting-Hsiang; Chiou, Pei-Yu

2012-04-24

415

Alexandrite laser pumped LiF:F 2- laser  

NASA Astrophysics Data System (ADS)

For the first time to our knowledge a direct alexandrite laser pumping of LiF:F 2- crystals was suggested and realized by means of energy transfer from the F 3- to the F 2- color centers (CCs). Tunable laser oscillation of LiF:F 2- in the 1000-1300 nm spectral range with a maximum efficiency of 10% was achieved. The process of two-step photo-ionization of the F 3- CCs under 740 nm excitation was demonstrated experimentally on the basis of the measured decay rate of F 3- centers. The photo-ionization cross-section from the first excited level of F 3- centers was calculated to be 2×10 -22 cm 2. Stable output lasing of the LiF:F 2- laser at room temperature under 793 nm excitation was predicted and realized.

Mirov, S. B.; Fedorov, V. V.; Xie, L.; Boczar, B.; Frost, R.; Pryor, B.

2001-11-01

416

High-definition color image in dye thermal transfer printing by laser heating  

NASA Astrophysics Data System (ADS)

In laser thermal transfer printing using dye sublimation type medium, a high definition and continuous tone image can be obtained easily because the laser beam is focused to small spot and heat energy can be controlled by the pulse width modulation of laser light. The donor ink sheet is composed of the laser absorbing layer and sublimation dye layer. The tone reproduction was depend on the mixture ratio of dye to binder and thickness of ink layer. The four color ink sheets such as cyan, magenta, yellow and black were prepared for color printing image which have a high resolution and good continuous tone reproduction using sublimation dye transfer printing by laser heating.

Kitamura, Takashi

1999-12-01

417

High-power solid-state cw dye laser.  

PubMed

In the present paper we describe a high-power tunable solid-state dye laser setup that offers peak output power up to 800 mW around 575 nm with excellent long-time power stability and low noise level. The spectral width of the laser emission is less than 3 GHz and can be tuned over more than 30 nm. A nearly circular mode profile is achieved with an M(2) better than 1.4. The device can be integrated in a compact housing (dimensions are 60 × 40 × 20 cm(3)). The limitation of long-time power stability is mainly given by photo decomposition of organic dye molecules. These processes are analyzed in detail via spatially resolved micro-imaging and spectroscopic studies. PMID:22274222

Bornemann, R; Thiel, E; Bolívar, P Haring

2011-12-19

418

Exciplex pumped alkali laser (XPAL) modeling and theory  

Microsoft Academic Search

The exciplex pumped alkali laser (XPAL) system has been demonstrated in mixtures of Cs vapor, Ar, with and without ethane, by pumping Cs-Ar atomic collision pairs and subsequent dissociation of diatomic, electronically-excited CsAr molecules (exciplexes or excimers). The blue satellites of the alkali D2 lines provide an advantageous pathway for optically pumping atomic alkali lasers on the principal series (resonance)

Andrew D. Palla; Joseph T. Verdeyen; David L. Carroll

2010-01-01

419

Pulses in the femtosecond range from a cw dye ring laser in the colliding pulse mode-locking (CPM) regime with down-chirp  

Microsoft Academic Search

Pulses in the range of 85-350 fs generated by a cw pumped, passively mode-locked dye ring laser where the counter-propagating pulses from a transient grating in the thin absorber have been found to have a down-chirp. This down-chirp corresponds to a wavelength sweep during the pulse duration of about 1 nm.

W. Dietel; E. Döpel; D. Kühlke; B. Wilhelmi

1982-01-01

420

Demonstration of the longitudinal modes and aberration-correction properties of a continuous-wave dye laser with a phase-conjugate mirror  

SciTech Connect

We have experimentally demonstrated a cw dye laser incorporating a phase-conjugate mirror (PCM). The mirror was generated by using four-wave mixing in sodium. The unique bandwidth and pump--probe detuning properties of such a PCM permitted the first reported demonstration of the c/4L spaced paired half-axial modes. In addition, the aberration correction ability is demonstrated.

Lind, R.C.; Steel, D.G.

1981-11-01

421

Demonstration of the longitudinal modes and aberration-correction properties of a continuous-wave dye laser with a phase-conjugate mirror  

Microsoft Academic Search

We have experimentally demonstrated a cw dye laser incorporating a phase-conjugate mirror (PCM). The mirror was generated by using four-wave mixing in sodium. The unique bandwidth and pump--probe detuning properties of such a PCM permitted the first reported demonstration of the c\\/4L spaced paired half-axial modes. In addition, the aberration correction ability is demonstrated.

Richard C. Lind; Duncan G. Steel

1981-01-01

422

Modeling of a diode transverse-pumped cesium vapor laser  

NASA Astrophysics Data System (ADS)

A physical model is established to demonstrate the mechanism and the kinetic process of a diode transverse-pumped cesium vapor laser. The distribution of pump laser power is described, and the effects of parameters such as the temperature, the cell length and the output coupler reflectivity on the output performance of a cesium vapor laser are simulated and analyzed. The simulation results agree well with the experiment data which shows the validity of this model. A set of optimization parameters is achieved for improving the output characteristics of a diode transverse-pumped Cs vapor laser.

Yang, Jing; Yang, Yanan; Luo, Jingbo; Pan, Bailiang

2014-06-01

423

Recalcitrant molluscum contagiosum successfully treated with the pulsed dye laser  

PubMed Central

Background and aims: Molluscum contagiosum is caused by the molluscum contagiosum virus (MCV) and is a very common skin disorder mainly involving young children Cryotherapy, curettage or some topical therapies have been applied for MC, but all of these treatments need several sessions, can be somewhat ineffective, and very painful. The present study assessed the impact of a single session of pulsed dye laser treatment of MC lesions which had proved resistant to other approaches Subjects and methods: Fifteen children comprised the study subjects, 11 boys and 4 girls, 3–5 years of age (mean 4.2 yr) with recalcitrant MC. Lesions were counted at baseline, and a single shot from a 585 nm pulsed dye laser was applied to each lesion (3 mm, 300 ms, 8.0 J/cm2). Lesions were counted again at 1 week post-treatment and followed for up to 3 months thereafter. Results: All patients completed the study and no patient dropped out through pain or discomfort. Purpura was seen at each treated lesion immediately after irradiation, but at 1 week after treatment, lesion clearance was virtually complete which was maintained for 1 month, and no recurrence was seen at 3 months in 8 of the 15 patients who remained available for followup. Conclusions: A single treatment of MC lesions with the pulsed dye laser successfully cured even recalcitrant lesions with no recurrence on follow up, and was well tolerated by the young subjects.

Omi, Tokuya; Kawana, Seiji

2013-01-01

424

A pulsed, optically-pumped rubidium laser at high pump intensity  

Microsoft Academic Search

A rubidium laser operating at 795nm is optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of Diode Pumped Alkali Lasers (DPALs). Linear scaling of output intensity for longitudinal excitation at intensities of 1.3–43kW\\/cm2 and as much as 32 times threshold is observed. The slope efficiency depends directly on the number of absorbed photons for alkali concentrations

Clifford V. Sulham; Glen P. Perram; Michael P. Wilkinson; David A. Hostutler

2010-01-01

425

A pulsed, optically-pumped rubidium laser at high pump intensity  

Microsoft Academic Search

A rubidium laser operating at 795 nm is optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of Diode Pumped Alkali Lasers (DPALs). Linear scaling of output intensity for longitudinal excitation at intensities of 1.3-43 kW\\/cm2 and as much as 32 times threshold is observed. The slope efficiency depends directly on the number of absorbed photons for

Clifford V. Sulham; Glen P. Perram; Michael P. Wilkinson; David A. Hostutler

2010-01-01

426

Investigation of pumping dynamics in rare earth doped solid state laser materials  

Microsoft Academic Search

The pumping dynamics of rare earth-doped solid-state laser materials are discussed here with an emphasis on the effects occurring in laser-pumped laser systems. A tunable alexandrite laser is used as the pump source for Nd(3+)-doped laser materials. It is found that the slope efficiency of the Nd laser operation depends strongly on the wavelength of the pump laser. For pump

Richard C. Powell; Michael L. Kliewer

1989-01-01

427

High-power CW tunable solid state dye lasers: from the visible to UV  

NASA Astrophysics Data System (ADS)

We describe a high power CW solid-state dye laser setup. With perylene orange in PMMA as gain medium an output power up to 800 mW at 576 nm and a tuning range between 565 and 595 nm is reached. The laser output shows good long time power stability. The durability can be adjusted by variation of the pump power. A feedback loop controls the laser output. At a setpoint of e.g. 100 mW, the laser output can be provided for more than eight hours with a low noise level (RMS < 10%). The spectral width of the laser emission is less than 3 GHz and can be tuned over more than 30 nm. A circular mode-profile is achieved with M2 < 1.4 [1]. Via intra-cavity second harmonic generation more than 1 mW of 290 nm UV-radiation is achieved. As nonlinear element a 7 mm BBO (Beta-Barium Borate) crystal is used. The UV laser radiation can be tuned over 10 nm. The theoretical limit of UV output is estimated to 3.5 mW. To our knowledge we present the first tunable CW polymer UV laser. While the output stability at the fundamental wavelength is reasonably good, in the UV region a significant enhancement of the noise level is observed. In addition to this the long time stability is reduced to few minutes. The limitation is mainly given by the photo-decomposition of the organic dye molecules.

Bornemann, R.; Thiel, E.; Haring Bolívar, P.

2012-05-01

428

Dye-mixture laser tunable in three primary color regions with a linear variable filter  

NASA Astrophysics Data System (ADS)

The tuning characteristics of a Coumarine 460-Disodium Fluorescein-Rhodamine 640 dye-mixture laser in the blue, green, and yellow-orange regions are reported. A linear variable filter was inserted into the laser cavity as a tuning element. The tunable range was 439-485 nm in the blue region, 509-531 nm in the green region, and 592-601 nm in the yellow-orange region. Comparison of the characteristics of the one-wavelength tuning output with those of simultaneous broadband outputs in the three color regions showed that energy transfer was an important mechanism for the oscillations, especially in the longer-wavelength region, which was farthest away from a pumping wavelength.

Saito, Yasunori; Shimodaira, Koji; Nomura, Akio; Kano, Tetsuo

1995-01-01

429

Low threshold solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

Solar-pumped lasing of i-C3F7I and n-C4F9I at lower solar concentrations (170 solar constants) and longer gain lengths than previous solar lasers is demonstrated, with potential application to the lasing needs of space. Two xenon arc solar simulators provide an AM0 spectrum over the 60-cm gain length, and output pulse energies of 70 mJ and an average power of 550 mW are achieved. Low pressure lasing times of 600 ms are reached, and the observed 0.074 percent slope efficiency could approach the 0.2 percent maximum theoretical efficiency. Due to less quenching of I(asterisk), n-C4F9I is found to be a superior lasant to i-C3F7I.

Deyoung, R. J.

1986-01-01

430

Effect of Dye Laser Pulse Duration on Selective Cutaneous Vascular Injury  

Microsoft Academic Search

The pulsed dye laser at 577 nm, a wavelength well absorbed by oxyhemoglobin, causes highly selective thermal injury to cutaneous blood vessels. Confinement of thermal damage to microvessels is, in theory, related to the laser exposure time (pulsewidth) on selective vascular injury. This study investigates the effect of 577 nm dye laser pulsewidth on selective vascular injury. Nine Caucasian, normal

Jerome M. Garden; Oon T. Tan; Russell Kerschmann; James Boll; Horace Furumoto; R. Rox Anderson; John A. Parrish

1986-01-01

431

Optically end-pumped plastic waveguide laser with in-line Fabry-Pérot resonator.  

PubMed

A plastic waveguide laser doped with organic dye molecule was fabricated with self-written active (SWA) waveguide technique. The device has a Fabry-Perot resonator consisting of a pair of highly reflective dielectric mirrors, which has brought two advantages for efficient optical pumping; (i) the efficient optical feedback in the cavity can be induced, and (ii) the reflection band of the dielectric mirrors can be tuned to overlap only with the emission band of the doped dye. For the SWA waveguide devices, furthermore, the active waveguide core is essentially coupled with a fiber port for optical input. Owing to these advantages, an experimental configuration for the optical end pumping can be easily applied. The high absorption efficiency for the pumping light could be obtained in this pumping method. A remarkable lowering of the lasing threshold was observed. As the best results of this study, consequently, the lasing action under the optical pumping energy as low as 50 nJ was achieved. PMID:21164756

Yamashita, Kenichi; Ito, Masahiro; Sugimoto, Shuhei; Morishita, Takashi; Oe, Kunishige

2010-11-01

432

Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique  

NASA Astrophysics Data System (ADS)

This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

2011-09-01

433

Absolute tracer dye concentration using airborne laser-induced water Raman backscatter  

NASA Technical Reports Server (NTRS)

The use of simultaneous airborne-laser-induced dye fluorescence and water Raman backscatter to measure the absolute concentration of an ocean-dispersed tracer dye is discussed. Theoretical considerations of the calculation of dye concentration by the numerical comparison of airborne laser-induced fluorescence spectra with laboratory spectra for known dye concentrations using the 3400/cm OH-stretch water Raman scatter as a calibration signal are presented which show that minimum errors are obtained and no data concerning water mass transmission properties are required when the laser wavelength is chosen to yield a Raman signal near the dye emission band. Results of field experiments conducted with an airborne conical scan lidar over a site in New York Bight into which rhodamine dye had been injected in a study of oil spill dispersion are then indicated which resulted in a contour map of dye concentrations, with a minimum detectable dye concentration of approximately 2 ppb by weight.

Hoge, F. E.; Swift, R. N.

1981-01-01

434

Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique  

SciTech Connect

This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

Abdel-Kareem, O. [Conservation Department, Faculty of Archaeology, Cairo University (Egypt); Eltokhy, A.; Harith, M. A. [National Institute of Laser Enhanced Science, Cairo University (Egypt)

2011-09-22

435

Diode-pumped continuous-wave Nd:glass laser  

NASA Technical Reports Server (NTRS)

The paper reports on diode-laser pumping of monolithic Nd:glass laser oscillators. End pumping with a single-stripe diode laser, a threshold of 2.2 mW, and a slope efficiency of 42 percent were observed on a 2-mm-long oscillator with a mode radius of 35 microns. The oscillator generated 2.5 mW of single-ended output power in many axial modes.

Kozlovsky, W. J.; Fan, T. Y.; Byer, R. L.

1986-01-01

436

High power CW iodine laser pumped by solar simulator  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser was pumped by a long Ar arc as the solar simulator to produce a 10-W CW output. Continuous lasing for 1 h was achieved with a flow of the laser material n-C3F7I. The 10-W CW output is the highest produced to date and establishes the feasibility of developing a solar-pumped laser for space power transmission.

Lee, Ja H.; Lee, Min H.; Weaver, Willard R.

1987-01-01

437

Diode pumped alkali vapor lasers for high power applications  

NASA Astrophysics Data System (ADS)

General Atomics has been engaged in the development of diode pumped alkali vapor lasers. We have been examining the design space looking for designs that are both efficient and easily scalable to high powers. Computationally, we have looked at the effect of pump bandwidth on laser performance. We have also looked at different lasing species. We have used an alexandrite laser to study the relative merits of different designs. We report on the results of our experimental and computational studies.

Zweiback, J.; Krupke, B.; Komashko, A.

2008-02-01

438

A multi-color fast-switching microfluidic droplet dye laser.  

PubMed

We describe a multi-color microfluidic dye laser operating in whispering gallery mode based on a train of alternating droplets containing solutions of different dyes; this laser is capable of switching the wavelength of its emission between 580 nm and 680 nm at frequencies up to 3.6 kHz-the fastest among all dye lasers reported; it has potential applications in on-chip spectroscopy and flow cytometry. PMID:19967111

Tang, Sindy K Y; Li, Zhenyu; Abate, Adam R; Agresti, Jeremy J; Weitz, David A; Psaltis, Demetri; Whitesides, George M

2009-10-01

439

Diode pumped thin slab solid-state lasers  

NASA Astrophysics Data System (ADS)

Thermal effect is a serious problem in solid-state lasers. Because of superior thermal property which owed to high aspect ratio of laser crystal, solid-state lasers with thin slab configuration can be scaling to high output power with different laser crystal material and pump structure. In this paper, we present side-pumped passive Q-switched and acousto-optic Q-switched Nd: YAG lasers and end-pumped Tm: YAP lasers. We got a maximum 70W output power of passive Q-switched Nd: YAG laser with 220W pump power, which the pulse duration is around 10ns and the pulse repetition rate is higher than 10kHz. And 73W output power is got while pump power is 200W in acousto-optic Q-switched Nd: YAG lasers. Especially, we also applied the thin slab configuration to end pumped Tm: YAP laser and got a maximum 9.6W output power which the doping concentrations is 4% and cut by c-axis.

Cheng, Xiaojin; Wang, Zhiming; Chen, Fan; Xu, Jianqiu

2008-12-01

440

Nuclear-Pumped Lasers. [efficient conversion of energy liberated in nuclear reactions to coherent radiation  

NASA Technical Reports Server (NTRS)

The state of the art in nuclear pumped lasers is reviewed. Nuclear pumped laser modeling, nuclear volume and foil excitation of laser plasmas, proton beam simulations, nuclear flashlamp excitation, and reactor laser systems studies are covered.

1979-01-01

441

Recent nuclear pumped laser results. [gas mixtures and laser plasmas  

NASA Technical Reports Server (NTRS)

Recent direct nuclear pumped laser research has concentrated on experiments with three gas mixtures (Ne-N2, He-Ne-O2, and He-Hg). One mixture has been made to lase and gain has been achieved with the other two. All three of these mixtures are discussed with particular attention paid to He-Hg. Of interest is the 6150-angstroms ion transition in Hg(+). The upper state of this transition is formed directly by charge transfer and by Penning ionization.

Miley, G. H.; Wells, W. E.; Akerman, M. A.; Anderson, J. H.

1976-01-01

442

Operating temperature of diode-pumped alkali vapor laser  

Microsoft Academic Search

Diode-pumped alkali vapor laser (DPAL) is a new class of laser, and it is expected to realize high efficiency and high-average-power laser with good beam quality (near-diffraction-limited). DPAL offers CW laser radiation at near-infrared wavelengths and can find a lot of applications in power beaming, drilling oil and gas well and laser material processing. Operating temperature affects not only the

Qiang Zhu; Jianhua Yu; Wei Zheng; Hongyan Quan

2008-01-01

443

XeCl laser pumped iodine laser using t-C4F9I  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

Hwang, In Heon; Han, Kwang S.

1989-01-01

444

XeCl laser pumped iodine laser using t-C4F9I  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser using t-C4F9I as the active material was pumped by a XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodine pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

Hwang, In Heon; Han, Kwang S.; Lee, Ja H.

1989-01-01

445

Optical chaos and hysteresis in a laser-diode pumped Nd doped fiber laser  

Microsoft Academic Search

Modulated pumping of a Nd(3+) doped silica monomode fibre laser has been investigated experimentally. For small modulation depths the laser exhibits a resonance at the relaxation oscillation frequency, providing pulses of a few microseconds duration at a repetition rate in the region of 10 kHz, dependent on the average pump level above threshold. As the pump modulation depth is increased,

M. W. Phillips; H. Gong; A. I. Ferguson; D. C. Hanna

1987-01-01

446

Alexandrite Laser Pumped by Semiconductor Lasers. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

We report the first operation of a direct diode-pumped tunable chromium-doped solid-state laser. A small alexandrite (Cr.BeAl204) crystal was longitudinally pumped by two visible laser diodes. The threshold pump power was 12 mW using the R1 line at 680.4 ...

R. Scheps B. M. Gately J. F. Myers J. S. Krasinski D. F. Heller

1990-01-01

447

15-Terahertz pulse generation arising from modulation instability oscillation in a colliding-pulse mode-locking dye laser  

SciTech Connect

15-Thz trains of a few-tens-of-femtoseconds optical pulses were generated by modulation instability oscillation in a colliding-pulse mode-locked dye laser. A repeatable and stable modulation instability regime was obtained with the laser operating in the anomalous-dispersion regime and with a low saturable-absorber concentration. Autocorrelation measurements indicate that subpulses were completely separated in the real time. Variations of the modulation with the pump power and the amount of dispersion in the cavity are in good agreement with the modulation instability theory.

Wang, C.; Baldeck, P. L.; Budansky, Y.; Alfano, R.

1989-05-15

448

Experimental investigation of a waveguide submillimetre optically pumped laser  

SciTech Connect

A multifunctional single-frequency submillimetre (sub-mm) optically pumped laser with rapid replacement of the active medium was investigated experimentally. The output characteristics of the laser were obtained for different parameters of the medium and the cavity. The lasing frequency shift of the sub-mm laser was studied as a function of the pump frequency ({approx}39 Hz kHz{sup -1}). A method of stabilising the frequency of the sub-mm laser by phase locking to a microwave frequency synthesiser is briefly described. (control of laser radiation parameters)

Grachev, Gennadii N; Zakharyash, Valerii F; Klementyev, Vasilii M; Khamoyan, A G [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

1999-08-31

449

Development of injection-seeded optical parametric laser systems with pulsed dye amplifiers for high-spectral-resolution combustion diagnostics  

NASA Astrophysics Data System (ADS)

The development and application of optical parametric (OP) systems with pulsed dye amplifiers producing single frequency mode (SFM), narrow linewidth, and tunable laser radiation for high-spectral-resolution laser diagnostics is described. An optical parametric generator (OPG) was developed, consisting of a pair of counter-rotating ? barium borate (?-BBO) crystals pumped by third-harmonic output of an injection-seeded Nd:YAG laser. The OPG crystals themselves are injection-seeded using a continuous wave (cw) distributed feedback (DFB) diode laser or external cavity diode laser (ECDL) at idler wavelength. The OPG is converted for some applications into an optical parametric oscillator (OPO) by incorporating a feedback cavity. The signal output from the OP system is amplified using pulsed dye amplifiers. The PDAs are pumped either by second-harmonic or third-harmonic output of the Nd:YAG laser depending on the OP output wavelength and the dye solution used in PDAs. The linewidth of the laser beam produced using OP/PDA systems is 200 MHz and the spatial beam profile is nearly Gaussian. Initial application of OP/PDA system included two-photon laser induced fluorescence (LIF) of atomic oxygen in counter-flow flames, dual pump coherent anti-Stokes Raman spectroscopy (CARS) for N2 and CO2, and nitric oxide (NO) planar laser induced fluorescence (PLIF) in compressible flowfield. A two-photon pump polarization spectroscopy probe (TPP-PSP) laser system has also been developed using two SFM OPG/PDA systems for the detection of atomic hydrogen (H-atom) in flames. In TPP-PSP, a 243-nm pump beam excites the 1S-2S two photon transition and the excited atoms in 2S level are probed by polarization spectroscopy between n=2 and n=3 manifolds using a circularly polarized 656-nm pump and a linearly polarized 656-nm probe laser beam. Using the TPP-PSP scheme, atomic hydrogen was detected at concentrations as low as 11 ppm. The use of injection-seeded OPG/PDAs as SFM sources for the pump and probe beams allows accurate measurement of signal intensities and spectral lineshapes. A detailed investigation of the effect of 243-nm and 656-nm pump beam energies on the different transitions of atomic hydrogen was performed. TPP-PSP lineshapes for high energy 243-nm and 656-nm pump beams showed significant broadening when compared with lineshapes for lower energy 243-nm and 656-nm pump beams. A continuous shifting of the center of n=2-n=3 transition was also observed with increasing 243-nm pump beam energy. Sub-Doppler H-atom lineshapes were also investigated and exhibited significant narrowing. The effect of varying collisional environments on the TPP-PSP signal from atomic hydrogen was investigated by performing measurements in near-adiabatic hydrogen-air flames. The results of these measurements are very encouraging for quantitative measurements of atomic hydrogen in flames.

Bhuiyan, Aizaz Hossain

450

Tunable narrow linewidth laser output from PM567 doped nematic liquid crystal under holographic pumping  

NASA Astrophysics Data System (ADS)

LC cell injected the mixture of dye pyrromethene 567 (PM567) and nematic liquid crystal (NLC) by capillary action was prepared. Holographic pumping with a Nd:YAG laser (532 nm, 1 Hz, 10 ns) to form gain distributed feedback in the cell, tunable laser output from the cell was investigated. Through changing the intersection angles of the two coherent light beams from 46° to 50°, the tuning range we obtained is about 37 nm (550-587 nm). Additionally, the FWHM of the laser under such experimental setup was less than 0.1 nm even without the resonant cavity, and the threshold of the laser was about 26 ?J, which was very low as we known.

Chen, D. Y.; Fan, Y. K.; Fan, R. W.; Xia, Y. Q.

2011-12-01

451

Tunable CW Er:YLF Diode-Pumped Laser.  

National Technical Information Service (NTIS)

We report a 4-W, 2810-nm, diode-pumped, cw Er:YLF laser, to the best of our knowledge the highest power yet achieved for a cw Er-doped laser operating on the(4)I(11/12) - (4)I(13/2) transition. We tuned the laser on 11- different lines in the 2720-2840-nm...

A. Dergachev P. F. Moulton

2003-01-01

452

Concepts for efficient high power solar pumped solid state lasers  

Microsoft Academic Search

The energetic efficiencies obtainable with current solid state laser systems are examined and used in a theoretical study of a combined solar-pumped laser power plant. It is suggested that the incident light in such a system would be split into two parts. In one part the wavelength would be adjusted to the absorption spectra of the special laser crystals. This

H. Opower; F. Lindner; W. Zittel

1988-01-01

453

Optical properties of a nuclear reactor pumped gas laser.  

National Technical Information Service (NTIS)

Ray paths and focal lengths are derived to fourth order for a nuclear-reactor wall-pumped gas laser. Ray paths in the laser gain cell are shown to be nearly random for a long gain region. Focal lengths calculated from the ray paths exiting the laser are s...

A. Corvo

1991-01-01

454

Diatomic Cesium in a Diode-Pumped Alkali Laser System  

Microsoft Academic Search

Abstract Diode Pumped Alkali Laser (DPAL) systems combine the positive characteristics of chemical and diode lasers. These systems create a laser that is compact and ecient, while working well at high temperatures and high powers. In conjunction with the Air Force Research Laboratory (AFRL), an attempt was made to improve DPAL technology by using a diatomic alkali metal as a

Jamey Christy; Eric Martinez; Tanner Oakes; Jake Smith; Kendrick Walter

2008-01-01

455

Exciplex pumped alkali laser (XPAL) modeling and theory  

NASA Astrophysics Data System (ADS)

The exciplex pumped alkali laser (XPAL) system has been demonstrated in mixtures of Cs vapor, Ar, with and without ethane, by pumping Cs-Ar atomic collision pairs and subsequent dissociation of diatomic, electronically-excited CsAr molecules (exciplexes or excimers). The blue satellites of the alkali D2 lines provide an advantageous pathway for optically pumping atomic alkali lasers on the principal series (resonance) transitions with broad linewidth (>2 nm) semiconductor diode lasers. Because of the addition of atomic collision pairs and exciplex states, modeling of the XPAL system is more complicated than classic diode pumped alkali laser (DPAL) modeling. Results from a time-dependent finite-volume model including transport, thermal, and kinetic effects appropriate for the simulation of a cylindrical closed cell XPAL system are presented. An initial kinetic set appropriate for modeling XPAL systems is presented. A two-dimensional, time-dependent baseline simulation of an operating XPAL cell is presented and compared to data. Good agreement is achieved on the time gap between pump and laser pulses, laser pulse full width at half maximum, laser pulse rise time, and output energy. A more detailed analysis of a similar case is presented in which good agreement is obtained between laser pulse energy as a function of pump pulse absorbed energy data and predictions. Higher XPAL efficiencies are predicted as temperature increases. Initial calculations of quasi-steady-state XPAL operation, a theoretical analysis of CW XPAL systems, along with advantages over the DPAL system are also presented.

Palla, Andrew D.; Verdeyen, Joseph T.; Carroll, David L.

2010-09-01

456

Power transmission using a solar-pumped laser  

NASA Astrophysics Data System (ADS)

A lab simulation which demonstrates the power beaming concept, based on solar pumped laser and photovoltaic cell, was performed. The simulation included a parabolic dish, a 3D CPC, a 2D CPC as a laser head for transmission and a photovoltaic cell for converting the laser light into electricity. A waveguide was used in order to obtain a uniform illumination upon the photovoltaic cell. A Nd:YAG laser rod was solar pumped using imaging and nonimaging systems producing 52 Watt laser at sun flux of 830 Watt/m2. In successive experiments the solar cell was exposed to a laser light using Nd:YAG and Alexandrite lasers. The efficiencies achieved were 33% laser to electricity efficiency for the Nd:YAG laser and approximately 40% for the Alexandrite.

Naftali, Nir; Pe'Er, Idit; Yogev, Amnon

1997-10-01

457

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

This report describes results of NASA Grant NAG-1-1148, entitled Direct Solar Pumping of Semiconductor Lasers: A Feasibility Study. The goals of this study were to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space with directly focused sunlight and to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or storage battery electrically pumping a current injection laser. With external modulation, such lasers could perhaps be efficient sources for intersatellite communications. We proposed specifically to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation at low pump intensities. These tasks have been accomplished, as described in this report of our completed project. The report is organized as follows: Some general considerations relevant to the solar-pumped semiconductor laser problem are discussed in Section 2, and the types of structures chosen for specific investigation are described. The details of the laser model we developed for this work are then outlined in Section 3. In Section 4, results of our study are presented, including designs for optimum lattice-matched and strained-layer solar-pumped quantum-well lasers and threshold pumping estimates for these structures. It was hoped at the outset of this work that structures could be identified which could be expected to operate continuously at solar photoexcitation intensities of several thousand suns, and this indeed turned out to be the case as described in this section. Our project is summarized in Section 5, and information on publications resulting from this work is provided in Section 6.

Anderson, Neal G.

1992-01-01

458

Edge multi-facet pumping configuration for thin gain lasers  

NASA Astrophysics Data System (ADS)

In this article an edge-facet and multi aperture pumped thin gain laser with highly efficient and simple pump optics is reported. The crystal configuration is a symmetrical hexagonal Composite Yb:YAG/YAG with slanted sides. Three diodes are placed outside the hexagonal shape disk, and the emitting light is coupled via three lens ducts through its three slanted edges and propagates through the disk along the zigzag path and repeatedly passes the gain medium, thus pump uniformity and absorption efficiency are improved. A comprehensive numerical model is utilized in the laser designing process. 192 W output power with good beam quality was achieved from this laser configuration.

Javadi-Dashcasan, M.; Hajiesmaeilbaighi, F.

2012-07-01

459

Diode-array-pumped repetitively pulsed neodymium phosphate glass laser  

SciTech Connect

Repetitively pulsed generation (200 {mu}s, 40 Hz) was obtained in a neodymium phosphate glass laser pumped by a 870-nm diode array. The maximum slope lasing efficiency with respect to the optical pump energy equal to 13% is restricted by the factor ({approx}0.23) of active-medium filling by the mode field. By adjusting the laser cavity, the single-transverse mode regime, in particular, the generation of the TEM{sub 00} mode is obtained in the entire range of pump energies. (active media. lasers)

Bogatov, A P; Drakin, A E; Miftakhutdinov, D R; Starodub, A N [P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Mikaelyan, G T [Inject Research and Manufacturing Enterprise, Saratov (Russian Federation)

2008-09-30

460

Preparation of certain m-aminophenols and the use thereof for preparation of laser dyes  

DOEpatents

Methods are provided for making certain m-aminophenols using a sulfonation/alkali fusion procedure. The aminophenols are key intermediates in the synthesis of dyes, particularly efficient, stable dyes for laser application. Preparations of some rhodamine and phenoxazone dyes from the m-aminophenols are described.

Hammond, P.R.

1983-12-29

461

Preparation of certain m-aminophenols and the use thereof for preparation of laser dyes  

DOEpatents

Methods are provided for making certain m-aminophenols using a sulfonation/alkali fusion procedure. The aminophenols are key intermediates in the synthesis of dyes, particularly efficient, stable dyes for laser application. Preparations of some rhodamine and phenoxazone dyes from the m-aminophenols are described.

Hammond, Peter R. (Livermore, CA)

1986-01-01

462

Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique  

Microsoft Academic Search

This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as

O. Abdel-Kareem; A. Eltokhy; M. A. Harith

2011-01-01

463

Effects of dc electric fields on a dye laser amplifier  

SciTech Connect

Electric field dependence of the output polarization was investigated in the dye laser light amplifier, using the dimethyl sulfoxide (DMSO) solution of coumarin 30, which was found to have a large Kerr coefficient and a high resistivity. Output polarization was found to be determined by the Kerr effect of the solvent DMSO and the anisotropic gain due to the anisotropic orientation distribution of excited dye molecules. The nonlinear electric susceptibility vertical-barchi/sub x/xxx-chi/sub z/zxxvertical-bar of DMSO was estimated to be 9.5 x 10/sup -12/ cgs esu. The orientational distribution time constant tau/sub r/ for coumarin 30 dissolved in DMSO was estimated to be about 1.3 x 10/sup -9/ s.

Urisu, T.; Sugeta, T.; Mizushima, Y.

1980-02-01

464

Assignment of the /Li-7/2 optically pumped laser transitions pumped by Ar/+/ and Kr/+/ laser lines  

NASA Technical Reports Server (NTRS)

Welling and Wellegehausen (1977) have reported a list of Na2 and Li2 lines (belonging to B-X and A-X systems) which lase when vapors of these dimers are pumped with an Ar(+) or Kr(+) laser. A description is presented of a fluorescence study of the A-X system of the (Li-7)2 molecule excited by a Kr(+) laser (6471 A). The optically pumped laser lines are identified as P and R doublets in two different fluorescence series. The conditions which favor lasing action of these lines are pointed out. All but one of the known optically pumped laser lines of (Li-7)2 along with their assignments are presented in a table. For each pumping line, several additional wavelengths are listed which satisfy the condition for laser oscillations and which might well lase well under slightly improved conditions.

Verma, K. K.; Stwalley, W. C.; Zemke, W. T.

1981-01-01

465

Evaluation of laser dye mutagenicity using the Ames/Salmonella microsome test  

SciTech Connect

Twenty-five laser dyes and four analogs were tested for mutagenicity in the Ames/Salmonella test. Seven dyes and two analogs gave positive mutagenic responses with bacterial strains TA-1538 and TA98. Of two widely used families of laser dyes (coumarins and rhodamines), four coumarin samples, but none of the rhodamine samples, were mutagenic. Using high-performance liquid chromatography (HPLC), it was determined that five mutagenic dye samples had multiple components. The dyes themselves may not be the mutagenic agents in all cases (as with Nile Blue) but may contain impurities that are mutagenic. This study indicates the need for further toxicological testing of these types of compounds. The mutagenic components of these dye mixtures, whether it is the dye or a contaminant, presents a possible hazard to those handling them. Therefore, practices and procedures for the safe handling of specific dyes should be reviewed in light of these findings.

Wuebbles, B.J.Y.; Felton, J.S.

1985-01-01

466

Methanol and the optically pumped far-infrared laser  

SciTech Connect

New results on the generation and spectroscopic analysis of optically pumped far-infrared (FIR) laser emission from CH{sub 3}OH have been obtained as part of a systematic study of methanol isotopomers as FIR laser sources utilizing the extended line coverage available from a recently developed high-resolution CO{sub 2} laser of high efficiency. For normal CH{sub 3}OH, six new short-wavelength lines have been found using a 2 m long Fabry-Perot FIR laser cavity. Accurate heterodyne frequency measurements are reported for 14 CH{sub 3}OH FIR laser lines, nearly all above 100 cm{sup {minus}1}, as well as accurate frequency offsets for most of the corresponding CO{sub 2} pump lines. Spectroscopic assignments are presented for nine high-frequency FIR laser lines in four pump systems.

Xu, L.H. [Univ. of New Brunswick, Saint John, New Brunswick (Canada); Lees, R.M. [Univ. of New Brunswick, Fredericton, New Brunswick (Canada); Vasconcellos, E.C.C.; Zerbetto, S.C. [UNICAMP, Campinas, Sao Paulo (Brazil); Zink, L.R.; Evenson, K.M. [National Inst. of Standards and Technology, Boulder, CO (United States). Time and Frequency Div.

1996-03-01

467

^4He optical pumping with intensity modulated laser light  

NASA Astrophysics Data System (ADS)

^4He (2 ^3S1) metastable atoms are optically pumped with intensity modulated light. The use of a single mode diode-pumped LNA laser as the pumping source, allows the study of resonance signals predicted by the optical pumping theory but not yet observed. Resonances are detected on the transmitted pumping beam at the modulation frequency and its harmonics. Application of this method to high sensitivity magnetometers is suggested. Les atomes métastables ^4He (2 ^3S1) sont pompés optiquement en lumière modulée en intensité. L'utilisation, comme source de pompage, d'un laser monomode LNA pompé par une diode laser permet l'étude de signaux de résonance prédits par la théorie du pompage optique mais non encore observés. Les résonances sont détectées sur le faisceau de pompage transmis à la fréquence de modulation et ses harmoniques. L'application de cette méthode à la réalisation de magnétomètres de haute sensibilité est suggérée.

Cassimi, A.; Cheron, B.; Hamel, J.

1991-02-01

468

Laser Assisted Cancer Immunotherapy: Optical Dye Distribution in Tumors  

NASA Astrophysics Data System (ADS)

Laser Assisted Cancer Immunotherapy is an experimental modality used to treat superficial tumors implanted on sterile Balb/C mice. The goal of the project is to induce a positive immune response toward a complete eradication of the primary tumor. Optimal necrosis results from depositing the maximum amount of thermal energy into the tumor without damaging the surrounding healthy tissue. In our laboratory, the optical dye, indocyanine green (ICG), is injected into the center of the tumor prior to surface and interstitial laser irradiation. A diode laser operating at a wavelength near 804 nm exerts thermal energy into the tumor via ICG absorption at 790 nm. Maximum immune response should occur with a uniform distribution of ICG throughout the tumor. By mapping the ICG distribution, the spatial homogeneity of the dye can be determined, which, in turn, mimics the tumor temperature profile. After excision, the tumors were cut into samples of approximately 250 microns thick and dissolved in a chemical detergent. Each sample was run through an absorption spectrometer to determine the distribution of ICG throughout the tumor. Results for both radial and depth profiles of ICG tumor distribution will be presented.

Swindle, Ryan

2005-03-01

469

Overview and future direction for blackbody solar-pumped lasers  

NASA Technical Reports Server (NTRS)

A review of solar-pumped blackbody lasers is given which addresses their present status and suggests future research directions. The blackbody laser concept is one system proposed to scale to multimegawatt power levels for space-to-space power transmissions for such applications as onboard spacecraft electrical or propulsion needs. Among the critical technical issues are the scalability to high powers and the laser wavelength which impacts the transmission optics size as well as the laser-to-electric converter at the receiver. Because present blackbody solar-pumped lasers will have laser wavelengths longer than 4 microns, simple photovoltaic converters cannot be used, and transmission optics will be large. Thus, future blackbody laser systems should emphasize near visible laser wavelengths.

Deyoung, R. J.

1988-01-01

470

A diode-laser-pumped tunable Ho: YLF laser in the 2 µm region  

Microsoft Academic Search

We report the cw laser emission of Ho: YLF in an astigmatically compensated resonator under pumping by a laser diode array. We measured the laser efficiency at different operating temperatures of the crystal and the non-saturated gain coefficient at the peak wavelength of laser emission. The laser tunability extends from 2.040 µm to 2.075 µm.

A. Di Lieto; P. Minguzzi; A. Toncelli; M. Tonelli; H. P. Jenssen

1994-01-01

471

Analysis of the pump-beam path in corner-pumped slab laser  

SciTech Connect

The propagation of the pump radiation in active slab elements is considered. Conditions of the total internal reflection of the pump radiation are obtained, and are used to construct a series of graphical illustrations of reflection characteristics of different active elements. (control of laser radiation parameters)

Chen Li; Qiang Liu; Mali Gong; Gang Chen; Ping Yan [Center for Photonics and Electronics, State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University (China)

2007-06-30

472

Energy deposition measurements for e-beam pumped excimer lasers  

SciTech Connect

The energy deposition of the e-beam pumped MLI Two-Meter Laser was measured and compared using dosimetry films, electron calorimetry, current measurements, and pressure rise measurements. The measurements agreed within their uncertainties. 7 refs., 10 figs.

Cates, M.C.; Robertson, K.L.; Melcher, P.C. (Maxwell Labs., Inc., San Diego, CA (USA)); Greene, D.P.; Romero, V.O. (Los Alamos National Lab., NM (USA))

1989-01-01

473

Further remarks on electron beam pumping of laser materials.  

PubMed

This article demonstrates that recently completed studies on the energy dissipation of kilovolt electron beams in solids provide readily applicable methods for assessing the situation in electron beam pumped lasers. PMID:20057662

Klein, C A