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1

Research of the quenched dye lasers pumped by excimer lasers  

SciTech Connect

In this paper, the quenched dye lasers pumped by XeCl and KrF excimer lasers were investigated theoretically and experimentally. Dye laser pulses with duration of 0.8 ns for XeCl laser pumping and 2 ns for KrF laser pumping were obtained. The dye Rhodamine 6G dissolved in methyl was used as the active medium in the quenched dye laser. When the pump laser was KrF and the active medium was Coumarin 498 the quenched dye laser emitted pulse with duration of about 2 ns. The characteristics of the quenched dye laser was also investigated in detail.

Xue Shaolin; Lou Qihong [Academia Sinica, Shanghai (China). Shanghai Inst. of Optics and Fine Mechanics

1996-12-31

2

Low-threshold dye laser pumped by visible laser diodes  

SciTech Connect

A continuous-wave (CW) dye laser has been pumped by laser diodes for the first time. Two 10-mW visible laser diodes were polarization-combined to pump a rhodamine 700 dye jet laser. The absorbed pump threshold power was 5.6 mW, and 0.28 mW of output power was produced at 758 nm. The resonator was scalable and generated over 360 mW with a slope efficiency of 57% when pumped with a DCM dye laser at 660 nm.

Scheps, R. (Naval Command, Control and Ocean Surveillance Center, San Diego, CA (United States). RDT and E Div.)

1993-10-01

3

Inexpensive, pulsed, tunable ir dye laser pumped by a flashlamp-driven dye laser  

Microsoft Academic Search

A flashlamp-driven dye laser with a 250-ns, 10-mrad divergence, 2-mm-diam beam at 620 nm is used to pump an ir dye laser. The ir laser pulses are tunable from 700 to 900 nm with spectral widths of less than 1 A. Peak ir powers of 100 W have been obtained with 5-kW pump power.

A. Passner; T. Venkatesan

1978-01-01

4

Near-IR dye laser for diode-pumped operation  

Microsoft Academic Search

A dye laser pumped by AlGaInP laser diodes produced efficient, low threshold operation at wavelengths between 740 and 800 nm. Rhodamine 700, oxazine 750, DOTCI and oxazine 1 dyes were demonstrated. Optical conversion efficiencies approaching 50% and output power as high as 361 mW were obtained when pumping with a DCM-based dye laser. Parametric variations of the pump power and

R. Scheps

1995-01-01

5

Pulse Modulation Of An Excimer Pumped Dye Laser  

NASA Astrophysics Data System (ADS)

The generation of subnanosecond dye laser pulses from an excimer pumped dye laser, using a saturable absorber, is investigated. Subnanosecond pulses from rhodamine 610 and rhodamine 640 dye lasers, using cresyl violet as a saturable absorber, are reported. Self-pulse modulation was also observed.

Efthimiopoulos, T.

1985-08-01

6

Near-IR dye laser for diode-pumped operation  

SciTech Connect

A dye laser pumped by AlGaInP laser diodes produced efficient, low threshold operation at wavelengths between 740 and 800 nm. Rhodamine 700, oxazine 750, DOTCI and oxazine 1 dyes were demonstrated. Optical conversion efficiencies approaching 50% and output power as high as 361 mW were obtained when pumping with a DCM-based dye laser. Parametric variations of the pump power and wavelength were performed over the range of 615 nm to 690 nm to provide a more complete characterization of the dye laser.

Scheps, R. [Naval Command, Control and Ocean Surveillance Center, San Diego, CA (United States). RDT and E Div.] [Naval Command, Control and Ocean Surveillance Center, San Diego, CA (United States). RDT and E Div.

1995-01-01

7

Optical pumps for organic dye lasers.  

PubMed

Several types of low energy, ultrafast flashlamps systems have been investigated as optical pumps for lasers using fast decaying fluorescent materials, in particular, organic dyes. Of the various systems examined, the coaxial lamp with a spark gap switch proved to be the most useful for pumping the organic dyes. Parameters optimized were gas type, gas pressure, discharge volume, and electrical circuitry. At optimum operation, the annular volume of the coaxial lamp is completely filled with the discharge and the current rise time is determined mainly by the external circuit inductance. The rapidity and uniformity of the discharge is attributed to photoionization of the gas fill. Current rise times are typically 140 nsec for energies up to 100 J. Because of the photoionization process, these coaxial lamps are considered to be a different class of flashlamps from the standard capillary discharge lamp, the sliding spark lamp, and the ablating wall lamp. Less useful systems that were investigated are described, and the reason for their deficiencies are analyzed. PMID:20072486

Furumoto, H W; Ceccon, H L

1969-08-01

8

Infrared Nâ laser as a pump for IR dyes  

Microsoft Academic Search

An infrared molecular nitrogen laser cooled by liquid nitrogen was used to pump a simple grating tuned infrared dye laser in the wavelength range from 0.915 ..mu..m to 1.04 ..mu..m. Broad-band operation of the dye lasers produced efficiencies as high as 20%, and produced output at wavelengths as long as 1.096 ..mu..m.

Hocker

1977-01-01

9

Tunable repetitively pulsed flashlamp-pumped dye lasers  

SciTech Connect

An experimental investigation was made of the spatioangular and spectral-energy characteristics of high-power tunable repetitively pulsed flashlamp-pumped dye lasers. A high directionality of the output radiation was attained in a wide range of the concentrations of the active molecules when aqueous solutions of dyes, in particular an inclusion complex of coumarin-120 and {beta}-cyclodextrin, were used. Such high directionality was obtained for alcohol and water-alcohol solutions only when the concentrations of these molecules were low. Continuous variation of the tuning range of lasers of this class should be possible by the use of suitable mixtures of efficient donor and acceptor dyes. (lasers)

Dzyubenko, M I; Maslov, V V; Pelipenko, V P; Shevchenko, V V [A.Ya. Usikov Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine, Khar'kov (Ukraine)

1998-12-31

10

Dye laser pumping with red-emitting diode lasers. Professional paper  

SciTech Connect

This paper discusses the recent introduction of moderate-power red-emitting visible laser diodes. The laser resonator and pump optics represent an important advance in the operation of dye lasers. Since visible laser diodes can emit near the peak absorption point of several near-IR-emitting devices, diode pumping can be an effective alternative to krypton-ion laser pumping.

Scheps, R.

1995-02-01

11

Passive apparatus for stabilizing a flashlamp-pumped dye laser  

SciTech Connect

A flash lamp pumped, dye laser apparatus is described which consists of a flash lamp and a liquid dye solution in a transparent compartment proximate to the flash lamp. The compartment is also connected to a tubular circulatory system for moving the liquid dye. The dye solution is activated by flashing of the lamp for lasing to emit light, the lamp and compartment enclosed in a cooling first water jacket, the jacket enclosing deionized water for cooling, an improved cooling system wherein the temperature of the deionized water and the liquid dye solution are maintained within 0.5/sup 0/C of one another, enabling the laser for pulsing at a stabilized 10 pulses per second rate.

De Wilde, M.A.; Decker, L.J.

1986-04-29

12

The generation of tunable near IR radiation using a nitrogen laser pumped dye laser  

Microsoft Academic Search

Excitation transfer between the two components of a dye mixture has allowed a near IR dye laser to be pumped by a nitrogen laser. Several dye mixtures were employed to achieve lasing at all wavelengths within the range 6400-7720 Å. The output pulse powers were in excess of 10 kW over most of this range.

F. B. Dunning; E. D. Stokes

1972-01-01

13

Laser head for simultaneous optical pumping of several dye lasers. [with single flash lamp  

NASA Technical Reports Server (NTRS)

The invention is a laser head for simultaneous pumping several dye lasers with a single flash lamp. The laser head includes primarily a multi-elliptical cylinder cavity with a single flash lamp placed along the common focal axis of the cavity and with capillary tube dye cells placed along each of the other focal axes of the cavity. The inside surface of the cavity is polished. Hence, the single flash lamp supplies the energy to the several dye cells.

Mumola, P. B.; Mcalexander, B. T. (inventors)

1975-01-01

14

Continuous-wave synchronously pumped femtosecond dye laser at 1. 3. mu. m  

SciTech Connect

We report a synchronously pumped, cw mode-locked, near-IR dye laser based on the Kodak Q-switch dye No. 5. Benzyl alcohol is used as the solvent to form a flowing dye jet. Synchronously pumped by 2-psec, 950-mW, compressed pulses of a Nd:YAG laser, the dye laser can be tuned from 1210 to 1340 nm with a maximum output of 5 mW and a pulse duration of 600 fsec.

Choa, F.S.; Liu, Y.; Liu, P.

1989-02-15

15

Continuous-wave synchronously pumped femtosecond dye laser at 1.3 µm  

Microsoft Academic Search

We report a synchronously pumped, cw mode-locked, near-IR dye laser based on the Kodak Q-switch dye No. 5. Benzyl alcohol is used as the solvent to form a flowing dye jet. Synchronously pumped by 2-psec, 950-mW, compressed pulses of a Nd:YAG laser, the dye laser can be tuned from 1210 to 1340 nm with a maximum output of 5 mW

Fow-Sen Choa; Y. Liu; Pao-Lo Liu

1989-01-01

16

Compact high flow dye cell for laser-pumped dye lasers  

SciTech Connect

The rotor of a split-pole asynchronous motor is used to circulate a dye solution in a cylindrical dye cell. A compact high flow dye cell which is suitable for high repetition rate (>100 Hz ) pumping has been thus developed.

Stankov, K.A.

1988-04-01

17

All-solid-state tunable DCM dye laser pumped by a diode-pumped Nd:YAG laser  

Microsoft Academic Search

Lasing is observed near 620 nm in a DCM dye doped TiO 2 -content organically modified silicate (ORMOSIL) pumped by frequency-doubled radiation from a diode-pumped Q -switched Nd:YAG laser. The laser wavelength is tunable over 60 nm. A conversion efficiency of 18 is obtained at its central wavelength of 621 nm. The laser output energy has only a 10 reduction

Wentao Hu; Hui Ye; Chuangdong Li; Zhonghong Jiang; Fuzheng Zhou

1997-01-01

18

The infrared N2laser as a pump for IR dyes  

Microsoft Academic Search

An infrared molecular nitrogen laser cooled by liquid nitrogen was used to pump a simple grating tuned infrared dye laser in the wavelength range from 0.915 ?m to 1.04 ?m. Broad-band operation of the dye lasers produced efficiencies as high as 20 percent, and produced output at wavelengths as long as 1.096 ?m.

L. Hocker

1977-01-01

19

All-solid-state tunable DCM dye laser pumped by a diode-pumped Nd:YAG laser  

SciTech Connect

Lasing is observed near 620 nm in a DCM dye doped TiO{sub 2}-content organically modified silicate (ORMO-SIL) pumped by frequency-doubled radiation from a diode-pumped {ital Q}-switched Nd:YAG laser. The laser wavelength is tunable over 60 nm. A conversion efficiency of 18{percent} is obtained at its central wavelength of 621 nm. The laser output energy has only a 10{percent} reduction after 27,000 pulses at a pump repetition rate of 30 Hz and a pump intensity of 1 J/cm{sup 2}. An all-solid-state, compact, long-lifetime, and tunable dye laser has been demonstrated. {copyright} 1997 Optical Society of America

Hu, W.; Ye, H.; Li, C.; Jiang, Z.; Zhou, F. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

1997-01-01

20

Generation of picosecond pulses from a cavity-dumped synchronously pumped dye laser  

Microsoft Academic Search

Bandwidth-limited pulses of 2.5 ps in duration are reported for a cavity-dumped synchronously pumped dye laser when saturable absorber is mixed with the laser dye. The pulses are tunable over a 610–640-nm range, and the energy per pulse is in the range of 4–8 nJ.

M. J. Wirth; M. J. Sanders; A. C. Koskelo

1981-01-01

21

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

22

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

23

Operation of an infrared dye laser synchronously pumped by a mode-locked CW Nd; YAG laser  

SciTech Connect

Infrared dyes emitting around 1.3 ..mu..m exhibit fluorescence lifetimes T/sub FL/ of only approx. = 10 ps which are shorter than the duration of the pump pulses (t/sub P/ approx. = 70 ps). This fact results in performance characteristics different from those of visible dye lasers where the fluorescence lifetime is longer than t/sub P/. The pulse properties of IR dye lasers are investigated for various bandwidth-limiting elements. The generation of nearly transform-limited dye laser pulses as short as 6 ps-assuming a Gaussian temporal shape-is demonstrated.

Roskos, H.; Optiz, S.; Seilmeire, A.; Kaiser, W.

1986-05-01

24

Performance of an array of plasma pinches as a new optical pumping source for dye lasers  

SciTech Connect

A new optical pumping source consisting of an array of plasma pinches in the hypocycloidal-pinch geometry is employed to pump a variety of dye lasers. A dye cuvette is inserted along the symmetry axis of the plasma device such that it may be surrounded by the plasma pinch. The light from the plasma pinch is very intense and rich in ultraviolet, which makes it an attractive optical pumping source for dye lasers, particularly in the blue-green spectral region. Control of the plasma fluorescence is achieved by the choice of gas, its fill pressure, and the capacitor bank voltage and its stored energy. The rise time of this ''plasma flashlamp'' depends mainly on the gas species and the fill pressure. Output energy of approx.2 mJ per cm/sup 3/ of lasing medium, or 2 kW/cm/sup 3/ for a 1-..mu..s laser pulse, is obtained from rhodamine 6G, coumarin 480, LD 490, and coumarin 504 dyes. That both the coumarin 480 and rhodamine 6G lasers have the comparable output power is a direct proof that the present optical pumping source is more efficient than the commercial xenon flashlamps in pumping lasers in the blue-green spectral region.

Rieger, H.; Kim, K.

1983-11-01

25

Diode-pumped distributed-feedback dye laser with an organic–inorganic microcavity  

Microsoft Academic Search

We present a diode-pumped microcavity dye laser composed of a top organic reflector and a bottom inorganic reflector. The\\u000a top organic reflector consists of alternate thin films of cellulose acetate and poly(N-vinylcarbazole) doped with coumarin\\u000a 540A to construct a distributed-feedback (DFB) resonator. Pumped directly by an InGaN-based blue laser diode (LD) with a pulse\\u000a duration of 4 ns, the microcavity dye

H. Sakata; K. Yamashita; H. Takeuchi; M. Tomiki

2008-01-01

26

Synchronous pumping of picosecond dye laser using high efficiency second harmonic generation from optical fibres  

NASA Technical Reports Server (NTRS)

The stable operation of a mode-locked dye laser synchronously pumped by the second harmonic of an Nd:YAG laser produced in an Nd codoped germanosilicate optical fiber is reported. The optical fiber preparation technique, which results in a second harmonic conversion efficiency of 2 percent, is described. This optical fiber SHG conversion efficiency is the highest reported to date using a continuous-wave mode-locked laser.

Lawandy, N. M.; Bernardin, J. P.; Macdonald, R. L.; Demouchy, G.

1991-01-01

27

Lasing properties of several near-IR dyes for a nitrogen laser-pumped dye laser with an optical amplifier  

Microsoft Academic Search

The energy per pulse as a function of wavelength was measured for several near-IR dyes (and dye mixtures) spanning the wavelength region from 650 to 950 nm using a 900 kW nitrogen laser (Molectron UV24) and a tunable dye laser-amplifier combination (Molectron DL14). The peak energy per pulse for each dye ranges from a low of 90 ..mu..J at 855

B. M. Pierce; R. R. Birge

1982-01-01

28

Optical pumping of dye lasers using an array of plasma pinches  

SciTech Connect

A new optical pumping source consisting of an array of plasma pinches is employed to pump, for the first time, a variety of dye lasers. The plasma pinch is formed in a hollow cylindrical shape by electrically discharging a high-energy capacitor bank (approx. 14kJ) through a device containing a few torrs of hydrogen, deuterium or nitrogen gas. A dye cuvette is inserted along the symmetry axis of the plasma device such that it may be surrounded by the plasma pinch. Control of the plasma fluorescence is achieved by the choice of gas, its fill pressure, and the capacitor bank voltage and its stored energy. The rise time of this ''plasma flashlamp'' depends mainly on the gas species and the fill pressure. The shorter the rise time, the smaller the triplet quenching of the dye, resulting in higher laser output power. The light from the plasma pinch is very intense and rich in ultraviolet, which makes it an attractive optical pumping source for dye lasers, particularly in the blue-green spectral region. Output energy of approx.2 mJ per cm/sup 3/ of lasing medium or 2 kW/cm/sup 3/ for a 1-..mu..s laser pulse is obtained from rhodamine 6G, coumarin 480, LD-490, and coumarin 504 dyes.

Rieger, H.

1982-01-01

29

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

30

Small dye laser in a semiunstable resonator pumped by an argon-jet guided spark.  

PubMed

An argon-jet guided spark of 1-cm length has been constructed, and a small dye laser was pumped by that spark at 150 Hz with 60-nsec pulses. The use of high dye concentrations provided enough gain over a short pathlength. As a consequence of the high concentration and side pumping the cross section of the pumped volume measures only 1.5 x 0.1 mm(2) . This laser of rectangular, cross section lases in one transversal mode due to the application of a novel resonator configuration that is unstable in the vertical plane and stable in the horizontal. An analysis of the factors determining the threshold and of the spatial configuration of this astigmatic mode is given. PMID:20134795

Weysenfeld, C H

1974-12-01

31

Operation of an infrared dye laser synchronously pumped by a mode-locked CW Nd:YAG laser  

Microsoft Academic Search

Infrared dyes emitting around 1.3 ..mu..m exhibit fluorescence lifetimes T\\/sub FL\\/ of only approx. = 10 ps which are shorter than the duration of the pump pulses (t\\/sub P\\/ approx. = 70 ps). This fact results in performance characteristics different from those of visible dye lasers where the fluorescence lifetime is longer than t\\/sub P\\/. The pulse properties of IR

H. Roskos; S. Optiz; A. Seilmeier; W. Kaiser

1986-01-01

32

Lasing properties of several near IR dyes for a nitrogen laser-pumped dye laser with an optical amplifier  

SciTech Connect

The energy per pulse as a function of wavelength was measured for several near-IR dyes (and dye mixtures) spanning the wavelength region from 650 to 950 nm using a 900 kW nitrogen laser (Molectron UV24) and a tunable dye laser-amplifier combination (Molectron DL14). The peak energy per pulse for each dye ranges from a low of 90 ..mu..J at 855 nm (DTTC) to a high of 350 ..mu..J at 702 nm (Oxazine 720P:Rhodamine 610P (1:1)). Several new near-IR dye mixtures are discussed that make it possible to tune from 660 to 940 nm without having the energy per pulse drop below 50 ..mu..J. Pulse widths (FWHM) for HITC and IR 125 were measured at various wavelengths and were observed to vary by as much as 40 percent over the tuning ranges of the dyes.

Pierce, B.M.; Birge, R.R.

1982-07-01

33

Efficient 7-J flashlamp-pumped dye laser at 500-nm wavelength  

SciTech Connect

An existing transverse flow flashlamp-pumped dye laser capable of operation at 500 pps for extended periods of time has been modified and optimized for operation at 502 nm using coumarin 504. Energies of over 7 J/ pulse and efficiencies of over 1% have been demonstrated in single-shot operation. This has been achieved by using a spectral transfer dye in the flashlamp coolant to increase the useful output of the flashlamps. Flashlamps were tested at up to 400-J input per lamp for extended periods to develop lamp life data.

Everett, P.N.; Aldag, H.R.; Ehrlich, J.J.; Janes, G.S.; Klimek, D.E.; Landers, F.M.; Pacheco, D.P.

1986-07-01

34

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

35

Laser and spectral characteristics of a DCM-propylene carbonate dye laser system pumped by a XeCl excimer laser  

SciTech Connect

The energy output and spectral characteristics of a DCM-propylene carbonate dye laser system pumped by a XeCl excimer laser have been measured. The results obtained indicate that DCM-propylene carbonate dye laser system shows a lower energy output and wider frequency-tuning range compared with the case of using dimethylsulfoxide as solvent, which is expected from comparison of the fluorescence parameters of DCM in both solvents.

Shangguan Cheng; Lin Yingyi; Jiang Jinquan; Dou Airon; Wang Yiman; Liu Dianyou; Guo Chu

1987-12-01

36

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

37

Laser therapy without laser: a controlled trial comparing the flashlamp-pumped dye laser with the photoderm high-energy gas discharge lamp  

Microsoft Academic Search

This paper describes a comparison of port-wine-stain treatment using a flashlamp-pumped dye laser and a high-energy gas discharge lamp. This was a controlled trial in which 32 patients had one area of their port-wine stain treated with the dye laser and another area treated with the gas discharge lamp. Statistical comparison of the results using both subjective and objective criteria

H. Strempel; G. Klein

1996-01-01

38

Incendiary potential of the flash-lamp pumped 585-nm tunable dye laser.  

PubMed

The recently introduced pulsed flash-lamp pumped tunable dye laser is used to treat cutaneous port-wine stains. In our practice, infants and children receive general anesthesia for these brief, yet painful, treatments. Because the flammability of this laser has not been reported and because we administer supplemental oxygen and nitrous oxide, we analyzed the incendiary potential of this laser by measuring the flammability of gauze and Telfa strips, hair, clear plastic face masks and tracheal tubes, and green nasal cannulae in 21%-100% oxygen and in nitrous oxide at laser energies between 6.0 and 10.0 J/cm2. (Our clinical range is 6.0-7.0 J/cm2.) In room air, gauze, Telfa, masks, and tubes did not ignite; only gauze ignited at high energy in 100% oxygen. Hair ignited in room air only when struck repeatedly at high energy, but easily ignited in 100% oxygen. Wetting hair with saline prevented ignition in room air and decreased flammability in supplemental oxygen. Green nasal cannulae prongs were extremely flammable in oxygen. Caution should be taken when using supplemental oxygen/nitrous oxide during treatment with the tunable dye laser. PMID:2375518

Epstein, R H; Brummett, R R; Lask, G P

1990-08-01

39

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

A flash lamp pumped dye laser suitable for use as an amplifier stage was developed. The desired output laser pulses are of nanosecond duration, tunable in center frequency, and of good optical quality. Its usefulness as a laser oscillator is emphasized, because it constitutes a compact, relatively efficient source of tunable dye laser light.

Davidson, F.

1983-01-01

40

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

41

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

42

Adaptation for improving lifetime of dye laser using coumarin dyes  

SciTech Connect

The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about 300 nanometers or shorter wavelength.

Fletcher, A.N.

1984-10-23

43

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

44

Dye laser chain for laser isotope separation  

Microsoft Academic Search

Uranium enrichment by laser isotope separation uses a three step operation which requires four visible wavelengths to boost an individual U235 isotope from a low lying atomic energy level to an autoionizing state. The visible wavelengths are delivered by dye lasers pumped by copper vapor lasers (CVL). In this particular talk, a single dye chain consisting of a master oscillator

Denis Doizi; Jean Jaraudias; E. Pochon; G. Salvetat

1993-01-01

45

Laser beam control and diagnostic systems for the copper-pumped dye laser system at Lawrence Livermore National Laboratory  

SciTech Connect

The laser system described in the previous paper is used for experiments in which success requires tight tolerances on beam position, direction, and wavefront. Indeed, the optimum performance of the laser itself depends on careful delivery of copper laser light to the dye amplifiers, precise propagation of dye laser beams through restricted amplifier apertures, and accurate monitoring of laser power at key locations. This paper describes the alignment systems, wavefront correction systems, and laser diagnostics systems which ensure that the control requirements of both the laser and associated experiments are met. Because laser isotope separation processes utilize more than one wavelength, these systems monitor and control multiple wavelengths simultaneously.

Bliss, E.S.; Peterson, R.L.; Salmon, J.T.; Thomas, R.A.

1992-11-01

46

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

47

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

48

High energy and tunable picosecond laser pulses at a kHz - Synchronously pumping a dye laser with a mode-locked, Q-switched and cavity dumped Nd:YAG laser system  

Microsoft Academic Search

Efficient operation of a mode-locked, Q-switched and cavity dumped YAG laser and a synchronously pumped dye laser is described. Stable operation is observed up to repetition rates of 1.3 kHz. Introduction of the cavity dumping optics into the YAG oscillator results in only a modest decrease in the energy of the output pulse train, the operation of the dye laser

Xiaoliang Xie; John D. Simon

1989-01-01

49

Modeling of dye-laser photon statistics  

Microsoft Academic Search

We propose a model for dye lasers operating at resonance with a non-Gaussian fluctuating pump parameter. Analytical and numerical results are compared with recent experimental measurements on the intensity fluctuations of a dye laser and with previous theoretical predictions based on a fluctuating pump parameter of finite correlation time.

Fabio Marchesoni; Theoretische Physik

1986-01-01

50

Argon-pumped tunable dye laser for port-wine stains  

NASA Astrophysics Data System (ADS)

We have been using a continuous dye laser (coherent medical) for more than two years. The wavelength is 585 nm, the power 1.8 W and the fluence 16 - 18 J/cm2. We have treated 364 patients with port-wine stains and 15 children with ulcerated hemangiomas. The results were analyzed using a computer program developed by a team in Lille. The most frequent color was pale pink, followed by deep pink, red and purple. The mean number of laser sessions was 2.3.

Teillac-Hamel, Dominique; de Prost, Yves

1994-12-01

51

Tunable dye laser amplifier chain for laser isotope separation  

Microsoft Academic Search

A tunable dye laser amplifier chain developed for experiments on atomic vapour laser isotope separation (AVLIS) is described. The system, pumped by copper vapour lasers, consists of a master oscillator and an amplifier stage including a preamplifier and three main amplifiers working in the saturation mode. The master oscillator of the stage is a dye laser with a grazing incidence

Igor S Grigoriev; Aleksei B Dyachkov; Valerii P Labozin; Sergei M Mironov; Sergei A Nikulin; Valerii A Firsov

2004-01-01

52

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

NASA Astrophysics Data System (ADS)

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, and the cavity design and typical output traces are presented graphically. Best tuning performance is obtained using a 2400-line/mm Littrow grating with a prism beam expander in a 3 x expansion configuration, giving pulse-to-pulse energy stability of 10 percent at 561 nm. It is predicted that a tuning range of 400-900 nm and peak powers of up to 1 MW could be achieved by using this technique with pumping by the third harmonic of the Nd:YAG laser.

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

1985-07-01

53

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

54

Multi-kilowatt transform-limited picosecond pulses from a cavity-dumped synchronously-pumped dye laser using ``self-stabilisation''  

Microsoft Academic Search

A simple self-stabilisation technique is described for use with a cavity-dumped synchronously-pumped dye laser. Multi-kilowatt Fourier-transform-limited picosecond pulses are produced that exhibit a high degree of phase coherence into the far wings. It is shown experimentally that the underlying mechanism is an automatic self-phase locking process.

D. Cotter

1991-01-01

55

Picosecond Raman Spectroscopy: A Two Dye Laser Synchronously Pumped Raman System  

NASA Astrophysics Data System (ADS)

Raman spectroscopy is a mature field of science that does not need introduction nor rationalization for its use. The majority of the Raman spectroscopy literature is concerned with C.W. high resolution spectroscopy. The Raman Scattering instruments utilize almost exclusively laser light sources, and lately nanosecond and picosecond data on time resolved spectra have made their entrance into the scientific journals. The difficulty in most of these resonance Raman experiments is that they do not provide any more time dependent information than fluorescence. This is due to the limitation that a single laser, quite often, a dye laser and its second harmonic are the only two frequencies available for excitation and resonance probe of the excited state. In this scenario, a Raman Scattering signal is emitted and detected only during the lifetime of the excited state. As the excited state decays to either the ground state or other transient species which absorb at a different wavelength, the resonance with the probe wavelength disappears at the same rate as the population of the excited state decays. This rate of depopulation is also portrayed in an identical fashion. These systems are therefore drastically limited in their use as means for the measurement of the evolution of a chemical intermediate. An additional interesting aspect is that of the understanding of the process itself which is being studied, namely the majority of the research papers presented do not address the possibility of the data depicting stimulated emission gain rather than Raman Scattering.

Chung, Y. C.; Hopkins, J. B.; Rentzepis, P. M.

1986-11-01

56

Laser dye stability  

Microsoft Academic Search

Lasing characteristics and bleaching of four Eastman Kodak ir dyes have been examined in dimethyl sulfoxide. These ir dyes\\u000a are shown to improve in performance in the absence of oxygen. Their photochemical stability was found to be comparable to\\u000a the quinolone laser dyes when exposed to flashlamp excitation. Photodecomposition of the ir dyes under lasing conditions was\\u000a found to vary

N. Fletcher

1980-01-01

57

Small-beam, low-power argon-pumped tunable dye laser at 585 nm for the treatment of cherry angiomas  

NASA Astrophysics Data System (ADS)

An argon-pumped tunable dye laser tuned to 585 nm was used to treat clinically typical cherry angiomas in a preliminary study. A spot size of 0.1 mm and low power (0.1 - 0.15W) in the continuous mode was used for treatment. Results ranged from decrease in size of the cherry angioma to complete regression. In all cases, there was minimal to no scarring. Further study in the treatment of elevated cutaneous vascular lesions with the continuous wave dye laser seems warranted.

Littler, Curt M.

1990-06-01

58

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

59

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

A flashlamp pumped dye laser suitable for use as a single stage amplifier is described. Particular emphasis is placed on the efforts to increase output pulse energy and improve the temporal profile of the injected pulse. By using high power thin film polarizers, output energies reach from 4 to 45 mJ. Various dispersive elements are used to develop an amplified pulse with an extremely clean temporal profile.

Davidson, F.; Hohman, J.

1984-01-01

60

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

61

Tunable dye laser amplifier chain for laser isotope separation  

SciTech Connect

A tunable dye laser amplifier chain developed for experiments on atomic vapour laser isotope separation (AVLIS) is described. The system, pumped by copper vapour lasers, consists of a master oscillator and an amplifier stage including a preamplifier and three main amplifiers working in the saturation mode. The master oscillator of the stage is a dye laser with a grazing incidence diffraction grating. Longitudinal pumping of the amplifiers is used. The efficiency of the main amplifiers is 50 % - 55 %. The average power of laser radiation at the output of the last amplifier is 100 W. (lasers. amplifiers)

Grigoriev, Igor' S; D'yachkov, Aleksei B; Labozin, Valerii P; Mironov, Sergei M; Nikulin, Sergei A; Firsov, Valerii A [Russian Research Centre 'Kurchatov Institute', Moscow (Russian Federation)

2004-05-31

62

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

63

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 tream 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, Steve A. (Tracy, CA); Seppala, Lynn G. (Pleasanton, CA)

1986-01-01

64

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

65

Bleaching and diffusion dynamics in optofluidic dye lasers  

E-print Network

We have investigated the bleaching dynamics that occur in optofluidic dye lasers where the liquid laser dye in a microfluidic channel is locally bleached due to optical pumping. We find that for microfluidic devices, the dye bleaching may be compensated through diffusion of dye molecules alone. By relying on diffusion rather than convection to generate the necessary dye replenishment, our observation potentially allows for a significant simplification of optofluidic dye laser device layouts, omitting the need for cumbersome and costly external fluidic handling or on-chip microfluidic pumping devices.

Gersborg-Hansen, M; Kristensen, A; Mortensen, N A

2007-01-01

66

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

67

LASERS. AMPLIFIERS: Tunable dye laser amplifier chain for laser isotope separation  

Microsoft Academic Search

A tunable dye laser amplifier chain developed for experiments on atomic vapour laser isotope separation (AVLIS) is described. The system, pumped by copper vapour lasers, consists of a master oscillator and an amplifier stage including a preamplifier and three main amplifiers working in the saturation mode. The master oscillator of the stage is a dye laser with a grazing incidence

Igor'S. Grigoriev; Aleksei B. D'yachkov; Valerii P. Labozin; Sergei M. Mironov; Sergei A. Nikulin; Valerii A. Firsov

2004-01-01

68

Solid state dye laser for medical applications  

NASA Astrophysics Data System (ADS)

The development of solid state dye lasers could lead to a major breakthrough in the cost and compactness of a medical device. Advantages include: elimination of the flow system for the gain medium; ease with which to implement wavelength agility or the replacement of a degraded rod or sheet; and toxicity and flammability become a non-issue. Dye lasers have played a role in cardiology, dermatology, and urology. Of these cardiology is of interest to Palomar. The Palomar Model 3010 flashlamp-pumped dye laser medical device was used during phase 1 FDA clinical trials to break-up blood clots that cause heart attacks, a process known as coronary laser thrombolysis. It is the objective of this research and development effort to produce solid matrix lasers that will replace liquid dye lasers in these medical specialties.

Aldag, Henry R.

1994-06-01

69

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

70

The construction and operation of a flashlamp pumped tunable narrow linewidth dye laser  

E-print Network

tunability of a narrow 7 spectral linewidth, dispersive elements must be introduced into the laser cavity. Various possible configurations using different line- width narrowing schemes have been implemented and will be discussed in the following sections... in the same way as Eq. (2. 4). The resulting theoretical linewidth in wavelenoth units is 17 & Ae 2 M ( ? '" ' i~. (s ~ 1. xv Ia, ) The equivalent expression in frequency units is (2. 20) fc~a where d& is the laser linewidth. Combining Eqs. (2. 20...

Hilty, Bruce Robert

1979-01-01

71

Dual-amplified spontaneous emission from 7-diethyl amino-4-methyl coumarin (DAMC) laser dye under picosecond pumping  

NASA Astrophysics Data System (ADS)

Under picosecond laser excitation the ASE spectra of DAMC dye in polar solvents show two peaks whereas their fluorescence spectra always display only one peak. This paper presents the results of an experimental study of the ASE spectra of this molecule and offers an explanation for the observed dual ASE.

Vetrivel, L.; Sivaram, B. M.

1996-03-01

72

Theory of pulsed dye lasers including dye-molecule rotational relaxation  

SciTech Connect

In this paper a phenomenological semiclassical theory of pulsed-laser-pumped dye-laser light amplifiers is presented. The theory accounts for the broadband radiation absorption and emission characteristics of dye molecules in liquid solvents. Dye-molecule fluorescence, vibrational, rotational, and electric polarization relaxation processes are represented by phenomenological relaxation rates. In general, it is found that due to dye-molecule rotational relaxation the laser-pumped dye medium is optically anisotropic. The pump- and dye-laser beams propagate through the dye medium as essentially transverse electromagnetic waves whose amplitude and polarization state changes. The theory is applicable to pulse durations {tau}{approx lt}10--100 ns including the ultrashort pulse regime. The regime {tau}{approx gt}1 ps in which the pump- and dye-laser pulse lengths are long compared to the dye-molecule vibrational and electric polarization relaxation times is considered in detail. Amplification of partially polarized quasimonochromatic light is described by a self-consistent set of equations for the components of the pump- and dye-laser light coherency matrices and the orientation populations of the lowest vibronic levels of the dye molecule's {ital S}{sub 0} and {ital S}{sub 1} electronic states.

Haas, R.A.; Rotter, M.D. (Department of Applied Science, University of California, Davis-Livermore, L-794, P.O. Box 808, Livermore, California 94550 (US) Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550)

1991-02-01

73

Continuous-wave organic dye lasers and methods  

DOEpatents

An organic dye laser produces a continuous-wave (cw) output without any moving parts (e.g., without using flowing dye streams or spinning discs of solid-state dye media to prevent photobleaching) and with a pump beam that is stationary with respect to the organic dye medium. The laser's resonant cavity, organic dye medium, and pump beam are configured to excite a lasing transition over a time scale longer than the associated decay lifetimes in the organic dye medium without photobleaching the organic dye medium. Because the organic dye medium does not photobleach when operating in this manner, it may be pumped continuously so as to emit a cw output beam. In some examples, operation in this manner lowers the lasing threshold (e.g., to only a few Watts per square centimeter), thereby facilitating electrical pumping for cw operation.

Shapira, Ofer; Chua, Song-Liang; Zhen, Bo; Lee, Jeongwon; Soljacic, Marin

2014-09-16

74

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

75

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. PMID:24761097

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

2014-01-01

76

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

77

Water soluble laser dyes  

DOEpatents

Novel water soluble dyes of the formula 1 are provided by the formula described in the paper 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 {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

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

1998-08-11

78

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

79

Laser kinetic processes in dye mixtures  

SciTech Connect

Radiation from rhodamine 6G+cresyl violet and rhodamine B+cresyl violet dye mixtures in ethyl alcohol pumped by N/sub 2/ laser light were studied. The rate constants of resonant transfer in the mixtures were determined. The radiative transfer processes are discussed.

Lei Jie; Fu Honglang

1988-11-01

80

Solid state dye lasers with scattering feedback  

NASA Astrophysics Data System (ADS)

Over the last decade, significant advances have been made toward the development of practical, tunable solid state dye lasers, which resulted in improved lasing efficiency with reduced dye photodegradation. To achieve this goal, a “chemical” approach was followed, where attention was focused onto the particular dye/host interaction and compatibility, specifically choosing already existing hosts for a given dye, synthesizing new dyes and/or matrices, or chemically modifying existing ones. Nevertheless, this approach was limited by a single fact learnt from the experience: there is no universal matrix which optimizes the efficiency and photostability of all dyes. This limitation could be overcome by following a “physical” approach, where the emission properties of the active medium are tailored by means of physical and structural modifications of the dye host. Following this approach, in this paper recent theoretical and experimental work is reviewed where it is demonstrated that following a simultaneous “physical” and “chemical” approach to tailor the emission properties of the host materials for solid state dye lasers, may lead, under specific circumstances, to the improvement of both the laser efficiency and photostability. In particular, it is demonstrated that optical scattering is not always detrimental either to conventional bulk lasers (laser rods or colloidal suspensions) or to integrated devices, but may give place, on the contrary, to dramatic improvements in the laser operation of organic (hybrid) laser rods, and to alternative ways of obtaining laser light from integrated devices based on the phenomenon of coherent random lasing, where feedback is provided by light scattering in an appropriate medium, without the need to manufacture complex periodic structures in the substrate. The processing and pumping flexibility of these materials, together with their low cost and capability of efficient emission across the whole visible spectrum makes them very attractive for the fabrication and development of coherent light sources suitable for integration in optoelectronic and disposable spectroscopic and sensing devices.

Costela, A.; Cerdán, L.; García-Moreno, I.

2013-11-01

81

Investigation of RF plasma light sources for dye laser excitation  

Microsoft Academic Search

Analytical and experimental studies were performed to assess the applicability of radio frequency (RF) induction heated plasma light sources for potential excitation of continuous dye lasers. Experimental efforts were directed toward development of a continuous light source having spectral flux and emission characteristics approaching that required for pumping organic dye lasers. Analytical studies were performed to investigate (1) methods of

J. S. Kendall; J. E. Jaminet

1975-01-01

82

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

83

CW laser pumped emerald laser  

SciTech Connect

A CW laser-pumped emerald laser is reported. A 34 percent output power slope efficiency is observed with longitudinal pumping by a krypton laser in a nearly concentric cavity. The laser has been tuned from 728.8 to 809.0 nm. Losses in emerald are larger than those of alexandrite determined in a similar cavity. The present data also indicate that the excited state absorption minimum is shifted from that of alexandrite. 13 references.

Shand, M.L.; Lai, S.T.

1984-02-01

84

CW laser pumped emerald laser  

Microsoft Academic Search

A CW laser-pumped emerald laser is reported. A 34 percent output power slope efficiency is observed with longitudinal pumping by a krypton laser in a nearly concentric cavity. The laser has been tuned from 728.8 to 809.0 nm. Losses in emerald are larger than those of alexandrite determined in a similar cavity. The present data also indicate that the excited

M. L. Shand; S. T. Lai

1984-01-01

85

Chemical stabilization of the coumarin 1 dye laser  

SciTech Connect

The chemical stabilization of coumarin 1, 7-diethylamino-4-methylcoumarin, in a nitrogen laser pumped dye laser and coumarin 311, 7-dimethylamino-4-methylcoumarin, under cw conditions with sulfur-free radical chain transfer agents, are described. The mechanism for stabilization involves encounter of triplet coumarin and ground state coumarin with subsequent radical formation and radical disproportionation catalyzed by the chain transfer agents. The output of the coumarin 1 dye laser decreased 10% when the dye solution was stabilized with cysteine hydrochloride over a 12-h period. The output of the unstabilized dye laser decreased 50% during a similar period of operation.

von Trebra, R.J.; Koch, T.H.

1983-01-15

86

Spectrum converter dye for enhancement of blue-green laser efficiency  

SciTech Connect

In order to enhance the efficiency of a blue-green laser through spectrum conversion of the pumping light, a converter dye BBQ was mixed in the laser dye solutions. The laser was pumped with a plasma radiation source. The increase of laser output over the maximum obtainable from the pure dye operation was better than 80% for the dye mixture of LD490+BBQ or coumarin 503+BBQ. The estimated enhancement calculated by a simple spectrum conversion model agrees well with the experimental results. The enhancement is mainly effected by irradiance in the UV from the pumping source, the fairly good match of the fluorescence band of converter dye with the absorption band of the laser dye, and the lack of the overlap of the fluorescence band of the laser dyes with the triplet--triplet absorption band of the converter dye used.

Han, K.S.; Oh, C.H.; Lee, J.H.

1986-11-15

87

Sixteen new IR laser dyes  

Microsoft Academic Search

Sixteen new IR laser dyes are reported. All lased successfully under excitation from a simple linear flashlamp of about 700-ns rise time. Untuned lasing wavelengths ranged from 810 to 972 nm. Laser output pulse energies from the four best of these dyes were 5-15 times greater than from diethylthiatricarbocyanine iodide (DTTC), with peak output of about 50 mJ obtained from

J. P. Webb; F. G. Webster; B. E. Plourde

1975-01-01

88

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

89

Solar pumped laser  

NASA Technical Reports Server (NTRS)

A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed.

Lee, J. H.; Hohl, F.; Weaver, W. R. (inventors)

1984-01-01

90

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

91

Continuous-wave dye lasers in the DCM region  

SciTech Connect

Laser dye DCM in an ethylene glycol solution is a favored medium for converting the argon-ion 488- and 514-nm pump lines to tunable radiation in the 600--730-nm region. However, the dye precipitates from solution, is a powerful mutagen, and the glycol solvent is hygroscopic. Replacement dyes in 3-phenyl-1-propanol or 2-phenoxyethanol, particularly the latter, are proposed.

Hammond, P.; Cooke, D. (Lawrence Livermore National Laboratory, L-463, P.O. Box 808, Livermore, California 94550 (United States))

1992-11-20

92

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

93

Coumarin 6 as the active medium of a dye vapor laser with wide-band optical pumping and specific characteristics of such lasers  

SciTech Connect

An experimental investigation was made of the efficiency of conversion of flashlamp pump radiation to fluorescence of coumarin 6 at a buffer gas pressure of 0--1 MPa. The lasing dynamics of the flashlamp-pumped vapor of this compound was also studied. It was found that the fluorescence quantum efficiency averaged over the absorption spectrum, which characterized the pump conversion efficiency, was < or =0.3 at a buffer gas pressure of 0--1 MPa. Dependences of and the rate constant for optical bleaching of the dye on the buffer gas pressure were determined. A comparative analysis of the lasing dynamics of coumarin 6 in vapors and in an ether solution showed that the gas phase had a higher lasing threshold (18--20 times higher) and a larger increment of loss growth in the spectral range of lasing (four times higher). It also had a shorter maximum lasing duration (t/sub max/roughly-equal500 nsec).

Trusov, K.K.

1982-11-01

94

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

95

Dye laser studies using zig-zag optical cavity  

SciTech Connect

The authors report a substantial advance in dye laser performance using a zig-zag optical cavity. This configuration drastically reduces the effects of intrapulse medium disturbances due to acoustics and thermal lensing on pulse duration, beam quality, and extraction efficiency. Laser outputs of up to 2 J were observed from Coumarin-498 dye pumped by a KrF excimer laser. The dye laser output faithfully replicates the flat-top KrF laser pump pulse over the entire 1.7-[mu]s pulse duration. An intrinsic laser photon conversion efficiency (Photons[sub in]/Photons[sub absorbed]) of 44% was measured. When unstable resonator optics were used, beam qualities of about 2 XDL were measured.

Klimek, D.E.; Mandl, A.E.; Willman, B. (Textron Defense Systems, Everett, MA (United States))

1994-06-01

96

Explosively pumped laser light  

DOEpatents

A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)

1991-01-01

97

High-Intensity Coherent Vacuum Ultraviolet Source Using Unfocussed Commercial Dye Lasers  

E-print Network

1 High-Intensity Coherent Vacuum Ultraviolet Source Using Unfocussed Commercial Dye Lasers Daniel R Intruments Using two or three commercial pulsed nanosecond dye lasers pumped by a single 30 Hz Nd:YAG laser four-wave mixing of collimated (unfocussed) laser beams in mercury (Hg) vapor. Phase matching

Davis, H. Floyd

98

Laser Oscillation of Energy Transfer Solid-State Dye Laser with a Thin-Film Ring Resonator  

NASA Astrophysics Data System (ADS)

We fabricated an energy transfer solid-state dye laser with a thin-film ring resonator. We combined several organic dyes, such as stilbene 3, coumarin 153, rhodamine B, and cresyl violet. The mixed dyes were embedded into the xerogel thin film by the sol-gel method. We pumped the dye molecules with a pulsed Nd:YAG laser third-harmonic generation (THG). Using the mixed-dye doped thin-film ring resonator, we obtained laser oscillation at four different wavelengths with one pumping source.

Fukuda, Makoto; Mito, Keiichi

2000-06-01

99

Improved signal-to-noise in fluorescence scattering by means of nonlinear pumping with a frequency modulated dye laser  

Microsoft Academic Search

Laser-induced fluorescence (LIF) is a well established technique used to determine the neutral hydrogen density in fusion plasmas. There is a requirement to extend these measurements to the Divertor section of large plasma devices, but this is problematical due to the high levels of stray laser light and background plasma emission. Here we describe a method, based on harmonic saturated

M. J. Forrest; R. J. Winfield

1992-01-01

100

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

101

Lasing in dye vapor exposed to wide-band optical pumping  

SciTech Connect

Lasing in a flashlamp-pumped dye vapor was observed for the first time. The laser active medium was coumarin 6 vapor stabilized with ether vapor at a pressure of approx.3 MPa. The vapor was pumped by a transverse-discharge flashlamp with a pulse duration of approx.200 nsec. The lasing wavelength was 527 nm and the spectral width was 16 nm.

Basov, N.G.; Logunov, O.A.; Nurligareev, D.K.; Trusov, K.K.

1981-10-01

102

Pulse properties of a synchronously mode-locked, cavity dumped, picosecond dye laser system  

Microsoft Academic Search

A synchronously mode-locked, cavity-dumped picosecond dye laser is described. The structure and intensity of the picosecond\\u000a pulses measured under different conditions are reported. It was found that the structure of the pulses from the synchronously\\u000a pumped dye laser depends critically on the length of the Ar+ laser pulses. At the shortest Ar+ laser pulses of about 70 ps the dye

V. Sundström; T. Gillbro

1981-01-01

103

High-repetition-rate high-power variable-bandwidth dye laser  

SciTech Connect

An efficient high-repetition-rate dye laser is described which has a bandwidth that can be tailored to match typical atomic inhomogeneous linewidths. The dye laser is pumped by a 4-kHz 2--6 mJ/pulse copper vapor laser. The total efficiency of the dye laser (oscillator and amplifier) is 45% for rhodamine 6G and 30% for rhodamine B.

Lavi, S.; Amit, M.; Bialolanker, G.; Miron, E.; Levin, L.A.

1985-07-01

104

Holmium laser pumped with a neodymium laser  

SciTech Connect

This patent describes a solid-state laser device. It comprises a holmium laser having a first host material doped with an amount of holmium ions sufficient to produce an output laser emission at about 3 {mu}m when the holmium ions in the holmium laser are pumped by a pump beam at a wavelength of about 1.1 {mu}m; and neodymium laser pump source means for supplying a pump beam to pump the holmium ions in the holmium laser at a wavelength of about 1.1 {mu}m.

Bowman, S.R.; Rabinovich, W.S.

1991-07-30

105

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

Possible types of lasers were surveyed for solar power conversion. The types considered were (1) liquid dye lasers, (2) vapor dye lasers, and (3) nondissociative molecular lasers. These are discussed.

Harries, W. L.

1983-01-01

106

Fluorescence rejection in Raman spectroscopy using a synchronously pumped, cavity-dumped dye laser and gated photon counting  

Microsoft Academic Search

The application of a picosecond-pulsed laser system, in conjunction with a time-to-amplitude converter, to the suppression of fluorescence noise in Raman spectra is described. Enhancements of 14.6 (Raman signal\\/fluorescence background) and 2.8 (Raman signal\\/fluorescence noise) were obtained for a solution of benzene doped with a fluorophore with lifetime tau f=11.8 ns, while corresponding improvements of 5.5 and 2.0 were observed

J. Howard; N. J. Everall; R. W. Jackson; K. Hutchinson

1986-01-01

107

Alexandrite laser pumped by semiconductor lasers  

SciTech Connect

We report the first operation of a direct diode-pumped tunable chromium-doped solid-state laser. A small alexandrite (Cr:BeAl{sub 2}O{sub 4}) crystal was longitudinally pumped by two visible laser diodes. The threshold pump power was 12 mW using the {ital R}{sub 1} line at 680.4 nm for the pump transition, and the slope efficiency was 25%. The measured laser output bandwidth was 2.1 nm.

Scheps, R.; Gately, B.M.; Myers, J.F. (Naval Ocean Systems Center, Code 843, San Diego, California 92152 (USA)); Krasinski, J.S. (Allied-Signal, Inc., Corporate Technology Center, Morristown, New Jersey 07960 (USA)); Heller, D.F. (Light Age, Inc., 6 Powder Horn Drive, Warren, New Jersey 07060 (USA))

1990-06-04

108

Zeolite-dye micro lasers  

E-print Network

We present a new class of micro lasers based on nanoporous molecular sieve host-guest systems. Organic dye guest molecules of 1-Ethyl-4-(4-(p-Dimethylaminophenyl)-1,3-butadienyl)-pyridinium Perchlorat were inserted into the 0.73-nm-wide channel pores of a zeolite AlPO$_4$-5 host. The zeolitic micro crystal compounds where hydrothermally synthesized according to a particular host-guest chemical process. The dye molecules are found not only to be aligned along the host channel axis, but to be oriented as well. Single mode laser emission at 687 nm was obtained from a whispering gallery mode oscillating in a 8-$\\mu$m-diameter monolithic micro resonator, in which the field is confined by total internal reflection at the natural hexagonal boundaries inside the zeolitic microcrystals.

Vietze, U; Laeri, F; Ihlein, G; Schüth, F; Limburg, B; Abraham, M

1998-01-01

109

Increased laser action in commercial dyes from fluorination regardless of their skeleton  

NASA Astrophysics Data System (ADS)

The direct and simple fluorination of representative organic laser dyes with emission covering the entire visible spectrum, from blue to red, including Coumarin 460, Pyrromethene 546, Rhodamine 6G and Perylene Red, enhances laser efficiencies by a factor up to 1.8 with respect to the corresponding non-fluorinated parent dyes. More importantly, fluorination also significantly enhances the photostability of the dyes, even under drastic laser pumping conditions.

Duran-Sampedro, G.; Agarrabeitia, A. R.; Arbeloa Lopez, T.; Bañuelos, J.; López-Arbeloa, I.; Chiara, J. L.; Garcia-Moreno, I.; Ortiz, M. J.

2014-11-01

110

Excited molecular complexes in dye solutions and near-IR exciplex lasers  

Microsoft Academic Search

Laser action tunable in the 1.41-1.65 micron range has been obtained in an IR dye solution which can form excited molecular complexes under optical pumping. The energy and spectral characteristics of this exciplex dye laser which is pumped synchronously by an ultrashort-pulse train from an Nd:glass laser are determined. The formation mechanism of the excited complexes has been studied spectroscopically.

V. A. Babenko; Andrei A. Sychev

1987-01-01

111

Dye laser solutions  

SciTech Connect

This patent describes a composition of matter, a cyclodextrin inclusion compound of a fluorescent dye and an {alpha}- or {beta}-chclodextrin having a substituent bonded to an oxygen atom in a glucose unit in the cyclodextrin. The substituent is selected from the class consisting of: alkyl radicals having 1 to 6 carbon atoms, radicals having the formula {bond}CH{bond}CHR{sup 1}{bond}O{sub {ital n}}H wherein R{sup 1} is selected from hydrogen and alkyl radicals having up to about six carbon atoms, and n is equal to a small whole number up to six, and radicals having the formula {bond}CHR{sup 1}{bond}CHOH{bond}CHR{sup 1}{bond} wherein R{sup 1} has the same definition as above, such that the radicals bridge two cyclodextrin rings, and the number of the rings so bridged per molecule is from two to about six; the substituted cyclodextrin having not ore than two substituents per glucose unit.

Herkstroeter, W.G.

1990-06-12

112

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

113

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

114

Fiber-based tunable microcavity fluidic dye laser.  

PubMed

We investigate a tunable fluidic dye laser formed by a microcavity filled with a dye solution. We achieve a wide 18 nm tunability of the laser wavelength by controlling the cavity length for the first time. The microcavity is made of a silica capillary and two aligned fibers with end faces Au-coated. The Rhodamine 6G dye solution flowing through the microcavity is pumped by 532 nm wavelength laser pulses. Laser emission around 570 nm in the form of TE mode with a threshold of about 58???J/pulse is obtained. This work suggests a fiber-based convenient approach to achieve wavelength tunability and integration with lab-on-a-chip systems. PMID:24104825

Zhou, Hao; Feng, Guoying; Yao, Ke; Yang, Chao; Yi, Jiayu; Zhou, Shouhuan

2013-09-15

115

Simple tunable dye laser using a dielectric multilayer filter  

SciTech Connect

We describe a nitrogen laser pumped dye laser tuned by a dielectric multilayer filter. The construction is simple and the adjustment of tuning is easy. It is found that the tuning is possible over a range of 10 nm from 445 to 455 nm in alcoholic solutions of coumarin 1, that the linewidth (0.8 nm) is independent of the filter tilt angle, and that the output intensity is remarkably flat over this tuning range.

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

1982-04-01

116

The physics of dye laser amplifiers  

NASA Astrophysics Data System (ADS)

This paper describes a method for the complete analysis of the optical properties of a laser dye. The analysis uses direct measurements of the saturation intensities for absorption and emission. The complete analysis of an ultraviolet laser dye, 3,5,3,5-Tetra-t-butyl-p-sexiphenyl, demonstrates the power of the saturation analysis method. The dye TBS exhibits some unique optical properties which affect its emission wavelength range and photochemistry.

Jensen, C. C.

117

Solid state dye laser for medical applications  

Microsoft Academic Search

The development of solid state dye lasers could lead to a major breakthrough in the cost and compactness of a medical device. Advantages include: elimination of the flow system for the gain medium; ease with which to implement wavelength agility or the replacement of a degraded rod or sheet; and toxicity and flammability become a non-issue. Dye lasers have played

Henry R. Aldag

1994-01-01

118

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

119

Photonics of laser-excited symmetric cationic polymethine dyes  

SciTech Connect

Efficient lasing is obtained in the visible and near-IR spectral regions in solutions of symmetric polymethine dyes of the indolenine series (indocyanines) pumped by the second harmonic of a Nd{sup 3+}:YAG laser at 532 nm and an exciplex XeCl* laser at 308 nm into the first (long-wavelength) and higher-lying electronic absorption bands. The quantum lasing efficiency upon UV excitation achieves 37%. It is shown that these dyes can also limit the radiation power of these lasers. Polymethine dyes limit especially efficiently the second-harmonic power, their attenuation factor for the radiation power density of 100 MW cm{sup -2} achieving 14. The nanosecond flash-photolysis study of transient absorption spectra showed that the radiation power is limited by the mechanism of reverse saturated singlet-singlet absorption. It is established that the limiting ability of polymethines strongly depends on their structure. (active media)

Svetlichnyi, Valerii A; Maier, G V; Lapin, I N [Tomsk State University, Tomsk (Russian Federation); Kopylova, T N [V.D. Kuznetsov Siberian Physical-Technical Institute, Tomsk (Russian Federation); Derevyanko, Nadezhda A; Ishchenko, Aleksandr A [Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev (Ukraine)

2007-02-28

120

Monochromatic end-pumped operation of an alexandrite laser  

Microsoft Academic Search

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 efficiency measured was 63.8%, close to the calculated intrinsic efficiency and the highest reported for a Cr3+-doped laser. The threshold power was 5.5

Richard Scheps; Joseph F. Myers; Thomas R. Glesne; Harvey B. Serreze

1993-01-01

121

Polymeric-host sulforhodamine-B lasers - Doubled Nd:YAG pumped  

NASA Technical Reports Server (NTRS)

Solid-state dye lasers, pumped by a doubled Nd:YAG laser, were evaluated as a function of concentration, output coupler reflectivity and oscillator dimensions. A slope efficiency of up to 62 pct was achieved. A maximum irradiance of 59 MW/sq cm to the dye laser cavity was achieved.

Gettemy, D. J.; Hermes, R. E.; Barnes, N. P.

1991-01-01

122

Products of photodegradation for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

The products of conventional photolysis of the coumarin laser dyes, Cl, C35, Cl53, and Cl52 have been investigated. The previously reported dealkylation of Cl is documented for the fluorinated dyes, C35, and Cl52 in deaerated solvents. In addition, a reduction product is identified for Cl, consistent with a radical mechanism for decomposition. Evidence is provided that the concentration quenching (self quenching) of singlet dye is important to the degradation mechanism. For the rigid dye, Cl53, a photooxidation product involving the amine functionality results from decomposition in aerated media. For several dyes, very low triplet yields have been measured.

Jones, G., II; Jackson, W. R.; Kanoktanaporn, S.; Bergmark, W. R.

1983-10-01

123

Products of photodegradation for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

The products of conventional photolysis of the coumarin laser dyes, C1, C35, C153, and C152 have been investigated. The previously reported dealkylation of C1 is documented for the fluorinated dyes, C35, and C152 in deaerated solvents. In addition, a reduction product is identified for C1, consistent with a radical mechanism for decomposition. Evidence is provided that the concentration quenching (self quenching) of singlet dye is important to the degradation mechanism. For the rigid dye, C153, a photooxidation product involving the amine functionality results from decomposition in aerated media. For several dyes, very low triplet yields have been measured.

Jones, Guilford; Bergmark, W. R.; Jackson, W. R.

1984-07-01

124

A study of mode-locked argon ion-dye laser systems  

NASA Astrophysics Data System (ADS)

A new argon ion dye laser double mode locking cavity is presented that allows simultaneous pulse period variation in both laser pulse trains. The predicted number of pulses are analyzed and hence the period of pulses for different cavity length adjustments. A novel approach to creating synchronous picosecond pulse trains at two wavelengths is presented. The method uses a synchronously pumped argon ion laser to cause population inversion and lasing in a mixture of rhodamine 6G and cresyl violet dye. This synchronously pumped double mode locking is simpler to implement than other two wavelength methods. The pulses produced are superior to those generated in the widely used commercial synchronously pumped systems.

Selfridge, R. H.

1984-06-01

125

Lasing efficiency and photochemical stability of IR laser dyes in the 710-1080-nm spectral region  

Microsoft Academic Search

The lasing efficiencies and photochemical stabilities of laser dyes useful in the 710-1080-nm spectral region have been investigated using aQ-switched ruby laser pumping source. The measured bleaching ratesPdefined as the probability of irreversible decomposition of a dye molecule per absorbed photon, varied fromleq 1 times 10^{-5}to3 times 10^{-4}for the different dye-solvent combinations investigated. Broad-band lasing efficiencies (the ratios of dye

PETER E. OETTINGER; C. F. Jr. Dewey

1976-01-01

126

Ultraviolet single-frequency coupled optofluidic ring resonator dye laser.  

PubMed

Ultraviolet single-frequency lasing is realized in a coupled optofluidic ring resonator (COFRR) dye laser that consists of a thin-walled capillary microfluidic ring resonator and a cylindrical resonator. The whispering gallery modes (WGMs) in each resonator couple to each other and generate single-frequency laser emission. Single-frequency lasing occurs at 386.75 nm with a pump threshold of 5.9 ?J/mm. The side-mode-suppression ratio (SMSR) is about 20 dB. Moreover, the laser emits mainly in two directions, and each of them has a divergence of only 10.5°. PMID:23037052

Tu, Xin; Wu, Xiang; Li, Ming; Liu, Liying; Xu, Lei

2012-08-27

127

Modified polymers -- Effective host materials for solid-state dye lasers and laser beam control elements: A review  

SciTech Connect

In many respects solid polymers are attractive hosts for dyes to produce on their base various optical elements for laser applications including tunable lasers and laser beam control saturable filters. For this reason various dye-impregnated polymer materials were extensively studied in many laboratories during last 25 years. A critical review of these studies is presented in this paper with main attention to analysis of processes responsible for major laser characteristics of dye-impregnated polymer materials: lasing efficiency, bleaching efficiency, laser damage resistance of polymer matrix, photostability of dyes under high power laser radiation and dye deterioration during long-term use and storage. Results achieved on General Physics Institute of Russian Academy of Sciences and collaborating industrial research laboratories on creation of highly effective dye-impregnated modified polymer materials for visible and near IR laser application possessing high laser damage resistance, dye photostability, laser oscillation efficiency and laser induced bleaching efficiency are presented. Limitations for polymer-host dye lasers, due to rather low thermal conductivity of polymer materials, arising, in particular, at flash lamp pumping and high repetition rates, are discussed. Some practical methods allowing to overcome these limitations are also discussed.

Manenkov, A.A. [Russian Academy of Sciences, Moscow (Russian Federation). General Physics Inst.; Maslyukov, A.P.; Matyushin, G.A.; Nechitailo, V.S. [Research Inst. for Medical Polymers, Moscow (Russian Federation)

1994-12-31

128

High brightness diode-pumped organic solid-state laser  

NASA Astrophysics Data System (ADS)

High-power, diffraction-limited organic solid-state laser operation has been achieved in a vertical external cavity surface-emitting organic laser (VECSOL), pumped by a low-cost compact blue laser diode. The diode-pumped VECSOLs were demonstrated with various dyes in a polymer matrix, leading to laser emissions from 540 nm to 660 nm. Optimization of both the pump pulse duration and output coupling leads to a pump slope efficiency of 11% for a DCM based VECSOLs. We report output pulse energy up to 280 nJ with 100 ns long pump pulses, leading to a peak power of 3.5 W in a circularly symmetric, diffraction-limited beam.

Zhao, Zhuang; Mhibik, Oussama; Nafa, Malik; Chénais, Sébastien; Forget, Sébastien

2015-02-01

129

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

130

An electrically pumped germanium laser  

E-print Network

Electrically pumped lasing from Germanium-on-Silicon pnn heterojunction diode structures is demonstrated. Room temperature multimode laser with 1mW output power is measured. Phosphorous doping in Germanium at a concentration ...

Cai, Yan

131

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

132

Dye Doped Ormosil Materials for Solid State Dye Laser  

Microsoft Academic Search

Organically Modified Silicate (ORMOSIL) materials doped with organic dyes (Rhodamine 6G, Rhodamine B) have been prepared from sol-gel derived using Methyltrimethoxysilane (MTMS) as precursor. The synthesis process was investigated step by step using Raman spectroscopy, and the experimental results demonstrated that Methyl group bounds to silica oxide network remain in the final materials. Broadband laser emission of the materials has

Tran Hong Nhung; Nghiem Ha Lien; A. Brun; Vu Thi Bich; Nguyen Xuan Nghia; Do Quang Hoa; Truong Thi Anh Dao; Nguyen Dai Hung

2001-01-01

133

1746 J. Opt. Soc. Am. B/Vol. 6, No. 9/September 1989 Effects of pump modulation on a four-level laser amplifier  

E-print Network

is tested by carrying out an experiment using an alexandrite crystal pumped by a cw dye laser. A second dye- tally in ruby,9 alexandrite,'0 and fluorescein-doped glass.8 In this paper we will explore a closely of this theory in alexandrite. The experiment is carried out using one dye laser as a pump to produce

Stroud Jr., Carlos R.

134

Widely tunable, picosecond, distributed feedback dye laser  

SciTech Connect

A novel optical and mechanical arrangement for a tunable distributed feedback dye laser is described. The spectral bandwidth and the pulse duration of the laser emission are almost transform limited in a tunable spectral range from the near UV to the near IR.

Jasny, J.

1986-07-01

135

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

136

Selective Emitter Pumped Rare Earth Laser  

NASA Technical Reports Server (NTRS)

A selective emitter pumped rare earth laser provides an additional type of laser for use in many laser applications. Rare earth doped lasers exist which are pumped with flashtubes or laser diodes. The invention uses a rare earth emitter to transform thermal energy input to a spectral band matching the absorption band of a rare earth in the laser in order to produce lasing.

Chubb, Donald L. (Inventor); Patton, Martin O. (Inventor)

2001-01-01

137

Effects of pump modulation on a four-level laser amplifier  

SciTech Connect

A theory is developed to describe the way in which modulations in the pump intensity produce modulations in the gain of a four-level, homogeneously broadened laser amplifier. The theory is tested by carrying out an experiment using an alexandrite crystal pumped by a cw dye laser. A second dye laser is used to measure the gain in the inverted laser transition. The dependence of the magnitude and the bandwidth of the gain on the pumping rate is determined. Agreement between theory and experiment is good.

Chakmakjian, S.H.; Koch, K.; Papademetriou, S.; Stroud, C.R. Jr. (The Institute of Optics, University of Rochester, Rochester, New York 14627 (US))

1989-09-01

138

Effects of pump modulation on a four-level laser amplifier  

SciTech Connect

A theory is developed to describe the way in which modulations in the pump intensity produce modulations in the gain of a four-level, homogeneously broadened laser amplifier. The theory is tested by carrying out an experiment using an alexandrite crystal pumped by a c-w dye laser. A second dye laser is used to measure the gain in the inverted laser transition. The dependence of the magnitude and the bandwidth of the gain on the pumping rate is determined. Agreement between theory and experiment is good.

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

1989-01-01

139

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

140

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

141

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

142

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

143

Properties of an ultrashort-pumped near-IR high gain dye amplifier  

Microsoft Academic Search

.   An ultra-short-pumped optical dye amplifier operating in the near-IR (720 nm) has been developed. We present an experimental\\u000a study of the input–output characteristics of this simple device in a traveling wave collinear configuration. In essence, the\\u000a combined effects of the ultrafast nature of the anisotropy induced by the exciting laser pulse along with the short transit\\u000a time across the length

C. Pépin; S. Marengo; D. Houde

2002-01-01

144

Biscoumarins: New laser dyes in Coumarin series  

SciTech Connect

With a view to extend the tunability range using new derivatives in the coumarin series of dyes, a novel series have been synthesized, viz. the biscoumarins where two coumarin nuclei are coupled. These are studied for their lasing characteristics, optical spectra and quantum efficiencies. Laser spectra of these dyes in various solvents are also studied. Tunability range of these dyes have been found to cover blue green region of the spectrum and though there is shift to longer wavelength as compared to monocoumarins, extending the tunability range, it is not as much as would be normally expected with extended conjugation involving two coumarin nuclei.

Padhye, M.R.; Varadarajan, T.S.; Deshpande, A.V.

1984-06-01

145

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

146

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

147

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

148

Properties of two-photon pumped cavity lasing in novel dye doped solid matrices  

SciTech Connect

Two-photon pumped frequency upconversion cavity lasing at {approximately}600 nm is accomplished in three types of dye-doped solid rods pumped with {approximately}10 ns and 1.06-{micro}m IR laser pulses. The dopant is a new dye, trans-4-[p-(N-ethyl-N-(hydroxyethyl)amino)styryl]-N-methylpyridinium tetraphenylborate, abbreviated as ASPT, which possesses a greater two-photon absorption cross section and stronger upconversion fluorescence emission than common commercial dyes (such as rhodamine). Three different materials were chosen as solid matrices: poly(2-hydroxyethyl methacrylate), VYCOR porous glass, and sol-gel glass. Using a Q-switched Nd:YAG pulse laser as the pump source, strong cavity lasing could be achieved in these three ASPT doped solid rods as well as in ASPT solution in a liquid cell. The spectral, temporal, and spatial characteristics of the cavity lasing output have been systematically investigated. The measured output-input characteristics, lasing lifetime, and damage threshold for the three different rods are presented.

He, G.S.; Bhawalkar, J.D.; Zhao, C.; Prasad, P.N. [State Univ. of New York, Buffalo, NY (United States). Dept. of Chemistry] [State Univ. of New York, Buffalo, NY (United States). Dept. of Chemistry

1996-05-01

149

Off-axis coherently pumped laser  

NASA Technical Reports Server (NTRS)

A coherently optically pumped laser system is described. A pump laser beam propagates through a laser medium contained in a degenerate cavity resonator in a controlled multiple round trip fashion in such a way that the unused pump beam emerges from an injection aperture at a different angle from which it enters the resonator. The pump beam is angularly injected off of the central axis of the resonator body whereupon the pump beam alternately undergoes spreading and focusing while pumping the laser medium by a process of resonant absorption. The emergent pump beam can also be used as a second pump beam source by being reinjected back into the cavity or it can be used for pumping another laser.

Koepf, G. A. (inventor)

1984-01-01

150

Temperature dependence of the peak power of a Haensch-type dye laser  

NASA Astrophysics Data System (ADS)

The temperature dependence of the peak power produced by certain dyes in a Haensch-type dye laser is investigated. When used with 0.01-M solution of the dye Exciton C460 (7-diethylamino-4-methyl coumarin), the nitrogen-laser pumped dye laser is found to exhibit a maximum peak power near 15 C, with peak power decreasing linearly to 28.3 C, accompanied by an increase in the divergence angle of the laser beam. Possible explanations for the effects include the decrease in thermally induced refractive index gradients and an increase in fluorescence quantum yield upon a decrease in temperature. The second interpretation is shown to be favored by evidence of a strong temperature dependence of lasing in dyes with a 7-amino group capable of an internal rotation, and slight temperature dependence in coumarin dyes lacking a 7-amino group. It is pointed out that the technique of providing temperature for the circulating dye solution has yielded gains in peak power of up to 70% for certain dyes, including a dye without a 7-amino group but capable of an internal rotation.

Peters, D. W.; Mathews, C. W.

1980-12-01

151

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

152

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

153

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

154

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

155

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

156

Active media for near-IR polymethine dye lasers  

Microsoft Academic Search

The paper considers ways to optimize the lasing performance of polymethine dye lasers, active in the 707-1050-nm spectral range. Consideration is given to the relationship of structural, spectral, and lasing characteristics of polymethine dye molecules. A list of dye solutions which best meet the appropriate laser-technology requirements is presented.

M. A. Alperovich; G. G. Diadiusha; O. V. Przhonskaia; T. N. Smirnova; Iu. L. Slominskii; E. A. Tikhonov; A. I. Tolmachev; V. S. Tiurin; M. T. Shpak

1979-01-01

157

Laser-Driven Atomic Pump  

NASA Astrophysics Data System (ADS)

We propose a laser-driven pump for atomic transport through carbon nanotubes. A two beam coherent control is used to inject carrier population into the lowest unoccupied nanotube bands, which is anisotropic in momentum space. The resulting electron current moves intercalated atoms along the tube. This system is a unique prototype of a single atom deposition machine which overcomes the loading problem of the scanning tunneling microscope.

Král, Petr; Tománek, David

1999-06-01

158

Diode-pumped laser with improved pumping system  

DOEpatents

A laser wherein pump radiation from laser diodes is delivered to a pump chamber and into the lasing medium by quasi-three-dimensional compound parabolic concentrator light channels. The light channels have reflective side walls with a curved surface and reflective end walls with a curved surface. A flow tube between the lasing medium and the light channel has a roughened surface.

Chang, Jim J.

2004-03-09

159

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

160

Diode laser-pumped solid-state lasers  

Microsoft Academic Search

Recently, interest in diode laser-pumped solid-state lasers has increased due to their advantages over flashlamp-pumped solid-state lasers. The authors present a historical overview of semiconductor diode-pumped solid-state lasers beginning with work in the early 1960's and extending to recent work on wavelength extension of these devices by laser operation on new transitions. Modeling of these devices by rate equations to

T. Y. Fan; R. L. Byer

1988-01-01

161

LASERS: Efficient emission of 1.1-1.5 mum radiation from a superfluorescent laser with IR dyes in a solid host  

Microsoft Academic Search

Emission of 1.1-1.5 mum radiation from a superfluorescent laser with IR dyes in a polymer host was observed and investigated. The energy efficiency of conversion to the infrared radiation was ~3% for picosecond pumping with Nd:YAG laser radiation. Continuous tuning of the emission wavelength of the superfluorescent laser was possible in the 1.1-1.5 mum range by altering the dye concentration

V. A. Babenko; Andrei A. Sychev

1996-01-01

162

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

163

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. PMID:24753719

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

2010-01-01

164

Automated pressure scanning of tunable dye lasers  

NASA Astrophysics Data System (ADS)

A method for the remote control of tunable laser frequency tuning is proposed in the framework of real-time monitoring of the chemistry and physics of plasma, combustion, and chemical vapor deposition reactions. The technique presented involves indirect frequency tuning and stabilization by direct control of the laser cavity pressure. The long-term drift in power, resulting from the grating and etalon misalignment is suggested to be correctable by using a second feedback circuit which would optimize laser power by finely tuning the etalon or grating. Experimental results obtained with a dye laser of Hansch type are included; a maximum variation in LIF signal of + or - 7 percent, which corresponds to a frequency drift of + or - 0.005/cm, over a 30-min interval was achieved. A block diagram of the feedback loop and the LIF apparatus are included.

Gottscho, R. A.

1985-04-01

165

High power diode pumped alkali vapor lasers  

NASA Astrophysics Data System (ADS)

Diode pumped alkali lasers have developed rapidly since their first demonstration. These lasers offer a path to convert highly efficient, but relatively low brightness, laser diodes into a single high power, high brightness beam. General Atomics has been engaged in the development of DPALs with scalable architectures. We have examined different species and pump characteristics. We show that high absorption can be achieved even when the pump source bandwidth is several times the absorption bandwidth. In addition, we present experimental results for both potassium and rubidium systems pumped with a 0.2 nm bandwidth alexandrite laser. These data show slope efficiencies of 67% and 72% respectively.

Zweiback, J.; Krupke, B.

2008-05-01

166

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

167

Photolytic improvement of dye laser lifetimes  

SciTech Connect

The effective lasing lifetime of coumarin 102 in 50:50 ethylene glycol is significantly extended by increasing the rate of pumping and photolysis, with a flashlamp in a laser system having a pyrex ultraviolet filter and an inert cover gas.

Fletcher, A. N.; Knipe, R. H.

1985-12-31

168

Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet  

NASA Astrophysics Data System (ADS)

Laser action in methyl methacrylate (MMA) co-doped with sulforhodamine B and crystal violet dyes was investigated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd:YAG laser. Distributed feedback dye laser (DFDL) action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor—donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor—donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

Geethu Mani, R. G.; Basheer, Ahamed M.

2013-11-01

169

Compression mechanism of subpicosecond pulses by malachite green dye in passively mode-locked rhodamine 6G/DODCI CW dye lasers  

SciTech Connect

The pulse width compression effect of a malachite green (MG) dye upon subpicosecond pulses has been experimentally investigated in a CW passively mode-locked rhodamine 6G/DODCI dye laser. The pulse width reduces as MG concentration increases, and reaches 0.34 ps at 1.5 X 10/sup -6/ M. By adding the MG dye, good mode locking is achieved in a rather wide pumping-power range. A computer simulation of pulse growth has also been carried out by using simple rate equations, in which the fast-recovery component of loss due to the MG dye is taken into account. The simulated results can explain some experimental results qualitatively such as pulse width compression and pumping-power restriction. The pulse width compression results essentially from the fast recovery of cavity loss caused by the MG dye.

Watanabe, A.; Hara, M.; Kobayashi, H.; Takemura, H.; Tanaka, S.

1983-04-01

170

Trace detection of plutonium by three-step photoionization with a laser system pumped by a copper vapor laser  

Microsoft Academic Search

Laser photoionization has been used to detect trace amounts of plutonium. A high sensitivity and selectivity has been achieved by applying three-step excitation and ionization of the plutonium atoms with high pulse-repetition rates and additional mass determination by time-of-flight measurements. A laser system was developed which consists of a copper vapor laser pumping three dye lasers simultaneously. Samples containing between

P. Peuser; G. Herrmann; H. Rimke; P. Sattelberger; N. Trautmann; W. Ruster; F. Ames; J. Bonn; H.-J. Kluge; U. Krönert; E.-W. Otten

1985-01-01

171

Optically-pumped semiconductor lasers at 505-nm in the power range above 100 mW  

Microsoft Academic Search

Lasers based on optically pumped semiconductors (OPS) offer unique capabilities in both wavelength tailoring and power scaling compared to traditional solid-state lasers. In particular, these lasers can be designed in wavelength to realize for instance 505nm, which enables excitation of two fluorescent dye chemistry sets originally established by 488 and 514 nm legacy argon lasers. Highly efficient intra cavity frequency

Wolf Seelert; Stefan Kubasiak; Johannes Negendank; R. von Elm; Juan Chilla; Hailong Zhou; Eli Weiss

2006-01-01

172

A novel, simple and efficient dye laser with low amplified spontaneous emission background for analytical fluorescence and ionization spectroscopy  

SciTech Connect

A new, simple, compact and efficient, grazing- incidence type of dye laser is suggested which has a low level of Amplified Spontaneous Emission. By using a Coumarin dye (LD 5000) pumped with a 20 mJ XeCl excimer laser, and a diffraction grating with 3000 grooves/mm, an efficiency of 11%, a spectral bandwidth of 0.6 cm{sup -1} and a tuning range from 458 to 517 nm have been obtained.

Matveev, Oleg I.; Omenetto, Nicolo' [EC, Joint Research Centre, Environment Institute, 21020 Ispra, Varese (Italy)

1995-04-01

173

Solar-pumped solid state Nd lasers  

NASA Technical Reports Server (NTRS)

Solid state neodymium lasers are considered candidates for space-based polar-pumped laser for continuous power transmission. Laser performance for three different slab laser configurations has been computed to show the excellent power capability of such systems if heat problems can be solved. Ideas involving geometries and materials are offered as potential solutions to the heat problem.

Williams, M. D.; Zapata, L.

1985-01-01

174

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

175

Cladding For Transversely-Pumped Laser Rod  

NASA Technical Reports Server (NTRS)

Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

Byer, Robert L.; Fan, Tso Yee

1989-01-01

176

Prism preexpanded grazing-incidence grating cavity for pulsed dye lasers  

SciTech Connect

A modification to the grazing-incidence grating cavity for pulsed dye lasers is described whereby a prism is employed to expand the intracavity beam by a small factor before illumination of the grating. Suitable choice of the angles of incidence at both prism and grating permits good spectral resolution to be obtained while overall cavity losses are minimized. The performance characteristics of the modified cavity are analyzed and compared with those of simple grazing-incidence grating cavities. Spectral linewidths <0.01 A have been obtained at relatively high efficiencies (7--10%) for coumarin 500 dye pumped with a pulsed N/sub 2/ laser.

Duarte, F.J.; Piper, J.A.

1981-06-15

177

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

178

Frequency stabilization for a 486nm dye-ring laser  

E-print Network

For my thesis, I worked towards using two reference cavities to provide frequency stabilization to a 486nm dye-ring laser. After a doubling cavity doubles the frequency to 243nm, the laser beam is used to excite ground ...

Sievers, Charles A. (Charles Anders), 1979-

2004-01-01

179

Solar-pumped solid-state lasers  

SciTech Connect

Results are presented for direct solar pumping of a ND:YAG rod laser. Stable CW output of more than 60 W was obtained with a slope efficiency exceeding 2 percent. A compound parabolic concentrator, designed to increase the solar radiation coupled into the laser rod, was used in these experiments. The results are consistent with predictions based on a simple solar-pumped laser model, which is also presented. Using this model, it is shown that existing laser materials with broad-band absorption characteristics (e.g., alexandrite and Nd:Cr:GSGG) have a potential for better than 10 percent overall conversion efficiency when solar pumped.

Weksler, M.; Shwartz, J.

1988-06-01

180

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

181

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

182

Laser emission of a flash-lamp pumped Rhodamine 6 G solid copolymer solution  

NASA Astrophysics Data System (ADS)

A Rhodamine 6 G solid solution in a copolymer of 2 hydroxyethyl methacrylate and methyl methacrylate have been flash-lamp pumped in an untuned laser cavity. The pumping energy threshold to obtain laser emission is 20 percent higher than in equivalent methanol solutions. With a flash-lamp electrical excitation average energy of 150 joules per pulse, no photodegradation was observed in the laser emission after more than 30 pumping pulses. There was an absence of local irregular fluctuations found typically in high Fresnel number dye lasers. An interpretation based on the assumption of stereospecificity in the lodging cavity of dye molecules, is consistent with the high photostability and the absence of local fluctuations obtained with this polymeric solid-state laser.

Calderón, Oscar G.; Guerra, J. M.; Costela, A.; García-Moreno, I.; Sastre, R.

1997-01-01

183

Diode-Pumped Solid State Lasers  

E-print Network

III The use ofdiode lasers instead ofHashlamps as optical pump sources for solid state lasers offers significant advantages such as higher efficiency and longer lifetime. We have demonstrated three novel lasers based on this technology. The first is a zig-zag slab laser pumped by hybrid planar microchannel-cooled diode arrays that allow high-repetition-rate operation in a pulsed mode. The second is an end-pumped laser that uses multiple diode lasers for power scalabilitywhile maintaining high efficiency and good beam quality. The third is a Yb:YAG laser, pumped by strained-layer InGaAs diode lasers, that offers advantages over AlGaAs-pumped Nd:YAG lasers. These advances should lead to lower-cost higher-power solid state lasers. I NTEREST HAS INCREASED in the past few years in using semiconductor diode lasers to excite solid state lasers based on rare-earth ion-doped transparent solids such as neodymium-doped yttrium aluminum

T. Y Fan

184

GaAs laser diode pumped Nd:YAG laser  

NASA Technical Reports Server (NTRS)

A 1.5-mm by 3-cm neodymium-ion doped YAG laser rod has been side pumped using a GaAs laser diode array tuned to the 8680-A absorption line, achieving a multimode average output power of 120 mW for a total input power of 20 W to the final-stage laser diode drivers. The pumped arrangement was designed to take advantage of the high brightness of a conventional GaAs array as a linear source by introducing the pump light through a slit into a close-wrapped gold coated pump cavity. This cavity forms an integrating chamber for the pump light.

Conant, L. C.; Reno, C. W.

1974-01-01

185

Thin-layer chromatography of laser dyes and dye analogs with cyclodextrins in the mobile phase.  

PubMed

The addition of beta-cyclodextrin and substituted hydroxyethyl and hydroxypropyl-beta-cyclodextrins to aqueous urea-containing mobile phases, can be used to enhance the migration of various laser dyes on thin layer chromatography. Selected laser dyes from the coumarin, rhodamine and bimane families were examined, as well as a number of dye analogs. Silica gel, polyamide and C18 reverse phase plates were utilized. Overall, the substituted hydroxypropyl-beta-cyclodextrins appeared to be the most effective for increasing dye migration. PMID:18965477

Politzer, I R; Crago, K T; Amos, K; Mitchell, K; Hollin, T

1992-08-01

186

Studies of solvent-solute interactions in the photophysics of laser dyes  

SciTech Connect

The fluorescence lifetime of rhodamine B in the normal alcohols and normal nitriles was measured using a picosecond laser system. The lifetime-measuring technique is time-correlated single photon counting (TCSPC). Absorption and emission spectra of rhodamine B in the alcohols and nitriles have also been determined, thus allowing calculation of quantum yields, radiative, and nonradiative rates. The rotation of the dye's diethylamino groups is related to the nonradiative rate. A decreasing nonradiative rate corresponds to a greater energy barrier to rotation. Rotational relaxation times of two laser dyes (cresyl violet and oxazine-1) in polymer solution (poly(ethylene oxide) and methanol) was measured using the transient absorption spectroscopy (TAS) method. TAS is a pump-probe technique using a picosecond laser system. The pump beam optically bleaches the sample and the probe beam monitors the transient response. The effect of increasing polymer concentration is seen as an increasing rotational relaxation time.

Casey, K.G.

1988-01-01

187

LED pumped polymer laser sensor for explosives  

PubMed Central

A very compact explosive vapor sensor is demonstrated based on a distributed feedback polymer laser pumped by a commercial InGaN light-emitting diode. The laser shows a two-stage turn on of the laser emission, for pulsed drive currents above 15.7 A. The ‘double-threshold’ phenomenon is attributed to the slow rise of the ?30 ns duration LED pump pulses. The laser emits a 533 nm pulsed output beam of ?10 ns duration perpendicular to the polymer film. When exposed to nitroaromatic model explosive vapors at ?8 ppb concentration, the laser shows a 46% change in the surface-emitted output under optimized LED excitation.

Wang, Yue; Morawska, Paulina O; Kanibolotsky, Alexander L; Skabara, Peter J; Turnbull, Graham A; Samuel, Ifor D W

2013-01-01

188

Theoretcial studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

A method of pumping a COhZ laser by a hot cavity was demonstrated. The cavity, heated by solar radiation, should increase the efficiency of solar pumped lasers used for energy conversion. Kinetic modeling is used to examine the behavior of such a COhZ laser. The kinetic equations are solved numerically vs. time and, in addition, steady state solutions are obtained analytically. The effect of gas heating filling the lower laser level is included. The output power and laser efficiency are obtained as functions of black body temperature and gas ratios (COhZ-He-Ar) and pressures. The values are compared with experimental results.

Harries, W. L.; Fong, Z. S.

1984-01-01

189

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

190

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

191

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

The power output of a black body solar-pumped laser as a function of time (computer graphic solutions) and under steady state conditions (analytic conditions); computer analyses of polymerization using lasers; and metallic sodium as a laser medium were studied.

Harries, W. L.; Fong, Z. S.

1985-01-01

192

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

193

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

194

Research on solar pumped liquid lasers  

NASA Technical Reports Server (NTRS)

A solar pumped liquid laser that can be scaled up to high power (10Mw CW) for space applications was developed. Liquid lasers have the inherent advantage over gases in that they provide much higher lasant densities and thus high power densities. Liquids also have inherent advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13:Nd(3+):ZrC14 liquid was chosen for its high intrinsic efficiency as well as its relatively good stability against decomposition due to protic contamination. The development and testing of the laser liquid and the development of a large solar concentrator to pump the laser was emphasized. The procedure to manufacture the laser liquid must include diagnostic tests of the solvent purity (from protic contamination) at various stages in the production process.

Schneider, R. T.; Kurzweg, U. H.; Cox, J. D.; Weinstein, N. H.

1983-01-01

195

Diode laser pumped solid state laser with 2 micrometer wavelength  

NASA Astrophysics Data System (ADS)

Research at the FOA in the field diode laser pumped solid state lasers with 2 micrometer wavelength is presented. The research was made within the project Antisensor laser. Basic models for CW and pulsed lasers are presented together with results and experience from the design of a diode laser pumped CW laser based on Thulium (Tm), Holmium (Ho) doped Yttrium Lithium Fluoride (TLiF4), abbreviated Tm, Ho:YLF. Measurements on upconversion of energy from the upper laser level in the laser crystal has been made. The upconversion causes loss of energy which leads to higher laser threshold and lower upper state effective lifetime. The result shows less upconversion in Tm, Ho doped YLF than with the same active ions doped into Yttrium Aluminum Garnet (Tm, Ho: YAG). A simple pump configuration was assembled which produced a pump focus of about 200 micrometers radius. With 1 W pump power, an output power of 50 mW was achieved with the laser crystal at room temperature (25 C). With the crystal cooled to 5 C temperature, 77 mW output power was achieved. The measured laser threshold was in good agreement with the calculated value. The efficiency was only 10% compared to the predicted value of 50%. Measurements of laser beam cross section, wavelength and longitudinal laser modes have also been made and is presented in the report.

Hansson, G.; Callenas, A.

1994-06-01

196

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

197

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

198

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

199

Diode pumped Nd:YAG laser development  

NASA Technical Reports Server (NTRS)

A low power Nd:YAG laser was constructed which employs GaAs injection lasers as a pump source. Power outputs of 125 mW TEM CW with the rod at 250 K and the pump at 180 K were achieved for 45 W input power to the pump source. Operation of the laser, with array and laser at a common heat sink temperature of 250 K, was inhibited by difficulties in constructing long-life GaAs LOC laser arrays. Tests verified pumping with output power of 20 to 30 mW with rod and pump at 250 K. Although life tests with single LOC GaAs diodes were somewhat encouraging (with single diodes operating as long as 9000 hours without degradation), failures of single diodes in arrays continue to occur, and 50 percent power is lost in a few hundred hours at 1 percent duty factor. Because of the large recent advances in the state of the art of CW room temperature AlGaAs diodes, their demonstrated lifetimes of greater than 5,000 hours, and their inherent advantages for this task, it is recommended that these sources be used for further CW YAG injection laser pumping work.

Reno, C. W.; Herzog, D. G.

1976-01-01

200

GaAs laser diode pumped Nd:YAG laser  

Microsoft Academic Search

A 1.5-mm by 3-cm neodymium-ion doped YAG laser rod has been side pumped using a GaAs laser diode array tuned to the 8680-A absorption line, achieving a multimode average output power of 120 mW for a total input power of 20 W to the final-stage laser diode drivers. The pumped arrangement was designed to take advantage of the high brightness

L. C. Conant; C. W. Reno

1974-01-01

201

Solvent effects on photophysical parameters for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

The red shifts of absorption and emission bands of coumarin laser dyes were studied as a function of solvent polarity and hydrogen bonding. Spectra were correlated with solvent parameters, pi and alpha, and those solvents resulting in the largest Stokes shifts of dye emission were identified. Solvent effects on emission yield and lifetime revealed a major non-radiative decay path for dyes in which the 7 amine function is free to adopt a non-planar conformation.

Jones, G., II; Jackson, W. R.; Kanoktanaporn, S.; Halpern, A. M.

1980-01-01

202

Research on solar pumped liquid lasers  

NASA Technical Reports Server (NTRS)

A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined.

Cox, J. D.; Kurzweg, U. H.; Weinstein, N. H.; Schneider, R. T.

1985-01-01

203

Efficient emission of 1.1–1.5 ?m radiation from a superfluorescent laser with IR dyes in a solid host  

Microsoft Academic Search

Emission of 1.1–1.5 ?m radiation from a superfluorescent laser with IR dyes in a polymer host was observed and investigated. The energy efficiency of conversion to the infrared radiation was ~3% for picosecond pumping with Nd:YAG laser radiation. Continuous tuning of the emission wavelength of the superfluorescent laser was possible in the 1.1–1.5 ?m range by altering the dye concentration

V A Babenko; Andrei A Sychev

1996-01-01

204

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

205

Continuous-wave operation of a room-temperature, diode-laser-pumped, 946-nm Nd:YAG laser  

NASA Technical Reports Server (NTRS)

Single-stripe diode-laser-pumped operation of a continuous-wave 946-nm Nd:YAG laser with less than 10-mW threshold has been 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. KNbO3 and periodically poled LiNbO3 appear to be the most promising.

Fan, T. Y.; Byer, Robert L.

1987-01-01

206

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

207

Long gain length solar pumped box laser  

NASA Technical Reports Server (NTRS)

A solar pumped laser has its lasing path lengthened by forming a square loop in the lasing path by means of bending mirrors. Solar radiation is collected and concentrated into a donut shaped intensity pattern. This intensity pattern is directed onto the lasing path such that there is a maximum fit of the solar intensity pattern to the square loop laser cavity.

Deyoung, R. J.

1986-01-01

208

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

209

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

210

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

211

Flashlamp-excited dye laser therapy for treatment of cutaneous vascular lesions  

NASA Astrophysics Data System (ADS)

Flashlamp excited dye laser therapy represents an exciting new advance in the treatment of a variety of cutaneous vascular lesions. Portwine stains, angiomas and telangiectases can be treated in all age groups with this laser system. This paper will review the physics of flashlamp dye laser photothermolysis. The differences between argon laser photocoagulation and flashlamp excited dye laser therapy will be reviewed.

Goldberg, David J.

1990-06-01

212

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

213

Diode laser-pumped solid-state lasers  

NASA Technical Reports Server (NTRS)

An evaluation is made of the consequences for solid-state lasers of novel diode laser-pumping technology. Diode laser-pumped neodymium lasers have operated at an electrical-to-optical efficiency of 10 percent in a single spatial mode, with linewidths of less than 10 kHz, and with a spectral power brightness sufficiently great to allow frequency extension by harmonic generation in nonlinear crystals; this has yielded green and blue sources of coherent radiation. Q-switched operation with kW peak powers and mode-locked operation with 10-picosec pulse widths have also been demonstrated. All-solid-state lasers at prices comparable to those of current flash-lamp-pumped laser systems are foreseen, as are power levels exceeding 1 kW, for coherent radar, global satellite sensing, and micromachining.

Byer, Robert L.

1988-01-01

214

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

215

Pulsed dye laser therapy for port-wine stains in children: psychosocial and ethical issues.  

PubMed

The port-wine stain is a disfiguring vascular birthmark that commonly occurs on the face. Amelioration of this condition in children was difficult or impossible until the introduction of the flashlamp-pumped pulsed dye laser in the late 1980s. This article provides an interdisciplinary social and ethical examination of pulsed dye laser therapy for port-wine stain in childhood. Specific issues raised relate to the management of pain during therapy, rationale for care, expectations of treatment, the high costs of care, equity, marketing pressures, and therapeutic activism. Laser therapy in the dermatologic care of children is an exciting innovation that has transformed clinical practice and raised important social, ethical, and health policy issues. PMID:8463892

Strauss, R P; Resnick, S D

1993-04-01

216

Optimisation of a multistage pulsed dye laser system  

SciTech Connect

A multistage narrow-band dye laser amplifying system with an output power of up to several kilowatts is considered as a whole. Such systems became necessary due to the development of the method of laser isotope separation (the AVLIS method). The use of the simplified model of an amplifying cell allowed us to solve analytically the equations describing the laser system and to determine optimal parameters of each stage. The dye laser system with an output power of 1 kW is optimised based on the model proposed. The accuracy of the obtained estimates was verified by a direct numerical simulation of the system based on a rigorous solution of the equations describing the interaction of radiation with the dye solution. (lasers, active media)

Vasil'ev, S V; Kuz'mina, M A; Mishin, V A [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2001-06-30

217

Diode pumped potassium gadolinium tungstate lasers  

NASA Astrophysics Data System (ADS)

Electrical discharge of one or more flash-lamps under high voltage in an optical cavity, has been well established as an excitative mechanism for pulsed lasers, since the simultaneous discoveries of the optical maser and the first ruby laser in 1958-60. Diode laser excitation of crystals is relatively new but have been proven as the generator of efficient, mobile, reliable and scalable lasers and laser systems, with numerous applications in a variety of arenas including, remote sensing, manufacturing, global & local data communications, medicine, and telecommunications including communications through intranets and the global information superhighway (the internet), for electronic Commerce and multimedia interactions. As a suitable model for our diode-pumped experiments and analysis, we have considered the basic concepts of pulsed or flash-lamps and diode-pumped Nd:YAG lasers in Chapter 1. Also we have utilized identically constructed optical cavities for our Nd:YAG and Nd:KGW rods and slabs, to qualitatively and quantitatively compare for the first time, the results of high voltage flash-lamp and high power diode laser pumping of Nd:YAG and Nd:KGW laser materials in the specified situations outlined above. Preliminarily, we setup our experiments in the pulsed mode of laser operation at 1064 nm. We have used identical cylindrical rods and rectangularly symmetric slabs of Nd:YAG & Nd:KGW in an input energy range of 1-25 Joules and we have shown that pulsed Nd:KGW laser rods, near 1064 nm and with many different dopant concentrations of Nd3+ ions, is more than two times more efficient than Nd:YAG laser rods under similar experimental conditions. To generate quality lasers at many tunable wavelengths, in terms of excitation by a diode laser, we have used 10 W and 240 W fiber coupled diode lasers as the pumping sources and compared the results of the diode pumped lasers from Nd:KGW and Nd:YAG rods and slabs doped with low dopant concentrations of Nd3+ ions and emitting near 1064 nm and 1300 nm under similar conditions.

Major, Lawrence Earl

218

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

219

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.

220

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

221

Scalable diode array pumped Nd rod laser  

NASA Technical Reports Server (NTRS)

Experiments were carried out on a five-array pump head which utilizes gold-coated reflective cones to couple the pump energy to Nd:YAG and Nd:YLF rod lasers, demonstrating high efficiency and uniform energy deposition. Because the cones function as optical diodes to light outside their acceptance angle (typically 10-15 deg), much of the diode energy not absorbed on the first pass can be returned to the rod.

Zenzie, H. H.; Knights, M. G.; Mosto, J. R.; Chicklis, E. P.; Perkins, P. E.

1991-01-01

222

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

223

Achievement of a wide wavelength tuning range for lasing in the green and red spectral regions using new laser dyes  

NASA Astrophysics Data System (ADS)

The lasing characteristics of two new dyes related to the naphthalimide and benzantron classes were measured during pumping by second-harmonic ruby laser radiation. The tuning of the lasing wavelength was achieved in the range of about 100 nm (from 500 to 600 nm for naphthalimide and from 640 to 740 nm for benzantron). It is shown that the lasing energy of these compounds exceeds that of the widely used dyes coumarin 7 and uranin in the green region and cresyl violet in the red; moreover, their wavelength tuning range is substantially broader than that of conventional dyes.

Krymova, A. I.; Petukhov, V. A.

1986-03-01

224

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

225

FRET-assisted laser emission in colloidal suspensions of dye-doped latex nanoparticles  

NASA Astrophysics Data System (ADS)

The use of commercial long-wavelength (>650 nm) laser dyes in many biophotonic applications has several important limitations, including low absorption at the standard pump wavelength (532 nm) and poor photostability. Here, we demonstrate that the use of Förster type (FRET) energy transfer can overcome these problems to enable efficient, stable near-infrared lasing in a colloidal suspension of latex nanoparticles containing a mixture of Rhodamine 6G and Nile Blue dyes. Experimental and theoretical analyses of the photophysics suggest that the dominant energy transfer mechanism is Förster type via dipole-dipole coupling, and also reveal an unexpected core/shell morphology in the dye-doped nanoparticles. FRET-assisted incoherent random lasing is also demonstrated in solid samples obtained by evaporation of colloidal suspensions.

Cerdán, Luis; Enciso, Eduardo; Martín, Virginia; Bañuelos, Jorge; López-Arbeloa, Iñigo; Costela, Angel; García-Moreno, Inmaculada

2012-09-01

226

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

227

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

228

Uniformity of pump intensity distribution in diode-array side-pumped laser rod  

NASA Astrophysics Data System (ADS)

Diode-pumped solid-state lasers are high efficiency, long lifetime, compact and reliable, so they have been covering a wide range of applications. Thermal effect is a major limiting factor in scaling the average power of high-power solid-state lasers, so it is a critical issue in designing diode-pumped solid-state lasers. The uniform pump intensity distribution in laser rod can weaken the influence of thermal effects in laser, and the research of improving the pump distribution uniformity has attracted a great deal of attention. People usually establish a model of single diode-bar pumped laser rod to calculate the distribution. However, for diode-array pumped high-power lasers, the model is limited and has deviation with the actual pump distribution, which cannot reflect the real working conditions in the laser. In this paper, the theoretical model of diode-array pumped laser rod is built. Based on the actual working environment of diode-array side-pumped Tm:YAG laser rod, the expression of pump intensity distribution in the laser medium is deduced. Additionally, the influence of total pump power, pump structure, Tm:YAG rod characteristic parameters and pump beam radius on pump intensity distribution are simulated and analyzed. Moreover, the parameters are optimized in order to obtain the optimistic results which are efficient to improve the uniformity of pump distribution. The results show that when the pumping distance from diode-array to the rod's surface is 3mm, the distance between two rows of diode-bars is 1mm, the absorption coefficient is 330m-1,the pump beam width is 2.5mm,the pump intensity distribution of five-way pumped laser rod is improved, and then the thermal effects could be weakened. The presented results can provide theoretical guidance to design and optimization of high-power lasers.

Liu, Wenwen; Niu, Yanxiong; Liu, Haixia; Wang, Caili; Niu, Haisha; Man, Da

2014-11-01

229

Temporal stability of cladding pumped Yb-doped fibre lasers  

Microsoft Academic Search

Summary form only given. Over the last several years cladding pumped fibre lasers have become a basic tool in research labs, replacing conventional solid-state lasers. A well-designed fibre laser offers excellent thermal properties, reliability, simplicity and compactness. Output power from fibre lasers can reach a 100 W level. Cladding pumped lasers and amplifiers find applications not only in telecommunications as

M. Hodzynski; A. B. Grudinin; J. Nilsson

2001-01-01

230

Heat pump processes induced by laser radiation  

NASA Technical Reports Server (NTRS)

A carbon dioxide laser system was constructed for the demonstration of heat pump processes induced by laser radiation. The system consisted of a frequency doubling stage, a gas reaction cell with its vacuum and high purity gas supply system, and provisions to measure the temperature changes by pressure, or alternatively, by density changes. The theoretical considerations for the choice of designs and components are dicussed.

Garbuny, M.; Henningsen, T.

1980-01-01

231

Tunable subpicosecond dye laser amplified at 1 kHz by a cavity-dumped, Q-switched, and mode-locked Nd:YAG laser  

Microsoft Academic Search

Tunable subpicosecond pulses are generated by synchronously pumping a dye laser with the pulse-compressed and frequency-doubled output of an acousto-optically mode-locked cw Nd:YAG laser. The pulses are amplified at a repetition rate of 1 kHz, using the frequency-doubled output of a cavity-dumped, acousto-optically mode-locked, Q-switched, cw pumped Nd:YAG laser. Amplified transform-limited pulses of 150--300 fsec have been obtained in the

Vincent J. Newell; F. W. Deeg; S. R. Greenfield; M. D. Fayer

1989-01-01

232

Free-running emerald laser pumped by laser diode  

Microsoft Academic Search

Free-running emerald laser pumped by 660-nm laser diode (LD) was reported. Free-running output power of 24 mW has been obtained with overall efficiency of 1.4% and slope efficiency of 11.9% when the LD incident power was 2.56 W. The laser threshold value of emerald crystal was estimated to be 0.7 W.

Zhenqiang Chen; Ge Zhang

2006-01-01

233

High efficiency cw laser-pumped tunable alexandrite laser  

SciTech Connect

High efficiency cw alexandrite laser operation has been achieved. With longitudinal pumping by a krypton laser in a nearly concentric cavity, a 51% output power slope efficiency has been measured. Including the transmission at the input coupler mirror, a quantum yield of 85% has been attained above threshold. Tunability from 726 to 802 nm has also been demonstrated. The low loss and good thermal properties make alexandrite ideal for cw laser operation.

Lai, S.T.; Shand, M.L.

1983-10-01

234

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

235

BRIEF COMMUNICATIONS: Investigation of the lasing characteristics of new laser dyes for the green and red parts of the spectrum  

NASA Astrophysics Data System (ADS)

An investigation was made of the lasing characteristics of solutions of various new dyes in the coumarin, naphthalimide, and benzanthrone classes pumped transversely by the second harmonic of ruby laser radiation. Lasing in the blue, green, and red parts of the spectrum was obtained for most of the compounds studied. A comparison was made between these materials and laser dyes widely used in these spectral ranges. The compounds studied included some with a lasing efficiency substantially higher than uranin in the green and cresyl violet in the red, and with a photostability not inferior to these two.

Krymova, A. I.; Petukhov, V. A.; Popov, M. B.

1985-10-01

236

CW arc-lamp-pumped alexandrite lasers  

Microsoft Academic Search

The performance characteristics of arc-lamp- (Xe and Hg) pumped, CW alexandrite lasers are described in detail. The modes of operation considered are free running, tuned, and repetitively Q-switched. The experimental arrangement and apparatus are also outlined. The experimental results are discussed in terms of a steady-state model, and the areas of agreement and difficulty are pointed out.

H. Samelson; J. C. Walling; T. Wernikowski; D. J. Harter

1988-01-01

237

CW arc-lamp-pumped alexandrite lasers  

SciTech Connect

The performance characteristics of arc-lamp- (Xe and Hg) pumped, CW alexandrite lasers are described in detail. The modes of operation considered are free running, tuned, and repetitively Q-switched. The experimental arrangement and apparatus are also outlined. The experimental results are discussed in terms of a steady-state model, and the areas of agreement and difficulty are pointed out.

Samelson, H.; Walling, J.C.; Wernikowski, T.; Harter, D.J.

1988-06-01

238

Electrical pumping of color center lasers  

NASA Astrophysics Data System (ADS)

This paper presents an assessment of the feasibility of using electrical pumping to achieve laser action in color centers in the alkali halides. The discussion is mainly of the self-trapped exciton in the alkali halides, which is a prime candidate for such a pumping scheme because it is known to produce strong electroluminescence. The theory of electrical contacts to insulating crystals is reviewed, as is the theory of space-charge-limited currents in insulators. It is shown that sufficient energy can be delivered to an alkali halide crystal by a space-charge-limited current to reach the threshold for laser action. Experimental evidence is presented which demonstrates that when ohmic contact is made to a KI single crystal, large space-charge-limited currents can flow. Finally, from the measured value of the electroluminescent intensity, the value of the population inversion achieved through electrical pumping of KI with blocking contacts is inferred.

Boyd, R. W.; Malcuit, M. S.; Teegarden, K. J.

1982-08-01

239

LD pumped red lasers and its application in Cr:LiSAF laser  

SciTech Connect

The authors report here the Nd:YAP-KTP red laser pumped by LD for pumping Cr:LiSAF tunable laser. Using a CW 802nm LD of 3W, 670nm CW red laser of 95 mW has been measured. The red laser is used to pump Cr:LiSAF laser, and over 4mW CW laser radiation from the Cr:LiSAF laser has been measured. They are to the authors knowledge the first Nd:YAP-KTP red laser pumped by LD and the first Cr:LiSAF laser pumped by Nd:YAP-KTP red laser.

Huo, Y.; Li, F.; He, S. [Tsinghua Univ., Beijing (China). Dept. of Electronic Engineering; Shen, D. [Research Inst. of Synthetic Crystals, Beijing (China); Li, G. [Fujian Inst. of Research on the Structure of Matter, Fuzhou (China)

1996-12-31

240

Prototype laser-diode-pumped solid state laser transmitters  

NASA Technical Reports Server (NTRS)

Monolithic, diode-pumped Nd:YAG ring lasers can provide diffraction-limited, single-frequency, narrow-linewidth, tunable output which is adequate for use as a local oscillator in a coherent communication system. A laser was built which had a linewidth of about 2 kHz, a power of 5 milliwatts, and which was tunable over a range of 30 MHz in a few microseconds. This laser was phase-locked to a second, similar laser. This demonstrates that the powerful technique of heterodyne detection is possible with a diode-pumped laser used as the local oscillator. Laser diode pumping of monolithic Nd:YAG rings can lead to output powers of hundreds of milliwatts from a single laser. A laser was built with a single-mode output of 310 mW. Several lasers can be chained together to sum their power, while maintaining diffraction-limited, single frequency operation. This technique was demonstrated with two lasers, with a total output of 340 mW, and is expected to be practical for up to about ten lasers. Thus with lasers of 310 mW, output of up to 3 W is possible. The chaining technique, if properly engineered, results in redundancy. The technique of resonant external modulation and doubling is designed to efficiently convert the continuous wave, infrared output of our lasers into low duty-cycle pulsed green output. This technique was verified through both computer modeling and experimentation. Further work would be necessary to develop a deliverable system using this technique.

Kane, Thomas J.; Cheng, Emily A. P.; Wallace, Richard W.

1989-01-01

241

Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers  

SciTech Connect

This paper reports on the efficiencies and threshold pump intensities of various solid-state laser materials that have been estimated to compare their performance characteristics as direct solar-pumped CW lasers. Among the laser materials evaluated in this research, alexandrite has the highest slope efficiency of about 12.6%; however, it does not seem to be practical for solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AMO) solar constants and its slope efficiency is about 12% when thermal deformation is completely prevented.

Hwang, I.H. (Hampton Univ., VA (United States). Dept. of Physics); Lee, J.H. (National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center)

1991-09-01

242

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

243

Chemical stabilization of laser dyes. Final report, 1 April 1987-31 March 1990  

SciTech Connect

Irradiation of ethanol solutions of coumarin laser dye lasers produces products which absorb at the lasing wavelength. This results in attenuation of dye laser output through interference of stimulated emission. A major photoprocess which produces material which absorbs at the lasing wavelength is dye sensitized solvent oxidative oligomerization, producing aldehydic and ketonic products. A dye laser stabilization technique is removal of these carbonyl compounds as they are formed by reduction with a polymer bound borohydride reducing agent.

Koch, T.H.

1990-04-10

244

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); Stein, William E. (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM)

1980-01-01

245

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

246

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

247

Optically pumped distributed feedback dye lasing with slide-coated TiO? inverse-opal slab as Bragg reflector.  

PubMed

We demonstrate an optical amplification of organic dye within a TiO2 inverse-opal (IO) distributed feedback (DFB) reflector prepared by a slide-coating method. Highly reflective TiO2 IO film was fabricated by slide coating the binary aqueous dispersions of polystyrene microspheres and charge-stabilized TiO2 nanoparticles on a glass slide and subsequently removing the polymer-opal template. TiO2 IO film was infiltrated, in turn, with the solutions of DCM, a fluorescent dye in various solvents with different indices of refraction. Optical pumping by frequency-doubled Nd:YAG laser resulted in amplified spontaneous emission in each dye solution. In accordance with the semi-empirical simulation by the FDTD method, DCM in ethanol showed the best emission/stopband matching for the TiO2 IO film used in this study. Therefore, photo excitation of a DCM/ethanol cavity showed a single-mode DFB lasing at 640 nm wavelength at moderate pump energy. PMID:25121863

Han, Sung Gu; Lim, Jongchul; Shin, Jinsub; Lee, Sung-Min; Park, Taiho; Yoon, Jongseung; Woo, Kyoungja; Lee, Hyunjung; Lee, Wonmok

2014-08-15

248

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

NASA Astrophysics Data System (ADS)

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 "etchless process" and fabricated gratings for DFB solid-state dye lasers quickly and at low cost. In this study, we attempted to fabricate a multi-beam DFB solid-state dye laser combining pitch-different gratings and dye-doped silica xero-gel. We succeeded at obtaining narrow-banded triple-beam laser oscillations in the same optical axis with the three-wavelength DFB solid-state dye laser device.

Nakai, N.; Fukuda, M.

2007-01-01

249

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

250

Theoretical study of iterative pump number of diode pumped solid state laser  

NASA Astrophysics Data System (ADS)

A novel conception of iterative pump number was introduced in this work for the first time. Based on the conservation of energy, the equivalent model for the lasering of solid state laser was built up, the iterative pump number was calculated, and a formula for the output power of laser was given. This formula presented the relationships among the output power of laser, pumping power of diode and the thickness of laser medium. The output power predicted by this formula is consistent with experimental results, so this formula could be an important tool for the designing of parameter for diode pumped solid state laser.

Liu, W.; Guo, J.; Sang, F.

2015-02-01

251

Diode-pumped femtosecond laser oscillator with cavity dumping  

Microsoft Academic Search

A diode pumped tunable Yb:glass femtosecond laser oscillator with electro-optical cavity dumping generates pulses with energies sufficient for various scientific and industrial applications. This laser forms a potential compact laser source for micromachining.

A. Killi; U. Morgner; M. J. Lederer; D. Kopf

2004-01-01

252

Quasi-aromatic heterocyclics as laser dyes. Interim technical report  

SciTech Connect

Superior laser dyes were recently discovered in the quasi-aromatic families of syn-dioxabimanes and pyrromethene-BF/sub 2/ complexes. The representative new dye mu-bis-(carboethoxy) methylene-syn-(methylene, methyl) bimane lased at 507 nm with 50% greater efficiency than was obtained with Coumarin 30. A similar determination showed 4, 4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene to lase at 546 nm with about 300% greater efficiency than was obtained from Coumarin 545. These quasi-aromatic systems are readily available and offer desirable properties of stability (photo, thermal, and chemical), solubility, and diminished triplet-triplet absorption in the lasing spectral region. Selected spectroscopic and lasing properties of these new laser dyes are presented.

Pavlopoulos, T.G.; Boyer, J.H.

1989-04-19

253

Terahertz graphene lasers: Injection versus optical pumping  

SciTech Connect

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 [Research Institute for Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Ryzhii, Maxim [Computational Nanoelectronics Laboratory, University of Aizu, Aizu-Wakamatsu 965-8580 (Japan); Mitin, Vladimir [Department of Electrical Engineering, University at Buffalo, SUNY, Buffalo, New York 14260-1920 (United States)

2013-12-04

254

EDGE-PUMP HIGH POWER MICROCHIP Yb:YAG LASER  

Microsoft Academic Search

This paper presents new concepts for pumping very thin active laser media at pump level of hundreds of watts, output performances obtained from Yb-based microchip laser. Continuous-wave (cw) laser operation at 1.03 ?m with slope efficiency of 0.40 in Yb:YAG and low thermal lens was realized using an edge-pump configuration and a laser diode emitting at 0.94 ?m. Over 90

TRAIAN DASCALU

2008-01-01

255

Study of acid-base dye laser systems  

Microsoft Academic Search

Rate equations with temporal, spectral and spatial dependences are derived to obtain the characteristics of the laser emission of dye molecules that undergo acid-base processes. The model has been tested to reproduce the experimental results of the laser emission due to the monoprotonated species of 4-amino-7-phenyl-8H-pyrazino[2,3-c]-1,2,6-thiadiazine 2,2-dioxide in acetonitrile. Numerical solution of the rate equations is performed to predict general

R. Weigand; J. M. Guerra

1995-01-01

256

Solid state tunable lasers with nanosecond flashlamp pumping  

NASA Astrophysics Data System (ADS)

Stable and high gain of U-violet laser pulses was achieved in Ce:YiLF4 with nanosecond flash lamp pumping (nsFL)-`Soft' pump. it is due to neglectly low probability of two-step ionizations of Ce3+ with nsFL pumping. Gain was not observed for this crystal under KrF-laser pumping-`Hard' pump. Two-step ionization of Ce3+ reduces of quantum yield emission of Ce3+ and prevents to population inversion 5D-4F of Ce3+ at laser pumping.

Baryshnikov, V. I.; Sarukura, Nobuhiko; Segawa, Yusaburo

1996-04-01

257

Enhancement of pump efficiency of a visible wavelength organic distributed feedback laser by resonant optical pumping.  

PubMed

A 22× reduction in laser pump threshold and a 23× enhancement in energy conversion have been demonstrated on a second order distributed feedback (DFB) laser using a resonant optical pumping (ROP) technique. The ROP scheme couples the excitation light into a distinct resonant mode of the laser cavity through the illuminating at a specific resonant incident angle. Coupling excitation light into the resonant mode results in an enhanced near-field, which significantly increases pump absorption by the active medium. Consequently, high power conversion efficiency between pumping light and lasing emission is achieved and laser pump threshold power is reduced. PMID:21445143

Ge, Chun; Lu, Meng; Tan, Yafang; Cunningham, Brian T

2011-03-14

258

Passively mode-locked cw Coumarin 6 ring dye laser  

SciTech Connect

The passive mode locking of a cw Coumarin 6 dye laser in a colliding-pulse ring configuration is reported. Pulses of less than 500-fsec duration have been obtained from 518 to 554 nm, with the shortest pulses obtained being of 96-fsec duration.

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

1989-02-15

259

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

260

BRIEF COMMUNICATIONS: Attainment of a wide wavelength-tuning range in the green and red parts of the spectrum using new laser dyes  

NASA Astrophysics Data System (ADS)

A study was made of the lasing characteristics of two new dyes belonging to the naphthalimide and benzanthrone classes, when they were pumped with the second harmonic of ruby laser radiation. The emission wavelength could be tuned over a range of ~100 nm (from 500 to 600 nm in the case of naphthalimide and from 640 to 740 nm in the case of benzanthrone). The use of these compounds in lasers increased the output energy compared with the widely used coumarin 7 and uranin dyes in the green region or cresyl violet in the red region. Moreover, the new dyes ensured a considerably wider wavelength-tuning range.

Krymova, A. I.; Petukhov, V. A.

1986-03-01

261

Optically (solar) pumped oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

We present the results of theoretical and experimental studies demonstrating the possibility of developing an oxygen-iodine laser (OIL) with direct optical pumping of molecular oxygen involving inter-molecular interaction with charge transfer from donor molecule (buffer gas) to acceptor molecule (oxygen). This interaction lifts degeneracy of the lower energy states of molecular oxygen and increases its absorption cross section in the visible spectral region and the UV Herzberg band, where high quantum yield of singlet oxygen is achieved (QY ˜ 1 and QY ˜ 2, respectively) at the same time. A pulse-periodic optical pump sources with pulse energy of ˜50 kJ, pulse duration of ˜25 ?s, and repetition rate of ˜10 Hz, which are synchronized with the mechanism of singlet oxygen generation, are developed. This allows implementation of a pulse-periodic oxygen-iodine laser with an efficiency of ˜25%, optical efficiency of ˜40%, and parameter L/ T ˜ 1/1.5, where T is the thermal energy released in the laser active medium upon generation of energy L. It is demonstrated that, under direct solar pumping of molecular oxygen, the efficiency parameter of the OIL can reach L/ T ˜ 1/0.8 in a wide range of scaling factors.

Danilov, O. B.; Zhevlakov, A. P.; Yur'ev, M. S.

2014-07-01

262

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

263

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

264

Comparative Histological Studies of the Tunable Dye (at 577 nm) Laser and Argon Laser: The Specific Vascular Effects of the Dye Laser  

Microsoft Academic Search

This study compares the histological changes occurring after argon laser and dye laser (operating at 577 nm) treatment of normal human skin. The initial effect of the argon laser is a diffuse nonspecific epidermal and upper dermal necrosis with subsequent cell death and a neutrophilic response at 48 hr. These changes occur at 15 joules\\/cm2 and their extent closely correlates

Jeffrey Greenwald; Seymour Rosen; R. Rox Anderson; Terence Harrist; Francille MacFarland; Joel Noe; John A. Parrish

1981-01-01

265

Passive mode locking of a cw energy-transfer dye laser operating in the infrared near 800 nm  

SciTech Connect

The cw tuning range, and subsequent passive mode locking of a new argon-ion pumped energy-transfer dye laser operating in the near IR, is reported for the first time to our knowledge. The gain medium, consisting of an energy-transfer mixture of Pyridin 1 as the donor dye and Rhodamine 800 as the acceptor dye, has been found to lase continuous waves from 742 to 823 nm. Passively mode locked with bis-4-(1-ethylquinoline) (..gamma..-4'-(1'-ethylquino-line)) pentamethine cyanine diiodide dye, this active medium yielded sub-500-fsec pulses from 783 to 815 nm in a linear cavity, with pulses as short as 260 fsec being generated.

Williams, J.A.R.; French, P.M.W.; Taylor, J.R.; Goldsmith, H.

1988-10-01

266

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)

1994-01-01

267

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

268

On-line computer controlled cw dye laser spectrometer for laser isotope separation  

Microsoft Academic Search

An on-line cw dye laser multichannel spectrometer is described, which can be controlled by FORTRAN. Automatic tuning of a\\u000a dye laser to the wavelength of maximum excitation selectivity for photochemical isotope separation is achieved. Applying the\\u000a system to the selective photoaddition of iodine chloride ICl to acetylene, an enrichment factor of37Cl in the photoproduct C2H2ICl of ?=1005 was obtained. Both

M. Stuke; E. E. Marinero

1978-01-01

269

Self-healing organic-dye-based random lasers  

NASA Astrophysics Data System (ADS)

One of the primary difficulties in the implementation of organic-dye-based random lasers is the tendency of organic dyes to irreversibly photodecay. In this letter we report the observation of "reversible" photodegradation in a Rhodamine 6G and ZrO$_2$ nanoparticle doped polyurethane random laser. We find that during degradation the emission broadens, redshifts, and decreases in intensity. After degradation the system is observed to self-heal leading to the emission returning to its pristine intensity, giving a recovery efficiency of 100%. While the peak intensity fully recovers, the process is not strictly "reversible" as the emission after recovery is still found to be broadened and redshifted. The combination of the peak emission fully recovering and the broadening of the emission leads to a remarkable result: the random laser cycled through degradation and recovery has a greater integrated emission intensity than the pristine system.

Anderson, Benjamin R.; Gunawidjaja, Ray; Eilers, Hergen

2015-02-01

270

Self-healing organic-dye-based random lasers  

E-print Network

One of the primary difficulties in the implementation of organic-dye-based random lasers is the tendency of organic dyes to irreversibly photodecay. In this letter we report the observation of "reversible" photodegradation in a Rhodamine 6G and ZrO$_2$ nanoparticle doped polyurethane random laser. We find that during degradation the emission broadens, redshifts, and decreases in intensity. After degradation the system is observed to self-heal leading to the emission returning to its pristine intensity, giving a recovery efficiency of 100%. While the peak intensity fully recovers, the process is not strictly "reversible" as the emission after recovery is still found to be broadened and redshifted. The combination of the peak emission fully recovering and the broadening of the emission leads to a remarkable result: the random laser cycled through degradation and recovery has a greater integrated emission intensity than the pristine system.

Anderson, Benjamin R; Eilers, Hergen

2015-01-01

271

Self-healing organic-dye-based random lasers.  

PubMed

One of the primary difficulties in the implementation of organic-dye-based random lasers is the tendency of organic dyes to irreversibly photodecay. In this Letter, we report the observation of "reversible" photodegradation in a Rhodamine 6G and ZrO2 nanoparticle-doped polyurethane random laser. We find that during degradation, the emission broadens, redshifts, and decreases in intensity. After degradation, the system is observed to self-heal leading to the emission returning to its pristine intensity, giving a recovery efficiency of 100%. While the peak intensity fully recovers, the process is not strictly "reversible", as the emission after recovery is still found to be broadened and redshifted. The combination of the peak emission fully recovering and the broadening of the emission leads to a remarkable result: the random laser cycled through degradation, and recovery has a greater integrated emission intensity than the pristine system. PMID:25680154

Anderson, Benjamin R; Gunawidjaja, Ray; Eilers, Hergen

2015-02-15

272

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

273

Simultaneous three primary color laser emissions from dye mixtures  

SciTech Connect

Simultaneous two- and three-band laser emissions were obtained in a process of mixing two and three kinds of dyes excited by a nitrogen laser. They were blue, green, and yellow in a coumarin 460 (C460)/disodium fluorescein (DF)/rhodamine 610 (R610) dye mixture, and blue, green, and red in a C460/DF/rhodamin 640 (R640) dye mixture. Strong energy transfers from DF to R610 and to R640 were shown. R610 and R640 laser emissions on mixing with DF were obtained at very low concentrations. They were 4{times}10{sup {minus}6} mol/l for R610 and 1{times}10{sup {minus}5} mol/l for R640, compared to the lasing threshold concentration of 1{times}10{sup {minus}4} and 2{times}10{sup {minus}4} mol/l of each dye alone. Also, the R610 radiation moved about 35 nm to a shorter wavelength at the reduced concentration.

Saito, Y.; Kato, M.; Nomura, A.; Kano, T. (Faculty of Engineering, Shinshu University, Wakasato 500, Nagano 380, Japan (JP))

1990-02-26

274

Generation of picosecond pulses in a dye laser excited by radiation from an argon laser with passively locked modes  

SciTech Connect

Passive locking of argon laser modes was used in generation of tunable picosecond pulses in a synchronously excited dye laser. An experimental study was made of the characteristics of the dye laser radiation as a function of the argon laser characteristics.

Vinogradova, A.A.; Krindach, D.P.; Nazarov, B.I.; Tsapenko, A.M.

1980-01-01

275

Nanosecond transient absorption spectrophotometer with dye laser probing and computer control  

NASA Astrophysics Data System (ADS)

A computer controlled apparatus for laser flash spectroscopy has been constructed. Nitrogen laser (energy 1 mJ, pulse width 1 ns) is used both for excitation of the sample and for pumping a tunable dye laser which serves as a source of monitoring light. Two different scan modes are possible: (i) a scan with a fixed wavelength of the monitoring light: the temporal evolution of the transient absorption in the range from -2 up to 100 ns can be observed by changing the length of the variable self-compensating optical delay line, or (ii) a scan with a fixed time delay: the corresponding transient absorption in the range 380-800 nm can be measured. For illustration, the transient absorption spectrum of benzophenone in methylcyclohexane, decay curves of the singlet state of benzanthracene in ethanol in the presence of a quencher, and a ``negative absorption'' of rhodamine B in nitriles are reported.

Jasny, Jan; Sepit, Jerzy; Karpiuk, Jerzy; Gilewski, Janusz

1994-12-01

276

Efficient scalable optically pumped HBr laser  

NASA Astrophysics Data System (ADS)

A concept combining the advantages of solid-state and gas-laser technologies is being developed to realize a scalable, efficient 4-micron laser. A Nd:YAG laser is tuned to 1.3391 microns by temperature-tuning and cavity selection. The addition of diode seeding permits excitation of a specific v = 3 rotational state of HBr. Lasing can potentially occur in three subsequent steps to the ground state, emitting numerous lines in the 4-micron region, which enhances efficiency and spectral coverage. Using up to 25-mJ pump energy, two elements of the possible three-level cascade have been observed. We have observed emission selectivity due to intracavity carbon dioxide and inferred the presence and contributory influence of pure-rotational stimulated emission, which may have importance to the overall behavior of other similar molecular pulsed lasers (and even continuous-wave HX lasers). We present theoretical and experimental results demonstrating the operational principle and utility of this laser system.

Jones, C. R.; Campbell, R. N.; Kletecka, C.; Rudolph, Wolfgang G.

2004-09-01

277

Tunable dye laser applications in environment pollution monitoring  

NASA Astrophysics Data System (ADS)

Results about the use of lasers in monitoring pollutants in water and soil are reported, as follows: Tunable dye laser absorption spectrophotometry was used for organochlorurate pesticides (atrasine, propasine, simasine, etc.) measuring in water; detection limit 10 -3-10 -4 ppm. Laser induced fluorescence (LIF) was applied to monitor organochlorurate pesticides in water, crude oil and oil components in water and soil; detection limits: 10 -1-10 -2 ppm. The experimental set-up developed for pollutants monitoring in water and soil are described. Conclusions are drawn regarding the proper techniques for pesticides and oil detection in situ in water and soil.

Pascu, M. L.; Moise, N.; Staicu, A.

2001-10-01

278

Photostability, laser energy conversion efficiency and absorption of IR heptamethine cyanine dyes absorbing beyond 1 ?m  

Microsoft Academic Search

The optical absorption, photostability and energy conversion efficiency of a series of heptamethine IR dyes are reported and results related to chemical structure. The high photostability and high laser energy conversion efficiency of several of the dyes indicate potential use in IR dye lasers.

Jinlong Zhang; Weimei Luo; Zhenghua Zhu

1995-01-01

279

High power CW dye laser emission around 888 nm M. Leduc and G. Trenec  

E-print Network

and the near IR using various classes of dyes and/or colour centres in crystals. CW laser emission near 900 nm has previously been reported in two cyanine dyes : HITC [1, 2] and IR 140 [3]. More recently colour355 High power CW dye laser emission around 888 nm M. Leduc and G. Trenec Laboratoire de

Paris-Sud XI, Université de

280

Investigation of controlled ultrashort pulse dye laser for femtosecond nonlinear spectroscopy  

E-print Network

on a hybridly mode-locked, cavity- dumped cw dye laser, with high stability, broad tunability and specific phase. An alternative approach is to use the hybridly mode-locked, cavity- dumped, cw dye laser coupled with a single the cavity [4]. However, the pulse properties become complicated, as the saturable absorber dye degrades

Paris-Sud XI, Université de

281

Self-scanning of a continuous-wave dye laser having a phase-conjugating resonator cavity  

SciTech Connect

A continuous-wave dye laser having a self-pumped phase conjugator in place of its usual output mirror will slowly change it own output wavelength with time. The laser has a bandwidth of 1.5 GHz and can self-scan to either longer or shorter wavelengths over a 37-nm range. The phase conjugator uses self-pumped four-wave mixing in a BaTiO/sub 3/ crystal. A ring laser that uses two-mixing in the same crystal is also observed to have a frequency offset of a few hertz compared with the frequency of the pumping beam. These two effects are related; both are causes by a spontaneously moving photorefractive-index grating in the BaTiO/sub 3/ crystal.

Feinberg, J.; Bacher, G.D.

1984-09-01

282

Millennia V Diode-Pumped, CW Visible Laser  

E-print Network

on safety. The Millennia V is a Class IV laser and, as such, emits laser radiation which can permanently-1:1992 Radiation Safety for Laser Products." Refer to the "CE Dec- laration of Conformity" statements in Chapter 2Millennia V Diode-Pumped, CW Visible Laser User's Manual The Solid-State Laser Company 1335 Terra

Kleinfeld, David

283

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.

2011-03-01

284

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

285

Fissioning uranium plasmas and nuclear-pumped lasers  

NASA Technical Reports Server (NTRS)

Current research into uranium plasmas, gaseous-core (cavity) reactors, and nuclear-pumped lasers is discussed. Basic properties of fissioning uranium plasmas are summarized together with potential space and terrestrial applications of gaseous-core reactors and nuclear-pumped lasers. Conditions for criticality of a uranium plasma are outlined, and it is shown that the nonequilibrium state and the optical thinness of a fissioning plasma can be exploited for the direct conversion of fission fragment energy into coherent light (i.e., for nuclear-pumped lasers). Successful demonstrations of nuclear-pumped lasers are described together with gaseous-fuel reactor experiments using uranium hexafluoride.

Schneider, R. T.; Thom, K.

1975-01-01

286

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.

2006-02-01

287

Studies of Solvent-Solute Interactions in the Photophysics of Laser Dyes.  

NASA Astrophysics Data System (ADS)

The fluorescence lifetime of rhodamine B in the normal alcohols (C_1-C_ {10}) and normal nitriles (C_2 ,C_5,C_6,C _8,C_9) has been measured using a picosecond laser system. The lifetime measuring technique is time-correlated single photon counting (TCSPC). Absorption and emission spectra of rhodamine B in the alcohols and nitriles have also been determined, thus allowing calculation of quantum yields, radiative, and nonradiative rates. The rotation of the dye's diethylamino groups is related to the nonradiative rate. A decreasing nonradiative rate corresponds to a greater energy barrier to rotation. The behavior of the nonradiative rates, and thus the rotational energy barrier, is modelled as a function of (1) solvent viscosity and (2) solvent polarity. The polarity-dependent model shows better correlation with the data. The nitrile data differs from the alcohol data in that the barrier appears to be constant and therefore independent of solvent viscosity and polarity. Hydrogen bonding is used to explain the differences between the alcohols and nitriles. Rotational relaxation times of two laser dyes (cresyl violet and oxazine-1) in polymer solution (poly(ethylene oxide) and methanol) has been measured using the transient absorption spectroscopy (TAS) method. TAS is a pump-probe technique using a picosecond laser system. The pump beam optically bleaches the sample and the probe beam monitors the transient response. The effect of increasing polymer concentration is seen as an increasing rotational relaxation time. This result is examined with respect to the Debye -Stokes-Einstein (DSE) equation governing viscosity-dependent, rotational reorientational times. The greater increase in the rotational times of cresyl violet is explained on the basis of increased polymer-dye interaction, specifically hydrogen bonding.

Casey, Kelly Gamble

288

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

289

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

290

Dye Amplifiers Pumped by One and Two-Photon Processes  

Microsoft Academic Search

One- and two-photon absorption (at 5300 Å) thresholds for laser action in aqueous bromocresol green and aqueous bromocresol purple were measured, and a novel method of measuring gain, requiring only one photomultiplier, is reported.

John G. Kepros; Edward M. Eyring

1972-01-01

291

Dye laser amplifier including an improved window configuration for its dye beam  

DOEpatents

A dye laser amplifier in which a continuously replenished supply of dye is excited with a first light beam in order to amplify the intensity of a second different light beam passing therethrough is disclosed herein. This amplifier includes a cell though which a continuous stream of the dye is caused to pass, and means for directing the first beam into the cell while the second beam is directed into and through the same cell. There is also disclosed herein a specific improvement to this amplifier which resides in the use of a pair of particularly configured windows through which the second beam passes along fixed paths as the second beam enters and exits the dye cell. Each of these windows has a relatively thick main section which is substantially larger in dimensions transverse to its beam path than the cross section of the second beam itself, whereby to add structural integrity to the overall window. At the same time, the latter includes a second section which is disposed entirely within the confines of the main section and through which the second beam is intended to pass in its entirety. This second section is made substantially thinner than the main section in order to reduce optical distortion as the second beam passes therethrough. 4 figs.

O'Neil, R.W.; Davin, J.M.

1992-12-01

292

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. PMID:24155550

Omi, Tokuya; Kawana, Seiji

2013-01-01

293

Polymethine IR laser dyes for passive mode-locking of ruby lasers  

Microsoft Academic Search

Several polymethine IR laser dyes, in addition to the well known DDI and cryptocyanine, are found to be suitable for mode-locking of ruby lasers. While with DDI pulses as short as 12 psec are obtained these new mode-lockers generate pulses in the 40 to 100 psec range, presumably due to their longer recovery time of the ground-state absorption.

Chinlon Lin

1975-01-01

294

Tuning laser output characteristics of a pyrotechnically pumped free-running Nd:YAG laser in terms of pumping kinetics  

NASA Astrophysics Data System (ADS)

Using light radiation directly produced by combustion of some pyrotechnics as pumping sources of solid state lasers is a potentially effective way to obtain compact and high energy lasers. Kinetics of this kind of pumping is studied in terms of pulse energy and pulse time characteristics as well as laser output energy. Pumping kinetics is turned through changing fabrication methods of the pumping modules. It was found that the useful light energy and pulse time for the pyrotechnic pumping light showed opposite changing trend. Compressing pulse duration from 45 ms to about 10 ms would simultaneously cause 20%~ 50% decreases in useful light radiation energy. However, the laser output energy produced by these pumping sources only had a variation 9%, ranging from 427 mJ to 468 mJ. Reasons were related to the decrease in fluorescence loss in pumping energy below the threshold for the pyrotechnic modules having shorter pulse duration but higher radiation power.

Kang, Xiaoli; Yang, Fan; Luo, Jiangshan; Tang, Yongjian

2015-02-01

295

Laser photobleaching of dyes adsorbed in porous glass  

SciTech Connect

The kinetic dependences of transmission variation in porous glasses activated by various laser dyes (rhodamine 6G, coumarin 7, coumarin 30, oxazine 1, Nile blue B), on illumination by laser radiation with an energy density from 10/sup 18/ to 10/sup 21/ photons cm/sup /minus/2/ sec/sup /minus/1/ is studied. A technique is proposed for determining the quantum yield /gamma/ of photobleaching of the activated porous glasses from the dependences obtained in the work. The values of /gamma/ have been determined for the indicated compositions.

Boyarskii, K. K.; Vorobev, A. Y.; Zemskii, V. I.; Kolesnikov, Y. L.; Meshkovskii, I. K.

1988-10-01

296

High-power optically pumped semiconductor laser apllications  

NASA Astrophysics Data System (ADS)

OPS lasers have found applications in various industrial and scientific laser applications due to their power scaling capability, their wide range of emission wavelengths, physical size and their superior reliability. This paper provides an overview of commercially available OPS lasers and the applications in which they are used including biotechnology, medical, holography, Titanium-Sapphire laser pumping, non-lethal defense, forensics, and entertainment.

Morioka, S. Brandon

2011-03-01

297

Key techniques for space-based solar pumped semiconductor lasers  

NASA Astrophysics Data System (ADS)

In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

2014-12-01

298

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

299

The role of the solvent viscosity on the spatiotemporal instabilities of large aperture dye lasers  

E-print Network

The role of the solvent viscosity on the spatiotemporal instabilities of large aperture dye lasers for publication 27 May 1998 Local intensity fluctuations in a large aperture dye laser have been measured behavior as the molecular polarization orientation driven by the laser field. © 1998 American Institute

Rey Juan Carlos, Universidad

300

The role of the molecular dynamics in the local intensity instabilities of large aperture dye lasers  

E-print Network

lasers I. Leyvaa) and J. M. Guerra Departamento de O´ ptica, Facultad de Ciencias Fi´sicas Universidad fluctuations of large aperture dye lasers, and find dependencies on solvent viscosity and active molecular size dye lasers are used in a great deal of practical applications, from isotope enrichment to photody

Rey Juan Carlos, Universidad

301

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

302

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

303

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

304

Linewidth-tunable laser diode array for rubidium laser pumping  

SciTech Connect

To optimise the pump source for a high-power diodepumped rubidium vapour laser, we have designed a laser diode array (LDA) with a narrowed and tunable linewidth and an external cavity formed by two volume Bragg gratings (VBGs). Through controlling the temperature differences between the two VBGs, the LDA linewidth, which was 1.8 nm before mounting the two VBGs, was tunable from 100 pm to 0.2 nm, while the output power changed by no more than 4 %. By changing simultaneously the temperature in both VBGs, the centre wavelength in air of the linewidth-tunable LDA was tunable from 779.40 nm to 780.05 nm. (control of laser radiation parameters)

Li Zhiyong; Tan Rongqing; Xu Cheng; Li Lin

2013-02-28

305

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

306

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

307

Biological research by optically pumped far infrared lasers  

NASA Astrophysics Data System (ADS)

The FIR breeding for paddy rice, black bean and wheat, the chlorophyll mutation of paddy rice induced by optically pumped FIR laser, etc., are presented. The results of SDS electrophoresis analysis of soluble proteins of Drosophita melanrgaster irradiated by optically pumped FIR laser are described and discussed.

Zhengyu, Mi

1989-05-01

308

Conceptual design of LD side-pumped high-power disk fiber laser  

Microsoft Academic Search

Disk fiber laser is a novel fiber laser. The pumping scheme of such type of fiber laser is side pumping by LD arrays and the pumping scale is large in comparison with the core pumping manner in a typical clad pumping scheme. More pumping power could be coupled into the disk and higher output power could be achieved. To optimize

Qiang Zhang; Jianquan Yao; Wuqi Wen; Jianing Zhou; Rui Zhou

2005-01-01

309

Investigation Solvation Dynamics and Isomerization of Dye IR-140 Using pump supercontinuum-probing Technique  

E-print Network

The solvation dynamics and isomerization process of an organic dye, IR-140, in polar solvents and nonpolar solvents have been investigated using pump supercontinuum-probing (PSCP) technique. In all solvents, the dynamics exhibits solvent-dependent. Solvent induced spectral shifts of the absorption and emission spectra of IR-140 have also been studied in a variety of solvents. At the same time, the photoisomerization process has been examined. The approximate energy-band structure of IR-140 was also supposed firstly.

Wang, D; Wu, S; Yang, H; Xiang, Q G J; Xu, G; Wang, Danling; Jiang, Hongbing; Wu, Songjiang; Yang, Hong; Xiang, Qihuang Gong Junfeng; Xu, Guangzhi

2001-01-01

310

Stimulated Emission of Surface Plasmons at the Interface between a Silver Film and an Optically Pumped Dye Solution  

NASA Astrophysics Data System (ADS)

Surface plasmons (SPs) are surface-bound electromagnetic waves supported by metals, offering the possibility of strong spatial confinement of electromagnetic fields on the micro- and nanoscales. They suffer, however, from strong damping caused by internal absorption and radiation losses. Here we demonstrate amplification of SPs by stimulated emission, which marks a possible solution to this problem. We use an attenuated-total-reflection setup to detect stimulated emission of SPs at the interface between a silver film and an optically pumped dye solution acting as the amplifying medium. Clear evidence of stimulated emission is provided by an excellent agreement of the experimental observations with a theoretical analysis. Amplification of SPs can be considered analogous to photon amplification in a laser, thereby suggesting novel approaches in the field of nano-optics.

Seidel, J.; Grafström, S.; Eng, L.

2005-05-01

311

Long-Lifetime Laser Materials For Effective Diode Pumping  

NASA Technical Reports Server (NTRS)

Long quantum lifetimes reduce number of diodes required to pump. Pumping by laser diodes demonstrated with such common Nd laser materials as neodymium:yttrium aluminum garnet (Nd:YAG) and Nd:YLiF4, but such materials as Nd:LaF3, Nd:NaF.9YF3, and possibly Nd:YF3 more useful because of long lifetimes of their upper laser energy levels. Cost effectiveness primary advantage of solid-state laser materials having longer upper-laser-level lifetimes. Because cost of diodes outweighs cost of laser material by perhaps two orders of magnitude, cost reduced significantly.

Barnes, Norman P.

1991-01-01

312

Single-frequency tunable laser for pumping cesium frequency standards  

SciTech Connect

A single-frequency tunable laser for pumping the cesium frequency standard is studied. It is shown experimentally that the laser emits at a single frequency despite the fact that a few longitudinal modes of the external cavity fall within the reflection band of a fibre Bragg grating (FBG) written in the optical fibre. The laser wavelength can be tuned by varying the pump current of the laser, its temperature, and the FBG temperature. The laser linewidth does not exceed 2 MHz for 10 mW of output power. (lasers)

Zhuravleva, O V; Ivanov, Andrei V; Leonovich, A I; Kurnosov, V D; Kurnosov, K V; Chernov, Roman V; Shishkov, V V [M.F. Stel'makh Polyus Research and Development Institute, Moscow (Russian Federation); Pleshanov, S A [Federal State Unitary Enterprise 'Istok Research and Production Association', Fryazino, Moscow region (Russian Federation)

2006-08-31

313

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

314

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

315

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

316

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

Estimates of the absorption and emission characteristics of molecules required to develop materials for solar-pumped lasers are addressed. These characteristics are described in terms of the Franck Condon factors, which are calculated from the molecular wave functions. Wave functions for vibrational levels in the lower and upper electronic states of I2 and NSe are calculated numerically and methods of checking errors discussed. Errors arise when the vibrational quantum numbers are high; but, using a calculated rather than measured value of the dissociation energy, wave functions up to the fiftieth vibrational level are obtained. A numerical method of evaluating the wave functions is given, which should be more accurate in the region of electronic transitions during absorption. Franck Condon factors, plotted versus the wavelength of the absorbed photons, are shown, and a check on the Franck Condon factors is made using the vibrational sum rule.

Harries, W. L.

1981-01-01

317

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

318

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

319

Dewar design for optically pumped semiconductor ring laser  

SciTech Connect

A simple liquid-nitrogen Dewar has been constructed to hold semiconductor platelets for use in a ring laser assembly. Laser action in an external ring cavity is observed when the platelets are longitudinally pumped by an Ar/sup +/ laser. Microscope objectives mounted outside the Dewar are used to focus the pump beam as well as the lasing beam onto the crystal. Positioning of the platelets in horizontal and vertical directions is accomplished by attaching the Dewar to an xyz stage.

Fuchs, A.; Salour, M.M.

1983-09-01

320

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

321

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

322

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

323

Hydrogen peroxide sensor using laser grade dye Rhodamine B  

NASA Astrophysics Data System (ADS)

Many chemical sensors based on fluorescence spectroscopy have been reported in applications, ranging from biomedical and environmental monitoring to industrial process control. In these diverse applications, the analyte can be probed directly, by measuring its intrinsic absorption, or by incorporating some transduction mechanism such as reagent chemistry to enhance sensitivity and selectivity. Hydrogen Peroxide is a colorless liquid. It is a common oxidizing and bleaching agent. It plays an important role in High Power Laser such as Chemical Oxygen Iodine Laser (COIL). As it is on the Hazardous substance list and on the special health hazard substance list, detection of Hydrogen Peroxide is of great importance. In the present study the detection of hydrogen Peroxide is by fluorescence quenching of laser grade dye Rhodamine B. Estimation of rate constant of the bimolecular quenching reaction is made.

Pattanaik, Amitansu; Sahare, P. D.; Nanda, Maitreyee

2007-11-01

324

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

325

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

326

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

327

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

328

Continuously tunable energy transfer laser operation in four-dye mixture systems  

NASA Astrophysics Data System (ADS)

Theoretical as well as experimental investigation of the energy transfer dye laser (ETDL) operation has been performed, aimed at development of a dye laser which covers a wide wavelength range without exchanging a dye mixture. The following two dye mixtures are shown to be very effective: Rhodamine 6(R6G)-Safrain T(ST)-Cresyl Violet (CV)-Nile Blue(NB) and Coumarin 1 (C1)-Acriflavine(A)-Uranine(U)-R6G. Their desirable dye concentrations are derived and the tuning characteristics are measured. Continuous tuning was achieved over 130 nm in either case, and hence almost the entire visible range is covered with these two ETDL's.

Muto, S.; Ito, C.; Inaba, H.

1983-11-01

329

Resonant tandem pumping of Tm-doped fiber lasers  

NASA Astrophysics Data System (ADS)

We have demonstrated efficient lasing of a Tm-doped fiber when pumped with another Tm-doped fiber. In these experiments, we use a 1908 nm Tm-doped fiber laser as a pump source for another Tm-doped fiber laser, operating at a slightly longer wavelength (~2000 nm). Pumping in the 1900 nm region allows for very high optical efficiencies, low heat generation, and significant power scaling potential due to the use of fiber laser pumping. The trade-off is that the ground-state pump absorption at 1908 nm is ~37 times lower than at 795nm. However, the absorption cross-section is still sufficiently high enough to achieve effective pump absorption without exceedingly long fiber lengths. This may also be advantageous for distributing the thermal load in higher power applications.

Creeden, Daniel; Johnson, Benjamin R.; Rines, Glen A.; Setzler, Scott D.

2014-06-01

330

Development of a nanosecond-laser-pumped Raman amplifier for short laser pulses in plasma  

E-print Network

Development of a nanosecond-laser-pumped Raman amplifier for short laser pulses in plasma Y. Ping,1 picosecond seed pulse and the nanosecond pump pulse in a gas jet plasma at a density of 1019 cm-3 , the upper by the nanosecond pump pulse results in strong Landau damping of the plasma wave, an amplified pulse with an energy

331

Comparison of the argon tunable dye laser with the flashlamp pulsed dye laser in treatment of facial telangiectasia  

NASA Astrophysics Data System (ADS)

A prospective, side-by-side comparison study of two different lasers for the treatment of solar- induced telangiectasia was carried out in 14 patients at the Beckman Laser Institute and Medical Clinic. The argon tunable dye laser (Coherent, Palo Alto, Calif.) was used in the method modified from Orenstein and Nelson to completely treat discrete telangiectasias on one cheek. Specifically, the argon tunable dye laser (ATDL) was set at 0.7 - 0.8 watts, 585 nm wavelength, shutter-pulsed at 0.1 second duration with a spot size of 0.1 mm, and individual vessels were 'traced out' with 4X loupe magnification. Each patient's opposite cheek was then treated in the standard fashion with the flashlamp pulsed dye laser (Candela, Natick, Mass.) using a technique similar to Polla's et al. Specifically, the flashlamp pulsed dye laser (FPDL) was set at 585 nm wavelength, pulsed mode of 450 microseconds pulse duration, spot size of 5 mm, overlapping 10 - 20%, with power densities of 5.5 to 6.5 joules/cm2. All patients had symmetrical cheek telangiectasias of several years' duration. Patients were treated on day 0, and examined on weeks 2, 4, and 6. Photos were taken at each visit, and evaluation was done by questionnaire and direct observation, as well as by photographic slides later projected to an impartial panel. Final evaluation by the panel at week 6 showed 11/14 patients with excellent results (75 - 100% clearing) at sites treated with the FPDL, compared with 4/14 with the ATDL. In contrast, 4/14 FPDL sites were graded as fair to minimal improvement, and 9/14 as fair for the ATDL. The patients' self-evaluations graded the final results very similar to that of the panel. Most patients were bothered by the ecchymosis and hyperpigmentation associated with the FPDL, resulting in less than 50% of the patients preferring the FPDL despite its more impressive results. We conclude that the final results favor the FPDL over the ATDL for treatments of facial telangiectasia. However, non- ecchymosis producing methods of treating these lesions are an important option to be optimized in order to improve patient acceptance.

Broska, Pamela; Martinho, Elena; Goodman, Matthew M.

1992-06-01

332

12-KW high-power diode-pumped laser module  

NASA Astrophysics Data System (ADS)

For the advantage of long-life, high efficiency, low heat load and compact structure, diode pumped Laser (DPL) is used widely in different field such as military, communication and medicine etc. Diode-pumped Nd:YAG laser module is the integration of diodes (pumping source), coupling structure, cooling structure and laser medium through optimization. Being the core component of diode-pumped MOPA laser, the gain distribution of diode-pumped amplifier module influences the beam quality greatly. So it is very important to improve the uniformity of the module with high pumping power. This paper investigates, theoretically and experimentally, the elements which influence the gain distribute of laser medium. A high energy storage laser module have been manufactured. In this module a 8mm diameter Nd:YAG rod which is 120mm long is pumped by twelve diodes-arrays (the peak pump-power is 12kw). Each array is consisted of twelve diodes. Numerical calculation has been done to optimize the coupling structure. The experiment result approved that the gain coefficient of this module is 0.186/cm, from it we can infer that the storage power is about 700mJ per pulse.

Cai, Zhen; Lu, Wen Qiang; Wu, De-yong; Gao, Song Xing; Tang, Chun; Zhang, Kai

2005-01-01

333

DPSS Laser Beam Quality Optimization Through Pump Current Tuning  

SciTech Connect

The goal of this study is to demonstrate how a DPSS laser beam's quality parameters can be simultaneously optimized through pump current tuning. Two DPSS lasers of the same make and model were used where the laser diode pump current was first varied to ascertain the lowest RMS noise region. The lowest noise was found to be 0.13% in this region and the best M{sup 2} value of 1.0 and highest laser output power were simultaneously attained at the same current point. The laser manufacturer reported a M{sup 2} value of 1.3 and RMS noise value of .14% for these lasers. This study therefore demonstrates that pump current tuning a DPSS laser can simultaneously optimize RMS Noise, Power and M{sup 2} values. Future studies will strive to broaden the scope of the beam quality parameters impacted by current tuning.

Omohundro, Rob; /Newport Spectra-Physics, Santa Clara; Callen, Alice; /SLAC; Sukuta, Sydney; /San Jose City Coll.

2012-03-30

334

CW-pumped polarization-maintaining Brillouin fiber ring laser  

E-print Network

CW-pumped polarization-maintaining Brillouin fiber ring laser: I. Self-structuration of Brillouin for a large set of (G, R) parameters, in a polarization-maintaining Brillouin fiber ring laser in the best performed in a polarization- maintaining Brillouin fiber ring laser in good conditions of stability

Boyer, Edmond

335

High-power laser chains used for laser isotope separation  

Microsoft Academic Search

Since 1985, France has chosen to focus on the selective photo-ionization process called SILVA for uranium enrichment. The general SILVA schedule has led to the construction of a pilot facility called ASTER, aimed to a general assessment of SILVA. It utilizes a mid power dye laser chain pumped by copper vapor laser chains. An alternative solution to pump dye laser

Louis A. Lompre

2000-01-01

336

Molecular engineering and photostability of laser dyes within sol-gel hosts  

NASA Astrophysics Data System (ADS)

The use of solid-state dye laser for commercial applications has been limited largely by the poor photostability of the gain medium. Techniques are examined to improve the photostability of Coumarin and Pyrromethene-BF2 567 (PM- 567) laser dyes within xerogel and Polyceram hosts synthesized by sol-gel processing. The photochemical mechanisms by which laser dyes degrade are discussed and determined specifically for PM-567. PM-567 was determined to degrade both by photo-oxidation and acid degradation. Techniques for improving photostability are described from a molecular engineering perspective. These techniques include: covalently attaching the laser dye to the host; controlling the chemical environment of the dye; increasing dye caging by increasing the SiO2 content; removing porosity from the host; and incorporating additives such as hindered amine light stabilizers to minimize photodegradation.

Suratwala, Tayyab I.; Davidson, Kevin; Gardlund, Zack; Uhlmann, Donald R.; Bonilla, Sandra I.; Peyghambarian, Nasser

1997-03-01

337

Narrow band infrared picosecond pulses tunable between 1. 2 and 1. 4. mu. m generated by a travelling-wave dye laser  

SciTech Connect

A novel type of picosecond light source is the traveling-wave dye laser. It consists of a generator and an amplifier cell, both pumped by single pulses. Using the fast switching dye No.5 with a fluorescence quantum efficiency of 5 x 10/sup -4/, one obtains an energy conversion of the pump to the IR pulse of up to 10 percent. The spectral width of the IR pulses is 15 cm/sup -1/ over the tunability range of 1.18-1.4..mu..m. At 1.33 ..mu..m we observe Gaussian shaped pulses of 4.4 ps duration for pump pulses of 4.5 ps generated by a mode-locked Nd:glass laser. The output pulses show a high stability with a jitter of less than 0.2 ps.

Elsaesser, T.; Polland, H.J.

1984-03-01

338

Collagen Remodeling After 585-nm Pulsed Dye Laser Irradiation: An Ultrasonographic Analysis  

E-print Network

treatment with a 585-nm pulsed dye laser. The patients were all female, ranging in age from 47 to 67 with the NLite 585-nm pulsed dye laser (ICN Photonics, Costa Mesa, CA). The patients were all female, ranging after treatment. Ultrasound images were obtained with the Episcan I-100 (Longport Inc., Swarthmore, PA

McCarthy, John E.

339

High energy erbium laser end-pumped by a laser diode bar array coupled to a Nonimaging Optic Concentrator  

E-print Network

High energy erbium laser end-pumped by a laser diode bar array coupled to a Nonimaging Optic laser end pumped by a laser diode array emitting at 980 nm coupled to a Nonimaging Z .Optic Concentrator , 3q w xYb phosphate glass 2 end pumped by a laser diode bar array leads to a low-cost, compact micro

Boyer, Edmond

340

Laser performance of Coumarin 540A dye molecules in polymeric host media with different viscosities: From liquid solution to solid polymer matrix  

SciTech Connect

Photophysical parameters and lasing properties of Coumarin 540A dye molecules are studied in solutions of increasing viscosity, from liquid solutions in 1,4-dioxane to solid solutions in poly(methyl methacrylate). The fluorescence quantum yield and lasing efficiencies decrease as the viscosity of the solution increases, reflecting the strong influence of the rigidity of the medium on the radiative processes. The photodegradation mechanisms acting on the fluorophores are analyzed by following the dependence of laser induced fluorescence and laser output on the number of pump laser pulses. The fluorescence redistribution after pattern photobleaching technique is used, and Fick{close_quote}s second law is applied to study the diffusion of dye molecules in the highly viscous polymer solutions. The diffusion coefficients of the dye molecules as a function of the increased viscosity of the medium are determined. {copyright} {ital 1998 American Institute of Physics.}

Costela, A.; Garcia-Moreno, I. [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)] [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Barroso, J.; Sastre, R. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)] [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)

1998-01-01

341

Efficient laser performance of a cryogenic Yb:YAG laser pumped by fiber coupled 940 and 969?nm laser diodes  

NASA Astrophysics Data System (ADS)

Laser performance of Yb:YAG at different cryogenic temperatures pumped by a fiber coupled diode laser emitting at 940 and 969?nm were presented. The pump laser diode bandwidth, absorption bandwidth as well as absorption of the laser material at cryogenic temperatures play a vital role on laser performance. The laser threshold decreases and the output power and slope efficiency increase when cooled to cryogenic temperatures.

Jambunathan, V.; Miura, T.; T?snohlídková, L.; Lucianetti, A.; Mocek, T.

2015-01-01

342

Xenon Flash Lamp Pumped Self-Frequency Doubling NYAB Q-Switched Laser  

Microsoft Academic Search

By using xenon flash lamp as pumping light source and BDN dye film as passive Q-switch or KD* P crystal as active Q-switch, we have, for the first time, realized Q-switching run from 1.06 mum to 0.53 mum in the NdxY1-xAl3(BO3)4 (NYAB) self-frequency doubling laser and obtained MW\\/cm2 giant pulse output at 0.53 mum wave length. Meanwhile, the green light

Xingyu Zhang; Shengzhi Zhao; Qingpu Wang; Hua Liu; Baosheng Lu; Hengfu Pan

1992-01-01

343

High efficiency >26 W diode end-pumped Alexandrite laser.  

PubMed

We show for the first time that multi-ten Watt operation of an Alexandrite laser can be achieved with direct red diode-pumping and with high efficiency. An investigation of diode end-pumped Alexandrite rod lasers demonstrates continuous-wave output power in excess of 26W, more than an order of magnitude higher than previous diode end-pumping systems, and slope efficiency 49%, the highest reported for a diode-pumped Alexandrite laser. Wavelength tuning from 730 to 792nm is demonstrated using self-seeding feedback from an external grating. Q-switched laser operation based on polarization-switching to a lower gain axis of Alexandrite has produced ~mJ-pulse energy at 1kHz pulse rate in fundamental TEM(00) mode. PMID:24977887

Teppitaksak, Achaya; Minassian, Ara; Thomas, Gabrielle M; Damzen, Michael J

2014-06-30

344

AlGaAs diode pumped tunable chromium lasers  

DOEpatents

An all-solid-state laser system is disclosed wherein the laser is pumped in the longwave wing of the pump absorption band. By utilizing a laser material that will accept unusually high dopant concentrations without deleterious effects on the crystal lattice one is able to compensate for the decreased cross section in the wing of the absorption band, and the number of pump sources which can be used with such a material increases correspondingly. In a particular embodiment a chromium doped colquiriite-structure crystal such as Cr:LiSrAlF.sub.6 is the laser material. The invention avoids the problems associated with using AlGaInP diodes by doping the Cr:LiSrAlF.sub.6 heavily to enable efficient pumping in the longwave wing of the absorption band with more practical AlGaAs diodes.

Krupke, William F. (Pleasanton, CA); Payne, Stephen A. (Castro Valley, CA)

1992-01-01

345

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

346

Small signal gain measurement of liquid oxygen under different wavelength laser pump  

NASA Astrophysics Data System (ADS)

Oxygen molecules existed in pairs under liquid condition, the radiation from vibrational ground state of 1 ? state to the first vibrational excited state of 3 ? state was electronic dipole moment transition allowed, and a photon with wavelength of 1580 nm was emitted. In our experiment, dye laser with wavelength of 581 nm, 634 nm, 764 nm was used to excite liquid oxygen to different excited states, while a tunable OPO was used as the seeder laser, and the small signal gain was measured to be 0.23 cm-1, 0.3 cm-1 and 0.076 cm-1 respectively. The small signal gain (pump by photon of 634 nm) was significantly higher than that of common solid state lasers and chemical lasers. When the fundamental output of a Q-switched Nd:YAG laser was used as the pump source, the corresponding small signal gain was 0.12 cm-1. The profiles of small signal gain form 1579.2 nm to 1580.8 nm were also presented. These results were consistent with theoretical calculation. The high positive gain indicated that the liquid oxygen was a potential medium for high energy laser. A comprehensive parameter optimization was still necessary in order to improve the mall signal gain.

Shi, Zhe; Li, Hui; Zhou, Canhua; Liu, Jinbo; Cai, Xianglong; Hu, Shu; Gai, Baodong; Zhou, Dongjian; Liu, Dong; Guo, Jingwei; Jin, Yuqi

2015-02-01

347

LD-pumped high-power laser system  

Microsoft Academic Search

A QCW 100 W LD array side pumped high power laser has been developed. The 1.06 micrometer laser pulse energy of 2 mJ, with the pulse width 20 ns and repetition frequency 70 Hz to approximately 5 KHz is obtained. Using the non-cylinder lens focus system developed by our group, the efficient conversion of pump energy into 1.06 micrometer TEM00

Yujing Huo; Zhaoming Hu; Shufang He

1998-01-01

348

-mode Nd:YAG laser with annular pumping  

NASA Astrophysics Data System (ADS)

We demonstrated a radially polarized, LG01-mode Nd:YAG laser by applying annular-shaped pump light. The annular profile of the pump light was originated from the mode conversion inside a conventional multimode fiber under off-focus coupling condition. This laser gave a maximum output power of 1.2 W at 1,064 nm with a slope efficiency of 28.3 %.

Fang, Zhiqiang; Xia, Kegui; Yao, Yao; Li, Jianlang

2014-10-01

349

600-W lamp pumped CW Nd:YAG laser  

NASA Astrophysics Data System (ADS)

A lamp pumped CW Nd:YAG laser is presented in this paper for the requirement of industrial application. The main factors, which affect output power and beam quality of high power solid-state laser module, are theoretically analyzed. Total electro-optics efficiency of lamp pumped Nd:YAG crystal as high as 4.0% is obtained, and output power is higher than 647 W with beam parameter product 22 mm·mrad.

Li, Qiang; Wang, Zhimin; Wang, Zhiyong; Yu, Zhensheng; Lei, Hong; Guo, Jiang; Li, Gang; Zuo, Tiechuan

2003-09-01

350

Nuclear pumped lasers: Advantages of O2 (1 delta)  

NASA Technical Reports Server (NTRS)

Nuclear pumped laser technology was evaluated as a possible future weapons contender. It was determined that in order to become a primary weapon the following engineering problems must be solved: shielding, heat dissipation, high efficiency fixed focus pumping, good beam quality, and thermal blooming.

Taylor, J. J.

1979-01-01

351

LD pumped Q-switched self-frequency-doubling laser  

SciTech Connect

The authors report here LD pumped Q-Switched LNYAB Self-frequency-doubling Laser. Under 570mW of 0.802{micro}m pumping power, the series pulses of 0.53{micro}m green laser with 4.2ns of pulse width and 750W of peak power have been measured. The laser reliably operates when Q-switching rate ranges from CW to 100kHz. The highest peak power was obtained at repetition rate of 10kHz. To the authors` knowledge, it is the first LD pumped acoustooptic Q-switched LNYAB green laser in the world and should be a desirable and reliable pulsed green laser source in the future.

Huo, Y.; Wei, Z.; He, S. [Tsinghua Univ., Beijing (China). Dept. of Electronic Engineering; Dekker, P.; Dawes, J.; Piper, J. [Macquarie Univ., New South Wales (Australia). Centre for Lasers and Applications; Wang, P.; Lu, B. [Shandong Univ., Jinan (China). Inst. of Crystal Materials

1996-12-31

352

Feasibility of supersonic diode pumped alkali lasers: Model calculations  

SciTech Connect

The feasibility of supersonic operation of diode pumped alkali lasers (DPALs) is studied for Cs and K atoms applying model calculations, based on a semi-analytical model previously used for studying static and subsonic flow DPALs. The operation of supersonic lasers is compared with that measured and modeled in subsonic lasers. The maximum power of supersonic Cs and K lasers is found to be higher than that of subsonic lasers with the same resonator and alkali density at the laser inlet by 25% and 70%, respectively. These results indicate that for scaling-up the power of DPALs, supersonic expansion should be considered.

Barmashenko, B. D.; Rosenwaks, S. [Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)] [Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

2013-04-08

353

Application of reactor-pumped lasers to power beaming  

SciTech Connect

Power beaming is the concept of centralized power generation and distribution to remote users via energy beams such as microwaves or laser beams. The power beaming community is presently performing technical evaluations of available lasers as part of the design process for developing terrestrial and space-based power beaming systems. This report describes the suitability of employing a nuclear reactor-pumped laser in a power beaming system. Although there are several technical issues to be resolved, the power beaming community currently believes that the AlGaAs solid-state laser is the primary candidate for power beaming because that laser meets the many design criteria for such a system and integrates well with the GaAs photodiode receiver array. After reviewing the history and physics of reactor-pumped lasers, the advantages of these lasers for power beaming are discussed, along with several technical issues which are currently facing reactor-pumped laser research. The overriding conclusion is that reactor-pumped laser technology is not presently developed to the point of being technially or economically competitive with more mature solid-state technologies for application to power beaming. 58 refs.

Repetti, T.E.

1991-10-01

354

Clementine: diode-pumped laser qualification  

Microsoft Academic Search

This paper discusses the design and testing of the lasers built for the Clementine Laser Rangefinder that was used to map the lunar topology. a baseline Acceptance Test Procedure (ATP) was run once and the flight laser was built. Then the Laser Resonator Assembly (LRA) and the Laser Power Supply (LPS) were subjected to vibration and electromagnetic compatibility (EMC) testing

Mark E. Kushina; Michael G. Grote; Charles E. Wiswall; Dave A. Hall; Joe B. Russek

1995-01-01

355

Products of photodegradation for coumarin laser dyes. Technical report No. 7, 1 January-31 October 1982  

SciTech Connect

The products of conventional photolysis of the coumarin laser dyes, C1, C35, C153, and C152 have been investigated, The previously reported dealkylation of C1 is documented for the fluorinated dyes, C35, and C152 in deaerated solvents. In addition, a reduction product is identified for C1, consistent with a radical mechanism for decomposition. Evidence is provided that the concentration quenching (self quenching) of singlet dye is important to the degradation mechanism. For the rigid dye, C153, a photooxidation product involving the amine functionality results from decomposition in aerated media. For several dyes, very low triplet yields have been measured.

Jones, G. II; Jackson, W.R.; Kanoktanaporn, S.; Bergmark, W.R.

1983-10-31

356

A Modular Control Platform for a Diode Pumped Alkali Laser  

NASA Astrophysics Data System (ADS)

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 early experiments have shown promising results. However, a number of technical issues need to be overcome to realize high output power from these lasers. In order to achieve higher power, the efficiency of coupling between pump laser energy and the chemical cell must be increased, and eventually multiple high power diode pumps must be combined and synchronized so that their energy can pump the chemical cell. Additionally, an inter-cavity adaptive optics system may be a requirement to be able to propagate these lasers with high efficiency. DPAL systems are complex and require a significant amount of data fusion and active feedback to control and optimize their performance. There are a wide range of components including pump lasers, gain cells and monitoring points needed to study and refine the overall laser system. In support of this dynamic development environment, we have developed a hardware framework using commercial off the shelf (COTS) components which supports the rapid assembly of functional system blocks into a cohesive integrated system. Critical to this system are a simple communication protocol, industry standard communication pipes (USB, Bluetooth, etc), and flexible high level scripting. Simplifying the integration process has the benefit of allowing flexible "on the fly" modifications to adapt the system as needed and enhance available functionality. The modular nature of the architecture allows scalability and adaptability as more pieces are added to the system. Key components of this system are demonstrated for selected portions of a DPAL system using a USB backbone.

Shapiro, J.; Teare, S.

357

Free-electron lasers as pumps for high-energy solid-state lasers  

NASA Astrophysics Data System (ADS)

High average-power free-electron lasers may be useful for pumping high peak-power solid-state laser-amplifiers. At very high peak-powers, the pump source for solid-state lasers is non-trivial: flash lamps produce thermal problems and are unsuitable for materials with short florescence-times, while diodes can be expensive and are only available at select wavelengths. FELs can provide pulse trains of light tuned to a laser material's absorption peak, and florescence lifetime. An FEL pump can thus minimize thermal effects and potentially allow for new laser materials to be used. This paper examines the design of a high average-power, efficient high-gain FEL for use as pump source. Specifically, the cases of a 100 J class pump, and a 100 TW-class laser at a planned fourth-generation light-source are considered.

Travish, G.; Crane, J. K.; Tremaine, A.

2004-08-01

358

Ultralow detection limits for an organic dye determined by fluorescence spectroscopy with laser diode excitation  

SciTech Connect

Fluorescence of IR-140, a laser dye in methanol solution, is excited by a semiconductor laser diode. Analytical figures of merit are compared for three different instrumental configurations, with the dye measured in a cuvette, a liquid jet, and a compact instrument. The best limit of detection, 46,000 molecules, was achieved with a liquid jet. Linear dynamic range was 6 orders of magnitude. The laser diode operates in the near-infrared region, resulting in low background fluorescence.

Johnson, P.A.; Barber, T.E.; Smith, B.W.; Winefordner, J.D. (Univ. of Florida, Gainesville (USA))

1989-04-15

359

Four-Pass Coupler for Laser-Diode-Pumped Solid-State Laser  

NASA Technical Reports Server (NTRS)

A four-pass optical coupler affords increased (in comparison with related prior two-pass optical couplers) utilization of light generated by a laser diode in side pumping of a solid-state laser slab. The original application for which this coupler was conceived involves a neodymium-doped yttrium aluminum garnet (Nd:YAG) crystal slab, which, when pumped by a row of laser diodes at a wavelength of 809 nm, lases at a wavelength of 1,064 nm. Heretofore, typically, a thin laser slab has been pumped in two passes, the second pass occurring by virtue of reflection of pump light from a highly reflective thin film on the side opposite the side through which the pump light enters. In two-pass pumping, a Nd:YAG slab having a thickness of 2 mm (which is typical) absorbs about 84 percent of the 809-nm pump light power, leaving about 16 percent of the pump light power to travel back toward the laser diodes. This unused power can cause localized heating of the laser diodes, thereby reducing their lifetimes. Moreover, if the slab is thinner than 2 mm, then even more unused power travels back toward the laser diodes. The four-pass optical coupler captures most of this unused pump light and sends it back to the laser slab for two more passes. As a result, the slab absorbs more pump light, as though it were twice as thick. The gain and laser cavity beam quality of a smaller laser slab in conjunction with this optical coupler can thus be made comparable to those of a larger two-pass-pumped laser slab.

Coyle, Donald B.

2008-01-01

360

Passively Q-switched side pumped monolithic ring laser  

NASA Technical Reports Server (NTRS)

Disclosed herein are systems and methods for generating a side-pumped passively Q-switched non-planar ring oscillator. The method introduces a laser into a cavity of a crystal, the cavity having a round-trip path formed by a reflection at a dielectrically coated front surface, a first internal reflection at a first side surface of the crystal at a non-orthogonal angle with the front, a second internal reflection at a top surface of the crystal, and a third internal reflection at a second side surface of the crystal at a non-orthogonal angle with the front. The method side pumps the laser at the top or bottom surface with a side pump diode array beam and generates an output laser emanating at a location on the front surface. The design can include additional internal reflections to increase interaction with the side pump. Waste heat may be removed by mounting the crystal to a heatsink.

Li, Steven X. (Inventor)

2012-01-01

361

Capacitive-discharge-pumped copper bromide vapour laser  

SciTech Connect

A copper bromide vapour laser pumped by a high-frequency capacitive discharge is developed. It is shown that, by using of a capacitive discharge, it is possible to built a sealed off metal halide vapour laser of a simple design allowing the addition of active impurities into the working medium. (letters)

Sukhanov, V B; Fedorov, V F; Troitskii, V O [Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation); Gubarev, F A; Evtushenko, Gennadii S [Tomsk Polytechnical University, Tomsk (Russian Federation)

2007-07-31

362

A linewidth-narrowed and frequency-stabilized dye laser for application in laser cooling of molecules.  

PubMed

We demonstrate a robust and versatile solution for locking the continuous-wave dye laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers. The dye laser is first stabilized with respect to a reference cavity by Pound-Drever-Hall (PDH) technique which results in a single frequency with the linewidth 200 kHz and short-term stabilization, by stabilizing the length of the reference cavity to a stabilized helium-neon laser we simultaneously transfer the ± 2 MHz absolute frequency stability of the helium-neon laser to the dye laser with long-term stabilization. This allows the dye laser to be frequency chirped with the maximum 60 GHz scan range while its frequency remains locked. It also offers the advantages of locking at arbitrary dye laser frequencies, having a larger locking capture range and frequency scanning range to be implemented via software. This laser has been developed for the purpose of laser cooling a molecular magnesium fluoride beam. PMID:25402105

Dai, D P; Xia, Y; Yin, Y N; Yang, X X; Fang, Y F; Li, X J; Yin, J P

2014-11-17

363

Diode-pumped solid state laser for inertial fusion energy  

SciTech Connect

The authors evaluate the prospect for development of a diode-pumped solid-state-laser driver in an inertial fusion energy power plant. Using a computer code, they predict that their 1 GWe design will offer electricity at 8.6 cents/kW {center_dot} hr with the laser operating at 8.6% efficiency and the recycled power level at 31%. The results of their initial subscale experimental testbed of a diode-pumped solid state laser are encouraging, demonstrating good efficiencies and robustness.

Payne, S.A.; Krupke, W.F.; Orth, C.D. [and others

1994-11-01

364

Spectroscopy and efficient laser action from diode pumping of a new broadly  

E-print Network

Spectroscopy and efficient laser action from diode pumping of a new broadly tunable crystal: Yb3) and hence is of particular interest for diode-pumped femtosecond and tunable laser sources. Efficient operation from diode pumping (1.4 W of cw laser power obtained with 3.6 W of diode pump power and as much

Boyer, Edmond

365

Numerically calculated Q-switched laser output characteristics of high-power diode-laser-pumped Nd:YAG laser  

Microsoft Academic Search

A numerical model for high power diode laser-pumped Q-switched Nd:YAG laser is presented. Number of models based on analytical methods for describing the performance effects of diode-pumped solid-state (DPSS) lasers have appeared in the literature. But very few numerical models have so far been reported. Our model based on the numerical method takes into account all operational characteristics of pump

Prasanta Kundu; Arvind D. Shaligram; V. N. Saxena

1997-01-01

366

Composition and method of preparation of solid state dye laser rods  

DOEpatents

The present invention includes solid polymeric-host laser rods prepared using bulk polymerization of acrylic acid ester comonomers which, when admixed with dye(s) capable of supporting laser oscillation and polymerized with a free radical initiator under mild thermal conditions, produce a solid product having the preferred properties for efficient lasing. Unsaturated polymerizable laser dyes can also be employed as one of the comonomers. Additionally, a method is disclosed which alleviates induced optical stress without having to anneal the polymers at elevated temperatures (>85.degree. C.).

Hermes, Robert E. (Los Alamos, NM)

1992-01-01

367

LED end-pumped Nd:YAG lasers  

Microsoft Academic Search

Experimental results are reported on the room-temperature operation of Nd:YAG lasers end-pumped with a LED. The radiation from a 10%-efficient domed LED was coupled to the end of a 5-mm-long laser rod with a large hemispherical reflector. At 20 C, a multimode laser power of 0.25 mW was obtained at a LED current of 250 mA. By measuring the variation

F. W. Ostermayer Jr.

1977-01-01

368

Cavity-dumping of an optically pumped FIR laser  

Microsoft Academic Search

A conventional molecular gas far-infrared laser pumped by a low-pressure Q-switched CO2 laser has been cavity-dumped. The dumping of far-infrared radiation was accomplished by means of an optical semiconductor switch activated by the pulsed output of either a Q-switched or an actively mode-locked Q-switched Nd:YAG laser. As a result, 10 ns FIR pulses have been generated. Dumping efficiency turns out

J. Burghoorn; W. Roest; J. Bij; T. O. Klaassen; W. Th Wenckebach

1993-01-01

369

Electron beam pumped krypton fluoride lasers for fusion energy  

Microsoft Academic Search

High-energy electron beam pumped krypton fluoride (KrF) gas lasers are an attractive choice for inertial fusion energy (IFE). Their short wavelength and demonstrated high beam uniformity optimizes the laser-target physics, and their pulsed power technology scales to a large system. This paper presents the principals of this type of laser and the progress toward developing technologies that can meet the

JOHN D. SETHIAN; MATTHEW C. MYERS; ROBERT H. LEHMBERG; PAUL C. KEPPLE; S. P. Obenschain; FRANK HEGELER; M. Friedman; MATTHEW F. WOLFORD; RUSSELL V. SMILGYS; STEPHEN B. SWANEKAMP; DOUGLAS WEIDENHEIMER; DAVID GIORGI; DALE R. WELCH; DAVID V. ROSE; STUART SEARLES

2004-01-01

370

Lasers in dense gases pumped by low energy electron beams  

Microsoft Academic Search

Low energy (11keV) electron beams are used for pumping laser systems in dense gases in a transverse geometry. The laser setup uses thin (300nm) SiNx ceramic foils as entrance windows for the electron beam. An Ar-Xe infrared laser at a wavelength of 1.73 mum has been operated using a commercially available TV-cathode ray tube as the electron beam source. The

J. Wieser; M. Salvermoser; A. Ulrich; Hiromitsu Tomizawa; Claudia Niessl; D. E. Murnick; H. Dahi

1998-01-01

371

Some new laser dyes: solvent effect on QE and lasing action  

SciTech Connect

With a view to extend the tunability range and maximum output with the coumarin series of dyes, eleven new coumarins differing in the nature of substituents and their positions are synthesized. Two of these are found to be capable of laser action. Optical spectra and quantum efficiencies of these two dyes in various solvents are studied. Correlation between lasing capability structure of the dye and its optical characteristics is discussed.

Padhye, M.R.; Varadarajan, T.S.; Deshpande, A.V.

1982-08-01

372

The performance of dyes and dye mixtures of rhodamine 6G\\/rhodamine 560 and of styryl 8\\/styryl 9 for single mode cw ring laser operation  

Microsoft Academic Search

The concept of dye mixing is successfully applied to rhodamine 560\\/rhodamine 6G mixtures. The near IR dyes styryl 8 and styryl 9 can be operated with LD700 optics in the laser cavity producing laser action in the respective wavelength intervals 715-760 nm and 795-845 nm. The concept of dye mixing gives no improvement in this case. Reduction of the self-absorption

J. J. L. Mulders; L. W. G. Steenhuysen

1985-01-01

373

Thermo-optic nonlinearity of the laser dye LDS 867 under low power CW laser excitation  

NASA Astrophysics Data System (ADS)

Thermally induced optical nonlinearity of the laser dye LDS 867 is studied in ethanol solution using the self phase modulation and closed aperture z-scan techniques, employing a continuous wave low power He-Ne laser beam for excitation. The nonlinear optical (NLO) coefficients are obtained by analyzing the z-scan curve on the basis of the thermal lens model. The dye exhibits a negative thermal nonlinearity which can be inferred from the occurrence of a pre-focal peak followed by a post-focal valley in the z-scan. The large nonlinear refractive index (n2) measured at the excitation wavelength of 633nm reveals that the material is NLO active even at low excitation powers of less than 1 mW. Results indicate that LDS 867 is a promising material for optical power limiting applications.

Mary, K. A. Ann; Mary, E. J. Sonia; Vidyadharan, Viji; Philip, Reji; Unnikrishnan, N. V.

2015-02-01

374

Ho:YAP laser intra-cavity pumped by a diode-pumped Tm:YLF laser  

NASA Astrophysics Data System (ADS)

In this paper, we report a compact Ho:YAP laser which is intra-cavity pumped by a diode-pumped Tm:YLF laser. The Ho:YAP crystal is c-cut with a Ho-doped concentration of 0.3%. At rod mount temperatures of 15?°C, we obtained 8 W of average output at two wavelengths of 2102 and 2129 nm from the Ho:YAP laser for 135.4 W of diode power incident upon two Tm:YLF rods, with a slope efficiency of 10.9% and a beam quality factor of M2 ˜ 2.2.

Zhu, G. L.; He, X. D.; Yao, B. Q.; Wang, Y. Z.

2013-01-01

375

Simultaneous two-band laser emissions and three primary color outputs in the superradiant mode from dye mixtures  

SciTech Connect

A dye mixture of coumarin 460, disodium fluorescein, and nile blue 690 perchrolate was excited by a nitrogen laser. Simultaneous laser emissions in two spectra regions (blue and green, green and red, red and blue) were obtained in each of the two dye mixtures. Furthermore, simultaneous three primary color outputs in a superradiant mode from three dye mixtures were observed.

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

1988-11-14

376

Analysis on Thermal Management of High Power Diode-Pumped Lasers  

Microsoft Academic Search

Because the emitting wavelength of the laser diode (LD) pump source is matched with the absorption spectrum of the laser medium, high power diode-pumped lasers greatly reduce the useless heat into the laser medium, and alleviate the impact of thermal effect. However, with development of the output power of lasers toward a MW power level, thermal effect of the laser

Du Yan-qiu

2009-01-01

377

High average power diode pumped solid state lasers for CALIOPE  

SciTech Connect

Diode pumping of solid state media offers the opportunity for very low maintenance, high efficiency, and compact laser systems. For remote sensing, such lasers may be used to pump tunable non-linear sources, or if tunable themselves, act directly or through harmonic crystals as the probe. The needs of long range remote sensing missions require laser performance in the several watts to kilowatts range. At these power performance levels, more advanced thermal management technologies are required for the diode pumps. The solid state laser design must now address a variety of issues arising from the thermal loads, including fracture limits, induced lensing and aberrations, induced birefringence, and laser cavity optical component performance degradation with average power loading. In order to highlight the design trade-offs involved in addressing the above issues, a variety of existing average power laser systems are briefly described. Included are two systems based on Spectra Diode Laboratory`s water impingement cooled diode packages: a two times diffraction limited, 200 watt average power, 200 Hz multi-rod laser/amplifier by Fibertek, and TRW`s 100 watt, 100 Hz, phase conjugated amplifier. The authors also present two laser systems built at Lawrence Livermore National Laboratory (LLNL) based on their more aggressive diode bar cooling package, which uses microchannel cooler technology capable of 100% duty factor operation. They then present the design of LLNL`s first generation OPO pump laser for remote sensing. This system is specified to run at 100 Hz, 20 nsec pulses each with 300 mJ, less than two times diffraction limited, and with a stable single longitudinal mode. The performance of the first testbed version will be presented. The authors conclude with directions their group is pursuing to advance average power lasers. This includes average power electro-optics, low heat load lasing media, and heat capacity lasers.

Comaskey, B.; Halpin, J.; Moran, B.

1994-07-01

378

Laser Charecteristics of a New Dye: 7-Diethylamino-3-cyano Benzimidazo(1,2-a)quinoline by Energy Transfer Dye Laser Mechanism  

Microsoft Academic Search

An experimental study of the laser characteristics, by energy transfer machanism of a new dye: 7-Diethylamino-3-Cyano Benzimidazo (1,2-a) Quinoline (DCBQ) using 7-Diethylamiho-4-Methyl Coumarin (Coumarin 1,DAMC) as a donor are presented. The effect of the concentration of the components on the lasing characteristics like peak power and wavelength of lasing of dye mixture is studied and discussed. The effect of the

B. Bangar Raju; T. S. Varadarajan

1993-01-01

379

Irradiation of Dye-Doped Microspheres with a Strongly Focused Laser Beam  

E-print Network

Irradiation of Dye-Doped Microspheres with a Strongly Focused Laser Beam Results in Alignment upon Received December 12, 2001 ABSTRACT The irradiation of dye-doped polystyrene microspheres with an argon ion be manipulated by altering the location of the focal point inside the spheres. The illuminated microspheres

Zare, Richard N.

380

Laser behavior and photostability characteristics of organic dye doped silicate gel materials  

Microsoft Academic Search

The solgel process is a solution synthesis technique which provides a low temperature chemical route for the preparation of rigid transparent matrix materials. Luminescent organic dye molecules have been incorporated via the solgel method into organically modified silicate (ORMOSIL) polymer host matrices. Optical gain, laser oscillation, and photostability of rhodamine and coumarin dyes doped into ORMOSIL gels are reported. The

Edward T. Knobbe; Bruce Dunn; Peter D. Fuqua; Fumito Nishida

1990-01-01

381

Effect of flash lamp pulsed dye laser on discoid lupus erythematosus lesions  

Microsoft Academic Search

The treatment of discoid lupus erythematosus with pulsed dye has been evaluated in recent years. The improvement of telangiectasia and erythema in cutaneous lesions was based on selective photothermolysis ablation of the dilated capillaries and venules .While the improvement in scar and atrophy was referred to the effect of pulsed dye laser on collagenase activity. We describe the results of

Mona Soliman; Hesham Shokir; Samia Gabal; Abeer Attia

2006-01-01

382

Measuring the Dispersion Curve of a PMMA-Fibre Optic Cable Using a Dye Laser  

ERIC Educational Resources Information Center

An advanced undergraduate laboratory experiment is outlined which uses a dye laser to map out the chromatic dispersion curve of a polymethyl methacrylate (PMMA) optical fibre. Seven different wavelengths across the visible spectrum are employed using five different dyes. The light pulse is split into two pulses, one to a nearby photodetector and…

Zorba, Serkan; Farah, Constantine; Pant, Ravi

2010-01-01

383

Controlling the Photoluminescence from a Laser Dye through the Oxidation Level of  

E-print Network

Controlling the Photoluminescence from a Laser Dye through the Oxidation Level of Polypyrrolea (OLED).[3,5] Attempts to enhance the photoluminescence (PL) of conducting polymer-based materials (ppy) matrix. The photoluminescence (PL) of the dye was found to be controlled by the oxidation level

Brolo, Alexandre G.

384

Coupled Finite Element Analysis of Composite Laser Rods Thermal Characteristics under Longitudinal Diode Pumping  

Microsoft Academic Search

Diode laser pumped solid-state lasers are covering a wide range of applications. The longitudinal pumping geometry of laser\\u000a rod is particularly favorable as it provides a high degree of spatial overlap between pump and lasing modes. However, high\\u000a pump-power densities are required to achieve sufficient inversion in the laser material. This produces high thermal loading\\u000a in laser crystals, which, in

E. Stupak; R. Ka?ianauskas; A. S. Dementjev; A. Jovaiša

385

Potential of solar-simulator-pumped alexandrite lasers  

NASA Technical Reports Server (NTRS)

An attempt was made to pump an alexandrite laser rod using a Tamarak solar simulator and also a tungsten-halogen lamp. A very low optical laser cavity was used to achieve the threshold minimum pumping-power requirement. Lasing was not achieved. The laser threshold optical-power requirement was calculated to be approximately 626 W/sq cm for a gain length of 7.6 cm, whereas the Tamarak simulator produces 1150 W/sq cm over a gain length of 3.3 cm, which is less than the 1442 W/sq cm required to reach laser threshold. The rod was optically pulsed with 200 msec pulses, which allowed the alexandrite rod to operate at near room temperature. The optical intensity-gain-length product to achieve laser threshold should be approximately 35,244 solar constants-cm. In the present setup, this product was 28,111 solar constants-cm.

Deyoung, Russell J.

1990-01-01

386

Lasing threshold of one- and two-photon-pumped dye-doped silica powder  

NASA Astrophysics Data System (ADS)

The random laser features around threshold in a ground powder of a silica gel containing Rhodamine 6G-doped silica nanoparticles under one- and two-photon excitation are analyzed. The lasing threshold following two-photon pumping is fifty times higher than after one-photon excitation. Theoretical calculations by using a light diffusive propagation model are in agreement with the experimental results.

García-Ramiro, B.; Illarramendi, M. A.; García-Revilla, S.; Balda, R.; Levy, D.; Zayat, M.; Fernández, J.

2014-12-01

387

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

The primary goals of the feasibility study are the following: (1) to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space directly focused sunlight; and (2) 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 battery electrically pumping a current injection laser. With external modulation, such lasers may prove to be efficient sources for intersatellite communications. We proposed 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 for operation at low pump intensities. This report outlines our progress toward these goals. Discussion of several technical details are left to the attached summary abstract.

Anderson, Neal G.

1991-01-01

388

Infantile hemangioma: pulsed dye laser versus surgical therapy  

NASA Astrophysics Data System (ADS)

Hemangioma is a mesenchymal benign tumor formed by blood vessels. Anomalies affect up to 10% of children and they are more common in females than in males. The aim of our study was to compare the treatment efficacy, namely the curative effect and adverse events, such as loss of pigment and appearance of scarring, between classical surgery techniques and laser techniques. For that reason a group of 223 patients with hemangioma was retrospectively reviewed. For treatment, a pulsed dye laser (PDL) (Rhodamine G, wavelength 595 nm, pulsewidth between 0.45 and 40 ms, spot diameter 7 mm, energy density 9–11 J cm?2) was used and the results were compared with a control group treated with classical surgical therapy under general anesthesia. The curative effects, mainly number of sessions, appearance of scars, loss of pigment, and relapses were evaluated as a marker of successful treatment. From the results it was evident that the therapeutic effects of both systems are similar. The PDL was successful in all cases. The surgery patients had four relapses. Classical surgery is directly connected with the presence of scars, but the system is safe for larger hemangiomas. It was confirmed that the PDL had the optimal curative effect without scars for small lesions (approximately 10 mm). Surgical treatment under general anesthesia is better for large hemangiomas; the disadvantage is the presence of scars.

Remlova, E.; Dostalova, T.; Michalusova, I.; Vranova, J.; Jelinkova, H.; Hubacek, M.

2014-05-01

389

Invasive leg vein treatment with 1064/1319 Nd:YAG laser: combination with dye laser treatment  

NASA Astrophysics Data System (ADS)

More than 2 500 leg veins patients were treated with dye laser / ScleroPlus, Candela, USA / successfully in our clinic and we use this therapy as the basic cosmetics treatment. But especially diameter of leg vein is limiting factor. Very often we have to treat some cases that are not ideal for classical surgical or for dye laser method. We decided to make invasive perivenous laser coagulation. We adapted original Czech 1064/1319 nm Nd:YAG laser / US patent pending /, which is new combine tool, for invasive application. Principe: After we have penetrated the cutis with laser fiber we coagulate leg veins during slowly perivenous motion. Perfect preoperative examination is a condition of success. After 15 months we have very interesting results. Some patients / 15%/ were perfect treated only with this possibility but excellent results are acquired from combination with dye laser.

Smucler, Roman; Horak, Ladislav; Mazanek, Jiri

1999-06-01

390

Rapid remission of severe pruritus from angiolymphoid hyperplasia with eosinophilia by pulsed dye laser therapy.  

PubMed

A 48-year-old Japanese woman with angiolymphoid hyperplasia with eosinophilia (ALHE) was successfully treated with a flashlamp pulsed dye laser (585 nm, 450 micros pulse duration). The lesion was severely pruritic and had been enlarging slowly for 2 years but was resistant to conventional therapies, including topical, intralesional, and systemic corticosteroid, and cryotherapy. The severe pruritus immediately improved after the first treatment using the pulsed dye laser. The erythema and papules gradually improved without scarring and this was followed by further five treatments over approximately a 4-month interval. No clinical recurrences have been observed 1 year after completion of the treatment. We think that pulsed dye laser therapy is an effective treatment for ALHE in both Japanese as well as Caucasian patients. Pulsed dye laser therapy is also helpful in reducing the pruritus in ALHE patients. PMID:14616822

Nomura, T; Sato-Matsumura, K C; Kikuchi, T; Abe, M; Shimizu, H

2003-11-01

391

Investigating pulsed dye laser-blood vessel interaction with color Doppler optical coherence  

E-print Network

Investigating pulsed dye laser-blood vessel interaction with color Doppler optical coherence irradiated blood vessels has been achieved using Color Doppler Optical Coherence Tomography (CDOCT was used to irradiate hamster dorsal skin flap window preparations. Irradiation sites were imaged

Barton, Jennifer K.

392

Low-threshold stimulated emission from lysozyme amyloid fibrils doped with a blue laser dye  

NASA Astrophysics Data System (ADS)

Amyloid fibrils are excellent self-assembling nanotemplates for organic molecules such as dyes. Here, we demonstrate that laser dye-doped lysozyme type fibrils exhibit significantly reduced threshold for stimulated emission compared to that observed in usual matrices. Laser action was studied in slab planar waveguides of the amyloids doped with Stilbene 420 laser dye prepared using a film casting technique. The lowering of the threshold of stimulated emission is analyzed in the context of intrinsic structure of the amyloid nanotemplates, electrostatic interaction of different microstructures with dye molecules, as well as material properties of the cast layers. All these factors are considered to be of importance for introducing gain for random laser operation.

Sznitko, L.; Hanczyc, P.; Mysliwiec, J.; Samoc, M.

2015-01-01

393

Reducing thermal lensing in diode-pumped laser rods  

Microsoft Academic Search

We present a diode-end-pumped Nd:YAG laser with multiple composite rods. Composite rods (rods with undoped endcaps) were used in order to remove the part of thermal lens formed by the bending of the pump face of the rod. We give an analytical expression for determining the fraction of the thermal lens contributed by the end effect in a homogeneously doped

M. P. MacDonald; Th. Graf; J. E. Balmer; H. P. Weber

2000-01-01

394

Laser-Induced Release of Liposome-Encapsulated Dye: A New Diagnostic Tool  

Microsoft Academic Search

  This paper reviews applications of laser-induced release of liposome-encapsulated dye as a diagnostic tool. The technique\\u000a consists of encapsulating a fluorescent dye into liposomes at high concentration. Before injection, liposomes are not fluorescent.\\u000a After systemic liposome injection, a laser beam is used to increase the temperature at a specific site (blood vessel, biological\\u000a structures, etc.). This increase of temperature causes

S. Mordon; J. M. Devoisselle; S. Begu; T. Desmettre

1998-01-01

395

Tandem-pumped 1120-nm actively Q-switched fiber laser  

NASA Astrophysics Data System (ADS)

We report on a tandem-pumped actively Q-switched fiber laser system emitting at 1120 nm. Parasitic oscillation is challenging in Yb-doped Q-switched 1120-nm fiber laser, which is suppressed by pumping with a fiber laser at 1018 nm. At least four times improvement in output peak power is demonstrated in a single laser setup with 1018-nm fiber laser pumping instead of 976-nm laser diode pumping. This is, to the best of our knowledge, the first demonstration of a tandem-pumped Q-switched fiber laser.

Wang, Jian-Hua; Hu, Jin-Meng; Zhang, Shi-Qiang; Chen, Lu-Lu; Fang, Yong; Feng, Yan; Li, Zhi

2015-02-01

396

Broadly tunable, longitudinally diode-pumped Alexandrite laser  

NASA Astrophysics Data System (ADS)

We present design and first performance data of a broadly tunable Alexandrite laser longitudinally pumped by a newly developed high brightness single emitter diode laser module with output in the red spectral range. Replacing the flashlamps, which are usually used for pumping Alexandrite, will increase the efficiency and maintenance interval of the laser. The pump module is designed as an optical stack of seven single-emitter laser diodes. We selected an optomechanical concept for the tight overlay of the radiation using a minimal number of optical components for collimation, e.g. a FAC and a SAC lens, and focusing. The module provides optical output power of more than 14 W (peak pulse output in the focus) with a beam quality of M2 = 41 in the fast axis and M2 = 39 in the slow axis. The Alexandrite crystal is pumped from one end at a repetition rate of 35 Hz and 200?s long pump pulses. The temperature of the laser crystal can be tuned to between 30 °C and 190 °C using a thermostat. The diode-pumped Alexandrite laser reaches a maximum optical-optical efficiency of 20 % and a slope efficiency of more than 30 % in fundamental-mode operation (M2 < 1.10). When a Findlay-Clay analysis with four different output couplers is conducted, the round-trip loss of the cavity is determined to be around 1 %. The wavelength is tunable to between 755 and 788 nm via crystal temperature or between 745 and 805 nm via an additional Brewster prism.

Strotkamp, M.; Witte, U.; Munk, A.; Hartung, A.; Gausmann, S.; Hengesbach, S.; Traub, M.; Hoffmann, H.-D.; Hoeffner, J.; Jungbluth, B.

2014-02-01

397

Developing a narrow-line laser spectrometer based on a tunable continuous-wave dye laser  

NASA Astrophysics Data System (ADS)

We present the development of a dye-laser-based spectrometer operating at 550-600 nm. The spectrometer will be used to detect an ultra-narrow clock transition (1S0-3P0) in an Ytterbium optical lattice clock and perform high-resolution spectroscopy of iodine molecules trapped in the sub-nanometer channels of zeolite crystal (AlPO4-11). Two-stage Pound-Drever-Hall frequency stabilization is implemented on the tunable continuous-wave dye laser to obtain a reliable operation and provide stable laser radiations with two different spectral linewidths. In the first-stage frequency locking, a compact home-built intracavity electro-optic modulator is adopted for suppressing fast frequency noise. With an acquisition time of 0.1 s the 670-kHz linewidth of the free-running dye laser is reduced to 2 kHz when locked to a pre-stabilization optical cavity with a finesse of 1170. When the pre-stabilized laser is locked to a high-finesse optical cavity, a linewidth of 1.4 Hz (2 s) is observed and the frequency stability is 3.7 × 10-15 (3 s). We also measure and analyze the individual noise contributions such as those from residual amplitude modulation and electronic noise. The ongoing upgrades include improving long-term frequency stability at time scales from 10 to 100 s and implementing continuous frequency scan across 10 GHz with radio-frequency precision.

Wang, Chun; Lv, Shasha; Liu, Fang; Bi, Jin; Li, Liufeng; Chen, Lisheng

2014-08-01

398

Developing a narrow-line laser spectrometer based on a tunable continuous-wave dye laser  

SciTech Connect

We present the development of a dye-laser-based spectrometer operating at 550–600 nm. The spectrometer will be used to detect an ultra-narrow clock transition ({sup 1}S{sub 0}-{sup 3}P{sub 0}) in an Ytterbium optical lattice clock and perform high-resolution spectroscopy of iodine molecules trapped in the sub-nanometer channels of zeolite crystal (AlPO{sub 4}-11). Two-stage Pound-Drever-Hall frequency stabilization is implemented on the tunable continuous-wave dye laser to obtain a reliable operation and provide stable laser radiations with two different spectral linewidths. In the first-stage frequency locking, a compact home-built intracavity electro-optic modulator is adopted for suppressing fast frequency noise. With an acquisition time of 0.1 s the 670-kHz linewidth of the free-running dye laser is reduced to 2 kHz when locked to a pre-stabilization optical cavity with a finesse of 1170. When the pre-stabilized laser is locked to a high-finesse optical cavity, a linewidth of 1.4 Hz (2 s) is observed and the frequency stability is 3.7 × 10{sup ?15} (3 s). We also measure and analyze the individual noise contributions such as those from residual amplitude modulation and electronic noise. The ongoing upgrades include improving long-term frequency stability at time scales from 10 to 100 s and implementing continuous frequency scan across 10 GHz with radio-frequency precision.

Wang, Chun; Lv, Shasha; Bi, Jin [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Fang [College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093 (China); Li, Liufeng; Chen, Lisheng [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan 430071, China and Laboratory of Atomic Frequency Standards, Chinese Academy of Sciences, Wuhan 430071 (China)

2014-08-15

399

Medium effects of fluorescence quantum yields and lifetimes for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

Fluorescence quantum yields and lifetimes for a series of aminocoumarin laser dyes have been measured. The characteristics red shift of fluorescence in polar solvents is accompanied by a marked decrease in emission yield and lifetime for coumarins in which the substituted amine group at the 7 position is free to rotate. Strong emission is maintained in structurally rigid dyes. The non-radiative decay rates for non-rigid dyes which increase in polar solvents are associated with relaxation of emissive planar dye conformations to twisted zwitterionic species.

Jones, G., II; Jackson, W. R.; Halpern, A. M.

1980-01-01

400

Optimization of rod diameter in solid state lasers side pumped with multiple laser diode arrays  

NASA Technical Reports Server (NTRS)

Results of a study to determine the optimum laser rod diameter for maximum output energy in a solid state neodymium laser transversely pumped with multiple laser diode arrays are reported here. Experiments were performed with 1.0 mm, 1.5 mm and 2.0 mm rod radii of both neodymium doped Y3Al5O12 (Nd:YAG) and La2Be2O5 (Nd:BeL) pumped with laser diode arrays having a maximum combined energy of 10.5 mJ. Equations were derived which predict the optimum rod radius and corresponding output mirror reflectivity for a given laser material and total pump energy. Predictions of the equations agreed well with the experiments for each of the laser materials which possessed significantly different laser properties from one another.

Sims, Newton, Jr.; Chamblee, Christyl M.; Barnes, Norman P.; Lockard, George E.; Cross, Patricia L.

1992-01-01

401

Pump and probe spectroscopy with continuous wave quantum cascade lasers  

SciTech Connect

This paper details infra-red pump and probe studies on nitric oxide conducted with two continuous wave quantum cascade lasers both operating around 5 ?m. The pump laser prepares a velocity selected population in a chosen rotational quantum state of the v = 1 level which is subsequently probed using a second laser tuned to a rotational transition within the v = 2 ? v = 1 hot band. The rapid frequency scan of the probe (with respect to the molecular collision rate) in combination with the velocity selective pumping allows observation of marked rapid passage signatures in the transient absorption profiles from the polarized vibrationally excited sample. These coherent transient signals are influenced by the underlying hyperfine structure of the pump and probe transitions, the sample pressure, and the coherent properties of the lasers. Pulsed pump and probe studies show that the transient absorption signals decay within 1 ?s at 50 mTorr total pressure, reflecting both the polarization and population dephasing times of the vibrationally excited sample. The experimental observations are supported by simulation based upon solving the optical Bloch equations for a two level system.

Kirkbride, James M. R.; Causier, Sarah K.; Dalton, Andrew R.; Ritchie, Grant A. D., E-mail: grant.ritchie@chem.ox.ac.uk [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford (United Kingdom)] [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford (United Kingdom); Weidmann, Damien [Space Science and Technology Department, STFC Rutherford Appleton Laboratory, Harwell Oxford Campus, Didcot OX11 0QX (United Kingdom)] [Space Science and Technology Department, STFC Rutherford Appleton Laboratory, Harwell Oxford Campus, Didcot OX11 0QX (United Kingdom)

2014-02-07

402

Pump and probe spectroscopy with continuous wave quantum cascade lasers.  

PubMed

This paper details infra-red pump and probe studies on nitric oxide conducted with two continuous wave quantum cascade lasers both operating around 5 ?m. The pump laser prepares a velocity selected population in a chosen rotational quantum state of the v = 1 level which is subsequently probed using a second laser tuned to a rotational transition within the v = 2 ? v = 1 hot band. The rapid frequency scan of the probe (with respect to the molecular collision rate) in combination with the velocity selective pumping allows observation of marked rapid passage signatures in the transient absorption profiles from the polarized vibrationally excited sample. These coherent transient signals are influenced by the underlying hyperfine structure of the pump and probe transitions, the sample pressure, and the coherent properties of the lasers. Pulsed pump and probe studies show that the transient absorption signals decay within 1 ?s at 50 mTorr total pressure, reflecting both the polarization and population dephasing times of the vibrationally excited sample. The experimental observations are supported by simulation based upon solving the optical Bloch equations for a two level system. PMID:24511944

Kirkbride, James M R; Causier, Sarah K; Dalton, Andrew R; Weidmann, Damien; Ritchie, Grant A D

2014-02-01

403

Optically pumped mid-infrared laser action in the monohaloacetylenes  

NASA Astrophysics Data System (ADS)

Strong optically pumped laser action excited by a TEA carbon dioxide laser has been obtained from monofluoro-acetylene in the 560-610 cm -1 region with outputs of up to 25 mJ and superfluorescent operation readily achieved without optimisation. These result from excitation of a combination of the two bending modes v4+v5. Laser action was also obtained with 9 ?m excitation of the v3 C?F stretch, on a difference band terminating in v4, with similar properties. Lasers of this type are rare. As well as being a potentially useful laser source in a region sparsely populated with good lasers, the results are of interest in the context of on going investigations of the spectroscopy of HCCF. Most, but not all lines are assigned. Very weak, erratic laser action was observed from chloro- and bromo-acetylene.

Rutt, H. N.

1995-02-01

404

Increasing pumping efficiency by using gradient-doped laser crystals  

NASA Astrophysics Data System (ADS)

Investigations of a new class of optical materials with functional nonuniform distribution of optical dopant are continued. Longitudinal pumping and heat release in active elements with a gradient distribution of optical centers are simulated. It is shown that, for a given length of the laser element, pumping efficiency remains at a stably high level upon variation of its power density for different gradients of concentration of activators. It is demonstrated that, in addition to a high level of optical pumping efficiency, the temperature profile in the active medium becomes smoother.

Stroganova, E. V.; Galutskiy, V. V.; Tkachev, D. S.; Nalbantov, N. N.; Tsema, A. A.; Yakovenko, N. A.

2014-12-01

405

Dye-dispersion study at proposed pumped-storage project on Hudson River at Cornwall, New York  

USGS Publications Warehouse

Data were collected during a dye-dispersion study on a 6-mile, tide-affected reach of the Hudson River near the proposed Cornwall Pumped Storage Project on September 21-22, 1977. The results indicated that complete mixing did not occur during the first tidal cycle but was complete after two or more cycles. The fluorometric dye-tracing procedure was used to determine the dispersion characteristics of the water mass. Rhodamine WT dye, 20-percent solution, was continuously injected on the west side of the river throughout an ebb tide, and its movement was monitored during a 30-hour period. Samples were collected both individually and continuously. Automatic dye samplers were used at selected cross sections near each bank. Bathymetric measurements were made at eight cross sections between Newburgh and West Point to determine the depths. (Woodard-USGS)

Dunn, Bernard; Gravlee, George C.

1978-01-01

406

Nonlinear fibre-optic devices pumped by semiconductor disk lasers  

NASA Astrophysics Data System (ADS)

Semiconductor disk lasers offer a unique combination of characteristics that are particularly attractive for pumping Raman lasers and amplifiers. The advantages of disk lasers include a low relative noise intensity (-150 dB Hz-1), scalable (on the order of several watts) output power, and nearly diffraction-limited beam quality resulting in a high (~70 % — 90 %) coupling efficiency into a single-mode fibre. Using this technology, low-noise fibre Raman amplifiers operating at 1.3 ?m in co-propagation configuration are developed. A hybrid Raman-bismuth doped fibre amplifier is proposed to further increase the pump conversion efficiency. The possibility of fabricating mode-locked picosecond fibre lasers operating under both normal and anomalous dispersion is shown experimentally. We demonstrate the operation of 1.38-?m and 1.6-?m passively mode-locked Raman fibre lasers pumped by 1.29-?m and 1.48-?m semiconductor disk lasers and producing 1.97- and 2.7-ps pulses, respectively. Using a picosecond semiconductor disk laser amplified with an ytterbium-erbium fibre amplifier, the supercontinuum generation spanning from 1.35 ?m to 2 ?m is achieved with an average power of 3.5 W.

Chamorovskiy, A. Yu; Okhotnikov, Oleg G.

2012-11-01

407

Nonlinear fibre-optic devices pumped by semiconductor disk lasers  

SciTech Connect

Semiconductor disk lasers offer a unique combination of characteristics that are particularly attractive for pumping Raman lasers and amplifiers. The advantages of disk lasers include a low relative noise intensity (-150 dB Hz{sup -1}), scalable (on the order of several watts) output power, and nearly diffraction-limited beam quality resulting in a high ({approx}70 % - 90 %) coupling efficiency into a single-mode fibre. Using this technology, low-noise fibre Raman amplifiers operating at 1.3 {mu}m in co-propagation configuration are developed. A hybrid Raman-bismuth doped fibre amplifier is proposed to further increase the pump conversion efficiency. The possibility of fabricating mode-locked picosecond fibre lasers operating under both normal and anomalous dispersion is shown experimentally. We demonstrate the operation of 1.38-{mu}m and 1.6-{mu}m passively mode-locked Raman fibre lasers pumped by 1.29-{mu}m and 1.48-{mu}m semiconductor disk lasers and producing 1.97- and 2.7-ps pulses, respectively. Using a picosecond semiconductor disk laser amplified with an ytterbium-erbium fibre amplifier, the supercontinuum generation spanning from 1.35 {mu}m to 2 {mu}m is achieved with an average power of 3.5 W. (invited paper)

Chamorovskiy, A Yu; Okhotnikov, Oleg G [Optoelectronics Research Center, Tampere University of Technology, Tampere (Finland)

2012-11-30

408

Graphene surface emitting terahertz laser: Diffusion pumping concept  

SciTech Connect

We suggest a concept of a tunable graphene-based terahertz (THz) surface emitting laser with diffusion pumping. We employ significant difference in the electronic energy gap of graphene and a typical wide-gap semiconductor, and demonstrate that carriers generated in the semiconductor can be efficiently captured by graphene resulting in population inversion and corresponding?THz lasing from graphene. We develop design principles for such a laser and estimate its performance. We predict up to 50?W/cm{sup 2} terahertz power output for 100?kW/cm{sup 2} pump power at frequency around 10?THz at room temperature.

Davoyan, Arthur R., E-mail: davoyan@seas.upenn.edu [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019, Russia and Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Morozov, Mikhail Yu.; Popov, Vyacheslav V. [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019 (Russian Federation)] [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019 (Russian Federation); Satou, Akira; Otsuji, Taiichi [Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai, Miyagi 980-8577 (Japan)] [Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai, Miyagi 980-8577 (Japan)

2013-12-16

409

Graphene surface emitting terahertz laser: Diffusion pumping concept  

NASA Astrophysics Data System (ADS)

We suggest a concept of a tunable graphene-based terahertz (THz) surface emitting laser with diffusion pumping. We employ significant difference in the electronic energy gap of graphene and a typical wide-gap semiconductor, and demonstrate that carriers generated in the semiconductor can be efficiently captured by graphene resulting in population inversion and corresponding THz lasing from graphene. We develop design principles for such a laser and estimate its performance. We predict up to 50 W/cm2 terahertz power output for 100 kW/cm2 pump power at frequency around 10 THz at room temperature.

Davoyan, Arthur R.; Morozov, Mikhail Yu.; Popov, Vyacheslav V.; Satou, Akira; Otsuji, Taiichi

2013-12-01

410

Diode-Pumped Mode-Locked LiSAF Laser  

SciTech Connect

Under this contract we have developed Cr{sup 3+}:LiSrAlF{sub 6} (Cr:LiSAF, LiSAF) mode-locked lasers suitable for generation of polarized electrons for CEBAF. As 670 nm is an excellent wavelength for optical pumping of Cr:LiSAF, we have used a LIGHTWAVE developed 670 nm diode pump module that combines the output of ten diode lasers and yields approximately 2 Watts of optical power. By the use of a diffraction limited pump beam however, it is possible to maintain a small mode size through the length of the crystal and hence extract more power from Cr:LiSAF laser. For this purpose we have developed a 1 Watt, red 660nm laser (LIGHTWAVE model 240R) which serves as an ideal pump for Cr:LiSAF and is a potential replacement of costly and less robust krypton laser. This new system is to compliment LIGHTWAVE Series 240, and is currently being considered for commercialization. Partially developed under this contract is LIGHTWAVEs product model 240 which has already been in our production lines for a few months and is commercially available. This laser produces 2 Watts of output at 532 nm using some of the same technology developed for production of the 660nm red system. It is a potential replacement for argon ion lasers and has better current and cooling requirements and is an excellent pump source for Ti:Al{sub 2}O{sub 3}. Also, as a direct result of this contract we now have the capability of commercially developing a mode-locked 100MHz Cr:LiSAF system. Such a laser could be added to our 100 MHz LIGHTWAVE Series 131. The Series 131 lasers provide pico second pulses and were originally developed under another DOE SBIR. Both models of LIGHTWAVE Series 240 lasers, the fiber coupled pump module and the 100MHz LiSAF laser of Series 131 have been partially developed under this contract, and are commercially competitive products.

None

1996-02-01

411

Temperature distribution of laser crystal in LD end-pumped Nd:YAG/LBO blue laser  

NASA Astrophysics Data System (ADS)

In this study, LD end-pumped Nd:YAG/LBO solid state blue laser is realized by even hollow cavity. A thermal distribution model of Nd:YAG crystal is established. Based on the calculation, the temperature distribution of laser crystal is obtained. The results show that the temperature decreases from the pump end to the launch end exponentially. When the pumping power is 10 W and the radius of pumping beams is 240?m, a biggest output power 1.06 W of blue light is achieved, giving an optical conversion efficiency of 10.6%.

Zhang, Lei; Zheng, Yibo; Li, Simian; Jia, Liping; Kang, Junjian

2012-11-01

412

Photostability of laser dyes incorporated in formamide SiO 2 ORMOSILs  

NASA Astrophysics Data System (ADS)

The sol-gel process provides a low temperature chemical route for the preparation of rigid transparent matrix materials. Under this process, luminescent organic dye molecules were incorporated into organically modified silicate (ORMOSIL) host matrices. The photostability of these laser dyes encapsulated in a solid matrix was studied using optical absorption and luminescence. The photochemical mechanisms of the dye response under N 2 laser irradiation were studied using UV and fluorescence spectra measurement. The evolution of the maximum of the emission and excitation curves as function of accumulated irradiated energy was fitted by exponential equations. The matrix protects the dye from the oxidation and dimerization reactions. The dye molecules exhibited photobleaching due to their photodegradation. The ORMOSIL doped with Nile blue exhibits good photostability after 6 h of irradiation.

Valverde-Aguilar, Guadalupe

2006-07-01

413

Solar-simulator-pumped atomic iodine laser kinetics  

NASA Technical Reports Server (NTRS)

The literature contains broad ranges of disagreement in kinetic data for the atomic iodine laser. A kinetic model of a solar-simulator-pumped iodine laser is used to select those kinetic data consistent with recent laser experiments at the Langley Research Center. Analysis of the solar-simulator-pumped laser experiments resulted in the following estimates of rate coefficients: for alkyl radical (n-C3F7) and atomic iodine (I) recombination, 4.3 x 10 to the 11th power (1.9) + or - cu cm/s; for n-C3F7I stabilized atomic iodine recombination (I + I) 3.7 x 10 to the -32nd power (2.3) + or -1 cm to the 6th power/s; and for molecular iodine (I2) quenching, 3.1 x 10 to the -11th power (1.6) + or - 1 cu cm/s. These rates are consistent with the recent measurements.

Wilson, H. W.; Raju, S.; Shiu, Y. J.

1983-01-01

414

LED pumped Nd:YAG laser development program  

NASA Technical Reports Server (NTRS)

The results of a development program for light emitting diode (LED) pumped Nd:YAG lasers are described. An index matching method to increase the coupling efficiency of the laser is described. A solid glass half-cylinder of 5.0 by 5.6 centimeters was used for index matching and also as a pumping cavity reflector. The laser rods were 1.5 by 56 millimeters with dielectric coatings on both end surfaces. The interfaces between the diode array, glass cylinder, and laser rod were filled with viscous fluid of refractive index n = 1.55. Experiments performed with both the glass cylinder and a gold coated stainless steel reflector of the same dimensions under the same operating conditions indicate that the index matching cylinder gave 159 to 200 percent improvement of coupling efficiency over the metal reflector at various operating temperatures.

Farmer, G. I.; Kiang, Y. C.; Lynch, R. J.

1973-01-01

415

A diode-laser pump source with small focus diameter for end- pumped systems  

Microsoft Academic Search

A pump source with eight angular multiplexed laser diodes is built. The diode laser emission is collimated and focused using relatively inexpensive aspherical lenses. The maximum output power is 6.3W at 970nm. The overall transmittance of the beam shaping optics is T=85%. The electrical, temporal and spectral properties are studied. The variances of the spatial intensity distribution are ?r0x=99m and

Chr. P. Wyss; W. Lüthy; H. P. Weber; L. Brovelli; Ch. Harder; H. P. Meier

1999-01-01

416

Continuous-wave diode-pumped solid-state laser with an intracavity fiber Bragg grating  

E-print Network

Continuous-wave diode-pumped solid-state laser with an intracavity fiber Bragg grating Sylvie Yiou concept of laser that benefits from both fiber and laser crystals: a cw diode-pumped solid-state laser with an intracavity fiber Bragg grating as the output coupler. The design of the laser cavity and the experimental

Paris-Sud XI, Université de

417

A flashlamp-pumped 946 nm Nd:YAG laser  

Microsoft Academic Search

Generation of 946 nm radiation from a commercially available, flashlamp-pumped Nd:YAG laser was investigated. By suppression of the high-gain 1.064 µm transition and with a specially designed cooling system, a stable emission at 946 nm was achieved in the temperature range 300–240 K. At a repetition rate of 10 Hz laser output powers of 100mW and 500 mW were obtained

S. Dimov; E. Peik; H. Walther

1991-01-01

418

Cladding for transverse-pumped solid-state laser  

NASA Technical Reports Server (NTRS)

In a transverse pumped, solid state laser, a nonabsorptive cladding surrounds a gain medium. A single tranverse mode, namely the Transverse Electromagnetic (TEM) sub 00 mode, is provided. The TEM sub 00 model has a cross sectional diameter greater than a transverse dimension of the gain medium but less than a transverse dimension of the cladding. The required size of the gain medium is minimized while a threshold for laser output is lowered.

Byer, Robert L. (inventor); Fan, Tso Y. (inventor)

1989-01-01

419

Diode-pumped femtosecond laser oscillator with cavity dumping.  

PubMed

We report on a diode-pumped tunable Yb:glass femtosecond laser oscillator with electro-optic cavity dumping. Pulses with energies exceeding 400 nJ and peak powers greater than 1 MW were generated at repetition frequencies as high as 200 kHz. This laser forms a compact light source for various scientific and industrial applications such as micromachining. PMID:15209274

Killi, A; Morgner, U; Lederer, M J; Kopf, D

2004-06-01

420

Comparison of the Effectiveness of Nonablative Fractional Laser versus Pulsed-Dye Laser in Thyroidectomy Scar Prevention  

PubMed Central

Background The anterior neck is the site of open thyroidectomy and where postoperative scarring can cause distress to patients. Both fractional and pulsed-dye lasers are effective and safe methods for preventing and improving surgical scars. Objective This study evaluated the improvement in scar appearance with laser intervention during the wound healing process. We evaluated the effect of nonablative fractional and pulsed-dye lasers on fresh thyroidectomy scars. Methods Patients were treated 3 times at 4-week interval with a follow-up visit at the 6th month. Scars were divided into 2 halves for each optional treatment. At every visit, a questionnaire evaluating the scar and patient satisfaction was completed. Results Thirty patients completed the 6-month process. The mean Vancouver Scar Scale scores improved significantly from 8.0 to 4.6 and 8.2 to 4.7 with nonablative fractional and pulsed-dye lasers, respectively (p<0.001). However, there was no significant difference between the 2 methods (p=0.840). Conclusion There remains no consensus on the optimal treatment of scars. The present study indicates nonablative fractional and pulsed-dye lasers significantly improve scars. Nonablative fractional lasers are non-inferior to pulsed-dye lasers. Further studies are required to corroborate this finding. PMID:25324655

Ha, Ji Min; Kim, Han Su; Cho, Eun Byul; Park, Gyeong Hun; Kim, Kwang Ho; Kim, Lee Su; Kim, Kwang Joong

2014-01-01

421

Solar Pumped High Power Solid State Laser for Space Applications  

NASA Technical Reports Server (NTRS)

Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.

Fork, Richard L.; Laycock, Rustin L.; Green, Jason J. A.; Walker, Wesley W.; Cole, Spencer T.; Frederick, Kevin B.; Phillips, Dane J.

2004-01-01

422

Performance of a continuous-wave forsterite laser with krypton ion, Ti:sapphire, and Nd:YAG pump lasers  

Microsoft Academic Search

The authors characterize continuous-wave operation of a chromium-doped forsterite (Cr4+:Mg2SiO4) laser using krypton ion, Ti:sapphire, and Nd:YAG lasers as pump sources. Measurements were made pumping at 647 nm and 676 nm with the krypton ion laser, between 690 and 1010 nm with the Ti:sapphire laser, and at 1.06 ?m with the Nd:YAG laser. Threshold pump powers and slope efficiencies are

Timothy J. Carrig; Clifford R. Pollock

1993-01-01

423

Demonstration of an all-diode-pumped soft x-ray laser  

E-print Network

Demonstration of an all-diode-pumped soft x-ray laser Federico J. Furch,1,3, * Brendan A. Reagan,1); published October 27, 2009 We have demonstrated an 18.9 nm Ni-like molybdenum soft x-ray laser, pumped by a compact all-diode- pumped Yb:YAG laser. The solid-state pump laser produces 8.5 ps pulses with up to 1 J

Rocca, Jorge J.

424

Cooling schemes for longitudinally diode laser-pumped Nd:YAG rods  

Microsoft Academic Search

Longitudinal diode laser pumping causes pronounced inhomogeneous heating of the laser material. The effect of the thermal load on the mechanical and optical properties is significantly influenced by the method used for cooling the pumped surface. Four methods for longitudinally pumped Nd:YAG rods were compared experimentally and with finite-element (FE) analysis. The pumped surface exposed to air or to flowing

R. Weber; B. Neuenschwander; M. Mac Donald; M. B. Roos; Heinz P. Weber

1998-01-01

425

High power high repetition rate VCSEL array side-pumped pulsed blue laser  

NASA Astrophysics Data System (ADS)

High power, kW-class, 808 nm pump modules based on the vertical-cavity surface-emitting laser (VCSEL) technology were developed for side-pumping of solid-state lasers. Two 1.2 kW VCSEL pump modules were implemented in a dual side-pumped Q-switched Nd:YAG laser operating at 946 nm. The laser output was frequency doubled in a BBO crystal to produce pulsed blue light. With 125 ?s pump pulses at a 300 Hz repetition rate 6.1 W QCW 946 nm laser power was produced. The laser power was limited by thermal lensing in the Nd:YAG rod.

van Leeuwen, Robert; Zhao, Pu; Chen, Tong; Xu, Bing; Watkins, Laurence; Seurin, Jean-Francois; Xu, Guoyang; Miglo, Alexander; Wang, Qing; Ghosh, Chuni

2013-03-01

426

Investigations of laser pumped gas cell atomic frequency standard  

NASA Technical Reports Server (NTRS)

The performance characteristics of a rubidium gas cell atomic frequency standard might be improved by replacing the standard rubidium discharge lamp with a single mode laser diode. Aspects of the laser pumped gas cell atomic clock studied include effects due to laser intensity, laser detuning, and the choice of the particular atomic absorption line. Results indicate that the performance of the gas cell clock may be improved by judicious choice of the operating parameters of the laser diode. The laser diode also proved to be a valuable tool in investigating the operation of the conventional gas cell clock. Results concerning linewidths, the light shift effect and the effect of isotopic spin exchange in the conventional gas cell clock are reported.

Volk, C. H.; Camparo, J. C.; Fueholz, R. P.

1982-01-01

427

Random distributed feedback Raman fiber laser with polarized pumping  

NASA Astrophysics Data System (ADS)

In this letter, the polarization properties of a random fiber laser operating via Raman gain and random distributed feedback owing to Rayleigh scattering are investigated for the first time. Using polarized pump, the partially polarized generation is obtained with a generation spectrum exhibiting discrete narrow spectral features contrary to the smooth spectrum observed for the depolarized pump. The threshold, output power, degree of polarization and the state of polarization (SOP) of the lasing can be significantly influenced by the SOP of the pump. Fine narrow spectral components are also sensitive to the SOP of the pump wave. Furthermore, we found that random lasing’s longitudinal power distributions are different in the case of polarized and depolarized pumping that results in considerable reduction of the generation slope efficiency for the polarized radiation. Our results indicate that polarization effects play an important role on the performance of the random fiber laser. This work improves the understanding of the physics of random lasing in fibers and makes a step forward towards the establishment of the vector model of random fiber lasers.

Wu, H.; Wang, Z. N.; Churkin, D. V.; Vatnik, I. D.; Fan, M. Q.; Rao, Y. J.

2015-01-01

428

Optically pumped distributed feedback thin film waveguide lasers with multiwavelength and polarized emissions  

NASA Astrophysics Data System (ADS)

Zirconia titania organically modified silicate (ZrO2-TiO2-ORMOSIL) thin film waveguides of thickness from 0.4 to 7.0 ?m were synthesized using low temperature sol-gel method. Narrow linewidth distributed feedback (DFB) lasing was demonstrated in rhodamine 6G-doped ZrO2-TiO2-ORMOSIL waveguides. Simultaneous tuning of multiple-output wavelengths was achieved in the dye-doped waveguides by varying the period of the gain modulation generated by a nanosecond Nd:YAG laser at 532 nm. As many as eight separate output wavelengths were observed for a planar ZrO2-TiO2-ORMOSIL waveguide of thickness 7.0-?m. The output polarizations of the DFB waveguide lasers can be tuned by varying the polarization of the crossing pump beams. TE and TM optical waves belonging to the same propagation mode were generated by crossing two polarized pump beams, resulting in an effective double of the number of output wavelengths. Continuous tuning of the polarized laser outputs was also achieved by varying the crossing angle.

Wang, J.; Chen, F.; Li, R.; Dong, H.; Fan, J.; Zhang, L.; Shi, L.; Wong, K. Y.

2012-04-01

429

Anomalous dispersion and the pumping of far infrared (FIR) lasers  

NASA Technical Reports Server (NTRS)

It is shown that the anomalous dispersion at the pump transition in molecular far-infrared lasers (FIR) can lead to sizable focusing and defocusing effects. Criteria for beam spreading and trapping are considered with CH2F as an example.

Lawandy, N. M.

1978-01-01

430

Lasing properties of chromium-aluminum-doped forsterite pumped with an alexandrite laser  

Microsoft Academic Search

The lasing properties of chromium-aluminum-doped forsterite were investigated using a tunable alexandrite laser as the pump source. Results of measurements of the lasing threshold, slope efficiency, spectral and temporal profiles of the laser pulse, and the time delay between the alexandrite pump pulse and the laser emission are presented for pump wavelengths of 770, 746, and 730 nm and different

Edward G. Behrens; Mahendra G. Jani; Richard C. Powell; Horacio R. Verdun; Albert Pinto

1991-01-01

431

Nuclear-driven flashlamp pumping of the atomic iodine laser  

SciTech Connect

This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

Miley, G.H.

1992-03-01

432

Excited-state absorption of pump radiation as a loss mechanism in solid-state lasers  

SciTech Connect

The characteristics of optical pumping dynamics occuring in laser-pumped rare earth-doped, solid-state laser materials were investigated by using a tunable alexandrite laser to pump Y3Al5O12:Nd(3+) in an optical cavity. It was found that the slope efficiency of the Nd laser operation depends strongly on the wavelength of the pump laser. For pump wavelength resulting in low slope efficiencies, intense fluorescence emission is observed form the sample in the blue-green spectral region. This is attributed to the excited state absorption of pump photons which occurs during radiationless relaxation from the pump band to the metastable state. This type of process will be an important loss mechanism for monochromatic pumping of laser systems at specific pump wavelengths.

Kliewer, M.L.; Powell, R.C.

1989-08-01

433

Excited state absorption of pump radiation as a loss mechanism in solid-state lasers  

SciTech Connect

The characteristics of optical pumping dynamics occurring in laser-pumped rare earth-doped, solid-state laser materials were investigated by using a tunable alexandrite laser to pump Y/sub 3/Al/sub 5/O/sub 12/:Nd/sup 3+/ in an optical cavity. It was found that the slope efficiency of the Nd laser operation depends strongly on the wavelength of the pump laser. For pump wavelengths resulting in low slope efficiencies, intense fluorescence emission is observed from the sample in the blue-green spectral region. This is attributed to the excited state absorption of pump photons which occurs during radiationless relaxation from the pump band to the metastable state. This type of process will be an important loss mechanism for monochromatic pumping of laser systems at specific pump wavelengths.

Kliewer, M.L.; Powell, R.C.

1989-08-01

434

Femtosecond Cr:Colquiriite Lasers Pumped by a Single Tapered Diode Laser  

E-print Network

Ti:Sapphire lasers could provide tunable femtosecond pulses in the 680-1180 nm region; however, due to the requirement of expensive green pump sources, its current cost sets a barrier to its widespread adoption. As an ...

Demirbas, Umit

435

Traveling-wave laser-produced-plasma energy source for photoionization laser pumping and lasers incorporating said  

DOEpatents

A traveling-wave, laser-produced-plasma, energy source used to obtain single-pass gain saturation of a photoionization pumped laser. A cylindrical lens is used to focus a pump laser beam to a long line on a target. Grooves are cut in the target to present a surface near normal to the incident beam and to reduce the area, and hence increase the intensity and efficiency, of plasma formation.

Sher, Mark H. (Los Altos, CA); Macklin, John J. (Stanford, CA); Harris, Stephen E. (Palo Alto, CA)

1989-09-26

436

Development of Ho:YLF laser pumped by Tm:fiber laser  

NASA Astrophysics Data System (ADS)

We are developing a 2-micron Ho:YLF laser end-pumped by Tm:fiber laser. The oscillator has ring resonator of 3m length. The laser is operated at high repetition rate of 200-5000 Hz in room temperature. The oscillator and amplifier system showed outputs of about 9W in CW and more than 6W in Q-switched operation. This laser will be used for wind and CO2 concentration measurements.

Mizutani, Kohei; Ishii, Shoken; Itabe, Toshikazu; Asai, Kazuhiro; Sato, Atsushi

2014-11-01

437

LED end-pumped Nd:YAG lasers  

Microsoft Academic Search

Experimental results are reported on the room-temperature operation of Nd:YAG lasers end pumped with an LED. The radiation from a 10-percent-efficient 0.46-mm-diam domed LED was coupled to the end of a 0.46-mm-diam × 5.0-mm-long laser rod with a large hemispherical reflector. At 20°C, a multimode laser power of 0.25 mW was obtained at an LED current of 250 mA. By

F. W. Jr

1977-01-01

438

Loading atom lasers by collectivity-enhanced optical pumping  

SciTech Connect

The effect of collectivity on the loading of an atom laser via optical pumping is discussed. In our model, atoms in a beam are laser-excited and subsequently spontaneously decay into a trapping state. We consider the case of sufficiently high particle density in the beam such that the spontaneous emission is modified by the particle interaction. We show that the collective effects lead to a better population of the trapping state over a wide range of system parameters, and that the second-order correlation function of the atoms can be controlled by the applied laser field.

Macovei, Mihai A.; Evers, Joerg [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2010-01-15

439

Negative-coupling resonances in pump-coupled lasers  

E-print Network

We consider coupled lasers, where the intensity deviations from the steady state, modulate the pump of the other lasers. Most of our results are for two lasers where the coupling constants are of opposite sign. This leads to a Hopf bifurcation to periodic output for weak coupling. As the magnitude of the coupling constants is increased (negatively) we observe novel amplitude effects such as a weak coupling resonance peak and, strong coupling subharmonic resonances and chaos. In the weak coupling regime the output is predicted by a set of slow evolution amplitude equations. Pulsating solutions in the strong coupling limit are described by discrete map derived from the original model.

T. W. Carr; M. L. Taylor; I. B. Schwartz

2005-10-28

440

High peak power Nd:YAG laser pumped by 600-W diode laser stack  

Microsoft Academic Search

The Q-switched laser with triangle slab made of Nd:YAG crystal side pumped by 600-W quasi-cw diode laser stack has been designed. The multimode (M2?2.6) output energy of about 42mJ was demonstrated in free running mode for110-mJ pump energy. In Q-switch experiments, the KDDP Pockels cell was placed between the slab and rear mirror in plane-plane cavity with output coupler of

Waldemar Zendzian; Jan K. Jabczynski; Jacek Kwiatkowski

2008-01-01

441

Coherent communication link using diode-pumped lasers  

NASA Technical Reports Server (NTRS)

Work toward developing a diffraction limited, single frequency, modulated transmitter suitable for coherent optical communication or direct detection communication is discussed. Diode pumped, monolithic Nd:YAG nonplanar ring oscillators were used as the carrier beam. An external modulation technique which can handle high optical powers, has moderate modulation voltage, and which can reach modulation rates of 1 GHz was invented. Semiconductor laser pumped solid-state lasers which have high output power (0.5 Watt) and which oscillate at a single frequency, in a diffraction limited beam, at the wavelength of 1.06 microns were built. A technique for phase modulating the laser output by 180 degrees with a 40-volt peak to peak driving voltage is demonstrated. This technique can be adapted for amplitude modulation of 100 percent with the same voltage. This technique makes use of a resonant bulk modulator, so it does not have the power handling limitations of guided wave modulators.

Kane, Thomas J.; Wallace, Richard W.

1989-01-01

442

Electrically pumped edge-emitting photonic bandgap semiconductor laser  

DOEpatents

A highly efficient, electrically pumped edge-emitting semiconductor laser based on a one- or two-dimensional photonic bandgap (PBG) structure is described. The laser optical cavity is formed using a pair of PBG mirrors operating in the photonic band gap regime. Transverse confinement is achieved by surrounding an active semiconductor layer of high refractive index with lower-index cladding layers. The cladding layers can be electrically insulating in the passive PBG mirror and waveguide regions with a small conducting aperture for efficient channeling of the injection pump current into the active region. The active layer can comprise a quantum well structure. The quantum well structure can be relaxed in the passive regions to provide efficient extraction of laser light from the active region.

Lin, Shawn-Yu; Zubrzycki, Walter J.

2004-01-06

443

QUANTITATIVE DETECTION OF ENVIRONMENTALLY IMPORTANT DYES USING DIODE LASER/FIBER-OPTIC RAMAN  

EPA Science Inventory

A compact diode laser/fiber-optic Raman spectrometer is used for quantitative detection of environmentally important dyes. This system is based on diode laser excitation at 782 mm, fiber optic probe technology, an imaging spectrometer, and state-of-the-art scientific CCD camera. ...

444

Use of electron-excitation energy transfer in dye laser active media  

SciTech Connect

A study was made of the spectral luminescence and lasing characteristics of two-component dye mixtures, and of the use of electron-excitation energy transfer to improve the laser emission parameters. A considerable increase in the lasing efficiencyu was found on exciting Trypaflavine by energy transfer from coumarin dyes. The use of electron-excitation energy transfer enabled the laser emission spectrum to be broadened. It was found that by varying the energy donor and acceptor concentrations one could produce laser emission of constant intensity in the spectral range between the donor and acceptor lasing regions.

Rodchenkova, V.V.; Reva, M.G.; Akimov, A.I.; Uzhinov, B.M.

1984-01-01

445

Optimization in scaling fiber-coupled laser-diode end-pumped lasers to higher power: influence of thermal effect  

Microsoft Academic Search

The optimum mode-to-pump ratio in scaling fiber-coupled laser-diode end-pumped lasers to higher power has been investigated by including the thermal effect into the space-dependent rate equation analysis. The optical path difference (OPD) distribution has been derived as a function of the pump-beam quality, focus position of pumping light, and pump radius at the focal plane under the assumption that the

Y. F. Chen; T. M. Huang; C. F. Kao; C. L. Wang; S. C. Wang

1997-01-01

446

New diode wavelengths for pumping solid-state lasers  

SciTech Connect

High-power laser-diode arrays have been demonstrated to be viable pump sources for solid-state lasers. The diode bars (fill factor of 0.7) were bonded to silicon microchannel heatsinks for high-average-power operation. Over 12 W of CW output power was achieved from a one cm AlGaInP tensile-strained single-quantum-well laser diode bar. At 690 nm, a compressively-strained single-quantum-well laser-diode array produced 360 W/cm{sup 2} per emitting aperture under CW operation, and 2.85 kW of pulsed power from a 3.8 cm{sup 2} emitting-aperture array. InGaAs strained single-quantum-well laser diodes emitting at 900 nm produced 2.8 kW pulsed power from a 4.4 cm{sup 2} emitting-aperture array.

Skidmore, J.A.; Emanuel, M.A.; Beach, R.J. [and others

1995-01-01

447

Advances in solid state laser technology for space and medical applications  

NASA Technical Reports Server (NTRS)

Recent developments in laser technology and their potential for medical applications are discussed. Gas discharge lasers, dye lasers, excimer lasers, Nd:YAG lasers, HF and DF lasers, and other commonly used lasers are briefly addressed. Emerging laser technology is examined, including diode-pumped lasers and other solid state lasers.

Byvik, C. E.; Buoncristiani, A. M.

1988-01-01

448

Photophysical and photochemical properties of coumarin laser dyes in amphiphilic media. Technical report, 1 Jan-31 Oct 83  

SciTech Connect

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 for detergent solubilized dye. Electron transfer photochemistry is examined by flash photolysis.

Jones, G. II; Jackson, W.R.; Kanoktanaporn, S.; Bergmark, W.R.

1983-10-31

449

Environmental testing of a diode-laser-pumped Nd:YAG laser and a set of diode-laser-arrays  

NASA Technical Reports Server (NTRS)

Results of the environmental test of a compact, rigid and lightweight diode-laser-pumped Nd:YAG laser module are discussed. All optical elements are bonded onto the module using space applicable epoxy, and two 200 mW diode laser arrays for pump sources are used to achieve 126 mW of CW output with about 7 percent electrical-to-optical conversion efficiency. This laser assembly and a set of 20 semiconductor diode laser arrays were environmentally tested by being subjected to vibrational and thermal conditions similar to those experienced during launch of the Space Shuttle, and both performed well. Nevertheless, some damage to the laser front facet in diode lasers was observed. Significant degradation was observed only on lasers which performed poorly in the life test. Improvements in the reliability of the Nd:YAG laser are suggested.

Hemmati, H.; Lesh, J. R.

1989-01-01

450

Investigation of lasing from dye doped plastics using flash lamp and Nd:YAG excitation.  

NASA Astrophysics Data System (ADS)

We present an investigation of organic dye doped plastics as a lasing medium. The host materials examined are poly(methyl methacrylate) [acrylic], epoxy, polyester and polyurethane. Various solvents are used to improve dye dispersion within the material. Two forms of excitation (flash lamp and frequency doubled Nd:YAG) are used. For the Nd:YAG pumped dye lasers, a disk of dye doped plastic is mounted in a housing to provide random orbital motion. The disk is within a Littmann configuration cavity. Each dye disk is tested for threshold, durability, power output, bandwidth, and tuning range. An end pumped cylinder is also explored. For the flash lamp pumped dye lasers two configurations are used: a traditional dye cylinder within an elliptical reflector and a hollow cylinder with the flash lamp within the hollow. A monolithic cavity for the flash lamp pumped system is investigated.

Masters, Mark; de Armond, Mike; Reynolds, Clint; Suedhoff, Hans

2006-05-01

451

Third-order nonlinear optical studies of anthraquinone dyes using a CW He–Ne laser  

NASA Astrophysics Data System (ADS)

We present investigations on the third-order optical nonlinearity and optical power limiting of anthraquinone dyes. Z-scan measurements were performed using a continuous wave He–Ne laser at 633 nm wavelength as an excitation source. The nonlinear refraction studies exhibited self-defocusing behavior of the dyes. The nonlinear absorption in the dyes was dominated by a reverse saturable absorption process. Self-diffraction ring patterns were observed due to the change in refractive index and thermal lensing. Increase of the electron donating ability of the substituents resulted in enhanced values of the nonlinear optical parameters, establishing the structure–property relationship. The optical limiting study revealed that the dyes possess a lower limiting threshold and clamping level which is very important for eye and sensor protection. Hence, the dyes investigated here emerge as promising candidates for future opto-electronic and photonic device applications such as optical power limiters.

Pramodini, S.; Poornesh, P.

2014-05-01

452

LD pumped high efficiency, high power Tm:YLF laser with adhesive-free bond laser composites  

Microsoft Academic Search

Adhesive-free bonded (AFB®) un-doped end-capped and segmentally bonded Tm:YLF laser composites have been investigated for high efficiency LD-pumped laser operations. With a fiber coupled 792-nm diode laser as pump source and a single-end pump arrangement, an optical-to-optical laser efficiency of 48.3% (quantum efficiency of 116%) and a slope efficiency of 55% (quantum efficiency of 132%) have been measured at the

Xiaodong Mu; Helmuth Meissner; Huai-Chuan Lee

2011-01-01

453

High-power Er:YAG laser at 1646nm pumped by an Er,Yb fiber laser  

Microsoft Academic Search

In this paper we describe an Er:YAG laser pumped by a tunable, cladding-pumped Er,Yb fiber laser and discuss factors affecting the laser performance. Crystals with different Er 3+-concentrations in the range 0.5% to 4 at% and with crystal lengths selected for ~95% absorption of the pump light at 1532nm were used, and the laser performance was investigated for a range

Peter Jander; Jayanta K. Sahu; W. Andrew Clarkson

454

Optical pumping and laser cooling of magnesium atomic beam in metastable states  

Microsoft Academic Search

Here we report some initial results in the study of optical pumping and laser cooling of metastable Mg atomic beam. Eighty-five percent of optical pumping efficiency and laser cooling effect have been observed. We have successfully used frequency doubled diode laser in the experiments as a velocity analysis light source because diode laser is important for making a practical magnesium

Weiquan Cai; N. Beverini; S. del Tredici; J. V. Gomide; Enrico Maccioni; A. M. Messina; Franco Strumia

1992-01-01

455

946 nm Diode Pumped Laser Produces 100mJ  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

456

Laser demonstration and performance characterization of optically pumped Alkali Laser systems  

NASA Astrophysics Data System (ADS)

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 directed energy weapon. A rubidium laser operating at 795 nm is optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of DPALs at pump intensities between 1.3 and 45 kW/cm2. Linear scaling as high as 32 times threshold is observed, with no evidence of second order kinetics. Comparison of laser characteristics with a quasi-two level analytic model suggests performance near the ideal steady-state limit, disregarding the mode mis-match. Additionally, the peak power scales linearly as high as 1 kW, suggesting aperture scaling to a few cm2 is sufficient to achieve tactical level laser powers. The temporal dynamics of the 100 ns pump and rubidium laser pulses are presented, and the continually evolving laser efficiency provides insight into the bottlenecking of the rubidium atoms in the 2P3/2 state. Lastly, multiple excited states of rubidium and cesium were accessed through two photon absorption in the red, yielding a blue and an IR photon through amplified stimulated emission. Threshold is modest at 0.3 mJ/pulse, and slope efficiencies increase dramatically with alkali concentrations and peak at 0.4%, with considerable opportunity for improvement. This versatile system might find applications for IR countermeasures or underwater communications.

Sulham, Clifford V.

457

Nd:LNA laser optical pumping of He-4 - Application to space magnetometers  

NASA Technical Reports Server (NTRS)

Results obtained from laser pumping in a helium magnetometer sensor, using a tunable Nd:LNA laser pumped with a high-power diode laser, are reported. It is shown that it was possible to observe both the Hanle signals and the n = 0, p = 1 parametric resonance by monitoring the pumping radiation passing through the cell. As the diode laser-pumped Nd:LNA laser was tuned through the D0, D1, and D2 transitions, three distinct resonance signals were produced. A comparison of the slope of lamp-pumped signals and laser-pumped D1 signals showed that, under otherwise identical conditions, the slope of the D1 laser signal was 45 times greater than the lamp-pumped signal.

Slocum, R. E.; Schearer, L. D.; Tin, P.; Marquedant, R.

1988-01-01

458

Laser diode pumped Cr 4+:YAG passively Q-switched Nd 3+:S-FAP laser  

NASA Astrophysics Data System (ADS)

A laser diode pumped Cr 4+:YAG repetitively and passively Q-switched Nd 3+:S-FAP laser is studied theoretically and experimentally. The pulse energies, pulsewidths and pulse repetition rates in different conditions are measured and the experimental results are in agreement with the theoretical predictions on the whole.

Zhang, Xingyu; Zhao, Shengzhi; Wang, Qingpu; Sun, Lianke; Zhang, Shaojun; Yao, Guangtao; Zhang, Zhenya

1998-10-01

459

High-efficiency laser oscillation of a microcavity laser excited by resonant optical pumping  

Microsoft Academic Search

The first observation of high-efficiency laser oscillation and resonance wavelength shifts with excitation power under the resonant optical pumping of a microcavity laser is reported. The sample structure was a planar Fabry-Perot resonator with two distributed Bragg reflectors. The calculated absorptivity spectrum at theta = 20 deg and its dependence on the absorption coefficient alpha of the active layer was

T. Tezuka; M. Kushibe

1994-01-01

460

2.7mW output of emerald laser pumped by laser diode  

Microsoft Academic Search

Free-running emerald laser pumped by 660 nm LD was reported. 2.7mW of CW output power has been obtained with overall efficiency of 1% and slope efficiency of 1.33% when the LD incident power was 2.56 W. The laser threshold value of emerald crystal was estimated 0.5W.

Z. Q. Chen; G. Zhang

2005-01-01

461

Highly Efficient Operation of Tm:fiber Laser Pumped Ho:YLF Laser  

NASA Technical Reports Server (NTRS)

A 19 W, TEM(sub 00) mode, Ho:YLF laser pumped by continuous wave Tm:fiber laser has been demonstrated at the room temperature. The slope efficiency and optical-to-optical efficiency are 65% and 55%, respectively.

Bai, Yingxin; Petros, M.; Yu, Jirong; Petzar, Paul; Trieu, Bo; Chen, Sam; Lee, Hyung; Singh, U.

2006-01-01

462

Photoinduced processes in solid polymer solutions of dyes in an interference field of laser radiation  

SciTech Connect

An investigation was made of the relationships governing the photochemical mechanism of formation of light-induced gratings in solid polymer solutions of a dye with a high quantum yield of the triplet states. The combined analysis of the results of real and numerical experiments was made for a solution of eosin K in gelatin. The protonation rate constant of the dye was measured and the dependence of the diffraction efficiency on the duration of irradiation was explained taking diffusion of the dye into account. A method was proposed for determination of the duffusion coefficient in a spatially modified interference field of the laser radiation. The diffusion coefficients were found. (nonlinear optical phenomena)

Sizykh, A G; Tarakanova, E A [Quantum Electronics Division, Krasnoyarsk State University, Krasnoyarsk (Russian Federation)

1998-12-31

463

Dual-pump CARS temperature and major species concentration measurements in counter-flow methane flames using narrowband pump and broadband Stokes lasers  

SciTech Connect

Dual-pump coherent anti-Stokes Raman scattering (CARS) is used to measure temperature and species profiles in representative non-premixed and partially-premixed CH{sub 4}/O{sub 2}/N{sub 2} flames. A new laser system has been developed to generate a tunable single-frequency beam for the second pump beam in the dual-pump N{sub 2}-CO{sub 2} CARS process. The second harmonic output ({proportional_to}532 nm) from an injection-seeded Nd:YAG laser is used as one of the narrowband pump beams. The second single-longitudinal-mode pump beam centered near 561 nm is generated using an injection-seeded optical parametric oscillator, consisting of two non-linear {beta}-BBO crystals, pumped using the third harmonic output ({proportional_to}355 nm) of the same Nd:YAG laser. A broadband dye laser (BBDL), pumped using the second harmonic output of an unseeded Nd:YAG laser, is employed to produce the Stokes beam centered near 607 nm with full-width-at-half-maximum of {proportional_to}250 cm{sup -1}. The three beams are focused between two opposing nozzles of a counter-flow burner facility to measure temperature and major species concentrations in a variety of CH{sub 4}/O{sub 2}/N{sub 2} non-premixed and partially-premixed flames stabilized at a global strain rate of 20 s{sup -1} at atmospheric-pressure. For the non-premixed flames, excellent agreement is observed between the measured profiles of temperature and CO{sub 2}/N{sub 2} concentration ratios with those calculated using an opposed-flow flame code with detailed chemistry and molecular transport submodels. For partially-premixed flames, with the rich side premixing level beyond the stable premixed flame limit, the calculations overestimate the distance between the premixed and the non-premixed flamefronts. Consequently, the calculated temperatures near the rich, premixed flame are higher than those measured. Accurate prediction of the distance between the premixed and the non-premixed flames provides an interesting challenge for future computations. (author)

Thariyan, Mathew P.; Ananthanarayanan, Vijaykumar; Bhuiyan, Aizaz H.; Naik, Sameer V.; Gore, Jay P.; Lucht, Robert P. [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States)

2010-07-15

464

Measurement of liquid sheet using laser tagging method by photochromic dye  

NASA Astrophysics Data System (ADS)

Liquid atomization system has been extensively applied as the most significant process in many industrial fields. In the internal combustion engine, the combustion phenomenon is strongly influenced by the spray characteristics of the fuel given by the atomization process. In order to completely understand the whole atomization process, a detail investigation of relations between the liquid jet characteristics and the breakup phenomenon is required. In this study, a non-intrusive method called as laser tagging method by photochromic dye has been developed with aim to study the breakup process of liquid sheet in detail, covering from the behavior in film until disintegrated into ligament and droplets. The laser tagging method by photochromic dye is based on a shift in the absorption spectrum of photochromic dye molecules tagged by ultraviolet laser. The shift results a color change at the tagged region of liquid containing the dye. In this study, the motions of the dye traces were analyzed as the liquid surface velocity. As a result, liquid sheet was found to keep its velocity constantly in film before suddenly increase around broken point. However, it then decreased after broken into droplets. By forming a set of four points of dye traces on the liquid sheet, the change of relative position of the set enabled the measurement of deformation and rotational motion of the liquid sheet. As a result, the normal strain of the liquid sheet parallel to the flow direction depended on the flow behavior of ligament formation.

Rosli, Nurrina Binti; Amagai, Kenji

2014-12-01

465

Luminescent light source for laser pumping and laser system containing same  

DOEpatents

The invention relates to a pumping lamp for use with lasers comprising a porous substrate loaded with a component capable of emitting light upon interaction of the component with exciting radiation and a source of exciting radiation. Preferably, the pumping lamp comprises a source of exciting radiation, such as an electron beam, and an aerogel or xerogel substrate loaded with a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce light, e.g., visible light, of a suitable band width and of a sufficient intensity to generate a laser beam from a laser material.

Hamil, Roy A. (Tijeras, NM); Ashley, Carol S. (Albuquerque, NM); Brinker, C. Jeffrey (Albuquerque, NM); Reed, Scott (Albuquerque, NM); Walko, Robert J. (Albuquerque, NM)

1994-01-01

466

High-reliability pump module for non-planar ring oscillator laser  

NASA Astrophysics Data System (ADS)

We propose and have demonstrated a prototype high-reliability pump module for pumping a Non-Planar Ring Oscillator (NPRO) laser suitable for space missions. The pump module consists of multiple fiber-coupled single-mode laser diodes and a fiber array micro-lens array based fiber combiner. The reported Single-Mode laser diode combiner laser pump module (LPM) provides a higher normalized brightness at the combined beam than multimode laser diode based LPMs. A higher brightness from the pump source is essential for efficient NPRO laser pumping and leads to higher reliability because higher efficiency requires a lower operating power for the laser diodes, which in turn increases the reliability and lifetime of the laser diodes. Single-mode laser diodes with Fiber Bragg Grating (FBG) stabilized wavelength permit the pump module to be operated without a thermal electric cooler (TEC) and this further improves the overall reliability of the pump module. The single-mode laser diode LPM is scalable in terms of the number of pump diodes and is capable of combining hundreds of fiber-coupled laser diodes. In the proof-of-concept demonstration, an e-beam written diffractive micro lens array, a custom fiber array, commercial 808nm single mode laser diodes, and a custom NPRO laser head are used. The reliability of the proposed LPM is discussed.

Liu, Duncan T.; Qiu, Yueming; Wilson, Daniel W.; Dubovitsky, Serge; Forouhar, Siamak

2007-09-01

467

Efficient holmium:yttrium lithium fluoride laser longitudinally pumped by a semiconductor laser array  

NASA Technical Reports Server (NTRS)

Optical pumping of a holmium:yttrium lithium floride (Ho:YLF) crystal with a 790-nm continuous-wave diode-laser array has generated 56 mW of 2.1-micron laser radiation with an optical-to-optical conversion slope efficiency of 33 percent while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

Hemmati, H.

1987-01-01

468

Pulsed dye laser application in ablation of vascular ectasias of the larynx: a preliminary animal study  

NASA Astrophysics Data System (ADS)

Vascular ectasias (dilatation) and vascular lesions of the larynx are difficult to treat with exciting modalities. Varix (enlarged vessel) of the vocal folds, vocal fold hemorrhage, vascular polyp, hemangioma, intubation or contact granuloma are common problems which disturb voice. Current applications of CO2 laser and cautery often damage the delicate vocal fold cover. The 585 nm dermatologic pulsed dye laser may be an ideal substitute. Two adult canines were examined under anesthesia via microlaryngoscopy technique. Pulsed dye laser (SPTL-1a, Candela Laser Corp., Wayland, MA) energy was delivered via the micromanipulator with the 3.1-mm spot size in single pulses of 6, 8, and 10 Joules/cm2 and applied to the vessels of the vocal folds, epiglottis, and arytenoid cartilage. Endoscopic examination was carried out immediately after the treatment and at 4 weeks postoperatively. The animals were sacrificed at 3 weeks, larynges excised, and whole organ laryngeal section were prepared for histology. Pulsed dye laser thrombosed vessels of the vocal fold using 6 or 8 Joules/cm2. Vascular break and leakage occurred at 10 Joules/cm2. Follow up examination showed excellent vessel obliteration or thrombosis without scarring or injury to the overlying tissues. Histologic examination shows vascular thrombosis without inflammation and fibrosis in the vocal fold cover. Pulsed dye laser may have promise in treatment of vascular lesions of the larynx and upper airway.

Woo, Peak; Wang, Zhi; Perrault, Donald F., Jr.; McMillan, Kathleen; Pankratov, Michail M.

1995-05-01

469

Copper vapour laser pumped by a relativistic electron beam  

SciTech Connect

Experimental and theoretical investigations were made of the pumping of a copper vapour laser by a relativistic electron beam ({var_epsilon} {approximately}500 keV, I{approximately}3 KA, {tau} {approximately} 60 ns). The results obtained (energy of laser pulses {approximately} 30mJ, efficiency {approximately} 1.5%-3% at a neon pressure of {approximately}0.02 bar) were far from those expected. An analysis of the experimental and calculated data showed that the required concentration of the copper vapour in the atomic state was not reached in the active zone and that the process of pumping under these conditions was uncoventional: the energy was transferred from the electron beam to the medium not by collisions with gas atoms (ionisation losses) but by the interaction of a beam-induced eddy electric field with the beam plasma. 14 refs., 6 figs.

Arlantsev, S.V.; Borovich, B.L.; Molodykh, E.I. [Granat Special Design Bureau, Moscow (Russian Federation)] [and others] [Granat Special Design Bureau, Moscow (Russian Federation); and others

1994-11-01

470

Optically pumped carbon dioxide laser mixtures. [using solar radiation  

NASA Technical Reports Server (NTRS)

This work explores the concept of blackbody radiation pumping of CO2 gas as a step toward utilization of solar radiation as a pumping source for laser action. To demonstrate this concept, an experiment was performed in which laser gas mixtures were exposed to 1500 K thermal radiation for brief periods of time. A gain of 2.8 x 10 to the -3rd reciprocal centimeters has been measured at 10.6 microns in a CO2-He gas mixture of 1 Torr pressure. A simple analytical model is used to describe the rate of change of energy of the vibrational modes of CO2 and to predict the gain. Agreement between the prediction and experiment is good.

Yesil, O.; Christiansen, W. H.

1979-01-01

471

Kinetics of an optically pumped metastable Ar laser  

NASA Astrophysics Data System (ADS)

In recent studies, an optically pumped Ar*/He laser has been demonstrated using the Ar 4p[1/2]1?4s[3/2]2 transition at 912.55 nm. Time-resolved data for this system, recorded using CW laser excitation and pulsed discharge production of Ar* 4p[3/2]2, yielded laser output pulses that were of unexpectedly short duration. It was speculated that radiative relaxation from the upper laser level to the 4s[3/2]1 state (607 cm-1 above 4s[3/2]2) caused termination of the laser pulse. In the present study this hypothesis has been tested by observing the energy transfer kinetics of the 4s[3/2]2 and 4s[3/2]1 states in Ar/He gas mixtures. Following pulsed laser excitation out of 4s[3/2]2, population recovery was observed on a ?s time scale. Energy transfer from 4s[3/2]1 to 4s[3/2]2, induced by collisions with He, was characterized. The rate constant was found to be (1.0±0.5)x10-13 cm3 s-1. These observations confirmed that radiative transfer to 4s[3/2]1 was responsible for the short duration laser pulses. Modeling of a fully CW optically pumped Ar* laser shows that radiative transfer to 4s[3/2]1 reduces the number density of the Ar* atoms involved in lasing, but is otherwise benign.

Han, Jiande; Heaven, Michael C.; Hager, Gordon D.; Venus, George B.; Glebov, Leonid B.

2014-03-01

472

A portable lidar using a diode-pumped YAG laser  

NASA Technical Reports Server (NTRS)

A Mie lidar system is technically established and is used for monitoring air pollution, stratospheric and boundary layer aerosol distribution, plume dispersion, visibility, and the study of atmospheric structure and cloud physics. However, a lidar system is not widely used because of its cumbersome handling and unwieldy portability. Although the author developed a laser diode lidar system based on RM-CW technique, it has a limit of measurement distance. Here we report the development of an all solid Mie lidar system using a diode-pumped Nd:YAG laser and a Si-APD detector. This was constructed as a prototype of a handy lidar system.

Takeuchi, N.; Okumura, H.; Sugita, T.; Matsumoto, H.; Yamaguchi, S.

1992-01-01

473

Q-cw array LD-pumped Nd:YAG laser  

Microsoft Academic Search

A high power Q-CW array LD pumped Nd:YAG laser was successfully developed by building the model that Q-CW array LD pumped Nd:YAG laser. Using laser rate equation, the geometry formed by the pumping beam meeting laser beam in the resonant cavity was calculated out. In the experiment, two Q-CW array LDs were used. The average output power is 60w and

Guobin Ning; Zhu Ling; Guicai Song; Guangyong Jin; Xiaoyuan Yan; Zhong Ren

2002-01-01

474

Experimental study of a high-power CW side-pumped Nd:YAG laser  

Microsoft Academic Search

The paper reports on the characterization of a side-pumped 40W CW Nd:YAG laser. A side-pumping configuration with six laser diodes is used for the laser. We show the comparison between the calculated and measured pump energy distributions in the laser crystal. The birefringence and the thermal lens effect of the Nd:YAG crystal have been experimentally investigated, and their influence on

D. L Yu; D. Y Tang

2003-01-01

475

Scaling CW diode-end-pumped Nd:YAG lasers to high average powers  

Microsoft Academic Search

The authors analyze the scaling limits of diode-end-pumped Nd:YAG lasers imposed by pumping geometry, thermal distortion, birefringence, and fracture. A scalable 15-W output power diode-end-pumped laser which achieves a 60% slope efficiency is demonstrated. Thermal distortion in this laser is reduced from 2.6 waves to less than 0.15 waves with an aspheric laser rod. Depolarization is reduced by 40 times

Steve C. Tidwell; Jonathan F. Seamans; Mark S. Bowers; Ananda K. Cousins

1992-01-01

476

Histologic comparison of the pulsed dye laser and copper vapor laser effects on pig skin  

SciTech Connect

Albino pig skin was exposed to the copper vapor (CVL) and flash-lamp pulsed dye (PDL) lasers at 578 nm with a 3 mm diameter spotsize over a range of fluences until purpura and whitening were first established. The total irradiation time was the parameter that was varied in order for the CVL to reach the desired fluence. The lowest fluence producing each clinical endpoint was designated the threshold fluence: 34 J/cm{sup 2} was required to produce purpura using the CVL compared to 7.5 J/cm{sup 2} with the PDL laser. Histologically, skin exposed to purpura fluences from the CVL revealed the presence of constricted, disrupted papillary dermal blood vessels with trapped RBC's within them which were unlike those exposed to PDL where the irradiated vessels were dilated and packed with masses of intravascular agglutinated RBC's. The whitening threshold fluences for the CVL and PDL lasers were 67 J/cm{sup 2} and 29 J/cm{sup 2}, respectively. Streaming of epidermal cells and dermal collagen denaturation were observed in CVL irradiated skin, compared to occasional dyskeratotic epidermal cells and focal dermal collagen denaturation following PDL exposure. The mechanisms responsible for the clinical and histologic changes produced by the two laser systems are discussed.

Tan, O.T.; Stafford, T.J.; Murray, S.; Kurban, A.K. (Boston Univ. Medical Center, MA (USA))

1990-01-01

477

Dual-Wavelength Internal-Optically-Pumped Semiconductor Laser Diodes  

NASA Astrophysics Data System (ADS)

Dual-wavelength laser sources have various existing and potential applications in wavelength division multiplexing, differential techniques in spectroscopy for chemical sensing, multiple-wavelength interferometry, terahertz-wave generation, microelectromechanical systems, and microfluidic lab-on-chip systems. In the drive for ever smaller and increasingly mobile electronic devices, dual-wavelength coherent light output from a single semiconductor laser diode would enable further advances and deployment of these technologies. The output of conventional laser diodes is however limited to a single wavelength band with a few subsequent lasing modes depending on the device design. This thesis investigates a novel semiconductor laser device design with a single cavity waveguide capable of dual-wavelength laser output with large spectral separation. The novel dual-wavelength semiconductor laser diode uses two shorter- and longer-wavelength active regions that have separate electron and hole quasi-Fermi energy levels and carrier distributions. The shorter-wavelength active region is based on electrical injection as in conventional laser diodes, and the longer-wavelength active region is then pumped optically by the internal optical field of the shorter-wavelength laser mode, resulting in stable dual-wavelength laser emission at two different wavelengths quite far apart. Different designs of the device are studied using a theoretical model developed in this work to describe the internal optical pumping scheme. The carrier transport and separation of the quasi-Fermi distributions are then modeled using a software package that solves Poisson's equation and the continuity equations to simulate semiconductor devices. Three different designs are grown using molecular beam epitaxy, and broad-area-contact laser diodes are processed using conventional methods. The modeling and experimental results of the first generation design indicate that the optical confinement factor of the longer-wavelength active region is a critical element in realizing dual-wavelength laser output. The modeling predicts lower laser thresholds for the second and third generation designs; however, the experimental results of the second and third generation devices confirm challenges related to the epitaxial growth of the structures in eventually demonstrating dual-wavelength laser output.

Green, Benjamin

478

Spatially tunable laser emission in dye-doped photonic liquid crystals Yuhua Huang, Ying Zhou, and Shin-Tson Wua  

E-print Network

Spatially tunable laser emission in dye-doped photonic liquid crystals Yuhua Huang, Ying Zhou laser emission of the dye-doped cholesteric liquid crystal CLC cell using a one-dimensional temperature wavelength by external factors including electric, magnetic, acoustic fields, temperature, and light

Wu, Shin-Tson

479

Thin-Film Evaporative Cooling for Side-Pumped Laser  

NASA Technical Reports Server (NTRS)

A system and method are provided for cooling a crystal rod of a side-pumped laser. A transparent housing receives the crystal rod therethrough so that an annular gap is defined between the housing and the radial surface of the crystal rod. A fluid coolant is injected into the annular gap such the annular gap is partially filled with the fluid coolant while the radial surface of the crystal rod is wetted as a thin film all along the axial length thereof.

Stewart, Brian K. (Inventor)

2010-01-01

480

Highly efficient neodymium:yttrium aluminum garnet laser end pumped by a semiconductor laser array  

NASA Technical Reports Server (NTRS)

In recent experiments, 80-mW CW power in a single mode has been achieved from a neodymium:yttrium aluminum garnet (Nd:YAG) laser with only 1 W of electrical power input to a single semiconductor laser array pump. This corresponds to an overall efficiency of 8 percent, the highest reported CW efficiency for a Nd:YAG laser. A tightly focused semiconductor laser end pump configuration is used to achieve high pumping intensities (on the order of 1 kW/sq cm), which in turn causes the photon to photon conversion efficiency to approach the quantum efficiency (76 percent for Nd:YAG at 1.06 microns pumped at 0.810 micron). This is achieved despite the dual-lobed nature of the pump. Through the use of simple beam-combining schemes (e.g., polarization coupling and multireflection point pumping), output powers over 1 W and overall electrical to optical efficiencies as high as 10 percent are expected.

Sipes, D. L.

1985-01-01

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