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1

A cascade pumped picosecond dye laser system  

Microsoft Academic Search

A picosecond dye laser system producing 4 ..mu..J in a 10 ps pulse is described. This highly stable compact system consists of a nitrogen laser and two cascade pumped dye laser oscillators followed by one amplifier. The Roess-Lin cavity transient technique was applied to compress the input 60 ..mu..J 300 ps Nâ pulse twice to produce a final output duration

P. H. Chiu; Shaochung Hsu; S. Box; Hoi-Sing Kwok

1984-01-01

2

Energy transfer in flashlamp pumped organic dye lasers  

Microsoft Academic Search

The pumping characteristics of dye lasers using multiple dyes are discussed. It turns out that varying the dye concentration may change considerably the portion of the pump light spectrum which is effective in creating population inversion. Thus the effect of an energy transfer dye depends strongly on the concentration of the lasing dye. Multiple dye systems are shown to have

P. Burlamacchi; D. Cutter

1977-01-01

3

Flashlamp-Pumped, Organic Dye Lasers.  

National Technical Information Service (NTIS)

The report describes an experimental program directed at investigating the potential of visible, organic dye lasers. The dye Rhodamine 6G was chosen for the most intense study, and solutions to a mathematical model of a dye laser were compared to the expe...

B. G. Huth M. R. Kagan G. I. Farmer

1970-01-01

4

Atomic Fluorescence Using a Tunable Flashlamp Pumped Dye Laser.  

National Technical Information Service (NTIS)

Determination of analytical calibration curves for the atomic fluorescence of sodium vapor is described. A tunable flashlamp pumped Rhodamine 6G dye laser was used as the excitation source. The sample cell consisted of an evacuated quartz tube containing ...

H. L. Brod

1975-01-01

5

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

SciTech Connect

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

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

1990-01-01

6

High average power excimer laser-pumped dye oscillators  

SciTech Connect

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

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

1988-01-01

7

10 kHz repetition rate solid-state dye laser pumped by diode-pumped solid-state laser  

Microsoft Academic Search

We describe the operation of an all solid-state pulsed dye laser of high repetition rate (10 kHz) pumped by a diode-pumped laser. Three different active media in the form of coin-sized disks were investigated: the dye rhodamine 6G doped in a copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) [Rh6G\\/P(MMA:HEMA)], and the dye pyrromethene 567 (PM567) doped in copolymers

K. M. Abedin; M. Álvarez; A. Costela; I. Garc??a-Moreno; O. Garc??a; R. Sastre; D. W. Coutts; C. E. Webb

2003-01-01

8

Wavelength shifts of a suspended-single-droplet dye laser by successive laser pumping  

SciTech Connect

Gradual shifts toward shorter wavelengths (blue shifts) in a suspended-single-droplet dye laser by successive laser pumping are reported. These shifts seem to be due partly to scattering objects produced by the successive pumping. Blue shifts in dye lasing from artificially seeded droplets are also examined and compared with those in the successive pumping. Results of the spectral shifts are discussed through a cavity {ital Q}-value variation.

Taniguchi, H. [Department of Electrical and Electronic Engineering, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020 (Japan); Tomisawa, H. [Department of Electrical Engineering, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020 (Japan)

1994-11-15

9

Flashtube-pumped dye laser with multiple-prism tuning.  

PubMed

A four-prism tuning system has been built and tested in a flashtube-pumped rhodamine 6G dye-solution laser. Equations for calculating reflection losses and prism dimensions are given, and performance characteristics of the tuned laser are presented. The half-power points of the tuning range were 571 nm and 615 nm, and the output bandwidth at peak power was 0.17 nm at half-maximum. The energy output at 595 nm was 0.14 J. PMID:20111117

Strome, F C; Webb, J P

1971-06-01

10

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

11

Integration of Optical Pumped Dye Laser on Organic Microflowcytometry Chip  

Microsoft Academic Search

Integration techniques of tunable film dye laser on a plastic optical application chip were studied. The developed film dye lasers were waveguided distributed feedback (DFB) lasers, and they can cover the wavelength from 400 to 1100 nm. We fabricated microflowcytometry chip integrated with DFB film lasers as a first example. Partly film-coating technique and film lithography fabrication with an excimer laser

Yuji Oki; Yukinori Ogawa; Kenichi Yamashita; Masaya Miyazaki; Mitsuo Maeda

2007-01-01

12

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

13

Tunable subnanosecond pulses from short cavity dye laser systems pumped with a nitrogen-TEA laser  

SciTech Connect

The performance of a laser system consisting of piezoelectrically tunable short cavity dye lasers pumped with a nitrogen-TEA laser is presented. The design and construction details of the nitrogen laser are given, and its pulse energy and pulse duration under various operating conditions are presented. Typically, UV pulses (337 nm) from the N/sub 2/ laser had energies of 80 ..mu..J and durations of 600 ps. The shortest dye laser pulses measured were about 90 ps at 600 nm.

Scott, G.W.; Shen, S.G.; Cox, A.J.

1984-03-01

14

ARTICLES: Flashlamp-pumped lasers with aqueous micellar dye solutions  

NASA Astrophysics Data System (ADS)

A study was made of the parameters of the output radiation of lasers in which aqueous micellar solutions of dyes were excited by flashlamp pumping. The efficiency and photostability of such solutions were considerably poorer than alcohol solutions. It was found that the addition of cyclooctatetraene (COT) to aqueous micellar solutions of dyes was accompanied by a strong increase in the output radiation energy. Aqueous micellar solutions of rhodamines containing COT were characterized by a high photostability when excited with light of ? > 450 nm and the output energy was much higher than that obtained from alcohol solutions. It was found that the relative efficiency of lasing of aqueous micellar solutions of dyes with COT (compared with alcohol solutions) increased on increase in the resonator length and on increase in the pulse duration. The divergence of the radiation emitted from a laser utilizing aqueous micellar solutions was an order of magnitude less than in the case of alcohol solutions. The positive effect of the COT additive was demonstrated for a number of phosphors of different classes emitting in the spectral range 500-650 nm.

Levin, M. B.; Todres, Z. V.; Cherkasov, A. S.

1986-07-01

15

Effect of oxygen on flashlamp-pumped organic-dye lasers  

Microsoft Academic Search

Dissolved oxygen was found to dramatically influence the intensity of flashlamp-pumped organic-dye lasers. The relative energy per laser pulse was measured for nine new and 19 previously reported dye solutions in equilibrium with partial pressures of oxygen ranging from 0 to 1 atmosphere.

J. Marling; D. Gregg; S. Thomas

1970-01-01

16

Pulse shortening in dye laser side-pumped by TEA N/sub 2/ laser  

SciTech Connect

The temporal behavior of the output from a homemade TEA-N/sub 2/-laser (750 ps pulsewidth) pumped dye (R6G) laser was observed with the aid of a streak camera. The observed output pulsewidths are between 60 and 160 ps depending on the configuration of the dye laser cavity. The shortest (60 ps) pulse is obtained when the distances between output mirror and dye cell, and dye cell and grating, are 10 and 105 mm, respectively. The mechanism of the short pulse generation is clarified by comparing experimental results with the results obtained by solving rate equations numerically, where the position dependences of excited-state population and photon flux were taken into account.

Uchiki, H.; Kobayashi, T.; Yoshizawa, M.

1983-04-01

17

LASERS: Evolution of the beam divergence and other output characteristics of lamp-pumped dye lasers  

Microsoft Academic Search

The beam divergence and other output characteristics of dye lasers pumped by coaxial flashlamps have been studied experimentally. The divergence of the output beam is governed primarily by the simultaneous existence of, and competition between, refractive ray paths and closed paths. The refractive paths result from thermal distortions of the active medium. The closed paths exist in the cavity because

I. G. Naumenko; V. P. Pelipenko; M. I. Dzyubenko; V. V. Shevchenko

1993-01-01

18

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

NASA Astrophysics Data System (ADS)

We present a diode-pumped microcavity dye laser composed of a top organic reflector and a bottom inorganic reflector. The top organic reflector consists of alternate thin films of cellulose acetate and poly(N-vinylcarbazole) doped with coumarin 540A to construct a distributed-feedback (DFB) resonator. Pumped directly by an InGaN-based blue laser diode (LD) with a pulse duration of 4 ns, the microcavity dye laser exhibited a single-mode oscillation at 563 nm with a threshold pump LD power of 290 mW/pulse. The emission of the microcavity dye laser was measured through an optical fiber, resulting in a peak power of 2.5 mW for a pump LD power of 320 mW.

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

2008-08-01

19

Flashlamp Pumped Dye Laser Amplifier for Na Laser Guide Star.  

National Technical Information Service (NTIS)

Analysis identified the laser requirements for sodium guide star production to be a near diffraction, limited, 50 microsec, 100 mJ/pulse, less than 600 MHz bandwidth, 100 pulses/second laser tuned to one of the sodium D lines. A master oscillator/power am...

J. C. Hsia

1990-01-01

20

Unprecedented solid-state laser action from BODIPY dyes under UV-pumping radiation  

Microsoft Academic Search

Highly efficient and stable laser emission is demonstrated under drastic UV pumping conditions from recently synthesized BODIPY dye incorporated into polymer host. Under transversal pumping at 355 nm, lasing efficiencies of up to 29%, similar to those obtained in liquid phase, were obtained, with useful lifetimes (drop of the emission by 50%) of 70,000 pulses at 5 Hz repetition rate.

M. E. Pérez-Ojeda; V. Martín; A. Costela; I. García-Moreno; I. J. Arroyo Córdoba; E. Peña-Cabrera

2011-01-01

21

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

22

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

NASA Astrophysics Data System (ADS)

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

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

1992-08-01

23

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

24

Unprecedented solid-state laser action from BODIPY dyes under UV-pumping radiation  

NASA Astrophysics Data System (ADS)

Highly efficient and stable laser emission is demonstrated under drastic UV pumping conditions from recently synthesized BODIPY dye incorporated into polymer host. Under transversal pumping at 355 nm, lasing efficiencies of up to 29%, similar to those obtained in liquid phase, were obtained, with useful lifetimes (drop of the emission by 50%) of 70,000 pulses at 5 Hz repetition rate. The obtained efficiency and photostability are much higher than those obtained with usual commercial dyes emitting in the same spectral region, such as Coumarin 540A, under the same experimental conditions.

Pérez-Ojeda, M. E.; Martín, V.; Costela, A.; García-Moreno, I.; Arroyo Córdoba, I. J.; Peña-Cabrera, E.

2012-03-01

25

Modification of a krypton ion pumped dye laser for selected multimode operation.  

PubMed

We describe a method for tailoring the output spectrum of a cw krypton-ion-pumped dye laser to suit a particular multimode application. The method uses both theoretical calculations and simple experimental measurements to allow component selection for the required spectra. While a specific laser system is discussed, the method is generally applicable to other systems. Results of the described modifications are given. PMID:20556180

Connally, W J; Morton, R G

1990-02-20

26

Efficient high-energy SHG using a triaxial flashlamp-pumped dye laser  

Microsoft Academic Search

A triaxial flashlamp-pumped dye laser is described. It has sufficiently good beam quality to allow efficient high-energy SHG. This laser consists of a tunable oscillator and a single amplifier that operator in the vicinity of 610 nm. The harmonic generator is an angle-tuned KDP crystal that utilizes cylindrical focusing optics. Typical energy output at 305 nm is 100 mJ at

Richard M. Schotland

1980-01-01

27

Transform-limited picosecond pulse generation in a synchronous mode-locked dye laser pumped by doubled Nd:YAG  

Microsoft Academic Search

Synchronous mode locking of a dye laser longitudinally pumped by the second-harmonic pulse train from a passively mode-locked, repetitively pulsed Nd:YAG laser has been studied. The dye laser, incorporating Fabry-Perot tuning elements, has produced intense TEM00 pulses as short as 12 psec in duration with a transform-limited bandwidth of 2 cm?1. The mode-locked dye pulses are time synchronizable with the

L. S. Goldberg; C. A. Moore

1975-01-01

28

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

29

Relation between photon statistics and pumping fluctuations in a dye laser  

SciTech Connect

Measurements of the photon-number fluctuations in a single-mode dye jet laser are compared with solutions of the equations of motion with colored pumping and white spontaneous-emission noise. A search of parameter space for best agreement between theory and experiment shows that the experimental results cannot be well modeled by a theory with white pumping noise, although the correlation time is small, but can be modeled with colored noise. This emphasizes the importance of not treating the pumping fluctuations as delta correlated even for time-independent quantities.

Kim, T.S.; Gage, E.C.; Mandel, L.

1988-08-01

30

Comparison of Ti:sapphire laser and excimer-laser-pumped dye laser for PDT with Zn(II)-phthalocyanine  

NASA Astrophysics Data System (ADS)

We compared the photodynamic efficiency of pulsed to cw laser irradiation in a cell culture experiment with a NIH ovarian cancer cell line (NIH-OVCAR3). Our photosensitizer was a cationic Zn(II)-phthalocyanine with an absorption maximum near 675 nm. The laser systems we use are an excimer laser pumped DCM-dye laser ((tau) equals 15 ns) and a cw Ti:sapphire laser. The photodynamic activity of the photosensitizer strongly depends on the pulse fluence and decreases with increasing fluence due to saturation of the sensitizer. In another experiment no changes in the light penetration depth into the tissue for pulsed irradiation could be detected up to a pulse intensity of 3 MW/cm2.

Abraham, Volkhard; Spaniol, Stefan B.; Schultes, Birgit C.; Schmidt, Stephan; Ertmer, Wolfgang

1994-07-01

31

Construction and Characterization of a Nanosecond Nd:YAG Laser Pumped Distributed Feedback Dye Laser Generating Picosecond Pulses  

NASA Astrophysics Data System (ADS)

We have constructed a Distributed Feedback Dye Laser (DFDL) using interferometric pumping. DFDL works according to the dynamic modulation of the gain medium creating short pulses. Shortening of the pulses, stability, and dynamic range of the DFDL were investigated. Pulses were measured with the help of a photodiode with a 30 picosecond response time. Traces were recorded with a Tektronics DSA73304D (33GHz) digital serial analyser. The gain medium contains an ethanol solution of Rhodamine 590 dye and DODCI saturable absorber. Increasing the concentration of DODCI saturable absorber resulted in significant pulse shortening (150 to 54 picoseconds). Single pulse generation was achieved when the power of the pump laser was adjusted 10 percent above the laser threshold. The central wavelength of the laser pulses was 587 nm. The mathematical modeling, optical layout of the DFDL, and the results of the temporal and spectral characterization of the laser are presented on the poster. The development of the DFDL will lead to an extensive investigation of short pulse dye lasers for educational purposes and for applications in nonlinear spectroscopy.

Clark, Timothy; Weckerly, Chris; Ujj, Laszlo

2013-03-01

32

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

33

Near-infrared picosecond pulse generation in a cw mode-locked dye laser pumped directly by an argon ion laser  

SciTech Connect

We describe the efficient generation of wavelength-tunable picosecond pulses in the deep red and near-infrared spectral regions (approx.6000--8000 A) in a synchronously mode-locked cw dye laser that is pumped directly by 5145-A radiation from an argon ion laser. Operation of the dye laser in the near infrared was achieved with the use of an excitation transfer mixture of commercial laser dyes. With 1 W of average pump power, an average output power of 70 mW was obtained at the peak of the tuning curve.

Jain, R.K.

1982-02-15

34

Infrared Dye Laser Study.  

National Technical Information Service (NTIS)

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

1973-01-01

35

Laser dye technology  

SciTech Connect

The author has worked with laser dyes for a number of years. A first interest was in the Navy blue-green program where a flashlamp pumped dye laser was used as an underwater communication and detection device. It made use of the optical window of sea-water--blue for deep ocean, green for coastal water. A major activity however has been with the Atomic Vapor Laser Isotope Separation Program (AVLIS) at the Lawrence Livermore National Laboratory. The aim here has been enriching isotopes for the nuclear fuel cycle. The tunability of the dye laser is utilized to selectively excite one isotope in uranium vapor, and this isotope is collected electrostatically as shown in Figure 1. The interests in the AVLIS program have been in the near ultra-violet, violet, red and deep-red.

Hammond, P R

1999-09-01

36

High power cw dye lasers  

Microsoft Academic Search

The dependance of the output power of cw dye lasers on the pump power and the system-and stream parameters is calculated and\\u000a experimentally tested. It was found that the pump power for a given system is limited to a critical value due to the influence\\u000a of thermal inhomogeneities. This critical pump power is predominantly dependant on the dye solvent, the

B. Wellegehausen; L. Laepple; H. Welling

1975-01-01

37

Passive stabilization of a synchronously pumped mode-locked dye laser with the use of a modified outcoupling mirror.  

PubMed

Recently a new passive stabilization technique for synchronously pumped dye lasers was reported that allows one to generate nearly transform-limited pulses. The idea of this technique is to split off an extremely small fraction of the laser pulse and to superimpose it back on itself slightly advanced in time. In these experiments the seeding pulse was provided by an external cavity, which led to an undesirable frequency hopping. Here we present a simple modification of an outcoupling mirror that integrates the generation of the seeding pulse into the main laser cavity. In this way frequency-stable, nearly transform-limited pulses are generated. PMID:19773948

Peter, D S; Beaud, P; Hodel, W; Weber, H P

1991-03-15

38

Determination of pulse shape asymmetry in a CW synchronously pumped dye laser using the method of spectrum-resolved SHG correlation  

SciTech Connect

We have determined the pulse shape asymmetry in a synchronously pumped dye laser using the method of spectrum-resolved SHG correlation. In this paper, we first present the basic principle of spectrum-resolved SHG correlation, and then analyze the possibility of determining the pulse shape asymmetry in a CW synchronously pumped dye laser by this method. The experimental results were found to be in good agreement with the results of our analysis.

Bao Xiaoyi; Guan Xinan; Lu Fuyun; Yuan Shuzhong

1987-01-01

39

Dye system for dye laser applications  

SciTech Connect

This patent describes 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, P.R.

1991-05-21

40

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

41

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

42

Solid state dye laser  

NASA Astrophysics Data System (ADS)

Polymer filled porous glass impregnates with dye molecules is used as an active medium. The most important feature of this medium is that its thermo-optical and mechanical parameters are determined by a matrix of silica which thermo-optical constants are better by two orders of magnitude then those of polymers. The investigation of generation characteristics of solid state dye laser on basis of Rhodamine 6G has shown the feasibility of its application in pulse coherent pumping laser systems. The generation thresholds are practically the same for solid state and ethanol solution. The yield of conversion of pumping energy into generation energy for solid state active element is up to 50%. The advantages of solid state active element based on polymer filled porous glass matrix realize at high temperature operation mode, for instance at frequency mode. The step refraction index temperature dependence for polymers results in increase of optical with increase of pumping energy. In the reported medium this effect does not occur nonuniformity up to pumping energy values exceeding the generation threshold by 40-50 times. Polymer based active media are destructed at the exposition of 50 ns pulses with energy of 1 J/cm2 while porous glass + polymer + Rhodamine 6G composition is not destructed at the exposition of energy up to 7-10 J/cm2. The introduced solid state dye laser is intended to be used in on-board systems, including vacuum under low temperature, where the application of flow systems operation is problematic. It should be emphasized, that using the synthesized compositions, the generation mode with microsecond pulse pumping becomes available. It opens the possibility for application of flashlamp for pumping.

Meshkovskii, Igor K.; Zemskii, Vladimir I.; Kolesnikov, Yuri L.

1995-04-01

43

Dye lasers. Citations from the NTIS data base  

NASA Astrophysics Data System (ADS)

Studies on dye laser theory, design, components, optical systems, and frequency range are presented in approximately 96 citations. Abstracts on lasing dyes, pumping, tuning, excitation, molecular structure, and modulation are included. Studies on dye laser use in spectroscopy are covered.

Cavagnaro, D. M.

1980-08-01

44

Optofluidic dye lasers  

Microsoft Academic Search

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

Zhenyu Li; Demetri Psaltis

2008-01-01

45

Synchronous pumping of a visible dye laser by a frequency doubled mode-locked Ti:sapphire laser and its application for difference frequency generation in the near infrared  

Microsoft Academic Search

The output of a dye laser that is synchronously pumped by the second harmonic of a self mode-locked femtosecond Ti:sapphire laser is mixed in a BBO crystal with the fundamental of the pump laser to achieve femtosecond pulses tunable between 1230 nm and 1760 nm at ~ 80 MHz repetition rate.

F. Seifert; V. Petrov

1993-01-01

46

Infrared Dye Laser Study.  

National Technical Information Service (NTIS)

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

B. E. Plourde J. P. Webb

1973-01-01

47

High Efficiency Flashlamps for Pulsed Dye Lasers  

Microsoft Academic Search

This paper discusses the possibilities of pulsed high pressure mercury capillary lamps as efficient pumping sources for dye lasers. Spectral measurements show that a spectral efficiency as high as 24 per cent may be reached for a typical blue lasing dye. Laser action has been obtained with Rhodamine 6G with a repetition rate of up to 100 p.p.s., and an

P. dal Pozzo; R. Polloni; F. Zaraga

1976-01-01

48

Anomalous bistable behavior of a dye laser  

SciTech Connect

We report the observation of bistability and hysteresis in a dye laser at low excitation when the pump power is varied slowly in the neighborhood of the oscillation threshold. We also find that the laser exhibits an unusual memory effect lasting several minutes if the pump beam is blocked and unblocked, in that the laser then returns to the original on or off branch of the hysteresis cycle. By contrast the laser remains off if the dye-laser beam is blocked briefly and then unblocked. A possible explanation in terms of thermally induced desorption of moisture upon a multilayer mirror is discussed.

Gage, E. C.; Cheng, F.; Mandel, L.

1989-07-01

49

Ultrafast distributed feedback dye lasers  

NASA Astrophysics Data System (ADS)

A distributed feedback dye laser (DFDL) was experimentally studied to determine the utmost lower limit on ultrafast pulse generation. The ultimate aim was to determine its suitability as a cheaper high peak power laser source. The dye cell was excited by the second harmonic of a laboratory built cavity dumped passively q switched and modelocked Nd:YAG Laser to induce temperature phase grating in dye solution. Different features studied include threshold conditions, pulse shortening, by reducing cavity length, polymerization limitations, simultaneous induction of multiple superimposed gratings, line narrowing, polarization, temporal and spectral characteristics. The pump polarization affect on dynamic gratings and threshold conditions indicated the number of lasing lines (maximum nine) or intensity of a single line depends upon the state of pump polarization (SOP). Various types of tuning methods such as Bragg index, refractive index, half angle and state of pump polarization were tested for improved divergence, bandwidth, line-width and wider spectral ranges. The combined effect of coherence length and SOP of excitation laser on emission of multiple lines was studied without using external gratings. The results of this critical and contemporary work on DFDL is in agreement with most of the published results and opens a new era for their potential suitability in optical communication, sensing and photonic devices.

Khan, Nasrullah

2000-04-01

50

cw dye laser synchronously pumped by the third harmonic of a modelocked cw Nd:YLF laser for tunable blue and green excitation and picosecond time-correlated photon counting detection  

Microsoft Academic Search

The range of excitation wavelengths for a setup of time-resolved detection of fluorescence was extended with tunable blue by the synchronous pumping of a Stilbene 3 dye laser. A conversion efficiency of over 30% was found when pumping a coherent radiation (CR) model CR590 with extended cavity length using the third harmonic output of a cw mode-locked Nd:YLF laser (CR

Arie van Hoek; Antonie J. Visser

1992-01-01

51

Optofluidic ring resonator dye lasers  

NASA Astrophysics Data System (ADS)

We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall thickness of a few micrometers. The capillary circular cross-section forms the ring resonator and supports the whispering gallery modes (WGMs) that interact evanescently with the gain medium in the core. The laser cavity structure is versatile to adapt to the gain medium of any refractive index. Owing to the high Q-factor (>109), the lasing threshold of 25 nJ/mm2 is achieved. Besides directly pump the dye molecules, lasing through fluorescence resonance energy transfer (FRET) between the donor and acceptor dye molecules is also studied in COFRR laser. The energy transfer process can be further controlled by designed DNA scaffold labeled with donor/acceptor molecules. The ICOFRR dye laser is based on a cylindrical ring resonator fused onto the inner surface of a thick walled glass capillary. The structure has robust mechanical strength to sustain rapid gain medium circulation. The CpOFRR utilizes a cylindrical ring resonator fused on the inner surface of the COFRR capillary. Since the capillary wall is thin, the individual WGMs of the cylindrical ring resonator and the COFRR couples strongly and forms Vernier effect, which provides a way to generate a single mode dye laser.

Sun, Yuze; Suter, Jonathan D.; Fan, Xudong

2010-02-01

52

Infrared Dye Laser Study.  

National Technical Information Service (NTIS)

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

B. E. Plourde J. P. Webb

1972-01-01

53

Properties of two-photon absorption-induced cavity lasing of an organic dye HEASPI pumped by picosecond infrared laser beam  

Microsoft Academic Search

The first operation of cavity lasing of a two-photon absorption (TPA) organic dye, trans-4-[p-(N-ethyl-N-hydroxyethylamino) styryl]-N-methylpyridinium iodide (HEASPI), by using picosecond infrared laser as pump source is reported in this paper. Temporal profile of cavity lasing shows obvious oscillations, and magnification of the feedback light can be obtained. By using the difference of re-absorption coefficient at different conditions, we explained the

Guangyong Zhou; Dong Wang; Xiaomei Wang; Xinguang Xu; Xiufeng Cheng; Zongshu Shao; Xian Zhao; Q. Fang; Minhua Jiang

2001-01-01

54

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

55

Optofluidic circular grating distributed feedback dye laser  

NASA Astrophysics Data System (ADS)

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

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

2009-07-01

56

Comparative gain measurements for twelve organic laser dye solutions  

Microsoft Academic Search

Gain versus frequency is measured for twelve organic laser dye solutions in identical transversely pumped configurations.\\u000a Results show lasing performance and give relative values of dye parameters.

A. Dienes

1975-01-01

57

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

58

Dye film leaky waveguide laser  

NASA Astrophysics Data System (ADS)

Based on a dye-doped polymer film with a refractive index less than that of the glass substrate, a leaky waveguide laser device has been investigated. The film is made from a polyurethane based commercial epoxy which is doped with a newly synthesized dye material: trans-4-[P-(N-ethyl-N-hydroxylethylamino) styryl]-N-methylpyridinium tetraphenylborate. The key element of the laser device is a flint-glass made equilateral prism on one surface of which the dye doped film forms a leaky waveguide structure. By combining this prism with a lateral linear pump source and two cavity mirrors, the quasiwaveguide lasing can be obtained. The absorption and fluorescence spectra of the new dye doped film, and the spatial, spectral and temporal behavior of the lasing output from the device are presented. Under pump conditions of 532 nm wavelength, 10 ns pulsewidth and 5 Hz repetition rate, this device provides the peak lasing wavelength at ~ 590nm, a lasing efficiency of ~ 12%, and a lasing lifetime >= 3 X 104 pulses.

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

1994-09-01

59

Chaos in a good-cavity single-mode dye laser due to turbulent dye flow  

SciTech Connect

Experimental results are presented that demonstrate that the light intensity of a good-cavity single-mode standing-wave dye laser can exhibit chaotic behavior. The governing attractor is of dimensionality 6.5 and entropy 50 kbits/sec. An examination of the pump-laser beam before and after its interaction with the dye indicates that the chaos is probably due to the turbulent flow of dye within the dye cell. This interpretation is confirmed by the absence of chaos in two similar dye lasers that use a dye jet rather than a dye cell.

Chyba, T.H.; Gage, E.C.; Ghosh, R.; Lett, P.; Mandel, L.; McMackin, I.

1987-06-01

60

Dye lasers. Citations from the NTIS data base  

NASA Astrophysics Data System (ADS)

This bibliography covers studies on dye laser theory, design, components, optical systems, and frequency range. Abstracts on lasing dyes, pumping, tuning, excitation, molecular structure, and modulation are included. Studies on dye laser use in spectroscopy are covered. This updated bibliography contains 217 citations, none of which are new entries to the previous edition.

Cavagnaro, D. M.

1980-08-01

61

Fanshaped superradiance of a dye laser  

SciTech Connect

The experimental apparatus used to achieve fan shaped superradiance of a dye laser by using second harmonics from a giant pulsed YAP:Nd(3+) laser oscillator-amplifier to pump Rhodamine 6G is described. The laser device employs a single 45 deg LiNbO3 electro-optical Q-switched yttrium aluminate laser as the oscillation stage, and after one stage of oscillation of yttrium aluminate laser amplification, it puts out a laser peak power of approximately 30 MW, with a repetition rate of once per second using LiLO3 (I type phase matching, theta m approximately 30 deg) outer cavity frequency doubling, it puts out 0.539 micrometer frequency doubled light, with a peak power of 1.8 MW and then uses the 0.539 micrometer frequency doubled light to pump Rhodamine 6G laser dye. The emission obtained assumes a fan shape which is planar.

Wang, X.; Peng, G.

1982-09-01

62

Dye-laser development for plasma magnetic-field diagnostic  

SciTech Connect

A flash-lamp-pumped dye laser has been constructed and operated in DCM dye, yielding outputs greater than 400 W for 100 ..mu..s in broadband operation. Attempts to tune this laser by injection locking to a narrow-band cw laser poor efficiency and relatively short locked operation.

Weber, P.G.

1982-05-01

63

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

64

Beam Quality of Pulsed Organic Dye Lasers.  

National Technical Information Service (NTIS)

Various aspects of flashlamp-pumped organic dye laser efficiency and beam quality are investigated. A coaxial Marx-Bank driver circuit and flashlamp system are described. Shock wave induced optical distortion in the active solution was identified as a cau...

T. F. Ewanizky

1973-01-01

65

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

66

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

67

Diode pumped alkali lasers  

Microsoft Academic Search

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

B. V. Zhdanov; R. J. Knize

2011-01-01

68

Rapid photobleaching of organic laser dyes in continuously operated devices  

Microsoft Academic Search

Rapid bleaching of Rhodamine 6G and several other dyes has been observed in capillary-guide liquid lasers longitudinally pumped atlambda = 5145Å. This bleaching appears to be permanent and is shown to present a severe limitation to the operation of nonflowing continuously excited dye lasers. The rate of bleaching has been measured under a variety of conditions and is found to

E. Ippen; C. Shank; A. Dienes

1971-01-01

69

Direct nuclear pumped laser  

DOEpatents

There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

Miley, George H. (Champagne, IL); Wells, William E. (Urbana, IL); DeYoung, Russell J. (Hampton, VA)

1978-01-01

70

Optically pumped alkali lasers  

Microsoft Academic Search

Optically pumped alkali vapor lasers have been developed during last several years. Efficient operation of Cesium, Rubidium and Potassium vapor lasers has been demonstrated. Laser slope efficiencies higher than 80% have been achieved. In this paper we present the latest achievements in this field, discuss the main directions and problems in high power alkali lasers development and possible solutions of

Boris V. Zhdanov; Thomas Ehrenreich; Randall J. Knize

2007-01-01

71

Optically pumped alkali lasers  

NASA Astrophysics Data System (ADS)

Optically pumped alkali vapor lasers have been developed during last several years. Efficient operation of Cesium, Rubidium and Potassium vapor lasers has been demonstrated. Laser slope efficiencies higher than 80% have been achieved. In this paper we present the latest achievements in this field, discuss the main directions and problems in high power alkali lasers development and possible solutions of these problems.

Zhdanov, Boris V.; Ehrenreich, Thomas; Knize, Randall J.

2007-06-01

72

CW operation of laser dyes styryl-9 and styryl-11  

Microsoft Academic Search

Laser dyes Styryl-9 and Styryl-11 exhibit large tuning ranges of 780 to 900 nm respectively 770 to 850 nm with a lasing efficiency as high as 14% respectively 8% when pumped by all lines of the argon-ion laser, placing them among the most efficient and broadly tunable dyes known in the near-infrared wavelengths. Performance of these dyes is investigated for

J. Hoffnagle; L. Ph. Roesch; N. Schlumpf; A. Weis

1982-01-01

73

Diode Pumped Cesium Laser  

Microsoft Academic Search

We have demonstrated a Cs vapor laser with diode laser pumping and have achieved a slope efficiency of 41% and overall optical efficiency better than 32%. A narrowband diode laser operating at 852 nm pumps the 6P3\\/2 state (D2 line) which is then rapidly quenched to the 6P1\\/2 state by an ethane buffer gas. This creates a population inversion between

T. Ehrenreich; B. Zhdanov; T. Takekoshi; S. P. Phipps; R. J. Knize

2005-01-01

74

Microfluidic tunable dye laser with integrated mixer and ring resonator  

NASA Astrophysics Data System (ADS)

We report on results of design and fabrication of a microfluidic dye laser that consists of a ring resonator, a waveguide for laser emission output, and microfluidic elements for flow control, all integrated on a chip. The optical resonator and the waveguide were obtained by photolithography, whereas microfluidic elements such as channels, valves, and pumps were fabricated by multilayer soft lithography. As results, the prototype device worked with a few nanoliters of Rhodamine 6G dye molecules in ethanol solution and showed a laser threshold of ~15 ?J/mm2 when optically pumped with a frequency doubled Nd:YAG laser at 532 nm wavelength. The modification of the laser output intensity due to photobleaching effect was characterized by changing the dye flow velocity through the cavity. In addition, the emission wavelength of the laser could be easily tuned by changing the dye molecule concentration with the integrated microfluidic elements.

Galas, J. C.; Torres, J.; Belotti, M.; Kou, Q.; Chen, Y.

2005-06-01

75

Laser dye toxicity, hazards and recommended controls  

NASA Astrophysics Data System (ADS)

Laser dyes are complex fluorescent organic compounds which, when in solution with organic solvents, form a lasing medium. The wavelength of a dye laser's output beam can vary with different dyes, concentrations, and solvents, giving it a tunable feature capable of emitting ultraviolet, visible, or infrared radiation. Toxicity information on the approximately 100 commercially available laser dyes is very scarce. Limited animal experimentation has been performed with only a few dyes. This paper summarizes what is known about laser dye toxicity, and offers recommendations for controlling dye hazards. The laser dyes investigated were categorized according to their central chemical structures. Prepared laser dye solutions usually contain very small quantities of dye--typical dye concentrations are 10(+2) to 10(+5) molar. For this reason, the solvent in which the dye is dissolved plays an important role when defining potential hazards. Practically all the solvents used are flammable and toxic by inhalation and skin absorption, and therefore must be controlled properly.

Mosovsky, J. A.

76

cw dye laser synchronously pumped by the third harmonic of a modelocked cw Nd:YLF laser for tunable blue and green excitation and picosecond time-correlated photon counting detection  

NASA Astrophysics Data System (ADS)

The range of excitation wavelengths for a setup of time-resolved detection of fluorescence was extended with tunable blue by the synchronous pumping of a Stilbene 3 dye laser. A conversion efficiency of over 30% was found when pumping a coherent radiation (CR) model CR590 with extended cavity length using the third harmonic output of a cw mode-locked Nd:YLF laser (CR Antares). For decreasing the repetition rate of excitation pulses, an electro- optic modulator in a dual pass configuration was used. In this way, pulses with durations of less than 4 ps were generated with energies of up to 2.6 nJ and a repetition rate of 600 kHz, fitting very well with the requirements of the time-correlated photon counting detection technique. The tuning range of Stilbene 3 was from 415 to 465 nm. A further extension of the wavelength range is planned by pumping Coumarin 151 (465 -520 nm) and a mixture of Stilbene 3 and Coumarin 7 (495 - 570 nm) using the same pump laser source.

van Hoek, Arie; Visser, Antonie J.

1992-04-01

77

Diode pumped alkali lasers  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

78

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

79

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

NASA Astrophysics Data System (ADS)

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

Hsu, Jon Shaochung

80

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

81

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

82

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

83

Molecular encapsulation of fluorescent dyes affords efficient narrow-band dye laser operation in water.  

PubMed

A water-based narrow-band high-efficiency dye laser was designed by means of a supramolecular host-guest chemical approach. The lasing characteristics of rhodamine B and sulforhodamine B (Kiton Red S) dyes in aqueous solution with the macrocyclic host cucurbit[7]uril (CB7) as additive were investigated in a narrow-band dye laser setup. Significant improvements in both photostability and thermo-optical properties of the aqueous CB7-complexed dye systems were observed as compared to the uncomplexed dyes in ethanol solution. The tuning curves for the new dye-CB7-water systems were constructed by measuring the laser output at different wavelengths, which showed similar peak efficiencies and red-shifted gains compared to the ethanolic solutions of the dyes, while dye laser operation revealed comparable pump threshold energies and slope efficiencies. The combined results render the dye-CB7-water system an attractive active medium for high-repetition rate dye laser operation. PMID:20839271

Mohanty, Jyotirmayee; Jagtap, Krishna; Ray, Alok K; Nau, Werner M; Pal, Haridas

2010-10-25

84

Chemical Laser Pump.  

National Technical Information Service (NTIS)

The sharply defined bright zone produced by the detonation of a cyanogen-oxygen mixture in small test vehicles looks promising as a pump for solid-state lasers such as neodymium-doped glass and ruby. Brightness temperatures between 6000 to 7000 K are rout...

J. L. Wright

1966-01-01

85

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

86

FY 1980 Report on Dye Laser Materials.  

National Technical Information Service (NTIS)

Ten commercially available rhodamine dyes have been examined for their stability in dye lasers. Except for rhodamine 101 and sulforhodamine 101, the output of the dye laser showed a time dependence in addition to the dependence upon total input energy per...

A. N. Fletcher

1981-01-01

87

Scalable, End-Pumped, Diode-Laser-Pumped Laser.  

National Technical Information Service (NTIS)

A novel technique for scaling end-pumped lasers is demonstrated using three diode-laser arrays to pump a single Nd:YAG laser. Diffraction-limited output with a 58% slope efficiency was obtained. Simple arguments indicate that this method should allow at l...

T. Y. Fan A. Sanchez-Rubio W. E. DeFeo

1989-01-01

88

Precisely tunable, narrow-band pulsed dye laser  

SciTech Connect

A narrow-band, precisely tunable dye laser pumped by an injection-seeded YAG laser is described. The laser achieves an output of 100 mJ/pulse and 40{percent} efficiency when one uses Rhodamine 6G dyes. The output pulse is Gaussian both in time and spatial profile. The laser oscillator employs an intracavity {acute e}talon that is repetitively pressure scanned over one free spectral range while the grating successively steps to consecutive {acute e}talon modes. We pressure scanned the {acute e}talon under computer control using a bellows. Methods are described for calibrating the tuning elements for absolute precision. We demonstrated that the laser has an absolute precision of {plus_minus}0.4 pm over a 1.0-nm scan. This accuracy is achievable over the wavelength range of a dye. {copyright} {ital 1996 Optical Society of America.}

Bhatia, P.S.; Keto, J.W. [Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081 (United States)

1996-07-01

89

Solar Pumped Laser Microthruster  

SciTech Connect

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

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

2010-10-08

90

Investigation of Optimum Laser Pumping.  

National Technical Information Service (NTIS)

An important task of the Optimum Pumping Technology program is the investigation of the feasibility of discharge pumping electronic transition lasers. Such an investigation requires a detailed knowledge of the secondary electron transport properties that ...

B. N. ivastava J. H. Jacob M. Rokni

1978-01-01

91

A synchronously mode-locked dye laser source for tunable picosecond spectroscopy and nonlinear frequency mixing  

Microsoft Academic Search

A mode-locked tunable dye laser has been developed which is synchronously pumped at high repetition rates by the doubled output of a mode-locked Nd:YAG laser. The dye laser provides intense pulses of 35 psec duration that are widely tunable, of near-transform-limited bandwidth, and in time coincidence with the pumping pulses. Conditions for achieving optimal pulse duration, lasing efficiency, spectral narrowing

L. S. Goldberg; C. A. Moore

1974-01-01

92

Evaluation of new organic pigments as laser-active media for a solid-state dye laser  

Microsoft Academic Search

Solid-state dye lasers are small, low-cost, simple, and coherent light sources. These lasers can output a laser beam at many wavelengths by changing the organic dyes or pigments. Photodegradation of the laser-active medium, however, is difficult with this type of laser. Research regarding new fluorescent materials that are not easily degraded by exposure to the pump light is therefore important

Makoto Fukuda; Kunihiko Kodama; Hiroshi Yamamoto; Keiichi Mito

2004-01-01

93

Flashlamp-excited organic dye lasers  

Microsoft Academic Search

The flashlamp-excited dye laser is presently the only type of laser capable of tunable emission throughout most of the visible spectrum. Gain and power output of the device are comparable to solid-state systems although the laser performance is hindered by thermal effects, produced by spatially nonuniform excitation of the dye, and optical losses associated with the molecular triplet state. In

BENJAMIN B. SNAVELY

1969-01-01

94

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

95

Collinear dual-color laser emission from a microfluidic dye laser  

NASA Astrophysics Data System (ADS)

Collinear dual-color laser emission on a chip is obtained from a liquid dye mixture flowing through an optical microcavity. Soft lithography has been used to fabricate the microfluidic channels and integrate the optical resonator. The laser cavity, of nanoliter volume, is made of two parallel gold mirrors coated on the end faces of optical fibers and integrated into a polydimethylsiloxane chip. Such a design allows a simple but efficient coupling of the laser emission with an optical fiber. The amplification medium is composed of rhodamine 6G and sulforhodamine, dissolved in a common ethanol solution. When the dye mixture is optically pumped by a pulsed and frequency-doubled Nd:YAG laser, simultaneous laser emission at wavelengths 559 nm and 597 nm is observed, showing yellow and red colors with a complete spatial overlap within the single output beam. Moreover, the overall laser efficiency for the dye mixture system is significantly increased compared to that for the individual dyes.

Kou, Q.; Yesilyurt, I.; Chen, Y.

2006-02-01

96

Polarization properties of dye-based random lasers  

NASA Astrophysics Data System (ADS)

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

Knitter, Sebastian; Kues, Michael; Fallnich, Carsten

2013-03-01

97

Hysteresis effects in the two-mode dye ring laser  

SciTech Connect

By inserting an optical diode consisting of Faraday and quartz rotators into the cavity of a dye ring laser and by applying a sinusoidal current at 10 Hz to the Faraday rotator, we have been able to observe hysteresis in the intensity of each counterpropagating laser mode. The hysteresis results from the laser's attempts to switch among metastable states in response to the external stimulus. We have studied the hysteresis as a function of laser pump parameter a and find that it starts when a exceeds about 25, reaches a peak when a is about 60, and becomes small when a exceeds about 70. At this stage the laser is unable to respond because of the high potential barrier between metastable states. The results are in general agreement with computer solutions of the equations of motion and are related to recent work on stochastic resonance in a dye ring laser.

Gage, E.C.; Mandel, L.

1989-03-01

98

Solar pumped, alkali vapor laser  

NASA Astrophysics Data System (ADS)

High power lasers based in space have been considered as sources for power transmission, laser propulsion, materials processing and space defense. The feasibility of such systems is based on the cost per unit power delivered, with detailed studies indicating that light weight has a greater impact on cost than laser efficiency. Solar radiation is a natural source of power for these devices and two methods for conversion of solar radiation to laser radiation can be considered. An indirectly solar pumped laser would first convert the solar radiation to electricity or longer wavelength blackbody radiation which is then used to power the laser. A directly longer wavelength blackbody radiation which is then used to power the laser. A directly pumped solar laser would utilize a portion of te solar spectrum to directly pump the laser medium, eliminating the intervening step and substantially reducing the systems weight and complexity. Detailed comparisons showed a directly pumped laser with an overall efficiency of only 1.5 percent can compete with an indirectly energized solar laser with an overall efficiency of ten percent. With this in mind, a concept for a directly solar pumped laser was developed based on an alkali vapor (sodium) as the laser medium.

Ham, David; Defaccio, Mark A.

1987-09-01

99

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

100

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

Microsoft Academic Search

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

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

2006-01-01

101

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

102

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

SciTech Connect

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% was achieved. A maximum irradiance of 59 MW/cm{sup 2} to the dye laser cavity was achieved. 7 refs., 2 figs., 4 tabs.

Gettemy, D.J.; Hermes, R.E. (Los Alamos National Lab., NM (USA)); Barnes, N.P. (National Aeronautics and Space Administration, Hampton, VA (USA). Langley Research Center)

1991-01-01

103

Two-Photon-Pumped Frequency-Upconverted Blue Lasing in Coumarin Dye Solution  

Microsoft Academic Search

Two-photon-pumped (TPP) frequency-upconverted blue lasing of Coumarin 500 dye solution has been experimentally investigated. The shortest lasing wavelength was measured to be 479 nm from a Coumarin 500 solution in chloroform pumped with 800-nm laser pulses of 5-ns duration. The spectral, temporal, and spatial structures as well as the output input characteristics of TPP cavity lasing were measured with a

Guang S. He; Raffaella Signorini; Paras N. Prasad

1998-01-01

104

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

PubMed

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

Huang, Yuhua; Wu, Shin-Tson

2010-12-20

105

Two-photon pumped frequency-upconversion lasing of a new blue-green dye material  

Microsoft Academic Search

The two-photon absorption and two-photon pumped (TPP) frequency-upconverted green lasing properties of a new dye, 1-(N-methyl-4-pyridinio)-2-(N-methylpyrrol-2-yl)ethene triflate (abbreviated as M-PPE) have been experimentally investigated. This new dye exhibits a low lasing threshold and high lasing efficiency when pumped with a 800-nm pulsed laser beam. The spectral, temporal, and spatial structures as well as the output\\/input characteristics of the TPP cavity

Guang S. He; Lixiang Yuan; Paras N. Prasad; Alessandro Abbotto; Antonio Facchetti; Giorgio A. Pagani

1997-01-01

106

Investigation of Fluctuations in - and Two - Dye Lasers.  

NASA Astrophysics Data System (ADS)

The intensity fluctuations of one- and two-mode dye lasers are investigated experimentally and theoretically, in the latter case by means of numerical integration of the equations of motion for the various laser models. Third -order theories appropriate for lasers not too far above threshold are augmented by an additive noise term to represent spontaneous emission and a multiplicative noise term to model population inversion fluctuations. Two sources of the pump fluctuations, variations in the optical pump power and fluctuations in the dye flow are studied, and the former is found to be a stochastic process whereas the latter is chaotic due to the turbulent fluid flow. The introduction of finite-bandwidth, colored pump noise leads to predictions of new features in the laser behavior, and the model is compared to the standard laser model without pump noise, and a model with white pump noise. The new features predicted and observed include large intensity fluctuations below threshold, a first-order phase transition analogy, and an initial flat region in the shape of the time-dependent intensity auto-correlation. The features are all well modelled by the equations of motion with colored pump noise, but some discrepancies remain. The most striking one is the need for different pump noise correlation times to accurately model both the normalized intensity fluctuations as a function of mean intensity and the time-dependent correlation functions. Possible explanations are given and further work is suggested. In the homogeneously broadened two-mode ring laser, the strong mode competition leads to random anti-correlated mode-switching. The behavior of the system when a dye jet and a dye cell are used is compared. Attention is given to the role of an induced differential loss for the two-counterpropagating modes. The insertion of an optical diode, an electromagnetic Faraday rotator and a crystal quartz rotator, allows the intensity statistics to be investigated as a function of asymmetry. The results are found to be in good agreement with the model with colored pump noise, and if a rescaling of the effective asymmetry is allowed the results are also in reasonable agreement with the model without pump noise. The effect of a modulated asymmetry is also investigated and the predicted hysteresis is observed. This phenomenon is connected to recent observations of stochastic resonance.

Gage, Edward Charles

107

Transverse-pumped Cs vapor laser  

Microsoft Academic Search

Scaling of alkali lasers to higher powers requires combining beams of multiple diode laser pump sources. For longitudinal pumping this can be very complicated if more than four beams are to be combined. In this paper we report a first demonstration of a transversely pumped Cs laser with fifteen laser diode arrays. The LDA pump beams were individually collimated with

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

2009-01-01

108

Hair ignition by dye laser for port-wine stain: risk factors evaluated.  

PubMed

Flashlamp-pumped pulsed dye laser is the preferred treatment for port-wine stain. Vascular hemoglobin and epidermal melanin are competing sites for dye laser absorption and damage. The case presented illustrates the potential hazard of ignition induced by dye laser treatment on the face of a patient receiving inhalation anesthesia. A 6-year-old girl with almost black hair was treated for a port-wine stain covering most of the right half of her face. She was treated with dye laser under general anesthesia administered by mask. A laser pulse close to the upper part of the eyebrow induced a blaze and the eyebrow was instantly destroyed by the fire. Regrowth of the eyebrow was complete after a few months. Hair specimens of various colors were exposed experimentally to dye laser irradiation in room and oxygen-saturated atmospheres. Risk factors of ignition are high laser dosage, a high oxygen level, repeated pulses and dark colored hair. PMID:11357290

Molin, L; Hallgren, S

1999-04-01

109

Effect of quenching of molecular triplet states in organic dye lasers  

Microsoft Academic Search

The effect of quenching of metastable triplet states upon the efficiency of organic dye lasers is considered in detail by solving the coupled differential equations describing the laser process. It is shown that specific quenching agents for excited triplet states can 1) cause a dramatic increase in the laser efficiency, 2) negate the previous requirements of very fast pumping sources,

R. Keller

1970-01-01

110

Tunable lasers pumped by visible laser diodes  

NASA Astrophysics Data System (ADS)

A laser having a Cr(3+) doped Colquiriite mineral host gain element, such as Cr:LiCAF, Cr:LiSAF or Cr:LiSGAF, is pumped by the pumping beam from at least one visible laser diode to provide tunable laser emission. The Cr(3+) doped Colquiriite mineral host gain element has an exterior face provided with a dichroic coating highly transmissive to the pumping beam and highly reflective to the tunable laser emission and has an interior face provided with an AR coating antireflective to the tunable laser emission. An output coupler mirror, provided with a coating that is partially reflective to the tunable laser emission, has an appropriate radius of curvature and is appropriately located to concentrate reflected tunable laser emission in a waist in a resonator mode on an exterior face of the Cr(3+) doped Colquiriite gain element to assure the visible light diode pumping thereof. A lens is disposed to receive the pumping beam to focus it at or near the waist on the exterior face of the Cr(3+) doped Colquiriite gain element.

Scheps, Richard

1993-09-01

111

Laser-dye synthesis; Group F compounds. Final report, March-July 1987  

SciTech Connect

This report describes progress toward the syntheses of new potential laser dyes. It is anticipated that new substrates will allow upscaling of flashlamp-pumped dye lasers to higher energies. The criteria for assessment of these dyes include a) the extent to which they show a lower, laser action threshold, b) their operational efficiencies, and c) their photochemical stabilities compared with laser dyes previously evaluated. In principle, high optical quality and convenient cooling are obtainable using a flow system. Also, costs should be relatively small compared with those for solid-state lasers if reasonably short, high-yield synthetic routes can be found. Pavlopoulos has proposed that improvements in presently available laser dyes may be realized by restricting chromophores and auxochromic groups to coplanarity or near coplanarity. The desired result of imposing these structural conditions is the reduction of intersystem crossing and thus improvements in quantum-fluorescence yields. The targeted compounds described were designed to meet these objectives.

Grubbs, E.J.

1988-02-01

112

Total Internal Reflecting Laser Pump Cavity.  

National Technical Information Service (NTIS)

A laser device in accordance with the present invention includes a diode pump for generating pump light and a pump cavity for receiving the pump light for conversion into an output laser beam. The pump cavity is formed as a trapezoidal prism, or a prism h...

D. N. Barr J. E. Nettleton

2004-01-01

113

Titanium-doped sapphire lasers with high energy pumping  

NASA Astrophysics Data System (ADS)

A titanium doped sapphire is pumped with up to 900 mJ of blue-green energy from a dye laser. An 8 percent energy conversion to the near IR is demonstrated. The experimental input/output data agree well with calculations based on the measured characteristics of crystal and pump beam. Analysis of the conversion efficiency reveals the potential to achieve values of about 35 percent in optimized, but simple, devices.

Payne, M. J. P.; Lowde, N. A.

1989-06-01

114

A laser induced cavitation pump  

NASA Astrophysics Data System (ADS)

We demonstrate and discuss a liquid pumping effect based on the interaction between periodically generated cavitation microbubbles and a millimeter diameter tube. The bubbles are generated by the heat of laser adsorption at the tip of an optical fiber immersed in liquid. When the bubbles are generated well away from the tube, a steady streaming flow with a relatively large and energetic ring vortex is observed. Coaxial placement of the fiber within the tube, with the fiber tip near one end of the tube, results in relatively weak pumping of liquid. In contrast, placement of the fiber outside the tube with a similar fiber tip position results in a synergetic and strong pumping effect. This paper presents quantitative measures of pumping performance as a function of relevant parameters including the axial fiber tip position, fiber orientation and laser duty cycle.

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

2004-07-01

115

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

116

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

117

Two-photon-pumped frequency-upconverted blue lasing in coumarin dye solution.  

PubMed

Two-photon-pumped (TPP) frequency-upconverted blue lasing of Coumarin 500 dye solution has been experimentally investigated. The shortest lasing wavelength was measured to be ~479 nm from a Coumarin 500 solution in chloroform pumped with ~800-nm laser pulses of ~5-ns duration. The spectral, temporal, and spatial structures as well as the output-input characteristics of TPP cavity lasing were measured with a 1-cm-long Coumarin 500 solution-filled quartz cuvette. The cavity lasing spectral structure and the numbers of longitudinal modes were easily controlled simply by attachment of an optical plate to the output window of the dye-solution cuvette. The net conversion efficiency from the absorbed 800-nm pump pulse energy to the blue-upconverted cavity lasing energy was ~4.8%. PMID:18286061

He, G S; Signorini, R; Prasad, P N

1998-08-20

118

Compact and highly efficient laser pump cavity  

SciTech Connect

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, J.J.; Bass, I.L.; Zapata, L.E.

1999-11-02

119

Effect of flow velocity on the photon statistics of a cw dye laser  

SciTech Connect

The effect of changing the velocity of dye flow on the behavior of a cw dye laser in investigated by photon counting measurements. The results strongly suggest that changing the velocity over the range 10--13 m/sec merely changes the pump parameter, but leaves the other laser characteristics essentially unaltered. The average light intensity is found to be a linear function of flow velocity.

Short, R.; Roy, R.; Mandel, L.

1980-12-01

120

Efficient Optically Pumped Cesium Vapor Laser  

Microsoft Academic Search

We have demonstrated a cesium laser with 81% slope efficiency relative to the input pump power. The maximum output power at 894 nm was 0.36 W with a pump power of 0.57 W (the overall optical efficiency was 63%). Optically pumped alkali lasers have a number of desirable features as compared to solid state or fiber lasers: the quantum efficiency

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

2006-01-01

121

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

122

Tunable optofluidic dye laser with integrated air-gap etalon  

NASA Astrophysics Data System (ADS)

In this work we demonstrate an integrated air-gap etalon that enables single wavelength operation and tuning ability for optofluidic dye laser. The integrated elastomeric air-gap etalon is controlled by air pressure. The chip was fabricated with polydimethylsiloxane (PDMS) via replica molding. It comprises a liquid waveguide and micro-scale air-gap mirrors providing the feedback. The lasing wavelength is chosen by the interference between two parallel PDMS-air interfaces inside the internal tunable air-gap etalon, of which pneumatic tuning can be realized by inflating the air-gap etalon with compressed air. This dye laser exhibits a pumping threshold of 1.6 ?J/pulse, a lasing linewidth of 3 nm and a tuning range of 14 nm.

Song, Wuzhou; Vasdekis, Andreas E.; Psaltis, Demetri

2010-11-01

123

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

PubMed

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

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

2013-10-30

124

Optical bistability and hysteresis in a colliding pulse mode locked femtosecond dye laser  

Microsoft Academic Search

The observation of optical bistability in a colliding pulse mode locked dye laser is described. Two lasing states can occur, one at 612 nm and with femtosecond pulse formation and the other at 570 nm and with a CW output. An hysteresis loop can be obtained plotting the output power as a function of the pump laser power. Control of

G. R. Jacobovitz; C. H. Brito Cruz; N. P. Mansur; M. A. Scarparo

1986-01-01

125

Far-red polyurethane-host solid-state dye laser  

SciTech Connect

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

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

2009-09-30

126

Trans-spectral organic dye laser photocoagulation.  

PubMed Central

Clinical research utilizing the yellow, orange, and red wavelengths of the dye laser (Rhodamine 6G and MD-631) appears to have considerable promise and may demonstrate that the liquid organic dye laser is the laser of choice for photocoagulation of many types of ocular defects. The effectiveness of the dye laser as a photocoagulation source is due to the trans-spectral availability of relatively high output power wavelengths. Therefore, a target tissue can be selectively coagulated with minimal laser energy transmitted through the refractive media and minimal damage to nearby normal tissues. The dye laser, as a photocoagulation system, should prove valuable in the therapy of many ocular diseases. Images FIGURE 6 A FIGURE 6 B FIGURE 6 (Cont'd) C FIGURE 6 (Cont'd) D FIGURE 5 (Cont'd) E FIGURE 5 (Cont'd) F FIGURE 8 A FIGURE 8 B FIGURE 7 A FIGURE 7 B FIGURE 5 A FIGURE 5 B FIGURE 7 (Cont'd) C FIGURE 7 (Cont'd) D FIGURE 5 (Cont'd) C FIGURE 5 (Cont'd) D FIGURE 7 (Cont'd) E FIGURE 7 (Cont'd) F FIGURE 1 FIGURE 2 FIGURE 6 (Cont'd) E FIGURE 8 (Cont'd) C FIGURE 9

L'Esperance, F A

1985-01-01

127

Stimulated Raman Scattering with a Multimode Pulsed Dye Laser  

NASA Astrophysics Data System (ADS)

An experimental study of the effects of pump bandwidth on stimulated Raman generation has been carried out. It has been shown that stimulated Raman generation is sensitive to temporal intensity variations of the pump light. First the multimode pulsed dye laser used as the pump in stimulated Raman generation was statistically characterized. Then the statistical properties of the light generated were studied by measuring the Stokes intensity autocorrelation function and the cross correlation function between the Stokes and pump intensities. Good agreement was found between theory and experiment. In order to experimentally study the cross correlations between the pump and Stokes intensities, methods for statistically characterizing multimode radiation were developed. These methods include measuring the intensity autocorrelation function of the radiation and measuring the intensity cross correlations between the individual cavity modes. The method for measuring intensity autocorrelation functions can be easily adapted to measure the cross correlation function between the intensities of two radiation fields of widely differing frequencies. These methods were applied to our grazing-incidence -type multimode pulsed dye laser. It was found that the statistical properties of its output are very sensitive to the degree of gain competition the modes experience. By measuring the mode intensity cross correlation coefficients it was found that certain modes become positively correlated. Autocorrelation measurements of the output intensity revealed that the laser can operate in two limiting configurations: a "correlated intensity, random phase" configuration and a "random intensity, FM-phase-locked" configuration. One of the key results of this thesis is that the Stokes intensity is not always perfectly correlated with the pump intensity. By perfect correlations it is meant that the Stokes intensity variations follow those of the pump and have the same magnitude. This occurs when the pump bandwidth is smaller than the molecular Raman linewidth. When this occurs the medium is able to follow the pump intensity variations. Since the Stokes gain has an exponential dependence on the pump intensity the large peaks in the pump intensity variations experience more gain than the small peaks, leading to overall enhancement of the intensity variations of the Stokes light.

Westling, Lynn Adrea

128

Solar-pumped solid state laser program  

Microsoft Academic Search

Solar pumped lasers are candidates for wireless power transmission in space, free space optical communication and photochemistry. The present paper describes the progress on a joint project to develop solar pumped lasers, focusing on the temporal and spectral shaping of the laser beam, which comply with those applications. The program emphasizes the design, fabrication and testing of laser rods, passive

Mordechai Lando; Jacob A. Kagan; Yehoshua Shimony; Yehoshua Y. Kalisky; Yoram Noter; Amnon Yogev; Stanley R. Rotman; Zamik Rosenwaks

1997-01-01

129

Generation of ultrashort light pulses in a dye laser with injection of a stimulated seed signal  

Microsoft Academic Search

An analysis is made of the conditions for the self-excitation of a dye laser subjected to extremely unsteady pumping when after each pump pulse the initial gain changes greatly during a round trip of a wave across the laser cavity. An analytic expression is obtained for the criterion of unsteady self-excitation which reduces in the limit to the familiar steady-state

S G Rozuvan; E A Tikhonov

1994-01-01

130

PHYSICAL PHENOMENA ACCOMPANYING THE GENERATION AND AMPLIFICATION OF LASER RADIATION: Ionization-recombination mechanism of growth of the losses due to triplet-triplet absorption in vapor dye lasers  

NASA Astrophysics Data System (ADS)

Internal losses in vapor dye lasers are attributed to preferential formation of triplet-state molecules as a result of the volume recombination of electrons and cations formed by multistage photoionization of active molecules under the action of the pump radiation. Calculations for a longitudinal pumping variant are used to show that this loss mechanism causes a severe deterioration in the lasing energy characteristics of vapor dye lasers compared with liquid dye lasers.

Abakumov, G. A.; Simonov, Alexander P.; Yaroslavtsev, V. T.

1989-05-01

131

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

132

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

133

Optofluidic microcavities: Dye-lasers and biosensors  

Microsoft Academic Search

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

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

2010-01-01

134

Photon statistics of a dye laser far below threshold  

SciTech Connect

The relative mean square fluctuations <(..delta..I)/sup 2/>//sup 2/ of the intensity I of a single-mode dye laser have been measured by a photon counting technique, in the region from about threshold to intensities 1000 times below threshold. The results show a steady increase of <(..delta..I)/sup 2/>//sup 2/ from less than 1 to about 150 as is reduced, followed by a rapid drop to zero. This behavior appears to be described fairly well by an equation of motion containing both additive spontaneous emission fluctuations and multiplicative pumping fluctuations.

Lett, P.; Short, R.; Mandel, L.

1984-01-30

135

Blackbody-pumped CO2 laser experiment  

NASA Astrophysics Data System (ADS)

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

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

1983-07-01

136

Cyclotron Resonance Pumping of Gas Lasers.  

National Technical Information Service (NTIS)

Experiments employing pure d-c pumping and combined d-c/microwave pumping were performed on argon lasers. The effort was directed toward obtaining a basic understanding of the laser discharge dynamics for the d-c case and its effects on laser output and e...

S. Ahmed T. Faith

1966-01-01

137

Pulsed pumping of semiconductor disk lasers  

Microsoft Academic Search

Efficient operation of semiconductor disk lasers is demonstrated using uncooled and inexpensive 905nm high-power pulsed semiconductor pump lasers. Laser emission, with a peak power of 1.7W, is obtained from a 2.3mum semiconductor disk laser. This is seven times the power achieved under continuous pumping. Analysis of the time-dependent spectral characteristics of the laser demonstrate that significant device heating occurs over

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

2007-01-01

138

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

139

High-gain end-pumped lasers  

Microsoft Academic Search

New-generation diode pump sources allow end-pumped cw lasers to achieve gain levels previously reached only in quasi-cw diode-pumped systems. We report end-pumped lasers with single-pass small signal gain G=10, producing Q-switched output at the 16-W level in 6-ns pulses at 20 kHz. We achieved these results with a modified version of the Opto Power Beam Shaper, capable of producing a

M. Fuller; D. Matthews; L. R. Marshall

1998-01-01

140

Solar powered blackbody-pumped lasers  

NASA Astrophysics Data System (ADS)

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

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

141

Optically pumped isotopic ammonia laser system  

DOEpatents

An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

Buchwald, Melvin I. (Santa Fe, NM); Jones, Claude R. (Los Alamos, NM); Nelson, Leonard Y. (Seattle, WA)

1982-01-01

142

Solid-state dye lasers based on PMMA co-doped with PM597 and PM650  

NASA Astrophysics Data System (ADS)

In order to enhance the laser performances, solid-state samples based on polymethyl methacrylate (PMMA) co-doped with pyrromethene 597 (PM597) and pyrromethene 650 (PM650) were prepared. With SHG of Q-switched Nd:YAG laser (532 nm, ˜15 ns) pumping the samples, laser emission from the mixtures of PM597 and PM650 both in liquid solution and incorporated into solid polymeric matrices were investigated. The highest slope efficiency of co-doped solid-state dye samples 30.8% was achieved. Through the dye PM650 being co-doped into the dye PM597, the dye laser output wavelength was extended for the existence of energy transfer from the dye PM597 to the dye PM650.

Wang, G. M.; Zhang, Z. H.

2011-06-01

143

Ultralow-pump-threshold laser-diode-pumped continuous Cr:LiSAF laser  

NASA Astrophysics Data System (ADS)

Operation of laser diode pumped Cr:LiSAF laser in 1 m long V-resonator with pump-threshold as low as 650 uW is reported. This threshold was observed simultaneously with threshold of single stripe (width of 50 um) 670 nm laser diode used as a pumping source.

Kubecek, Vaclav; Quintero-Torres, Rafael; Diels, Jean-Claude M.

2003-07-01

144

Generation of microsecond laser pulses in polyurethane matrices doped with dyes  

SciTech Connect

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

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

2006-08-31

145

Suitability of Polymeric Media In Solid State Dye Lasers  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

146

Solid-state dye lasers based on polymethyl methacrylate doped with pyrromethene 650  

NASA Astrophysics Data System (ADS)

Solid-state dye samples based on polymethyl methacrylate (PMMA) doped with different concentrations of the dye PM650 were prepared. With SHG of Q-switched Nd:YAG laser (532 nm, ˜15 ns) pumping the samples longitudinally, the fluorescence, lasing spectra and slope efficiencies of the samples were obtained. The highest slope efficiency 27.49% and laser output energy 22.0 mJ was achieved in the sample with a dye concentration of 2.0 × 10-4 mol/L. To our knowledge, the results are the best under the same condition so far. The maxima of output lasing spectrum is about 653.5 nm. Our results have shown that using solid-state samples doped with PM650 can extend the dye laser wavelength to the red.

Wang, G. M.; Zhang, Z. H.

2010-10-01

147

Electrically Pumped Erbium Pumped Silicon Lasers.  

National Technical Information Service (NTIS)

Rare earth doped semiconductors offer the possibility of electrically pumped, efficient, and inexpensive integrated optical amplifiers and CW sources for use in optical communications systems. This final report discusses research into Er doped GaN and Si ...

R. Feuerstein J. Pankove J. Torvik B. Willner

1995-01-01

148

NaK 22?+ ? 11?+ band optically pumped laser near 1.02 ?m  

NASA Astrophysics Data System (ADS)

Optically pumped laser emission has been observed on the NaK 2( A)1?+ ? 1( X)1?+ electronic state transition. The emission occurs between 1.015 and 1.035 ?m when a sodium-potassium heat-pipe oven is pumped with 695 745 nm pulsed dye laser radiation. The laser emission occurs on many ro-vibrational transitions without the use of cavity mirrors. However, the addition of a simple cavity increases both the number of observed lasing transitions and the amplitude of the emission on each line. We report our results for the dependence of the emission intensity on pump laser power, oven temperature, and buffer gas pressure.

Clark, B. K.; Luh, W. T.; Huennekens, J.

1989-08-01

149

On the spiking phenomenon in organic dye lasers  

Microsoft Academic Search

The spiking condition of dye lasers is analyzed by means of a small-signal approximation of the rate equations. Dye lasers are generally operated close to the border region between spiking and nonspiking. An initial spike is observed in the output beam of a flash-lamp-excited rhodamine 6G laser with a shortened cavity.

Y. Miyazoe; M. Maeda

1971-01-01

150

Dye laser amplifier including a specifically designed diffuser assembly  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continuous replened 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 relatively high flow rate and a specifically designed diffuser assembly for slowing down the flow of dye while, at the same time, assuring that as the dye stream flows through the diffuser assembly it does so in a stable manner.

Davin, James (Gilroy, CA); Johnston, James P. (Stanford, CA)

1992-01-01

151

Diode-pumped alkali laser-bleached wave dynamics  

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

152

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

153

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

154

Ti:sapphire laser pumped Nd:tellurite glass laser  

Microsoft Academic Search

A Ti:sapphire laser pumped Nd3+-doped tellurite bulk glass laser operating at 1066 nm is described. We believe this is the first demonstration of bulk glass laser in tellurite glass. A lasing threshold of 4.20 mJ of 804.3 nm absorbed pump energy and a slope efficiency output energy versus pump energy of 14.7% were observed.

Lei Ning; Xu Bing; Jiang Zhonghong

1996-01-01

155

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

156

Laser sclerostomy by pulsed-dye laser and goniolens  

SciTech Connect

We describe an ab-interno laser sclerostomy procedure using the method termed dye-enhanced ablation with a slit-lamp delivery system and special goniolens such that only the laser light beam penetrates the anterior chamber. The procedure uses a microsecond-pulsed-dye laser emitting at 666 nm and iontophoresis of methylene blue dye (absorption of 668 nm) into the sclera at the limbus to enhance the absorption of the laser light. We compared the number of pulses needed to perforate excised human sclera at pulse durations of 1.5, 20, and 300 microseconds. Pulse durations of 1.5 and 20 microseconds required 20 pulses or fewer to perforate excised human sclera with pulse energies of 75 to 100 mJ. The ab-interno laser sclerostomy procedure was performed in 54 eyes of Dutch-belted rabbits with pulse durations of 1.5 or 20 microseconds and a 100- or 200-microns incident spot diameter delivered using a CGF goniolens. Full-thickness fistulas were successfully created at both pulse durations in approximately 80% of eyes treated. A range of three to 25 pulses was required to perforate sclera with slightly fewer pulses and lower pulse energies at 1.5 microseconds compared with 20 microseconds. There were no significant complications from the procedure. This technique could permit filtration surgery to be performed on an outpatient basis.

Latina, M.A.; Dobrogowski, M.; March, W.F.; Birngruber, R. (Massachusetts General Hospital, Boston (USA))

1990-12-01

157

Diode Pumped Solid-State Laser Oscillators for Spectroscopic Applications.  

National Technical Information Service (NTIS)

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 producti...

R. L. Byer S. Basu T. Y. Fan W. J. Kozlovsky C. D. Nabors

1987-01-01

158

Pulse-width fluctuations of a cascade transient oscillation dye laser  

NASA Astrophysics Data System (ADS)

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

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

1986-02-01

159

Photostability of some pyrromethene laser dyes  

NASA Astrophysics Data System (ADS)

Using flashlamp excitation, photostability data on 1,3,5,7,8-pentamethyl-, 1,2,3,5,6,7,8-hepta-methyl-, and 2,6-dipropyl-1,3,5,7,8-pentamethyl-, and 2,6-dinitro- 1,3,5,7,8-pentamethyl-pyrromethene- (P)-BF2 complexes in the solvent 1,4-dioxane and the solvent mixtures 1,4- dioxane/heptane, 1,4-dioxane/cyclohexane, 1,4- dioxane/ethanol and 1,4-dioxane/hexanol, all ratio 1:4, were obtained. As reference laser dyes, the photostability of Rhodamine 6G in ethanol and the solvent mixture ethanol/hexanol ratio 1:4 and Rhodamine 560 in ethanol and the solvent mixtures ethanol/hexanol, ethanol/cyclohexane, and ethanol/heptane, all ratio, 1:4 were also obtained. Specifically, the laser output energy, (Delta) E (in joules) was recorded as a function of flashlamp excitation pulses, N. 2,6-dinitro-pentamethyl-P-BF2 was very stable in the heptane mixture, and other P-BF2 complexes were more stable in 1,4-dioxane. Rhodamine 6G was very stable photo chemically in hexanol. The role of oxygen in laser dye solutions is briefly reviewed.

Pavlopoulos, Theodore G.

1999-05-01

160

Violet and blue upconversion-emission from erbium-doped ZBLAN-fibers with red diode laser pumping  

Microsoft Academic Search

Violet (402 nm) and blue (470 nm) upconversion-emission with powers of several 10 ?W from Er3+:ZBLAN fibers under red laser pumping have been obtained. Efficient red-to-violet and red-to-blue upconversion was found using laser diodes at 638 nm, a helium–neon-laser at 633 nm, and a tunable DCM-dye-laser. Pumping at the optimal excitation wavelength at 638 nm, the upconversion emission exhibited a

Sebastian Ferber; Volker Gaebler; Hans-Joachim Eichler

2002-01-01

161

Reactor-pumped laser experimental results  

Microsoft Academic Search

Reactor pumped lasers have the potential to be scaled to multi-megawatt power levels with long run times. In proposed designs, the laser will be capable of output powers of several megawatts of power for run times of several hours. Such a laser would have many diverse applications such as material processing, space debris removal and power beaming to geosynchronous satellites

G. A. Hebner; G. N. Hays

1994-01-01

162

Solar-pumped dimmer gas lasers  

Microsoft Academic Search

Many attempts were made in the past to convert Solar light to Laser light. To date, only two systems were demonstrated successfully: Photo-Dissociation Lasers and Solid State Solar lasers. The absorption spectrum of many dimmer molecules posses a broad structural spectrum overlapping with the solar spectrum and can be good candidates for direct solar pumping. In the gas phase, the

Idit L. Pe'Er; Irina Vishnevetsky; Nir Naftali; Amnon Yogev

1999-01-01

163

Temporal and spectral properties of picosecond two-photon pumped cavity lasing of an organic dye HEASPS  

Microsoft Academic Search

.   The operation of cavity lasing of a two-photon absorption (TPA) organic dye, trans-4-[p-(N-hydroxyethyl-N-ethylamino)styryl]-N-methylpyridinium\\u000a p-toluene sulfonate (abbreviated as HEASPS), by using a picosecond infrared laser as the pump source, is reported. The lifetimes\\u000a of TPA fluorescence of this dye in different solvents were measured. Temporal profiles of cavity lasing show obvious oscillations\\u000a and magnification of the feedback light. By using

G. Zhou; D. Wang; Y. Ren; S. Yang; X. Xu; Z. Shao; X. Cheng; X. Zhao; Q. Fang; M. Jiang

2002-01-01

164

Laser-diode-pumped Nd:YVO4 lasers  

NASA Astrophysics Data System (ADS)

We report on the first laser diode pumped Nd:YVO4 fundamental and second harmonic lasers made in China. The threshold pumping power of the LD-pumped Nd:YVO4 fundamental laser is 4.5 mW. The cw 1064 nm output power is 64 mW with slope efficiency of 10.7%. The threshold pumping power of the LD-pumped Nd:YVO4 intracavity frequency doubling laser with KTP doubler is 12.5 mW. Nineteen mW of fundamental-mode 532 nm green laser were measured with a slope with a slope efficiency of 3.2$%. Experiment setups and results are discussed.

Huo, Yujing; Li, Gansheng; He, Jianbin; Guo, Xibin; Zhou, Bingkun

1993-05-01

165

Alternative wavelengths for optically pumped alkali lasers  

NASA Astrophysics Data System (ADS)

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

Perram, Glen P.

2012-05-01

166

Temporal dynamics of a ring dye laser with a stimulated Brillouin scattering mirror  

SciTech Connect

We present a numerical study of the temporal dynamics of a stimulated Brillouin scattering ring resonator. A coaxial flash-lamp-pumped Rh6G dye laser is assumed. The influence of the most important parameters on the temporal evolution of the resonator is analyzed, namely, the acoustic decay time of the nonlinear material, the features of the external injection pulse{emdash}its pulse width, energy, and spatial quality{emdash}and the coupling mirror reflectivity. We found the conditions to initiate and maintain laser oscillation in the ring resonator as long as the duration of the pumping system pulse persisted. {copyright} {ital 1996 Optical Society of America.}

Barrientos, B.; Aboites, V. [Laser Laboratory, Centro de Investigaciones en Optica, Apartado postal 948, 37000 Leon, Gto. (Mexico); Damzen, M. [Blackett Laboratory, Imperial College of London, London SW7 2BZ (United Kingdom)

1996-09-01

167

Single-mode operation of a zig-zag dye laser  

SciTech Connect

The authors report single-mode operations of a laser pumped zig-zag dye laser for pulse length {gt}1{mu}s with beam quality close to the diffraction limit. A unique linear optical cavity using counter-propagating orthogonally polarized waves was used. Laser efficiency measurements performed with a stable cavity had outputs of greater than 1.7 J at 568 nm using Pyrromethene-567 dye. The intrinsic laser efficiency was 55% with a slope efficiency of 77%. Single-mode operation was achieved using an unstable resonator with intra-cavity etalons to control the free running modes of the cavity and seeding with a single-mode Kr-ion laser operating at 568 nm. Heterodyne measurements were used to determine that the bandwidth was near the transform limit with the frequency chirping at a rate {approximately}60 MHz/{mu}s. Far-field measurements of the beam quality indicated close to diffraction limited output.

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

1995-05-01

168

Conductively Cooled Laser Diode Array Pumped Laser.  

National Technical Information Service (NTIS)

A conductively cooled semiconductor laser comprises a laser rod surrounded by arrays of laser diodes. The laser diodes are mounted to ceramic plates that are excellent heat extractors and electrical insulators. The ceramic plates have steps which permit d...

L. K. Conaway

1986-01-01

169

A switchable digital microfluidic droplet dye-laser.  

PubMed

Digital microfluidic devices allow the manipulation of droplets between two parallel electrodes. These electrodes can act as mirrors generating a micro-cavity, which can be exploited for a droplet dye-laser. Three representative laser-dyes with emission wavelengths spanning the whole visible spectrum are chosen to show the applicability of this concept. Sub-microlitre droplets of laser-dye solution are moved in and out of a lasing site on-chip to down-convert the UV-excitation light into blue, green and red laser-pulses. PMID:21901207

Kuehne, Alexander J C; Gather, Malte C; Eydelnant, Irwin A; Yun, Seok-Hyun; Weitz, David A; Wheeler, Aaron R

2011-09-08

170

20 Hz lamp pumped erbium glass laser  

NASA Astrophysics Data System (ADS)

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

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

2004-04-01

171

Applications for reactor-pumped lasers.  

National Technical Information Service (NTIS)

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

R. J. Lipinski D. A. McArthur

1994-01-01

172

Double Pulse Pumping of Ruby Lasers.  

National Technical Information Service (NTIS)

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

P. Shajenko

1966-01-01

173

Laser-induced quantum pumping in graphene  

SciTech Connect

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

San-Jose, Pablo [Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid (Spain); Prada, Elsa; Kohler, Sigmund [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain); Schomerus, Henning [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

2012-10-08

174

DOE reactor-pumped laser program.  

National Technical Information Service (NTIS)

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

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

1993-01-01

175

CONTROL OF LASER RADIATION PARAMETERS. [BR]ULTRASHORT RADIATION PULSES: Generation of ultrashort light pulses in a dye laser with injection of a stimulated seed signal  

Microsoft Academic Search

An analysis is made of the conditions for the self-excitation of a dye laser subjected to extremely unsteady pumping when after each pump pulse the initial gain changes greatly during a round trip of a wave across the laser cavity. An analytic expression is obtained for the criterion of unsteady self-excitation which reduces in the limit to the familiar steady-state

S. G. Rozuvan; E. A. Tikhonov

1994-01-01

176

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

177

Optically Pumped Vibrational Transition Laser in OCS.  

National Technical Information Service (NTIS)

Laser oscillation between vibrational states has been demonstrated at 19 micrometers in OCS by optical pumping on the v sub 2 overtone with a CO2 TEA laser. Analysis of the molecular kinetics indicates this technique to be general and capable of yielding ...

H. R. Schlossberg H. R. Fetterman

1974-01-01

178

Diode-Pumped Alkali Atom Lasers.  

National Technical Information Service (NTIS)

The recent work at LLNL on alkali-atom lasers has been remarkably successful and productive. Three main phases (so far) can be identified. First, the concept and demonstration of red lasers using (Ti:sapphire pumping) took place; during this time, Rubidiu...

R. H. Page R. J. Beach

2005-01-01

179

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:GdVO4 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

180

High-average-power dye laser at Lawrence Livermore National Laboratory  

SciTech Connect

The copper-laser-pumped dye laser system developed at the Lawrence Livermore National Laboratory (LLNL) is now capable of sustained, efficient, and reliable operation at total powers exceeding 2500 W and single amplifier chain powers exceeding 1300 W. Wavelength center frequency stability is maintainable to [lt]50 MHz. Laser dyes developed at LLNL permit tunability from 550 to 650 nm. Wave-front quality is [lt][lambda]/4 peak to valley. The system is operated remotely with the aid of a comprehensive set of diagnostics. Besides supporting its primary atomic-vapor-laser-isotope-separation mission, the system is being used in alternate applications such as materials processing and the generation of artificial guide stars.

Bass, I.L. (Lawrence Livermore National Laboratory, 7000 East Avenue, P.O. Box 808, Livermore, California 94550 (United States)); Bonanno, R.E. (Lawrence Livermore National Laboratory, 7000 East Avenue, P.O. Box 808, Livermore, California 94550 (United States) CVI Laser Corporation, 470 Lindbergh Avenue, Livermore, California 94550 (United States)); Hackel, R.P.; Hammond, P.R. (Lawrence Livermore National Laboratory, 7000 East Avenue, P.O. Box 808, Livermore, California 94550 (United States))

1992-11-20

181

Multicolor diode-pumped upconversion fiber laser.  

PubMed

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

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

2010-07-01

182

Diode pumped alkali vapor fiber laser  

Microsoft Academic Search

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

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

2007-01-01

183

Diode pumped alkali vapor fiber laser  

Microsoft Academic Search

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

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

2006-01-01

184

Diode-laser-pumped blue light sources  

Microsoft Academic Search

Nonlinear optical techniques may be used in conjunction with GaAlAs diode laser technology to yield compact blue light sources applicable to optical data storage, color displays, and underwater optical communications. Attention is given to two approaches to blue light generation using second-harmonic and sum-frequency generation of diode laser-pumped Nd:YAG lasers. Using KNbO3 as the nonlinearcrystal, a 3-mW output power was

W. P. Risk; W. Lenth

1989-01-01

185

Characteristics of organic dye lasers as tunable frequency sources for nanosecond absorption spectroscopy  

Microsoft Academic Search

The properties of 1, 1' diethyl-?-cyano-2,2'-di-carbocyanine-tetrafluoroborate (DTCDCT)and 1, 1'-diethyl-?-nitro- 4, 4'-di-carbocyanine-tetrafluoroborate (DTNDCT) lasers have been investigated. High-efficiency (25 percent) spectral narrowing of the normal 150-Å-wide, 2-MW output of DTCDCT (around ? 7600 Å) to <0.01 Å, corresponding to a single longitudinal mode, is achieved with a novel longitudinally pumped (by giant pulse ruby laser) dye laser cavity. Beam divergence is

D. J. BRADLEY; A. J. F. DURRrlNT; G. M. GALE; M. Moore; P. D. SMITH

1968-01-01

186

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

187

Hysteresis effects in the two-mode dye ring laser  

Microsoft Academic Search

By inserting an optical diode consisting of Faraday and quartz rotators into the cavity of a dye ring laser and by applying a sinusoidal current at 10 Hz to the Faraday rotator, we have been able to observe hysteresis in the intensity of each counterpropagating laser mode. The hysteresis results from the laser's attempts to switch among metastable states in

Edward C. Gage; Leonard Mandel

1989-01-01

188

Single-mode dye laser with a double-action Fizeau interferometer.  

PubMed

The peculiar properties of the high-reflectivity Fizeau wedge used in reflection are pointed out and used to obtain single-mode operation of a Nd:YAG-pumped dye laser. It is demonstrated that the reflecting Fizeau wedge can have, as a cavity output coupler, the double action of selective-feedback mirror and an output filter, thus producing a background-free tunable narrow line. PMID:19701347

Meyer, Y H; Nenchev, M N

1981-03-01

189

Steady-state analysis of strongly colored multiplicative noise in a dye laser  

SciTech Connect

A new Langevin equation for dye-laser fluctuations below and near threshold is used to obtain the intensity distribution function in closed form. The effect of strongly colored multiplicative pump noise is incorporated by means of an ansatz of Hanggi et al. (Phys. Rev. A 32, 695 (1985)) for an effective diffusion coefficient at steady states. Excellent agreement with the measurements of Lett, Short, and Mandel (Phys. Rev. Lett. 52, 341 (1984)) is obtained.

Fox, R.F.; Roy, R.

1987-02-15

190

Diode Pumped Alkali Lasers: History, current state and perspectives  

Microsoft Academic Search

emission. However, the real interest to alkali vapor lasers appeared after the first demonstration in 2003 [2] of a really efficient lasing in Rb vapor optically pumped by Ti:Sapphire laser. This interest was stimulated by a possibility of using efficient diode lasers for pumping of alkali vapors that promised a very high total wall plug efficiency Diode Pumped Alkali Laser

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

2011-01-01

191

Thermal management strategies for high power semiconductor pump lasers  

Microsoft Academic Search

Semiconductor pump lasers are an important component in Erbium-doped fiber amplifiers and Raman amplifiers. Thermal management has become one of the major obstacles of pump laser development. Understanding of the thermal behavior of high power laser packages is crucial to the thermal design and optimization of pump lasers. In this paper, we report on the thermal characteristics of a high

Xingsheng Liu; Martin H. Hu; Catherine G. Caneau; Rajaram Bhat; Lawrence C. Hughes; Chung-En Zah

2004-01-01

192

Nuclear-pumped laser concepts for laser fusion or laser-heated solenoid reactors  

Microsoft Academic Search

The combination of a nuclear-pumped laser with a fusion reactor, using some of the neutrons emitted from the fusion reactor to pump the laser, is described. This paper describes several concepts which might be used, points out potential advantages of using a nuclear-pumped laser, and describes several areas which must be investigated to prove feasibility. (MOW)

D. A. McArthur; J. V. Walker

1976-01-01

193

Solar Pumped, Alkali Vapor Laser.  

National Technical Information Service (NTIS)

High power lasers based in space have been considered as sources for power transmission, laser propulsion, materials processing and space defense. The feasibility of such systems is based on the cost per unit power delivered, with detailed studies indicat...

D. Ham M. A. DeFaccio

1987-01-01

194

A replacement solvent for dimethylsulfoxide /DMSO/ in CW dye lasers  

NASA Astrophysics Data System (ADS)

The use of propylene glycol carbonate as a replacement solvent for dimethyl sulfoxide in a Coherent model 599-21 CW dye laser has been investigated. Up to 40 milliwatts of single frequency output was achieved at 875 nm.

Herbelin, J. M.; McKay, J. A.

1981-01-01

195

Ultralow-pump-threshold laser diode pumped Cr:LiSAF laser  

NASA Astrophysics Data System (ADS)

Operation of Cr:LiSAF laser pumped by 670 nm high brightness single stripe (width of 50 ?m) laser diode with pump-threshold as low as 650 ?w is reported. The lasing threshold was observed simultaneously with threshold of operation of laser diode. For short pulse generation we designed and tested different multiple quantum well saturable absorbers. The continuous mode-locked operation was achieved with tunability from 846 to 875 nm.

Kubecek, Václav; Quintero-Torres, Rafael; Diels, Jean-Claude M.

2003-10-01

196

Solar pumped, alkali vapor laser  

Microsoft Academic Search

High power lasers based in space have been considered as sources for power transmission, laser propulsion, materials processing and space defense. The feasibility of such systems is based on the cost per unit power delivered, with detailed studies indicating that light weight has a greater impact on cost than laser efficiency. Solar radiation is a natural source of power for

David Ham; Mark A. Defaccio

1987-01-01

197

Turnable Second Harmonic Generation from an Organic Dye Laser  

Microsoft Academic Search

Ultraviolet light has been generated from a Rhodamine 60 organic dye laser by frequency doubling with a KDP crystal. The second harmonic was tuned from 2900Å to 3000Å with peak powers of 40 watts.Organic dye lasers have now been reported with output wave-lengths extending throughout the visible and near infrared. The tunability and output energies now available in the visible

B. G. Huth; G. I. Farmer; L. M. Taylor; M. R. Kagan

1968-01-01

198

Applications for reactor-pumped lasers  

Microsoft Academic Search

Nuclear reactor-pumped lasers (RPL's) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032,

R. J. Lipinski; D. A. McArthur

1994-01-01

199

Degradation of microgun-pumped blue lasers  

Microsoft Academic Search

Microgun-pumped blue lasers with lasing thresholds in the 4–20 kW\\/cm2 range for temperatures between 83 and 225 K were fabricated by molecular beam epitaxy. The devices exploit graded index, separate confinement Zn1 ? xCdxSeZnSe heterostructures and use an array of low-voltage field-emission microtips for electron beam pumping. Degradation occurs through the formation of characteristic (100) dark-line defects, as in diode

D. Herve; J. M. Bonard; L. Vanzetti; J. J. Paggel; L. Sorba; J. D. Ganière; E. Molva; A. Franciosi

1996-01-01

200

DOE reactor-pumped laser program  

Microsoft Academic Search

FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. The

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

1993-01-01

201

DOE reactor-pumped laser program  

Microsoft Academic Search

FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. The major

James R. Felty; Ronald J. Lipinski; David A. McArthur; Paul S. Pickard

1994-01-01

202

Investigation of photon statistics and correlations of a dye laser  

SciTech Connect

The probability distribution p(n) for the detection of n photons emitted by a single-mode dye laser in a short time at various excitations is measured, together with the distribution of time intervals between pairs of detected photons. The first measurement yields the probability density P(I) and the moments of the light intensity I, and the second one the two-time intensity-correlation function. Measurements are also performed at three different wavelengths. P(I) is found to have a two-component structure, and the relative intensity fluctuations <(..delta..I)/sup 2/>//sup 2/ grow, apparently without limit, as the excitation tends to zero, so that no thermal state is reached. A possible explanation in terms of pumping fluctuations is discussed. The correlation function has the form of a sum of three exponential functions, and the amplitudes and decay constants of the three components are derived. The effective decay-time constant exhibits a thirteenth-power-law dependence on frequency of the laser light.

Kaminishi, K.; Roy, R.; Short, R.; Mandel, L.

1981-07-01

203

Scaling studies of solar pumped lasers  

NASA Astrophysics Data System (ADS)

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

Christiansen, W. H.; Chang, J.

1985-08-01

204

E-beam-pumped semiconductor lasers  

NASA Astrophysics Data System (ADS)

The collapse of the Soviet Union opened many areas of laser technology to the West. E-beam- pumped semiconductor lasers (EBSL) were pursued for 25 years in several Soviet Institutes. Thin single crystal screens of II-VI alloys (ZnxCd1-xSe, CdSxSe1-x) were incorporated in laser CRTs to produce scanned visible laser beams at average powers greater than 10 W. Resolutions of 2500 lines were demonstrated. MDA-W is conducting a program for ARPA/ESTO to assess EBSL technology for high brightness, high resolution RGB laser projection application. Transfer of II-VI crystal growth and screen processing technology is underway, and initial results will be reported. Various techniques (cathodoluminescence, one- and two-photon laser pumping, etc.) have been used to assess material quality and screen processing damage. High voltage (75 kV) video electronics were procured in the U.S. to operate test EBSL tubes. Laser performance was documented as a function of screen temperature, beam voltage and current. The beam divergence, spectrum, efficiency and other characteristics of the laser output are being measured. An evaluation of the effect of laser operating conditions upon the degradation rate is being carried out by a design-of-experiments method. An initial assessment of the projected image quality will be performed.

Rice, Robert R.; Shanley, James F.; Ruggieri, Neil F.

1995-04-01

205

Multiplicative colored noise in a dye laser at steady state  

SciTech Connect

The steady-state intensity fluctuations of a single-mode dye laser are investigated when the laser is operated far above threshold. An analytic expression for the variance of the laser intensity is obtained when both additive white and multiplicative colored noise are included in the laser model. The result is in excellent agreement with the measurements of Kaminishi, Roy, Short, and Mandel (Phys. Rev. A 24, 370 (1981)).

Zhu, S. (Center of Condensed Matter and Radiation Physics, Chinese Center of Advanced Science and Technology (World Laboratory), Beijing, People's Republic of China (CN) Department of Physics, Suzhou University, Suzhou, Jiangsu 215006, People's Republic of China)

1989-09-15

206

Frequency Stabilization of Diode-Laser-Pumped Solid State Lasers.  

National Technical Information Service (NTIS)

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...

R. L. Byer

1988-01-01

207

Miniaturized Q-switched diode pumped solid state laser  

Microsoft Academic Search

A compact Q-switched solid state laser for producing short high peak power pulses is described comprising: a miniaturized solid state laser rod; cavity forming means for defining a compact resonant cavity which contains the laser rod, the cavity forming means including output coupling means for extracting laser pulses from the cavity; laser diode pumping means positioned to longitudinally end pump

Baer

1988-01-01

208

Solar-pumped CO laser  

Microsoft Academic Search

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

Charles E. Treanor

1986-01-01

209

Thermal management strategies for high power semiconductor pump lasers  

Microsoft Academic Search

Semiconductor pump lasers are an important component in erbium-doped fiber amplifiers and Raman amplifiers. Thermal management has become one of the major obstacles of pump laser development. Understanding of the thermal behavior of high-power laser packages is crucial to the thermal design and optimization of pump lasers. In this paper, we report on the thermal characteristics of a high-power pump

Xingsheng Liu; Martin H. Hu; Catherine G. Caneau; Rajaram Bhat; Chung-En Zah

2006-01-01

210

Free-running emerald laser pumped by laser diode  

NASA Astrophysics Data System (ADS)

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.

Chen, Zhenqiang; Zhang, Ge

2006-11-01

211

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

212

Solar-pumped CO laser  

NASA Astrophysics Data System (ADS)

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

Treanor, Charles E.

213

High-energy transversely pumped alkali vapor laser  

Microsoft Academic Search

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

J. Zweiback; A. Komashko

2011-01-01

214

Towards XUV lasers with charge transfer pumping  

Microsoft Academic Search

Detailed studies of charge exchange pumping of ions in femtosecond laser-produced plasmas colliding with a pulsed gas jet are presented. Strong selective excitation of XUV ionic transitions in the reaction C4+ + H --> C3+ + H+ is observed. Dependences of line intensities on various experimental parameters are reported which are in good agreement with the theory of charge transfer

I. F. Shaikhislamov; V. A. Vorontsov; M. Born; B. N. Chichkov; B. Wellegehausen

2006-01-01

215

Theory of an Optically Pumped Gas Laser.  

National Technical Information Service (NTIS)

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

J. J. Healy T. F. Morse

1972-01-01

216

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

217

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

218

Coupled cw dye lasers using intracavity four-wave mixing  

SciTech Connect

An experimental investigation of laser-oscillator frequency locking by a four-wave interaction was conducted. An experiment was performed that successfully demonstrated the locking of two cw dye lasers using this concept with Na vapor serving as the nonlinear (coupling) medium.

Gaeta, C.J.; Lind, R.C.; Brown, W.P.; Giuliano, C.

1988-12-01

219

New 8-amino-BODIPY derivatives: surpassing laser dyes at blue-edge wavelengths.  

PubMed

The development of highly efficient and stable blue-emitting dyes to overcome some of the most important shortcomings of available chromophores is of great technological importance for modern optical, analytical, electronic, and biological applications. Here, we report the design, synthesis and characterization of new tailor-made BODIPY dyes with efficient absorption and emission in the blue spectral region. The major challenge is the effective management of the electron-donor strength of the substitution pattern, in order to modulate the emission of these novel dyes over a wide spectral range (430-500?nm). A direct relationship between the electron-donor character of the substituent and the extension of the spectral hypsochromic shift is seen through the energy increase of the LUMO state. However, when the electron-donor character of the substituent is high enough, an intramolecular charge-transfer process appears to decrease the fluorescence ability of these dyes, especially in polar media. Some of the reported novel BODIPY dyes provide very high fluorescence quantum yields, close to unity, and large Stokes shifts, leading to highly efficient tunable dye lasers in the blue part of the spectrum; this so far remains an unexploited region with BODIPYs. In fact, under demanding transversal pumping conditions, the new dyes lase with unexpectedly high lasing efficiencies of up to 63?%, and also show high photostabilities, outperforming the laser action of other dyes considered as benchmarks in the same spectral region. Considering the easy synthetic protocol and the wide variety of possible substituents, we are confident that this strategy could be successfully extended for the development of efficient blue-edge emitting materials and devices, impelling biophotonic and optoelectronic applications. PMID:21547964

Bañuelos, Jorge; Martín, Virginia; Gómez-Durán, C F Azael; Arroyo Córdoba, Ismael J; Peña-Cabrera, Eduardo; García-Moreno, Inmaculada; Costela, Ángel; Pérez-Ojeda, M Eugenia; Arbeloa, Teresa; López Arbeloa, Iñigo

2011-05-05

220

Spectral and lasing properties of J-series blue-green new laser dye  

SciTech Connect

Five J-series blue-green laser dyes were synthesized. It was found that these dyes have a wide laser tuning range from 436 to 500 nm excited by N/sub 2/ laser. The conversion efficiency is close to that of laser dye C120.

Yan Fuju; Teng Yueli; Cheng Zhusheng; Li Xiaotu; Huang Dezao

1987-12-01

221

Spectral and lasing properties of J-series blue-green new laser dye  

Microsoft Academic Search

Five J-series blue-green laser dyes were synthesized. It was found that these dyes have a wide laser tuning range from 436 to 500 nm excited by Nâ laser. The conversion efficiency is close to that of laser dye C120.

Yan Fuju; Teng Yueli; Cheng Zhusheng; Li Xiaotu; Huang Dezao

1987-01-01

222

Mechanism of dye-enhanced pulsed laser ablation of hard tissues: implications for dentistry  

Microsoft Academic Search

Alexandrite laser ablation of enamel enhanced by an indocyanine green dye was studied. A microjet system was employed to deliver precisely measured small amounts of absorbing dye solution to the site of irradiation. A sequence of physical phenomena involved in dye-enhanced laser ablation of dental enamel was revealed when laser pulse profiles were compared with the profiles of laser-induced pressure,

Rinat Esenaliev; Alexander Oraevsky; Sohi Rastegar; Chris Frederickson; Massoud Motamedi

1996-01-01

223

Tm Doped Fiber Laser Pumped by a Cladding-Pumped Er, Yb Fiber Laser.  

National Technical Information Service (NTIS)

This report results from a contract tasking University of Southampton as follows: The Grantee will investigate (a) optimization of the cladding- pumped Er-Yb doped fiber laser (EYDFL) for efficient pumping of Tm- doped fibers. (b) Investigation of core-pu...

W. A. Clarkson

2006-01-01

224

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

225

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

226

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

PubMed

We report the use of GaAlAs laser-diode arrays to pump a cw Nd:YAG laser operating on the 946-nm (4)F(3/2) ? (4)I(9/2) transition. At room temperature, the lasing threshold was reached with 58 mW of absorbed pump power, and, with 175 mW of absorbed pump power, 42 mW of output power at 946 nm was obtained in a TEM(00) mode by using 0.7% output coupling. In addition, pumping with an infrared dye laser operating in a pure TEM(00) mode was used to investigate the effects of reabsorption loss that are characteristic of the 946-nm laser transition. LiIO(3) was used as an intracavity doubling crystal, and 100 microW of blue light was generated by using diode-laser pumping in a nonoptimized cavity. PMID:19741939

Risk, W P; Lenth, W

1987-12-01

227

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

SciTech Connect

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

Risk, W.P.; Lenth, W.

1987-12-01

228

High-efficiency laser-pumping system for magnetic resonance imaging  

NASA Astrophysics Data System (ADS)

Recently the demand for hyperpolarized noble gases is arising to improve NMR spectroscopy resolution for imaging. Hyperpolarization of noble gases is achieved by spin- exchange with alkali metal. atoms that undergo optical pumping by circularly polarized radiation. Optical pumping is usually achieved by high power semiconductor lasers. These sources have a bandwidth very large when compared with the transition bandwidth of the optically active species. This has two serious consequences: (i) the request of high power lasers, (ii) the losses that the unemployed energy delivered to the Rb vapor can provide in the efficiency of the energy transfer. Object of our investigation will be the comparison of two experimental set ups for optical pumping of Rb vapor where pumping is given in one case by a dye laser pumped by a UV nitrogen laser built in our laboratory according to the Blumlein scheme and in the other case by a semiconductor laser. Major elements that will be discussed are (1) the role of stimulated emission of Rb vapor to increase the pumping efficiency, (2) the fate of resonant photons that are emitted during Rb decays, (3) the role of applied magnetic fields in the efficiency of pumping processes.

Milani, Marziale; Baroni, Guido; Ferraro, Lorenzo; Sozzani, P.; Adobati, Massimo; Ravetta, S.

2000-05-01

229

Polymer photonic crystal dye lasers as label free evanescent cell sensors  

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

230

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

SciTech Connect

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

231

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

232

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

SciTech Connect

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

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

2008-07-31

233

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

234

Enhancement of laser properties of pyrromethene 567 dye incorporated into new organic–inorganic hybrid materials  

Microsoft Academic Search

The incorporation of pyrromethene 567 dye into newly synthesized organic–inorganic hybrid materials, laser photostabilities were demonstrated, which are, to the best of our knowledge, the highest achieved to date for both inorganic and hybrid matrices doped with pyrromethene dyes. These results evidence that, in order to reach the necessary photostability for a solid-state dye laser being competitive with liquid dye

Angel Costela; Inmaculada Garc??a-Moreno; Clara Gómez; Olga Garc??a; Roberto Sastre

2003-01-01

235

UV laser interaction with a fluorescent dye solution studied using pulsed digital holography.  

PubMed

A frequency tripled Q-switched Nd-YAG laser (wavelength 355 nm, pulse duration 12 ns) has been used to pump Coumarin 153 dye solved in ethanol. Simultaneously, a frequency doubled pulse (532 nm) from the same laser is used to probe the solvent perpendicularly resulting in a gain through stimulated laser induced fluorescence (LIF) emission. The resulting gain of the probe beam is recorded using digital holography by blending it with a reference beam on the detector. Two digital holograms without and with the pump beam were recorded. Intensity maps were calculated from the recorded digital holograms and used to calculate the gain of the probe beam due to the stimulated LIF. In addition numerical data of the local temperature rise was calculated from the corresponding phase maps using Radon inversion. It was concluded that about 15% of the pump beam energy is transferred to the dye solution as heat while the rest is consumed in the radiative process. The results show that pulsed digital holography is a promising technique for quantitative study of fluorescent species. PMID:24150372

Amer, Eynas; Gren, Per; Sjödahl, Mikael

2013-10-21

236

Off-axis pumping of a photonic crystal fiber laser  

NASA Astrophysics Data System (ADS)

We present a new method for free space pumping of double-clad photonic crystal fiber lasers and amplifiers. The method is based on off-axis injection of the pump beam, exploiting the relatively high numerical aperture of the photonic crystal fiber cladding. It prevents feedback from the laser into the pump source, does not require any special treatment to the fiber, and could lead to a more compact resonator. Experimental results with the new pumping method show improved laser performance.

Shulga, B.; Ishaaya, A. A.

2010-12-01

237

Laser Wakefield acceleration with high relativistic pumps  

SciTech Connect

Preliminary scaling laws are found for the laser wakefield accelerator in the very non-linear regime where the normalized laser pump strengh {ital V}{sub osc}{ital c}={ital eE}{sub 0}/{ital m}{omega}{sub 0}{ital c}{gt}1. Two important non-linear effects are an increase in the wake phase velocity (and hence the particle dephasing length) and an increase in the laser pulse length for optimal wake excitation. Application of the results to the proposed Livermore High-Brightness Lasers (HBL) is discussed here and in the accompanying paper by C. B. Darrow, {ital et} {ital al}. A preliminary 1-D PIC simulation is presented. {copyright} 1989 American Institute of Physics

Katsouleas, T.; Mori, W.B. (University of California at Los Angeles, Los Angeles, CA 90024 (US)); Darrow, C.B. (Lawrence Livermore National Laboratory, Livermore, CA 94550 (US))

1989-10-15

238

Linearly polarised three-colour lasing emission from an evanescent wave pumped and gain coupled fibre laser  

NASA Astrophysics Data System (ADS)

A novel Whispering-Gallery-Mode (WGM) fibre laser, emitting linearly polarised three-colour light, is demonstrated by pumping and gain coupling with evanescent waves. The pump light is longitudinally coupled into a bare optical fibre immersed in a dye solution of lower refractive index. The dye molecules around the bare fibre are excited by the evanescent waves of pump light when they propagate along the fibre in a total internal reflection. When the pump beam within the fibre is a meridian beam, the WGM lasing emission from the fibre laser is a linearly polarised transverse electric wave, while it is a mixed wave of the linearly polarised transverse electric and magnetic waves if the pump beam is a skew beam within the fibre. Because the excited molecules are located within the evanescent field of WGM, a good spatial overlap between the dye gain and the evanescent field leads to a high pumping efficiency and a longer gain distance along the fibre. Once the bare fibre is inserted into three glass capillaries filled with Rhodamine 6G, 610 and 640 dye solutions, respectively, WGM laser oscillations at the wavelengths of 567-575, 605-614 and 656-666 nm occur simultaneously, and a linearly polarised three-colour lasing emission is achieved in a single optical fibre.

Pu, Xiao-Yun; Jiang, Nan; Han, De-Yu; Feng, Yong-Li; Ren, Yi-Tao

2010-05-01

239

In-well pumping of InGaN/GaN vertical-external-cavity surface-emitting lasers  

NASA Astrophysics Data System (ADS)

In-well-pumped blue InGaN/GaN vertical-external-cavity surface-emitting lasers are demonstrated. The laser structures were grown on bulk GaN substrates by using metal-organic vapor phase epitaxy near atmospheric pressure. The active zone consisted of up to 20 InGaN quantum wells distributed in a resonant periodic gain configuration. High-reflectivity dielectric distributed Bragg-reflectors were used as mirrors. Laser emission with a single longitudinal mode at 440 nm was achieved by exclusively pumping the quantum wells with the 384 nm emission line of a dye-/N2-laser.

Wunderer, Thomas; Northrup, John E.; Yang, Zhihong; Teepe, Mark; Strittmatter, André; Johnson, Noble M.; Rotella, Paul; Wraback, Michael

2011-11-01

240

Semiconductor Laser Diode Pumps for Inertial Fusion Energy Lasers  

SciTech Connect

Solid-state lasers have been demonstrated as attractive drivers for inertial confinement fusion on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) and at the Omega Facility at the Laboratory for Laser Energetics (LLE) in Rochester, NY. For power plant applications, these lasers must be pumped by semiconductor diode lasers to achieve the required laser system efficiency, repetition rate, and lifetime. Inertial fusion energy (IFE) power plants will require approximately 40-to-80 GW of peak pump power, and must operate efficiently and with high system availability for decades. These considerations lead to requirements on the efficiency, price, and production capacity of the semiconductor pump sources. This document provides a brief summary of these requirements, and how they can be met by a natural evolution of the current semiconductor laser industry. The detailed technical requirements described in this document flow down from a laser ampl9ifier design described elsewhere. In brief, laser amplifiers comprising multiple Nd:glass gain slabs are face-pumped by two planar diode arrays, each delivering 30 to 40 MW of peak power at 872 nm during a {approx} 200 {micro}s quasi-CW (QCW) pulse with a repetition rate in the range of 10 to 20 Hz. The baseline design of the diode array employs a 2D mosaic of submodules to facilitate manufacturing. As a baseline, they envision that each submodule is an array of vertically stacked, 1 cm wide, edge-emitting diode bars, an industry standard form factor. These stacks are mounted on a common backplane providing cooling and current drive. Stacks are conductively cooled to the backplane, to minimize both diode package cost and the number of fluid interconnects for improved reliability. While the baseline assessment in this document is based on edge-emitting devices, the amplifier design does not preclude future use of surface emitting diodes, which may offer appreciable future cost reductions and increased reliability. The high-level requirements on the semiconductor lasers involve reliability, price points on a price-per-Watt basis, and a set of technical requirements. The technical requirements for the amplifier design in reference 1 are discussed in detail and are summarized in Table 1. These values are still subject to changes as the overall laser system continues to be optimized. Since pump costs can be a significant fraction of the overall laser system cost, it is important to achieve sufficiently low price points for these components. At this time, the price target for tenth-of-akind IFE plant is $0.007/Watt for packaged devices. At this target level, the pumps account for approximately one third of the laser cost. The pump lasers should last for the life of the power plant, leading to a target component lifetime requirement of roughly 14 Ghosts, corresponding to a 30 year plant life and 15 Hz repetition rate. An attractive path forward involes pump operation at high output power levels, on a Watts-per-bar (Watts/chip) basis. This reduces the cost of pump power (price-per-Watt), since to first order the unit price does not increase with power/bar. The industry has seen a continual improvement in power output, with current 1 cm-wide bars emitting up to 500 W QCW (quasi-continuous wave). Increased power/bar also facilitates achieving high irradiance in the array plane. On the other hand, increased power implies greater heat loads and (possibly) higher current drive, which will require increased attention to thermal management and parasitic series resistance. Diode chips containing multiple p-n junctions and quantum wells (also called nanostack structures) may provide an additional approach to reduce the peak current.

Deri, R J

2011-01-03

241

Towards XUV lasers with charge transfer pumping  

Microsoft Academic Search

Detailed studies of charge exchange pumping of ions in femtosecond laser-produced plasmas colliding with a pulsed gas jet are presented. Strong selective excitation of XUV ionic transitions in the reaction C4++H?C3++H+ is observed. Dependences of line intensities on various experimental parameters are reported which are in good agreement with the theory of charge transfer processes. Analyses of experimental data provide

I. F. Shaikhislamov; V. A. Vorontsov; M. Born; B. N. Chichkov; B. Wellegehausen

2006-01-01

242

Experimental test of a four-level kinetic model for excited-state intramolecular proton transfer dye lasers  

NASA Astrophysics Data System (ADS)

The nanosecond pulses of a dye laser oscillator based on the excited-state intramolecular proton-transfer reaction (IPT) of salicylamide and 2'-hydroxylphenyl benzimidazole dyes have been studied as a function of several experimental parameters. To explain the operation of this laser a numerical four-level kinetic model was developed until the lasing properties of these dyes, in the presence of a variable oxygen concentration and pumped with a double pulse technique, could be reproduced. This was possible only by assuming that the efficiency of the laser is controlled by the absorption cross-section of a transient state with a lifetime in the nanosecond-picosecond range, which was tentatively identified as a ground state tautomeric species.

Costela, A.; Muñoz, J. M.; Douhal, A.; Figuera, J. M.; Acuña, A. U.

1989-12-01

243

Applications for reactor-pumped lasers  

SciTech Connect

Nuclear reactor-pumped lasers (RPLs) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

Lipinski, R.J.; McArthur, D.A. [Sandia National Labs., Albuquerque, NM (United States). Nuclear Systems Research

1994-10-01

244

Applications for reactor-pumped lasers  

NASA Astrophysics Data System (ADS)

Nuclear reactor-pumped lasers (RPL's) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth's shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

Lipinski, R. J.; McArthur, D. A.

245

A blackbody radiation-pumped CO2 laser experiment  

NASA Astrophysics Data System (ADS)

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

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

1982-09-01

246

Simultaneous wavelength-stabilization of 980-nm pump lasers  

Microsoft Academic Search

High power 980-nm strained QW semiconductor lasers connected to the input ports of a 4×4-fused fiber star coupler are simultaneously wavelength-locked through reflection from a single narrow-band fiber grating connected to one output port. This configuration enables simple pump wavelength control, inhibits deleterious pump-laser interactions, and improves amplifier reliability through pump redundancy

C. R. Giles; T. Erdogan; V. Mizrahi

1994-01-01

247

[Ureteral lithotripsy with rigid ureteroscopy and pulsed dye laser].  

PubMed

Pulsed dye laser lithotripsy represents nowadays a new approach to ureteral stones. 27 patients were treated with a pulsed dye laser unit (Pulsolith TM) at our department from november 1989 to january 1990. 21 had a single stone and the remaining a multiple ureteral lithiasis. The pulsed dye laser operated at a wave length of 504 nm, energy ranged between 90 and 160 mj with pulse of 1,5 ms. A 320 theta diameter quartz fiber with Helium Neon red laser (to visualize the top of the fiber) introduced in a rigid 9.5 ureteroscope (Wolf) was used during the procedure. Spinal, peridural or general anesthesia was done in all patients and the time of the procedure ranged between 8-150 minutes. Fiber was inserted in a 4 Ch ureteral catheter which provided easier manipulation of the fiber. Complete fragmentation was achieved in 88.9% of the patients, and combined manoeuvres were requested in another 3.7%. Failures were 7.4%. Minimal lesions of the ureter, due to ureteroscope advancement subsided spontaneously after placement of double F catheter. Pulsed dye laser lithotripsy seems to be a safe and useful procedure for treatment of impacted ureteral calculi and seems to offer low morbidity in respect of ultrasonic or electrohydraulic procedures especially when the stone location does not permit an ESWL approach. PMID:1677489

Scarpa, R M; Migliari, R; De Lisa, A; Campus, G; Usai, M; Usai, E

1991-03-01

248

High-power diode laser pumps for alkali lasers (DPALs)  

NASA Astrophysics Data System (ADS)

We present performance data of recent high-power laser diodes emitting at typical pump wavelengths for alkali vapor lasers: 852 nm for cesium, 780 nm for rubidium, 766 nm for potassium, and 670 nm for lithium atoms. Due to different approaches in alkali laser systems, we report on usual pumps at these non-standard wavelengths with typical line widths of a few nm used for collisional and pressure broadened gas absorption lines as well as on wavelength stabilized laser diodes using volume Bragg gratings (VBGs) for systems with narrow gas absorption lines. The detailed characterization of laser diodes available at DILAS includes power, efficiency, spectral data, and life time results. While bars at 6xx and 7xx nm are limited in optical output power due to the strong in-built strain, especially the bars at 852 nm with a small inbuilt strain have the biggest potential in terms of pump power. The power conversion efficiency in cw operation is as high as 60% at 100 W. Higher power and operation at increased heat sink temperatures up to 50°C are possible depending on lifetime requirements.

Kissel, Heiko; Köhler, Bernd; Biesenbach, Jens

2012-02-01

249

On the coherence measurement of a narrow bandwidth dye laser  

NASA Astrophysics Data System (ADS)

In this paper, we report a new technique for spatial and temporal coherence measurement of narrow bandwidth sources. In particular, coherence measurement of a narrow bandwidth dye laser using Young's double slit method and the Fabry-Perot interferometer has been carried out. In the spatial coherence measurement, a central fringe visibility of 0.85 was observed, and from this measurement, the dye gain medium source size was estimated. The variation in the visibility with slit separation (0.1-3.0 mm) for different source sizes (0.1-0.2 mm) was also analyzed. The temporal coherence length of the tunable dye laser was measured to be 10 and 60 cm for multimode and single-mode operations, respectively. The technique, in general, can also be used for spatial and temporal measurement of broadband spectrum source.

Singh, Nageshwar; Vora, H. S.

2013-03-01

250

Quantum-mechanical theory of the organic-dye laser  

Microsoft Academic Search

We develop a fully quantum-mechanical theory for the organic-dye-solution laser, obtain density-matrix equations of motion for the single-mode radiation-density operator and the matter-density operator, and solve and investigate the steady-state case. We generalize the usual Born-Markoff approximation master equation for two matter states to include four matter states, each one of which interacts with the laser radiation field. This allows

R. B. Schaefer; C. R. Willis

1976-01-01

251

Potential of Solar-Simulator-Pumped Alexandrite Lasers.  

National Technical Information Service (NTIS)

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 ...

R. J. Deyoung

1990-01-01

252

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

253

a Blackbody-Pumped Carbon Dioxide Laser  

NASA Astrophysics Data System (ADS)

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

Insuik, Robin Joy

254

Multimode-diode-pumped gas (alkali-vapor) laser  

NASA Astrophysics Data System (ADS)

We report what we believe to be the first demonstration of a multimode-diode-pumped gas laser: Rb vapor operating on the 795 nm D1 resonance transition. Peak output of ˜1W was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays) is therefore possible.

Page, Ralph H.; Beach, Raymond J.; Kanz, V. Keith; Krupke, William F.

2006-02-01

255

Multimode-diode-pumped gas (alkali-vapor) laser  

Microsoft Academic Search

We report the first demonstration of a multimode-diode-pumped gas laser--Rb vapor operating on the 795 nm resonance transition. Peak output of â1 Watt was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays) is therefore possible.

R H Page; R J Beach; V K Kanz

2005-01-01

256

Multimode-diode-pumped gas (alkali-vapor) laser  

SciTech Connect

We report the first demonstration of a multimode-diode-pumped gas laser--Rb vapor operating on the 795 nm resonance transition. Peak output of {approx}1 Watt was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays) is therefore possible.

Page, R H; Beach, R J; Kanz, V K

2005-08-22

257

Multimode-diode-pumped gas (alkali-vapor) laser  

Microsoft Academic Search

We report what we believe to be the first demonstration of a multimode-diode-pumped gas laser: Rb vapor operating on the 795 nm D1 resonance transition. Peak output of ˜1W was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays)

Ralph H. Page; Raymond J. Beach; V. Keith Kanz; William F. Krupke

2006-01-01

258

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

National Technical Information Service (NTIS)

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

D. A. McArthur J. V. Walker

1976-01-01

259

High-energy transversely pumped alkali vapor laser  

NASA Astrophysics Data System (ADS)

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

Zweiback, J.; Komashko, A.

2011-02-01

260

High efficiency CW green-pumped alexandrite lasers  

NASA Astrophysics Data System (ADS)

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

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

2006-03-01

261

Dye-enhanced laser welding for skin closure.  

PubMed

The use of a laser to weld tissue in combination with a topical photosensitizing dye permits selective delivery of energy to the target tissue. A combination of indocyanine green (IG), absorption peak 780 nm, and the near-infrared (IR) alexandrite laser was studied with albino guinea pig skin. IG was shown to bind to the outer 25 microns of guinea pig dermis and appeared to be bound to collagen. The optical transmittance of full-thickness guinea pig skin in the near IR was 40% indicating that the alexandrite laser should provide adequate tissue penetration. Laser "welding" of skin in vivo was achieved at various concentrations of IG from 0.03 to 3 mg/cc using the alexandrite at 780 nm, 250-microseconds pulse duration, 8 Hz, and a 4-mm spot size. A spectrum of welds was obtained from 1- to 20-W/cm2 average irradiance. Weak welds occurred with no thermal damage obtained at lower irradiances: stronger welds with thermal damage confined to the weld site occurred at higher irradiances. At still higher irradiances, local vaporization occurred with failure to "weld." Thus, there was an optimal range of irradiances for "welding," which varied inversely with dye concentration. Histology confirmed the thermal damage results that were evident clinically. IG dye-enhanced laser welding is possible in skin and with further optimization may have practical application. PMID:1377319

DeCoste, S D; Farinelli, W; Flotte, T; Anderson, R R

1992-01-01

262

Dye-enhanced diode laser photocoagulation of choroidal neovascularizations  

NASA Astrophysics Data System (ADS)

Dye-enhanced diode laser photocoagulation, using the dye indocyanine green (ICG), has shown some potential in the treatment of choroidal neovascularizations (CNV). A diode laser system was developed and optimized to emit at the absorption maximum of ICG. In a clinical study at two retinal centers, more than 70 patients, the majority of which had age-related macular degeneration, were treated. Eighteen cases with ill-defined subfoveal CNV were followed an average of 11 months after laser treatment. The results show success in resolving the CNV with an average long-term preservation of visual function equal to or superior to data provided by the Macular Photocoagulation Study for confluent burns of low intensity applied to the CNV. Details of the technique and discussion of the controversies inherent in such a treatment strategy will be presented.

Klingbeil, Ulrich; Puliafito, Carmen A.; McCarthy, Dan; Reichel, Elias; Olk, Joseph; Lesiecki, Michael L.

1994-06-01

263

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

SciTech Connect

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

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

1997-08-01

264

DOE reactor-pumped laser program  

SciTech Connect

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

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

1993-12-31

265

DOE reactor-pumped laser program  

NASA Astrophysics Data System (ADS)

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

Felty, James R.; Lipinski, Ronald J.; McArthur, David A.; Pickard, Paul S.

1994-05-01

266

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

267

Optical spectrum and lasing characteristics of the laser dye Carbostyil 124  

SciTech Connect

Laser dye Carbostyil 124 was synthesized. The spectral and laser properties of the dye were given, it is wavelength tunable from 400 to 438 nm, with lambda/sub max/ at 419 nm. Compared with the dye Coumarin 120, the wavelength is blue-shifted and the efficiency is lower.

Yen Fuchun; Huang Dejao; Zheng Zushen; Teng Yueli

1986-11-01

268

Enhancing Sun-pumped laser performance by a truncated fused silica elliptical pump cavity  

Microsoft Academic Search

Sun-pumped lasers are useful for space and terrestrial applications. In terms of collection efficiency and beam quality, solar lasers still have a way to go to seriously compete with solar PV-cell diode-pumped solid-state lasers. The main challenges are the needs of both doubling the reported collection efficiency of 6.7 W\\/m2 and improving the beam quality of today's solar lasers. To

Dawei Liang; R. Pereira; P. Bernardes

2007-01-01

269

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

SciTech Connect

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

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

1995-04-01

270

Nonlinear Pump Depletion and Electron Dephasing in Laser Wakefield Accelerators  

SciTech Connect

The nonlinear evolution of sub-ps laser pulses in underdense plasmas is analyzed for arbitrary laser intensity. Expressions for the nonlinear pump depletion, pulse steepening, and frequency shift of the laser pulse are derived. Numerical calculations based on fluid models that show the interplay between electron dephasing and pump depletion are presented. Implications for an optimized design of a 1 GeV laser-plasma-based accelerator stage are discussed.

Esarey, E.; Schroeder, C.B.; Leemans, W.P. [Center for Beam Physics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Shadwick, B.A. [Center for Beam Physics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Institute for Advanced Physics, Suite 199, 10875 US Hwy 285, Conifer, CO 80433 (United States)

2004-12-07

271

Comparison of lasers for photodynamic therapy with a phthalocyanine photosensitizer  

Microsoft Academic Search

Three different lasers were compared under the same conditions for their effectiveness at producing photodynamic damage to\\u000a normal colon following sensitization with aluminium sulphonated phthalocyanine (AlSPc). One laser was an argon ion pumped\\u000a continuous wave (CW) dye laser and the other two were pulsed at 10 kHz (copper vapour laser pumped dye laser, and 5 Hz (flashlamp\\u000a pumped dye laser).

H. Barr; P. B. Boulos; A. J. Macrobert; C. J. Tralau; D. Phillips; S. G. Bown

1989-01-01

272

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

2011-02-01

273

Preferential operation of an end-pumped Nd:YAG laser in high-order Laguerre--Gauss modes  

SciTech Connect

A small Nd:YAG laser with plano-concave resonator end pumped by a dye laser is observed to possess single Laguerre--Gauss transverse modes as the lowest-loss modes. This anomalous behavior occurs when the transverse dimension of the gain spot is much smaller than the fundamental TEM{sub 00}-mode spot size of the resonator; the Laguerre--Gauss transverse-mode order varies with resonator length.

Flood, C.J.; Giuliani, G.; van Driel, H. (Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (CA))

1990-02-15

274

Ti:sapphire laser pumped by a frequency-doubled diode-pumped Nd:YLF laser  

Microsoft Academic Search

We report on the operation of a tunable all-solid-state (holosteric) laser system consisting of a tunable Ti:sapphire laser pumped by a frequency-doubled diode-laser-pumped Nd:YLF laser. With a 1-W pump diode, the Nd-YLF laser has been frequency-modulation mode locked and {ital Q} switched at 1.047 μm. This produces a pulse envelope of 75-nsec duration with 45 μJ of energy in 21-psec

G. T. Maker; A. I. Ferguson

1990-01-01

275

1.3 ?m Solid-State Plastic Laser in Dye-Doped Fluorinated-Polyimide Waveguide  

NASA Astrophysics Data System (ADS)

1.3 ?m solid-state plastic lasers were fabricated using fluorinated-polyimide (FPI) as the host matrix of the active waveguide doped with near-infrared organic dye, IR26. Fabry--Perot type lasing oscillation was observed from the waveguide by using the cleaved waveguide edges under 1.064 ?m Nd:YAG laser pulse pumping. The lasing threshold was 4.3 mJ/cm2 and the lasing emission shows transverse electric mode polarization. Photostability of IR26-doped FPI waveguide is shown to be fairly good in the durability test under 1.064 ?m laser pumping. This is the first report of plastic lasers in optical communication waveband.

Morishita, Takashi; Yamashita, Kenichi; Yanagi, Hisao; Oe, Kunishige

2010-09-01

276

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

National Technical Information Service (NTIS)

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

P. R. Hammond

1983-01-01

277

Alexandrite laser pumped LiF:F2- laser  

NASA Astrophysics Data System (ADS)

For the first time to our knowledge a direct alexandrite laser pumping of LiF:F2- crystals was suggested and realized by means of energy transfer from the F3- to the F2- color centers (CCs). Tunable laser oscillation of LiF:F2- in the 1000-1300 nm spectral range with a maximum efficiency of 10% was achieved. The process of two-step photo-ionization of the F3- CCs under 740 nm excitation was demonstrated experimentally on the basis of the measured decay rate of F3- centers. The photo-ionization cross-section from the first excited level of F3- centers was calculated to be 2×10-22 cm2. Stable output lasing of the LiF:F2- laser at room temperature under 793 nm excitation was predicted and realized.

Mirov, S. B.; Fedorov, V. V.; Xie, L.; Boczar, B.; Frost, R.; Pryor, B.

2001-11-01

278

High reliability 980-nm pump lasers for Er amplifiers  

Microsoft Academic Search

The erbium-doped fiber amplifier (EDFA) has a profound impact on fiber optic transmission systems in telecommunications as well as cable television. The EDFA can employ pump laser diodes (pumps) at 980 nm or 1480 nm. Due to their fundamental performance advantages in noise figure and useful optical bandwidth 980 nm pumps have been preferred in all applications with the exception

C. S. Harder; L. Brovelli; H. P. Meier; A. Oosenbrug

1997-01-01

279

Resonantly pumped continuous wave Er:YAP laser  

NASA Astrophysics Data System (ADS)

A continuous wave Er:YAP laser pumped by Mgo:PPLN laser locked at 1535 nm was reported. 170 mW of 1609 nm output was achieved under total incident pump power of 7 W at 77 K. The slope efficiency were 5.0 and 3.1% with the cavity length 75 and 140 mm.

Yao, B. Q.; Liu, X. L.; Yu, L. X.; Sun, X. H.; Chen, Z. Y.; Wang, Y. Z.

2012-04-01

280

Optically Pumped 15.90 Micrometers SF6 Laser.  

National Technical Information Service (NTIS)

Optically pumped vibrational transition lasing has been achieved for the first time in a nonlinear molecule. Laser radiation at 628.74 + or - 0.02/cm was generated from SF6 using CO2 TEA laser excitation. The SF6 pumping is shown to be via absorption of t...

W. E. Barch H. R. Schlossberg H. R. Fetterman

1975-01-01

281

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

282

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

283

CO/sub 2/ optically pumped distributed feedback diode laser  

SciTech Connect

A diode laser optically pumped by a CO/sub 2/ coherent source is described. Interference fringes generated by feeding the optical pumping beam against a second beam, periodically alter the reflectivity of the diode medium allowing frequency variation of the output signal by varying the impingent angle of the CO/sub 2/ laser beams.

Rockwood, S.D.

1980-11-25

284

Diode-pumped femtosecond Cr:LiSAF laser  

NASA Astrophysics Data System (ADS)

In this paper, we report the diode pumped femtosecond Cr:LiSAF laser. Through numerical analysis on the astigmatism, a folded three-mirror cavity is designed. Then we investigate its CW and mode locking operation. When it is pumped by the pulse, the output laser with time duration less than 100 fs is obtained.

Ruan, Shuangchen; Mao, Yanli; Yang, Jianjun; Zhang, Fan; Hou, Xun; Liu, Yuhua

1999-06-01

285

Development of tunable Ti:sapphire laser using a laser-diode-pumped slide-state laser.  

National Technical Information Service (NTIS)

We developed the pulsed laser-diode-pumped solid-state laser and the tunable Ti-Sapphire laser as a basic research for developing holosteric(all solid-state) laser system. The radiation properties of the laser diode are measured to be used as a pumping so...

B. T. Kim C. S. Chung J. U. Lee D. S. Kim H. G. Lee

1994-01-01

286

Raman fiber laser-pumped 2-?m fiber laser  

NASA Astrophysics Data System (ADS)

We have demonstrated a Tm-Ho-codoped silica fiber laser pumepd by a third-stokes Raman Fiber Laser (RFL) at 1212 nm. RFL consists of Yb-double clad fiber laser (DCFL) as a pump, 1-km Single mode fiber (SMF) and cascated cavities made with fiber Bragg gratings (FBG). For the 30-cm-long Tm-Ho-codoped silica fiber, the output power of 400 mW is obtained at wavelength of 1790 nm (due to the laser radiations of Tm3+ ions). The optical-optical conversion efficiency and the slope efficiency are 18% and 23%, respectively. For the 270-cm-long Tm-Ho-codoped silica fiber, the output power of 450 mW is obtained at 1970 nm; this is the laser emission from Ho3+ ions. The optical efficiency is 18% and the slope efficiency is measured to be 31%. This is the highest output power ever reported for a Tm-Ho-codoped silica fiber laser.

Taniguchi, Atsushi; Kuwayama, Tetsuro; Shirakawa, Akira; Musha, Mitsuru; Ueda, Ken-ichi; Prabhu, Mahendra

2003-10-01

287

Treatment of facial skin using combinations of CO2, Q-switched alexandrite, and/or flashlamp-pumped dye and/or erbium lasers in the same treatment session  

NASA Astrophysics Data System (ADS)

Skin aging caused from chronological and photodamage processes results in many alterations in skin appearance. In many circumstances, patients who pursue CO2 laser resurfacing for facial rejuvenation are also concerned with other photoaging alternations that are beyond the efficacy of the CO2 laser. We demonstrated an approach to aged facial skin by using combined treatments of appropriate lasers.

Fitzpatrick, Richard E.; Manuskiatti, Woraphong; Goldman, Mitchel P.

1998-07-01

288

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

289

High average power diode array pumped frequency doubled YAG laser  

Microsoft Academic Search

In order to obtain high average power in the green, a diode pumped laser program is under development. High average power (tens of watts) and high repetition rate (tens of kilohertz) require: cw diode array pumping, high Q-switching and intra-cavity second harmonic array generation. We report the demonstration of a transversely diode array pumped frequency doubled Nd:YAG laser. The 35

B. J. Le Garrec; G. J. Raze; P. Y. Thro; M. Gilbert

1996-01-01

290

Improving the efficiency of certain optically pumped lasers  

SciTech Connect

The operating efficiency of CW optically pumped FIR lasers is investigated analytically, examining the small-signal absorption of a symmetric-top molecule undergoing a parallel-band Q rotational transition. It is shown that resonant pumping of a transition with a higher K quantum number can increase the absorption of pump power and hence the lasing efficiency. The case of a CH3F laser is analyzed numerically, and some results are presented in graphs and tables. 16 references.

Barkley, H.J.; Sharp, L.E.

1984-05-01

291

Operation of diode laser pumped Tm3+ ZBLAN upconversion fiber laser at 482 nm  

Microsoft Academic Search

Lasing at 482 nm is observed in Tm3+-doped ZBLAN glass fiber pumped with single-mode InP semiconductor diode lasers. Up to 5 mW of 482 nm light is obtained with <40 mW of absorbed pump power from a single 1135 nm pump diode laser. The optimum pump wavelength is measured to be 1135-1340 nm. More efficient laser operation is observed in

Ian J. Booth; Colin J. Mackechnie; Brian F. Ventrudo

1996-01-01

292

Demonstration of the longitudinal modes and aberration-correction properties of a continuous-wave dye laser with a phase-conjugate mirror  

SciTech Connect

We have experimentally demonstrated a cw dye laser incorporating a phase-conjugate mirror (PCM). The mirror was generated by using four-wave mixing in sodium. The unique bandwidth and pump--probe detuning properties of such a PCM permitted the first reported demonstration of the c/4L spaced paired half-axial modes. In addition, the aberration correction ability is demonstrated.

Lind, R.C.; Steel, D.G.

1981-11-01

293

Investigation of time-dependent correlation properties of the bidirectional dye ring laser  

SciTech Connect

Fluctuations of the two mode intensities in an Rh6G-dye ring laser have been investigated experimentally by two-time photoelectric autocorrelation and cross-correlation measurements, over a range of working points from well below to well above threshold. The results are compared with computer solutions of the laser equations of motion containing both additive (quantum) noise and multiplicative (pumping) noise. The former noise is taken to be white, and the latter Lorentzian. Reasonable agreement between theory and experiment is obtained. Very large intensity fluctuations are observed just below threshold, which are attributable to pumping fluctuations. In this domain of operation both laser modes turn on and off together, and the intensity cross-correlation function is positive with relatively short correlation time. Well above threshold, on the other hand, the laser switches alternately between the two modes, and the intensity cross correlation is negative with long time constant. The mode switching is associated with quantum, or spontaneous emission, fluctuations and disappears in their absence. A graph of correlation time versus intensity exhibits a drastic steepening in the region where mode switching commences, even on a logarithmic scale, and this is consistent with first-passage time calculations.

Lett, P.; Mandel, L.

1985-10-01

294

Polymer photonic crystal dye lasers as label free evanescent cell sensors  

Microsoft Academic Search

Dye doped polymer photonic crystal band edge lasers are applied for evanescent wave sensing of cells. The lasers are rectangular shaped slab waveguides of dye doped polymer on a glass substrate, where a photonic crystal is formed by 100 nm deep air-holes in the surface of the 375 nm high waveguides. The lasers are fabricated by combined nanoimprint and photolithography

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

2009-01-01

295

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

296

Resonantly diode-pumped Er:YAG laser: 1470-nm versus 1530-nm CW pumping case  

NASA Astrophysics Data System (ADS)

Growing interest to high power lasers in the eye-safe spectral domain initiated a new wave of activity in developing solid-state lasers based on bulk Er3+-doped materials. The resonant pumping of SSL allows for shifting significant part of thermal load from gain medium itself to the pump diodes, thus greatly reducing gain medium thermal distortions deleterious to SSL power scaling with high beam quality. The two major resonant pumping bands in Er:YAG are centered around 1470 and 1532 nm. Pumping into each of these bands has its pros and contras. The best approach to resonant pumping of Er:YAG active media in terms of pump wavelength is yet to be determined. We report the investigation results of high power diode-pumped Er:YAG laser aimed at direct comparison of resonant pumping at 1470 and 1532 nm. Two sources used for pumping were: 1530-nm 10-diode bar stack (>300 W CW) and 1470-nm 10-diode bar stack (>650 W CW). Both pumps were spectrally narrowed by external volume Bragg gratings. The obtained spectral width of less than 1 nm allowed for 'in-line' pumping of Er3+ in either band. The obtained CW power of over 87 W is, to the best of our knowledge, the record high power reported for resonantly pumped Er:YAG DPSSL at room temperature.

Kudryashov, Igor; Ter-Gabrielyan, Nikolai; Dubinskii, Mark

2009-05-01

297

Flashlamp-pumped Cr:LiSAF laser amplifier  

Microsoft Academic Search

A flashlamp-pumped Cr:LiSAF laser amplifier has been developed that is capable of producing ultrashort pulses with a peak power of ~TW. A systematic experimental study of laser oscillation, its small-signal gain, and chirped-pulse amplification has been performed under the same pumping conditions. The characteristic properties and performance of the Cr:LiSAF laser amplifier are reported

Hideyuki Takada; Kenzo Miyazaki; Kenji Torizuka

1997-01-01

298

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

299

CONTROL OF LASER RADIATION PARAMETERS. [BR]ULTRASHORT RADIATION PULSES: Generation of ultrashort light pulses in a dye laser with injection of a stimulated seed signal  

NASA Astrophysics Data System (ADS)

An analysis is made of the conditions for the self-excitation of a dye laser subjected to extremely unsteady pumping when after each pump pulse the initial gain changes greatly during a round trip of a wave across the laser cavity. An analytic expression is obtained for the criterion of unsteady self-excitation which reduces in the limit to the familiar steady-state condition. Recurrence relationships are derived for the kinetics of the rise of the subthreshold gain when the pumping is provided by a train of ultrashort light pulses. These relationships can be used to calculate the number of pulses needed to attain the self-excitation conditions. The results of the analysis are used to study the realisation and characteristics of two new scenarios of the excitation of synchronously pumped lasers with injection of a seed signal which can be either superfluorescence or radiation from an auxiliary low-Q, but 'rapidly switched', laser. Important advantages of these scenarios are a large reduction in the lasing threshold and a widening of the range of active media which can be used in synchronously pumped lasers.

Rozuvan, S. G.; Tikhonov, E. A.

1994-08-01

300

Operating temperature of diode-pumped alkali vapor laser  

Microsoft Academic Search

Diode-pumped alkali vapor laser (DPAL) is a new class of laser, and it is expected to realize high efficiency and high-average-power laser with good beam quality (near-diffraction-limited). DPAL offers CW laser radiation at near-infrared wavelengths and can find a lot of applications in power beaming, drilling oil and gas well and laser material processing. Operating temperature affects not only the

Qiang Zhu; Jianhua Yu; Wei Zheng; Hongyan Quan

2008-01-01

301

High-intensity coherent vacuum ultraviolet source using unfocussed commercial dye lasers  

NASA Astrophysics Data System (ADS)

Using two or three commercial pulsed nanosecond dye lasers pumped by a single 30 Hz Nd:YAG laser, generation of 0.10 mJ pulses at 125 nm (6 × 1013 photons/pulse) has been demonstrated by resonance enhanced four-wave mixing of collimated (unfocussed) laser beams in mercury (Hg) vapor. Phase matching at various vacuum ultraviolet (VUV) wavelengths is achieved by tuning one laser in the vicinity of the 6 1S0 --> 6 3P1 resonance near 253.1 nm. A number of different mixing schemes are characterized. Our observations using broadband lasers (~0.15 cm-1 bandwidths) are compared to previous calculations pertaining to four-wave mixing of low intensity narrowband laser beams. Prospects for further increases in pulse energies are discussed. We find that VUV tuning curves and intensities are in good agreement with theoretical predictions. The utility of the VUV light source is demonstrated by ``soft universal'' single-photon VUV ionization in crossed molecular beam studies and for generation of light at 130.2 nm for oxygen atom Rydberg time-of-flight experiments.

Albert, Daniel R.; Proctor, David L.; Floyd Davis, H.

2013-06-01

302

Optical chaos and hysteresis in a laser-diode pumped Nd doped fiber laser  

Microsoft Academic Search

Modulated pumping of a Nd(3+) doped silica monomode fibre laser has been investigated experimentally. For small modulation depths the laser exhibits a resonance at the relaxation oscillation frequency, providing pulses of a few microseconds duration at a repetition rate in the region of 10 kHz, dependent on the average pump level above threshold. As the pump modulation depth is increased,

M. W. Phillips; H. Gong; A. I. Ferguson; D. C. Hanna

1987-01-01

303

Alexandrite Laser Pumped by Semiconductor Lasers. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

We report the first operation of a direct diode-pumped tunable chromium-doped solid-state laser. A small alexandrite (Cr.BeAl204) crystal was longitudinally pumped by two visible laser diodes. The threshold pump power was 12 mW using the R1 line at 680.4 ...

R. Scheps B. M. Gately J. F. Myers J. S. Krasinski D. F. Heller

1990-01-01

304

Grazing Incidence Pumping for High Efficiency X-ray Lasers  

SciTech Connect

Over the last decade, most laser-driven collisional excitation x-ray lasers have relied on the absorption of the pump energy incident at normal incidence to a pre-formed plasma. The main advantage is that the inversion can be created at various plasma regions in space and time where the amplification and ray propagation processes are best served. The main disadvantage is that different plasma regions regardless of the contribution to the inversion have to be pumped simultaneously in order to make the laser work. This leads to a loss of efficiency. The new scheme of grazing incidence pumping (GRIP) addresses this issue. In essence, a chosen electron density region of a pre-formed plasma column, produced by a longer pulse at normal incidence onto a slab target, is selectively pumped by focusing a short pulse of 100 fs-10 ps duration laser at a determined grazing incidence angle to the target surface. The exact angle is dependent on the pump wavelength and relates to refraction of the drive beam in the plasma. The controlled use of refraction of the pumping laser in the plasma results in several benefits: The pump laser path length is longer and there is an increase in the laser absorption in the gain region for creating a collisional Ni-like ion x-ray laser. There is also an inherent traveling wave, close to c, that increases the overall pumping efficiency. This can lead to a 3-30 times reduction in the pump energy for mid-Z, sub-20 nm lasers. We report several examples of this new x-ray laser on two different laser systems. The first demonstrates a 10 Hz x-ray laser operating at 18.9 nm pumped with a total of 150 mJ of 800 nm wavelength from a Ti:Sapphire laser. The second case is shown where the COMET laser is used both at 527 nm and 1054 nm wavelength to pump higher Z materials with the goal of extending the wavelength regime of tabletop x-ray lasers below 10 nm.

Dunn, J; Keenan, R; Shlyaptsev, V N

2005-10-03

305

Diode-pumped lasers for ultra-high peak power  

NASA Astrophysics Data System (ADS)

The generation of the highest laser peak intensities at a high degree of system compactness can be achieved by combining modern diode-pump technologies with the chirped pulse amplification technique. In principle, the spectroscopic properties of the gain medium determine the scaling laws of both high output pulse energy and short pulse duration. Here we introduce a novel criterion classifying laser materials with respect to their ability to generate pulses of highest peak power in a diode-pumped solid state laser system. Furthermore, amplified spontaneous emission as well as laser damage issues affecting the efficiency and compactness of a laser amplifier system are discussed.

Siebold, M.; Hein, J.; Hornung, M.; Podleska, S.; Kaluza, M. C.; Bock, S.; Sauerbrey, R.

2008-03-01

306

Laser velocimetry with fluorescent dye-doped polystyrene microspheres.  

PubMed

Simultaneous Mie scattering and laser-induced fluorescence (LIF) signals are obtained from individual polystyrene latex microspheres dispersed in an air flow. Microspheres less than 1 ?m mean diameter were doped with two organic fluorescent dyes, Rhodamine B (RhB) and dichlorofluorescein (DCF), intended either to provide improved particle-based flow velocimetry in the vicinity of surfaces or to provide scalar flow information (e.g., marking one of two fluid streams). Both dyes exhibit measureable fluorescence signals that are on the order of 10(-3) to 10(-4) times weaker than the simultaneously measured Mie signals. It is determined that at the conditions measured, 95.5% of RhB LIF signals and 32.2% of DCF signals provide valid laser-Doppler velocimetry measurements compared with the Mie scattering validation rate with 6.5 W of 532 nm excitation, while RhB excited with 1.0 W incident laser power still exhibits 95.4% valid velocimetry signals from the LIF channel. The results suggest that the method is applicable to wind tunnel measurements near walls where laser flare can be a limiting factor and monodisperse particles are essential. PMID:23595429

Lowe, K Todd; Maisto, Pietro; Byun, Gwibo; Simpson, Roger L; Verkamp, Max; Danehy, Paul M; Tiemsin, Pacita I; Wohl, Christopher J

2013-04-15

307

Combined cw single-frequency ring dye/Ti:sapphire laser  

SciTech Connect

A new combined cw single-frequency dye/Ti:sapphire laser with a ring resonator located in the horizontal plane and improved radiation frequency stability is developed. The short-term radiation linewidth does not exceed 10 kHz for the Ti:sapphire laser and is smaller than 100 kHz for the dye laser. The drift velocity of the emission line does not exceed 25 MHz h{sup -1}. The scheme and design of the developed laser are presented which allow convenient switching of the laser between its solid-state and dye configurations. (lasers)

Kobtsev, Sergey M; Baraulya, Vladimir I [Novosibirsk State University, Novosibirsk (Russian Federation); Lunin, Vladimir M [Tekhnoscan Joint-Stock Company, Novosibirsk (Russian Federation)

2006-12-31

308

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

309

Ti:sapphire laser cavity mode and pump-laser mode calculations.  

PubMed

Comprehensive calculations of the cavity mode size throughout a Ti:sapphire laser, made with the ABCD Gaussian beam formalism are reported. These calculations show that the beam is not collimated, in general, in what are normally referred to as the collimated arms of the laser cavity. Additionally, the mode size and volume (in the gain medium) of the argon-ion laser, which is used to pump the Ti:sapphire laser optically, are evaluated for different focusing geometries, and graphs that can be used to select suitable mode-matching optics are produced. It is concluded that an appropriate strategy for mode matching the pump beam to the Ti:sapphire laser mode is to use a zoom telescope to tailor the collimated pump-laser beam diameter to an optimum value. Finally, comparisons of the pump-laser mode and the Ti:sapphire laser mode are presented for selected pumping geometries. PMID:20935725

Kane, D M

1994-06-20

310

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

311

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

312

Spectrum and lasing characteristics of a new blue-green laser dye  

SciTech Connect

A new laser dye in the blue-green spectral region was synthesized. The spectral and lasing properties are presented. The tuning range of the dye can be shifted in the spectral range between 457 and 521 nm by the choice of solvent. The dye has a high efficiency and good photochemical stability.

Yen Fwujiun; Hwang Derjau; Chen Zoushen; Teng Yuehlih

1986-12-01

313

Spectrum and lasing characteristics of a new blue-green laser dye  

Microsoft Academic Search

A new laser dye in the blue-green spectral region was synthesized. The spectral and lasing properties are presented. The tuning range of the dye can be shifted in the spectral range between 457 and 521 nm by the choice of solvent. The dye has a high efficiency and good photochemical stability.

Yen Fwujiun; Hwang Derjau; Chen Zoushen; Teng Yuehlih

1986-01-01

314

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

315

Multiple pass effects in high efficiency laser pumping cavities.  

PubMed

Some effects connected with multiple passes of pump radiation in laser pump cavities are discussed. These effects include changes in mercury arc lamp operating characteristics, when the lamps are used inside the cavities as pump sources, and unexpectedly low pulse (but not cw) thresholds in double elliptical cavities. It is shown analytically that these effects can, at least in part, be attributed to the shapes of the pump light energy distribution curves after multiple passes through the pump cavities, and to the relative opacities of flash and continuous lamps. PMID:20057775

Evtuhov, V; Neeland, J K

1967-03-01

316

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

317

Simulation and modeling of laser-tissue interactions based on a liposome-dye system.  

PubMed

This work presents an overview of the use of liposomes for targeted delivery of photosensitizers to tumors for Photodynamic Therapy (PDT). It assesses the results of a quantitative model to explain the interaction of short-pulsed lasers (in the nanosecond and picosecond domains) with a liposome-dye complex in terms of a localized photo-induced thermal mechanism. Incorporation of an organic dye (sulforhodamine) within lipid vesicles has been investigated in conjunction with the effect of laser irradiation on the integrity of the liposome-dye complex. The variation of the absorption coefficient as a function of wavelength for dye-encapsulated liposomes before and after laser-induced release of dye was studied and modeled. The commercial software Mathematica was used to develop a Gaussian model for the energy absorption by the liposome-dye complex. Dye release from 3 microm - liposome encapsulating 25 mM aqueous solution of sulforhodamine dye was studied using 8 ns laser pulses at the second harmonic of the Nd:YAG laser (at 532 nm) and compared with dye release employing 25 ps - laser pulses. In addition, the temperature-dependence of the dye release has been included in the photo-thermal model. PMID:21141674

Mensah, F E; Sridhar, R; Misra, P

2010-12-01

318

Laser Assisted Cancer Immunotherapy: Optical Dye Distribution in Tumors  

NASA Astrophysics Data System (ADS)

Laser Assisted Cancer Immunotherapy is an experimental modality used to treat superficial tumors implanted on sterile Balb/C mice. The goal of the project is to induce a positive immune response toward a complete eradication of the primary tumor. Optimal necrosis results from depositing the maximum amount of thermal energy into the tumor without damaging the surrounding healthy tissue. In our laboratory, the optical dye, indocyanine green (ICG), is injected into the center of the tumor prior to surface and interstitial laser irradiation. A diode laser operating at a wavelength near 804 nm exerts thermal energy into the tumor via ICG absorption at 790 nm. Maximum immune response should occur with a uniform distribution of ICG throughout the tumor. By mapping the ICG distribution, the spatial homogeneity of the dye can be determined, which, in turn, mimics the tumor temperature profile. After excision, the tumors were cut into samples of approximately 250 microns thick and dissolved in a chemical detergent. Each sample was run through an absorption spectrometer to determine the distribution of ICG throughout the tumor. Results for both radial and depth profiles of ICG tumor distribution will be presented.

Swindle, Ryan

2005-03-01

319

New laser action of optically pumped atomic vanadium vapor  

NASA Astrophysics Data System (ADS)

Laser action has been observed on the vanadium 560.4-, 575.3-, 581.7-, and 637.9-nm lines. Vanadium vapor is produced from vanadium metal plate by YAG laser (2.0 J/pulse) irradiation, and optically pumped by an XeCl excimer laser of 25-mJ energy. The vanadium laser pulse has a duration of 50 ns and peak output power of about 7 W.

Yoshida, H.; Takashima, N.; Ninomiya, H.

1992-01-01

320

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

321

Design, performance, and reliability of 980 nm pump lasers  

Microsoft Academic Search

This paper extensively studies the design and resulting performance of high power EDFA pump lasers to increase the operating power with each generation of chip developed while maintaining or improving other critical design features.

G. M. Smith; G. Yang; M. K. Davis; S. D. Solimine; R. Bhat; W. Liu; D. A. S. Loeber; F. Yang; A. Kussmaul; M. H. Hu; X. S. Liu; C. E. Zah

2003-01-01

322

High-power Colquiriite lasers with high slope efficiencies pumped by broad-area laser diodes.  

PubMed

Efficient high-power operation of Cr:LiSAF, Cr:LiSGAF, and Cr:LiCAF lasers pumped by broad-area laser diodes is demonstrated. A maximum slope efficiency of 51 % and output power of 0.55 W was reached at 1.2 W of absorbed pump power, which is the highest output power to date with broad-area laser diode pumping. With the laser design used the onset of thermal quenching in Cr:LiSAF due to high temperatures was pushed to higher pump powers and good mode matching was achieved. PMID:19461731

Isemann, Andreas; Fallnich, Carsten

2003-02-10

323

High-power Colquiriite lasers with high slope efficiencies pumped by broad-area laser diodes  

NASA Astrophysics Data System (ADS)

Efficient high-power operation of Cr:LiSAF, Cr:LiSGAF, and Cr:LiCAF lasers pumped by broad-area laser diodes is demonstrated. A maximum slope efficiency of 51 % and output power of 0.55 W was reached at 1.2 W of absorbed pump power, which is the highest output power to date with broad-area laser diode pumping. With the laser design used the onset of thermal quenching in Cr:LiSAF due to high temperatures was pushed to higher pump powers and good mode matching was achieved.

Isemann, Andreas; Fallnich, Carsten

2003-02-01

324

Vertical cavity surface-emitting semiconductor laser with CW injection laser pumping  

SciTech Connect

The authors report room temperature CW operation of a GaAs/AlGaAs vertical cavity surface-emitting laser with a resonant periodic gain medium, using a GaAs/AlGaAs diode laser array as a pump source. Pumping thresholds as low as 11 mW at 730 nm, output powers as high as 10 mW at 856 nm, and external quantum efficiencies as high as 70% were obtained, with considerably improved temporal and spatial coherence properties compared to the pump laser. This is the first reported operation of such a laser with an efficient, compact pump source, demonstrating its suitability for efficient integration.

McDaniel, D.L. Jr.; McInerney, J.G.; Raja, M.Y.A.; Schaus, C.F.; Brueck, S.R.J. (New Mexico Univ., Albuquerque, NM (USA). Center for High Technology Materials)

1990-03-01

325

Analysis of the pump-beam path in corner-pumped slab laser  

SciTech Connect

The propagation of the pump radiation in active slab elements is considered. Conditions of the total internal reflection of the pump radiation are obtained, and are used to construct a series of graphical illustrations of reflection characteristics of different active elements. (control of laser radiation parameters)

Chen Li; Qiang Liu; Mali Gong; Gang Chen; Ping Yan [Center for Photonics and Electronics, State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University (China)

2007-06-30

326

Thulium:ZBLAN blue fiber laser pumped by two wavelengths  

Microsoft Academic Search

We demonstrate and analyze an upconversion blue fiber laser pumped by two wavelengths. Lasing at 0.48 m with very low pump threshold power is obtained from a Tm-doped fluorozirconate fiber that is counterpropagating pumped by 1.21- and 0.649- m light. We employed a rate-equation analysis using parameters obtained by fitting to the experimental data to predict the 0.48- m output

Genji Tohmon; Hisanao Sato; Jun Ohya; Tomoaki Uno

1997-01-01

327

Second-harmonic generation in solar-pumped laser  

Microsoft Academic Search

Summary form only given. Solar-pumped lasers are candidates for wireless power transmission in space, free space optical communication, and photochemistry. The broad variety of applications necessitates a spectral coverage between the UV and the IR. Here, we report on second-harmonic generation (SHG) of a solar-pumped laser using a type II KTP crystal in an intracavity Q-switched resonator. Q-switching was obtained

M. Lando; Y. Shimony; R. M. J. Benmair; I. Vishnevetsky; A. Yogev

1998-01-01

328

Subthreshold diagnostics of active media for direct nuclear pumped lasers  

Microsoft Academic Search

Experimental results are presented to demonstrate the feasibility of the subthreshold diagnostics of active media for direct nuclear pumped lasers. The diagnostic approach proposed here is sufficiently universal and may be used for the study of both gas and condensed active media when pumped by nuclear reaction products of any kind. The neutron active materials can be both homogeneous and

P. P. D'Iachenko; Iu. B. Dorofeev; E. D. Poletaev; E. A. Seregina; V. V. Korobkin

1991-01-01

329

Single-Mode, 980 nm Pump Lasers for Fiber Amplifiers.  

National Technical Information Service (NTIS)

Pump lasers for Er3+-doped silica fiber optical amplifiers must demonstrate excellent spatial mode stability to high output power levels in order to achieve useful gain. 1,2 The pump band at 980 nm is the most efficient of the principle Er3+ absorption ba...

F. D. Crawford W. F. Sharfin B. Elman R. B. Lauer P. Mebrahtu

1992-01-01

330

Nuclear pumped lasers: Advantages of O2 (1 delta)  

Microsoft Academic Search

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.

J. J. Taylor

1979-01-01

331

Study of Ultrafast Internal Conversion in Molecules and Ultrafast Dephasing in Condensed Matter with Picosecond Dye Lasers.  

NASA Astrophysics Data System (ADS)

A picosecond cascaded transient oscillator (CTO) dye laser system was modified to generate continuous tunable, near transform-limited picosecond pulses. To improve the CTO system, the characteristics of a simple N_2 laser side-pumped dye laser (the first stage of CTO system) was thoroughly examined. It was found that both the pulse shape and the duration were affected strongly by the tuned wavelength, cavity length, pumping intensity, and the feedback signal from both the front and the back reflectors. A single output pulse as short as 40 ps could be generated by optimizing the operating parameters. The final output of the CTO system has a pulse duration less than 10 ps and a bandwidth less than 1 A. The technique of infrared multiphoton ionization was used to obtain state specific internal conversion rates in CrO_2Cl_2. Using narrow-band tunable 10 ps dye laser pulses, different vibrational states in the B_1 manifold were excited and the energy relaxation was monitored by an IR ps laser pulse. The relaxation can be characterized by a fast component, which is due to internal conversion to the ^1A_1 state, and a slow component, which is due to cooling of the vibrationally hot ^1A _1 ground state. The nonradiative energy transfer rate changes by almost three orders of magnitude for an excess vibrational energy change of merely 550 cm ^{-1}. With broadband incoherent picosecond dye laser pulse, the measurement of the dephasing time T _2 in dye solutions and semiconductor-doped glasses by the two pulse correlation method was demonstrated, with T_2<=ss than the correlation time of the excitation pulse tau_ {rm c}. It was found the dephasing time T_2 measured depended on the excitation photon energy relative to the band-edge or the energy difference between the ground state and the first excited electronic state. In the case of band-edge excitation, a quantum beat behavior with a beat frequency about 28 tera-hertz was observed in Rh-560 dye solutions.

Xie, Yongjin

332

Remote chemical sensing by laser optical pumping  

SciTech Connect

We are exploring a new approach to remote chemical identification that promises higher precision than can be achieved by conventional DIAL approaches. This technique also addresses and potentially solves the problem of detecting a target gas in the presence of an interfering gas or gases. This new approach utilizes an eye-safe infrared optical pumping pulse to deplete the population of a specific rotational level(s) and then sends probe pulses at the same or different wavelengths to interrogate the bleaching of the absorption. We have experimentally measured optical saturation fluence level at atmospheric pressure for HCl, and find this level to be {approximately}1 mJ/cm{sup 2}, significantly below eye-safe limits in agreement with calculations. Calculations have been performed on other molecules of interest with similar results. In the laboratory, using time-delay-replicated pulses at a single frequency we have made absorption measurements with precision levels routinely approaching 0.1% after averaging 200 laser pulses. These results as well as those of two other pulse experiments will be presented. 5 refs., 9 figs., 1 tab.

Stevens, C.G.; Magnotta, F.

1996-08-01

333

A mirror-free cavity configuration for a CW ring dye laser  

Microsoft Academic Search

A new cavity configuration without mirrors is described for a CW ring dye laser. The cavity design is based on a new type of focusing prism which uses the Brewster angle of incidence and total internal reflection. Special roof prisms allow wavelength tuning. All of these elements are made from uncoated quartz thus allowing dye laser operation over a large

J. Jasny; J. Sepiol; U. P. Wild

1985-01-01

334

Atomic beam deflection by the light of a tunable dye laser  

Microsoft Academic Search

The deflection of a sodium atomic beam by the radiation pressure of the light of a cw dye laser was investigated. From the deflection observed it is deduced that the linear momentum trasferred corresponds to an average of 60 excitations per atom. The linewidth of the dye laser used for the measurements was smaller than 50 MHz.

R. Schieder; H. Walther; L. Wöste

1972-01-01

335

Nonlinear optical investigation of Gaussian laser beam propagating in a dye-doped nematic liquid crystal  

Microsoft Academic Search

The laser beam shape and variation of the curvature radius of the wavefront have been simulated when the Gaussian laser beam passes through a dye-doped nematics liquid crystal. The effect of different dyes is investigated in the wavefront distortion as well as the beam shape due to its quality factor. We have reported the dependency of the curvature radius of

S. H. Mousavi; E. Koushki; H. Haratizadeh

2010-01-01

336

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

337

Femtosecond Cr:LiSAF laser pumped by a single diode laser  

Microsoft Academic Search

Using a single diode laser to pump a Kerr-lens mode-locked Cr:LiSAF laser, we demonstrate the generation of Fourier-transform limited 26-fs pulses with spectral bandwidth of 34 nm. A novel cavity design for the mode-locked laser was used to focus tightly the pump beam. We have pointed out that the prism edge near the folding mirrors in the laser cavity plays

Sadao Uemura; Kenzo Miyazaki

1997-01-01

338

Picosecond dye laser emission in the infrared between 1.4 and 1.8 mum  

Microsoft Academic Search

The stimulated emission of new infrared dyes was investigated. The dyes have short S 1-lifetimes between 5 and 12 ps with corresponding low fluorescence quantum efficiencies of 10-3 to 10-4. In spite of this, 2% of the pumping energy were converted to an intense infrared pulse with frequencies between 5550 cm-1 (1.8 mum) and 7150 cm-1 (1.4 mum). The dye

H. J. Polland; T. Elsaesser; A. Seilmeier; W. Kaiser; M. Kussler; N. J. Marx; B. Sens; K. H. Drexhage

1983-01-01

339

Compilation of Data Relevant to Nuclear Pumped Lasers. Volume V.  

National Technical Information Service (NTIS)

This volume, and Volumes III and IV, contain a compilation of data relevant to nuclear pumped lasers and are part of a series on atomic and molecular data for gas laser research and development. The first two volumes, contained 'Compilation of Data Releva...

E. W. McDaniel M. R. Flannery E. W. Thomas H. W. Ellis K. J. McCann

1979-01-01

340

Flash-pumped pulsed Cr:LiSAF laser action from a modified conventional solid state laser cavity  

Microsoft Academic Search

Conventional solid state laser pumping cavities has been used, after proper modification, in order to achieve efficient laser action by Cr:LiSAF crystals. The crystal samples were placed in the laser head, properly supported for efficient pumping to achieve satisfactory laser action. It has been proved that for a successful result a strong flash pumping source and a low output coupling

Bernhard J. Klinkenberg; Alexandros D. Papayannis; Alexandros A. Serafetinides

2003-01-01

341

Combined guiding effect in the end-pumped laser resonator.  

PubMed

A theoretical model as well as the experimental verification of the combined guiding mechanism for the transverse mode formation in the end-pumped laser resonator are investigated. The nonlinear Schrödinger-type wave equation in the gain medium is derived, in which the combined guiding mechanism: the thermal induced refractive index guiding effect as well as the gain guiding effect, is taken into account. The gain saturation and spatial hole burning are considered. The split step Fourier method is used to solve the nonlinear wave equation. A high power end-pumped Nd:YVO4 laser resonator is built up. After establishing the pump absorption model of our laser resonator, the temperature distribution in the gain medium is obtained by the numerical solving of the heat diffusion equation. The combined guiding effect is first observed in the end-pumped Nd:YVO4 laser resonator, and the experimental transverse mode profiles well agree with the theoretical prediction from the derived nonlinear Schrödinger-type wave equation. The geometric design criterion of the TEM00 mode laser is compared with our wave theory. The experimental- and theoretical- results show that our wave theory with the combined guiding mechanism dominates the transverse mode formation in high power end-pumped laser resonator. PMID:21451715

Yan, Xingpeng; Liu, Qiang; Wang, Dongsheng; Gong, Mali

2011-03-28

342

Diode pumped Cr3+:LiCAF fs-laser  

NASA Astrophysics Data System (ADS)

We demonstrate the first diode pumped, mode locked Cr3+:LiCAF-laser. Transform limited 52 fs pulses were generated at 793 nm with 75 mW mode locked output power. Low loss chirped mirrors were used for dispersion compensation. Pulsed operation was achieved by Kerr lens mode locking without the need for additional cavity elements. Sub-30 fs pulses could be produced with low transmission output couplers. The laser delivered 165 mW CW-power when pumped by two laser diodes with a total of 630 mW.

Gäbel, K. M.; Rußbüldt, P.; Lebert, R.; Valster, A.

1998-12-01

343

Optical properties of a nuclear reactor pumped gas laser  

NASA Astrophysics Data System (ADS)

Ray paths and focal lengths are derived to fourth order for a nuclear-reactor wall-pumped gas laser. Ray paths in the laser gain cell are shown to be nearly random for a long gain region. Focal lengths calculated from the ray paths exiting the laser are shown to oscillate between + or - infinity during pumping. The use of stimulated Brillouin scattering as a means for beam clean-up is discussed with the conclusion that the phase conjugated beam would cycle on and off as the ray paths and focal lengths oscillate between extremes. The parameters determining this cycling effect and its characteristics are also derived.

Corvo, A.

1991-01-01

344

Efficient Ultraviolet Organic Liquid Laser Pumped by a High Power Nitrogen Laser  

Microsoft Academic Search

An organic liquid laser pumped by a 1 MW nitrogen laser is investigated. Twenty chemical compounds which can lase at wavelengths shorter than 440 nm are examined, including six new lasing compounds. Energy conversion efficiencies are improved remarkably by high power pumping, especially in the ultraviolet. An efficiency of about 20% is obtained in the ultraviolet which is as high

Mitsuo Maeda; Yasushi Miyazoe

1974-01-01

345

Pump efficiency and beam quality control in an end-pumped Cr:LiSAF laser  

NASA Astrophysics Data System (ADS)

The laser radiation production in an end-pumped laser requires taking into consideration the following: (a) the optical pumping system, (b) the thermal and spectroscopic characteristics of the gain medium, (c) the mode overlap, and (d) the interaction with the optical resonator. The correlation between the previous four factors is needed to guide the design and evaluation of such a laser system. This suggestion is a better methodology than focusing the discussion on only one factor of the system ignoring interactions. Here, we use these arguments to supervise the complete process with a one-watt pump-diode laser largely astigmatic and a Cr:LiSAF gain medium highlighting the importance between interactions.

Castillo-Matadamas, H.; Quintero-Torres, R.

2008-05-01

346

Stimulated amplification of a broad-band optical signal through a benzene-core fiber system pumped by ultra-short laser pulses  

NASA Astrophysics Data System (ADS)

This paper presents a novel approach to amplify a broadband optical signal by using stimulated Rayleigh-Kerr scattering in a hollow core fiber system filled with liquid benzene. Using 4-ps dye laser pulses as the pump source, stimulated amplification of the accompanying about 550/cm broad spontaneous emission is achieved with an amplification factor reaching 23,000.

He, G. S.; Xu, G. C.; Burzynski, R.; Prasad, P. N.

1989-08-01

347

Design of ultrahigh brightness solar-pumped disk laser.  

PubMed

To significantly improve the solar-pumped laser beam brightness, a multi-Fresnel lens scheme is proposed for side-pumping either a single-crystal Nd:YAG or a core-doped ceramic Sm(3+) Nd:YAG disk. Optimum laser system parameters are found through ZEMAX and LASCAD numerical analysis. An ultrahigh laser beam figure of merit B of 53 W is numerically calculated, corresponding to a significant enhancement of more than 180 times over the previous record. 17.7 W/m(2) collection efficiency is also numerically attained. The strong thermal effects that have hampered present-day rod-type solar-pumped lasers can also be largely alleviated. PMID:22968278

Liang, Dawei; Almeida, Joana

2012-09-10

348

Evaluation of a Continuous Flow Furnance Atomizer for Laser Excited Atomic Fluorescence Spectrometry  

Microsoft Academic Search

A system for continuous sample introduction into a ceramic atomization furnace for laser excited atomic fluorescence spectrometry (LEAFS) was developed. The system was evaluated using two different excitation sources, a nitrogen laser-pumped dye laser and a copper vapor laser-pumped dye laser. Pure aqueous Pb solutions were used for system optimization and analytical calibration curves. These curves were linear over at

J. B. Womack; C. A. Ricard; B. W. Smith; J. D. Winefordner

1989-01-01

349

Dynamics of excimer laser-ablated aluminum neutral atom plume measured by dye laser resonance absorption photography  

Microsoft Academic Search

We report the first dye laser resonance absorption photographs of a single species of aluminum ground-state neutral atoms in the plume ablated from solid aluminum by KrF excimer laser radiation. Aluminum ground-state neutral atoms were diagnosed by illuminating the ablated plume with a dye laser tuned to the 3²{ital P}ââ--4²{ital S}ââ transition at 394.4 nm. Measurements have been performed in

Ronald M. Gilgenbach; Peter L. G. Ventzek

1991-01-01

350

Dynamics of excimer laser-ablated aluminum neutral atom plume measured by dye laser resonance absorption photography  

Microsoft Academic Search

We report the first dye laser resonance absorption photographs of a single species of aluminum ground-state neutral atoms in the plume ablated from solid aluminum by KrF excimer laser radiation. Aluminum ground-state neutral atoms were diagnosed by illuminating the ablated plume with a dye laser tuned to the 32P1\\/2–42S1\\/2 transition at 394.4 nm. Measurements have been performed in vacuum as

Ronald M. Gilgenbach; Peter L. G. Ventzek

1991-01-01

351

100W high-brightness multi-emitter laser pump  

Microsoft Academic Search

We report results of a spatially-multiplexed broad area laser diode platform designed for efficient pumping of fiber lasers or direct-diode systems. Optical output power in excess of 100W from a 105mum core, 0.15NA fiber is demonstrated with high coupling efficiency. The compact form factor and low thermal resistance enable tight packing densities needed for kW-class fiber laser systems. Broad area

Richard Duesterberg; Lei Xu; Jay A. Skidmore; James Guo; Jane Cheng; Jihua Du; Brad Johnson; David L. Vecht; Nicolas Guerin; Benlih Huang; Dongliang Yin; Peter Cheng; Reddy Raju; Kong Weng Lee; Jason Cai; Victor Rossin; Erik P. Zucker

2011-01-01

352

A high power, high efficiency, laser-diode-pumped, continuous wave miniature Nd:glass laser  

Microsoft Academic Search

We report the operation of a Nd:glass laser pumped by a 500 mW broad single stripe laser diode. We have observed a slope efficiency of greater than 30% and an output power of greater than 100 mW when pumping with one diode. The output power increased to greater than 150 mW when two such diodes were used to pump the

D. W. Hughes; J. R. M. Barr; D. C. Hanna

1991-01-01

353

Combined cw single-frequency ring dye\\/Ti:sapphire laser  

Microsoft Academic Search

A new combined cw single-frequency dye\\/Ti:sapphire laser with a ring resonator located in the horizontal plane and improved radiation frequency stability is developed. The short-term radiation linewidth does not exceed 10 kHz for the Ti:sapphire laser and is smaller than 100 kHz for the dye laser. The drift velocity of the emission line does not exceed 25 MHz h-1. The

Sergey M Kobtsev; Vladimir I Baraulya; Vladimir M Lunin

2006-01-01

354

Correlation functions of a dye laser: Comparison between theory and experiment  

SciTech Connect

Experimentally determined intensity correlation functions of a single-mode dye laser are compared with theoretically predicted forms given in a recent paper by Graham, Hoehnerbach, and Schenzle. Although good agreement is obtained in some cases for which the parameters are chosen for best fit, large discrepancies appear for other working points of the laser. These results suggest that the dynamical theory of the dye laser needs to be modified.

Short, R.; Mandel, L.; Roy, R.

1982-08-30

355

Models of DNA-dye-complexes: Energy transfer and molecular structures as evaluated by laser excitation  

NASA Astrophysics Data System (ADS)

Energy transfer in DNA-dye-complexes after excitation in the UV down to 220 nm by means of a tunable laser was investigated. DNA of different base composition and polynucleotides were compared. The dyes proflavine, acridine orange and ethidium bromide were used. The energy transfer from DNA-bases to dye molecules was measured in dependence of the excitation wavelength and the base composition of the DNA. Models of the energy transfer from DNA to dye and of the molecular structures of the DNA-dye-complex (intercalation) could be deduced.

Anders, A.

1979-04-01

356

Investigation of radial temperature gradients in diode pumped alkali lasers using tunable diode laser absorption spectroscopy  

NASA Astrophysics Data System (ADS)

Heat loads in Diode Pumped Alkali Lasers (DPAL) have been investigated using a diode laser to probe the radial dependence of the absorbance. A TiS pump laser heats the medium in a T=50-100°C cesium heat pipe with 5 Torr nitrogen used for quenching. A tunable diode laser probes the spectral absorbance of the cesium cell. Local alkali concentration, temperature, and saturation broadening modify Voigt lineshapes in the wing of the hyperfine split lines. The temperature within the pumped volume exceeds the wall temperature by almost 200 C.

Fox, Charles D.; Perram, Glen P.

2012-02-01

357

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

358

Modeling of Efficiency and Uniformity of Different Pumping Structures of Slab Lasers  

Microsoft Academic Search

Modeling for end-pumping and edged-pumping high power solid-state slab lasers. Both analytic and ray tracing methods were used to analyze the distributions of absorbed pumping power using laser-diode-array pump sources. The pumping light field profiles of the different pumping structures mentioned above are acquired, according to which the absorption power density and uniformity of the pumping light are analyzed. In

Junyan Hou; Yuefeng Wang

2009-01-01

359

2.8 ?m Er:YLF laser transversely pumped with a CW diode laser bar  

NASA Astrophysics Data System (ADS)

We present experimental results on the operation of a 1 cm diode bar-side-pumped Er:YLF laser. The mid-infrared laser produced a maximum average output power of 51 mW (102 mW peak power) for 3.1 W of chopped (50% duty cycle) pump power. When operated in true CW mode, 16 mW output power was recorded for a total pump power of 4.0 W. The centre wavelength of the spectral output of the laser was measured to be 2721 nm+/-5 nm. The threshold pump power and slope efficiency of the Er:YLF laser were measured as a function of the diode laser centre wavelength and the laser cavity length. Measurements of the spatial beam profile indicated TEM00 operation.

Tikerpae, Mark; Jackson, Stuart D.; King, Terence A.

1999-08-01

360

Gain-Induced Refractive Index Changes in Resonantly Pumped Optical Pumping Injection Cavity Lasers  

NASA Astrophysics Data System (ADS)

An optical pumping injection cavity (OPIC) laser contains a type-II W active region enclosed between two GaSb/AlAsSb distributed Bragg reflector mirrors, where the thickness of the etalon cavity surrounded by the mirrors is tuned to the desired pump wavelength. Multiple reflections of the pump photons result in more efficient absorption of the pump beam and consequently higher efficiencies and lower lasing thresholds. An optical parametric oscillator is used to pump the OPIC lasers at resonance, where the threshold pump intensities are minimized and output efficiencies are maximized. The resonant pump wavelength is found to vary quadratically with temperature, not linearly as would be expected from temperature-dependence of the lattice constant and refractive indices. Possible sources of this nonlinearity are lattice heating and gain-induced changes in the refractive indices resulting from the increase of optical pumping intensity with temperature. Through spectral measurements using step-scan Fourier Transform Infrared spectroscopy and multilayer reflectivity modeling, the relative contributions of these possible sources of parabolic temperature dependence of resonant wavelength are investigated.

Olafsen, Linda; Bain, Lauren; Ice, Lauren; Ball, Ben

2011-03-01

361

End-pumped continuous-wave alkali vapor lasers: experiment, model, and power scaling  

Microsoft Academic Search

End-pumped alkali vapor lasers excited on their D2 transition and lased on their D1 transition offer a pathway to high average power that potentially competes with diode-pumped solid-state lasers in many applications that require cw or quasi-cw laser operation. We report on the first experimental demonstration of an end-pumped Cs laser using a Ti:sapphire laser for pump excitation. Detailed experimental

Raymond J. Beach; William F. Krupke; V. Keith Kanz; Stephen A. Payne; Mark A. Dubinskii; Larry D. Merkle

2004-01-01

362

X-ray pumped Cr,Nd:GSGG laser  

SciTech Connect

It has been demonstrated that X-rays alone can be used to pump a 1,061 nm Cr,Nd:GSGG laser. Lasing action has been observed when the laser rod absorbs greater than 27 krad of 2 MeV X-rays. The laser cavity consists of a corner cube and a output mirror with a reflectivity of 67%. The X-rays are delivered in a 20 ns pulse, and laser action is observed several {micro}s after the X-ray pulse. This delay suggests that chromium is important in the laser pumping process since it is known that an excited chromium ion takes about 10 {micro}s to transfer its energy to a neodymium ion.

Brannon, P.J.; Hedemann, M.A.; Weichman, L.S.

1995-12-31

363

Diode pumped, q-switched Tm:YLF laser  

NASA Astrophysics Data System (ADS)

A compact and efficient, passively cooled, diode pumped Tm:YLF laser is presented. The power of over 15 W for 10% duty cycle and 55-W of pump power was achieved. When applying the pump power of 25 W and using elongated 120-mm long optical cavity, the output power as high as 5 W with a slope efficiency of 50% was also presented. The maximum pulse peak power and pulse duration achieved, recorded for 20 Hz of repetition rate and 10% pump duty factor was near 0.5 MW and 11 ns, respectively. The output laser beam was characterized by very good quality with divergence angle of 3.5 mrad and M2 < 1.15.

Gorajek, Lukasz

2013-07-01

364

Taming random lasers through active spatial control of the pump.  

PubMed

Active control of the spatial pump profile is proposed to exercise control over random laser emission. We demonstrate numerically the selection of any desired lasing mode from the emission spectrum. An iterative optimization method is employed, first in the regime of strong scattering where modes are spatially localized and can be easily selected using local pumping. Remarkably, this method works efficiently even in the weakly scattering regime, where strong spatial overlap of the modes precludes spatial selectivity. A complex optimized pump profile is found, which selects the desired lasing mode at the expense of others, thus demonstrating the potential of pump shaping for robust and controllable single mode operation of a random laser. PMID:22861853

Bachelard, N; Andreasen, J; Gigan, S; Sebbah, P

2012-07-20

365

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 commoners. Additionally, a method is disclosed which alleviates induced optical stress without having to anneal the polymers at elevated temperatures. (>85{degrees}C).

Hermes, R.E.

1989-10-13

366

Operating temperature of diode-pumped alkali vapor laser  

NASA Astrophysics Data System (ADS)

Diode-pumped alkali vapor laser (DPAL) is a new class of laser, and it is expected to realize high efficiency and high-average-power laser with good beam quality (near-diffraction-limited). DPAL offers CW laser radiation at near-infrared wavelengths and can find a lot of applications in power beaming, drilling oil and gas well and laser material processing. Operating temperature affects not only the density of alkali vapor atom in active region, but collision broadening and fine-structure mixing rate. In this paper, we study the operating temperature characteristics of DPAL. Based on the theory of quasi-three level CW laser, the dependence of cesium laser output power on the operating temperature has been simulated. The results showed that there exists an optimal operating temperature around 95 to 110 centigrade for high pumping power. In lower temperature region, the laser power rise linearly with increasing operating temperature, namely increasing active density. However, the laser power falls after the optimal operating temperature, because the spontaneous radiations deplete large numbers of stimulated population contributing to laser emissions. At the optimal temperature, an optical- optical efficiency of about 73% is able to reach theoretically.

Zhu, Qiang; Yu, Jianhua; Zheng, Wei; Quan, Hongyan

2008-03-01

367

Dye diffusion studies in PET fibres by confocal laser scanning microscopy and the interrelation with the glass transition  

Microsoft Academic Search

Confocal laser scanning microscopy (CLSM) is used to monitor the dye penetration in poly(ethylene terephthalate) fibres during a common commercial dyeing process. The study of optical sections of fibres dyed for prolonged times in the dyeing process allows for a qualitative interpretation of the dye diffusion process, which is not possible by other techniques. A major dissimilarity was revealed between

Karen De Clerck; Patrick Van Oostveldt; Hubert Rahier; Bruno Van Mele; Philippe Westbroek; Paul Kiekens

2004-01-01

368

Diode-pumped environmentally stable stretched-pulse fiber laser  

Microsoft Academic Search

We present results obtained with a stretched-pulse polarization additive pulse mode-locked (P-APM) fiber laser using an environmentally stable cavity design. With 980-nm diode-pumping levels of 200-mW 1.2-nJ pulses with 50 nm of spectrum are obtained. These pulses can be externally compressed to sub-100 fs. The effects of high output coupling (>80%) and pumping configuration on output performance an d intracavity

D. J. Jones; L. E. Nelson; H. A. Haus; E. P. Ippen

1997-01-01

369

Laser action of optically pumped atomic vanadium vapor  

NASA Astrophysics Data System (ADS)

Vanadium vapor is generated from a vanadium metal by irradiation of a pulsed YAG laser of 2.2 J energy, and the vanadium atoms are optically pumped by a XeCl laser of 7.3 mJ energy. Laser action has been observed on the vanadium 409.5 nm 4F(7/2)-4D(5/2) transition. This laser pulse has a pulse width of 4 ns and peak power of 1.08 W, and the optical gain is 0.46/cm.

Ninomiya, H.; Abe, M.; Takashima, N.

1991-04-01

370

A 500-J nuclear-pumped gas laser  

NASA Astrophysics Data System (ADS)

A 500-J pulsed gas laser (laser module) pumped by uranium nuclear fission products has been created, which operates on xenon 5 d[3/2]1 ? 6 p[3/2]1 transition with a wavelength of 2.03 ?m. Experiments have been performed on a BARS-5 + RUN-2 complex comprising a fast aperiodic self-quenching reactor and a neutron multiplier reactor. A specific laser radiation energy in experiments achieved ˜32 J/dm3 at an efficiency of 3% (ratio of the laser output pulse energy and the energy transferred from fission fragments to gas medium).

Zagidulin, A. V.; Bochkov, A. V.; Mironenko, V. V.; Sofienko, G. S.

2012-12-01

371

Conceptual Design Studies of a Laser Diode Pumped Solid State Laser System for the Laser Fusion Reactor Driver  

Microsoft Academic Search

We have developed a conceptual designing technique of a laser diode pumped solid state laser system having high peak power, high efficiency, good beam quality, and high repetition rate. Using this technique, we evaluated the feasibility of the systems with several solid state laser materials for the laser fusion reactor driver with 10 MJ blue output, 10% overall efficiency, and

Kenta Naito; Masanobu Yamanaka; Masahiro Nakatsuka; Tadashi Kanabe; Kunioki Mima; Chiyoe Yamanaka; Sadao Nakai

1992-01-01

372

Multiple oscillation of whispering-gallery-mode dye lasers in green and orange regions using mixed-dye-doped solid microspheres  

NASA Astrophysics Data System (ADS)

Mixed-dye-doped solid microspheres are excited by a transversely excited-atmospheric ultraviolet N2 laser to obtain a multiple oscillation of a whispering-gallery-mode (WGM) dye laser in both green and orange regions. The multiple oscillation exhibits separate modes of WGMs in both spectral regions.

Taniguchi, Hiroshi; Tanosaki, Shinji; Yamada, Hiroshi; Fujiwara, Tamiya; Baba, Mamoru

1993-06-01

373

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

374

Femtosecond mode-locked holmium fiber laser pumped by semiconductor disk laser.  

PubMed

We report on a 2085 nm holmium-doped silica fiber laser passively mode-locked by semiconductor saturable absorber mirror and carbon nanotube absorber. The laser, pumped by a 1.16 ?m semiconductor disk laser, produces 890 femtosecond pulses with the average power of 46 mW and the repetition rate of 15.7 MHz. PMID:22555700

Chamorovskiy, A; Marakulin, A V; Ranta, S; Tavast, M; Rautiainen, J; Leinonen, T; Kurkov, A S; Okhotnikov, O G

2012-05-01

375

Pump-Controlled Directional Light Emission from Random Lasers  

NASA Astrophysics Data System (ADS)

The angular emission pattern of a random laser is typically very irregular and difficult to tune. Here we show by detailed numerical calculations that one can overcome the lack of control over this emission pattern by actively shaping the spatial pump distribution. We demonstrate, in particular, how to obtain customized pump profiles to achieve highly directional emission. Going beyond the regime of strongly scattering media where localized modes with a given directionality can simply be selected by the pump, we present an optimization-based approach which shapes extended lasing modes in the weakly scattering regime according to any predetermined emission pattern.

Hisch, Thomas; Liertzer, Matthias; Pogany, Dionyz; Mintert, Florian; Rotter, Stefan

2013-07-01

376

Thulium:ZBLAN blue fiber laser pumped by two wavelengths.  

PubMed

We demonstrate and analyze an upconversion blue fiber laser pumped by two wavelengths. Lasing at 0.48 mum with very low pump threshold power is obtained from a Tm-doped fluorozirconate fiber that is counterpropagating pumped by 1.21- and 0.649-mum light. We employed a rate-equation analysis using parameters obtained by fitting to the experimental data to predict the 0.48-mum output characteristics as a function of fiber length and output reflectivity. PMID:18253352

Tohmon, G; Sato, H; Ohya, J; Uno, T

1997-05-20

377

Cusp shape reflectors to pump disk or slab lasers.  

PubMed

A two-dimensional ray tracing program is used to predict the performance of lighthouses to pump disk or slab lasers. The model is tested by comparing calculations with the results of light intensity and fluorescence measurements. Pumping efficiency and uniformity are investigated as functions of lamp spacing in a configuration employing cusp shape and plane back reflectors. It is found that doubling the number of lamps from an arrangement that provides optimal coupling brings an improvement in pumping of typically 60%. PMID:20165356

Siegrist, M R

1976-09-01

378

Thulium:ZBLAN blue fiber laser pumped by two wavelengths  

SciTech Connect

We demonstrate and analyze an upconversion blue fiber laser pumped by two wavelengths. Lasing at 0.48 {mu}m with very low pump threshold power is obtained from a Tm-doped fluorozirconate fiber that is counterpropagating pumped by 1.21- and 0.649-{mu}m light. We employed a rate-equation analysis using parameters obtained by fitting to the experimental data to predict the 0.48-{mu}m output characteristics as a function of fiber length and output reflectivity. {copyright} 1997 Optical Society of America

Tohmon, G.; Sato, H.; Ohya, J.; Uno, T. [Semiconductor Research Center, Matsushita Electric Industrial Company, Ltd., 3-1-1 Yagumonakamachi, Moriguchi, Osaka 570 (Japan)

1997-05-01

379

Optical pump-terahertz probe spectroscopy of dyes in solutions: Probing the dynamics of liquid solvent or solid precipitate?  

Microsoft Academic Search

The optical pump-terahertz probe spectroscopy was used together with ab initio calculations and molecular dynamics simulations to investigate ultrafast dynamics following electronic excitation of Coumarin 153 and TBNC (2,11,20,29-tetra-tert-butyl-2,3-naphtalocyanine) dyes in polar solvents. By scanning the terahertz waveform for different pump-probe delays this experimental technique allows us to obtain two dimensional spectra directly reflecting the temporal response of the system.

Filip Kadlec; Christelle Kadlec; Petr Kuzel; Petr Slavícek; Pavel Jungwirth

2004-01-01

380

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

381

Development of an optical parametric generator with pulsed dye amplification for high-resolution laser spectroscopy  

NASA Astrophysics Data System (ADS)

An injection-seeded optical parametric generator (OPG), coupled with three pulsed dye amplification (PDA) stages, was shown to produce tunable, narrow linewidth laser radiation. The OPG was composed of a pair of beta barium borate ( ?-BBO) crystals and pumped by the third harmonic (355 nm) output of a seeded Nd:YAG laser. The OPG was injection-seeded at the idler wavelength (824 nm) using an external cavity diode laser (ECDL) with a mode-hop-free tuning range of 20 GHz. Using the PDA stages, the OPG output signal (624 nm) was amplified to 19 mJ/pulse, while maintaining a spectral linewidth of approximately 160 MHz at full-width-half-maximum (FWHM) which was within a factor of 2 of the Fourier limit. A system of lenses and apertures was used to minimize amplified spontaneous emission (ASE) in the PDA stages. Using the OPG/PDA system, two-photon laser-induced fluorescence measurements of atomic oxygen were performed by sum-frequency-mixing the 624-nm beam with the third harmonic output of the seeded Nd:YAG laser to generate approximately 1 mJ/pulse of ultraviolet radiation near 226 nm. Voigt line shapes were found to be in good agreement with oxygen atom spectra in atmospheric-pressure, laminar, counter-flow flames; the magnitude of Doppler and collisional broadening was approximately the same. The measured O-atom concentration profile was found to compare well with that calculated using an opposed-flow flame code.

Bhuiyan, A. H.; Richardson, D. R.; Naik, S. V.; Lucht, R. P.

2009-03-01

382

Velocity measurements in the nanosecond range realized by variably delayed dye laser exposition  

Microsoft Academic Search

An imaging system with nanosecond resolution was developed and used for investigation of excimer laser induced ablation. The photographic recordings were made by means of a videocamera equipped with a microscope. Dye laser pulses used for exposition were delayed appropriately with respect to the incidence of the excimer laser light. The movement of the plume ejected from the sample and

Zsuzsanna Marton; Bela Hopp; Zsolt Toth; Maria Csete; Ferenc Ignacz; Zsolt Bor

1998-01-01

383

Second and first order phase transition analogy in the operation of an organic dye laser  

Microsoft Academic Search

By an extension of the Landau theory of phase transitions for the case of an organic dye laser, it is shown that the threshold behavior of such a laser may be interpreted as an example of a second or first order phase transition. The character of the phase transition primarily depends on the wavelength dependent internal reabsorption of the laser

G. Marowsky; W. Heudorfer

1978-01-01

384

A Pr 3+-doped ZBLAN fibre upconversion laser pumped by an Yb 3+-doped silica fibre laser  

Microsoft Academic Search

An Yb3+-doped silica fibre laser pumped at 840 nm has been used to provide the two pump wavelengths, 840 nm and 1020 nm, required for pumping a Pr3+-doped ZBLAN fibre upconversion laser. The performance of the upconversion laser at 491, 520 and 635 nm is presented, with measurements of fibre loss at 635 nm and 520 nm which indicate that

H. M Pask; A. C Tropper; D. C Hanna

1997-01-01

385

Structure elucidation of laser dye coumarin-540A by joint application of X-ray diffraction, X-ray fluorescence, prompt fluorescence, UV and visible spectroscopy  

Microsoft Academic Search

X-ray, ultraviolet, and visible light induced photophysical changes of coumarin-540A in ethanol have been studied by the joint applications of X-ray, ultraviolet, and visible spectroscopy. Some impurities were found by X-ray fluorescence measurements. During the high power optical pumping, coumarin showed photochemical changes. Photoproduct emission spectra characteristics showed that photoproduct molecules can also be used as a laser dye at

Sinan S. Keskin; Necdet Aslan; Fuat Bayrakçeken

2007-01-01

386

Structure elucidation of laser-dye coumarin-540A by joint application of X-ray diffraction, X-ray fluorescence, prompt fluorescence, UV and visible spectroscopy  

Microsoft Academic Search

X-ray, ultraviolet, and visible light induced photophysical changes of coumarin-540A in ethanol has been studied by the joint applications of X-ray, ultraviolet, and visible spectroscopy. Some impurities were found by X-ray fluorescence measurements. During the high power optical pumping, coumarin showed photochemical changes. Photoproduct emission spectra characteristics showed that photoproduct molecules could also be used as a laser-dye at a

Sinan S. Keskin; Necdet Aslan; Fuat Bayrakçeken

2007-01-01

387

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

388

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

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 percent/ 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

Intracavity frequency-doubling of quasi-cw pumped YAG laser  

SciTech Connect

We designed a quasi-CW pumped intracavity frequency-doubling YAG laser, which has a higher average power and peak-power output, better beam quality and less thermal effect than that of the CW pumped laser.

Yao Jianquan; Li Yu; Liu Yan-ming

1987-09-25

391

Direct Nuclear Pumped Neon-Nitrogen Laser.  

National Technical Information Service (NTIS)

A new neutron-driven laser that utilizes a boron-10 coating, Ne-N sub 2 gas, and provides simultaneous output at 8629 and 9393 A in nitrogen is described. The laser has several distinctive features; namely, the neutron flux i.e., power input at threshold ...

R. J. DeYoung

1975-01-01

392

LD dual-end-pumped CW Tm:YLF laser  

NASA Astrophysics Data System (ADS)

We report on a LD dual-end-pumped 792nm continuous wave operation Tm:YLF laser. Firstly, the rate equation of LD end-pumped CW operation Tm:YLF laser were established, in which the energy transfer upconversion and without energy transfer upconversion under continuous-wave considerate were considered, as well the pump threshold and the slope efficiency of the laser system were analyzed. Simultaneously, the cavity stability condition and the pattern matching of the plano- concave resonator were analyzed according to ABCD Matrix theory. Comparing respectively the laser threshold and the slope efficiency and optical-optical conversion efficiency under circumstances which the output mirror transmittance of 15% and 23%. In addition, the M2 of the output laser were contrasted and analyzed in adjusting the resonator cavity length by using different radius of curvature of the output mirror in 150mm, 200mm and 300mm all in the above case. As the process of thermal lens focal length changing greater than 90mm, it exhibited that the two fundamental modes in the cavity resonator matched well in numerical simulation when the radius of curvature of the output mirror was 300mm, as well the two fundamental modes matched well when it more than 100mm in a certain pump power. We designed a single LD dual-end-pumped continuous wave operation Tm:YLF laser. Using Tm:YLF (3 at.%) crystal for gain medium, which the size was 3×3×14mm3. In experiments, the Tm:YLF laser crystal keeps 291K and the temperature control method is water cooling. The length of the resonator was 135mm when L shape plano-concave resonator was applied, and the radius of curvature output mirror was 300mm, as well as the temperature of the Tm:YLF laser crystal was 291K. The output laser we observed by this system and the central laser wavelength was 1944nm. The threshold power was 8.11W and the highest output power reaches to 4.01W when the totally input pump power was 17W, and the optical conversion efficiency was 23.6%. The far-field divergence angle was 3.8mrad after calculation. Respectively. The experimental results are coinciding with the theory.

Chen, Xin-yu; Zhang, Yu; Yu, Yong-ji; Wang, Chao; Jin, Guang-yong

2013-09-01

393

Solid hosts for dye laser rods: Part 2, Some experimental results  

SciTech Connect

Attempts and problems encountered in producing high quality polymer dye laser rods are discussed. Purification methods used on the monomer materials, curing agent problems, and gamma radiation curing are considered. 7 figs.

Erickson, G.F.

1987-01-01

394

Vanadium-pumped titanium X-ray laser  

NASA Astrophysics Data System (ADS)

A new laboratory X-ray laser is described that is resonantly photopumped by two 3d-2p emission lines in fluorinelike vanadium (Z = 23) and lases on several 3p-3s transitions in neonlike titanium (Z = 22). Calculations show that five of the laser lines have gains greater than 5/cm for reasonable values of the pump lines, with the shortest wavelength of the five being at 32.65 nm.

Nilsen, Joseph

1990-07-01

395

Direct nuclear pumping of a helium?xenon laser  

Microsoft Academic Search

Excitation of a He?Xe laser was achieved by nuclear pumping, i.e., fission products interacted directly with the lasing gas and a portion of their energy was emitted as laser light. The transition observed is most likely the Xe 5d[7\\/2]03?6p[5\\/2]2, 3.508 ?m. The He?Xe gas mixture ratio was 20 : 1 at a total pressure of 200 Torr. The light output

H. H. Helmick; J. L. Fuller; R. T. Schneider

1975-01-01

396

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

397

1.38-µm mode-locked Raman fiber laser pumped by semiconductor disk laser.  

PubMed

A mode-locked Raman fiber laser pumped by 1.3 µm semiconductor disk laser is demonstrated. Direct Watt-level core-pumping of the single-mode fiber Raman lasers and amplifiers with low-noise disk lasers is demonstrated to represent a highly practical solution as compared with conventional scheme using pumping by Raman wavelength convertors. Raman laser employing passive mode-locking by nonlinear polarization evolution in normal dispersion regime produces stable pedestal-free 1.97 ps pulses at 1.38 µm. Using semiconductor disk lasers capable of producing high power with diffraction-limited beam allows Raman gain to be obtained at virtually any wavelength of interest owing to spectral versatility of semiconductor gain materials and wafer-fusing technology. PMID:21164732

Chamorovskiy, A; Rantamäki, A; Sirbu, A; Mereuta, A; Kapon, E; Okhotnikov, O G

2010-11-01

398

Laser Line Competition in Optically Pumped D2O THz Laser  

NASA Astrophysics Data System (ADS)

Based on the theory of semi-classical density matrix and a model of double three-energy-level (DTEL) system for laser line competition in optically pumped D2O super-radiant terahertz laser (THz Laser), the mathematical expressions of gain coefficients for pumping signal and THz laser signal are deduced, and the competition between 66 ?m and 116 ?m laser lines is calculated numerically by means of iteration method. The effects of the operation conditions (including pump power, working gas pressure and the length of cavity) on the competition are analyzed. It is found that 66 ?m emission dominated the competition; with the increase of working gas pressure (or the cavity length), the spectrum of 66 ?m emission experiences changes from discrete double-peak structure to overlapped double-peak structure and finally to a wide-band structure, and the optimum gas pressure varied conversely with the optimum length of the THZ laser cavity.

Liang, Pingyuan; Meng, Meng; Liang, Jiangchu; Luo, Xizhang

2012-10-01

399

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

Microsoft Academic Search

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

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

2007-01-01

400

Two-Photon Excitation of Dye-Doped Liquid Crystal by a CW-Laser Irradiation  

Microsoft Academic Search

We report on excitation of photoluminescence via two-photon absorption (2PA) in dye-doped liquid crystal droplets using tightly focused cw-laser illumination at 1064 nm wavelength. The photoluminescence of the 2PA dye C40H54N2O2 (MBAPB) dispersed inside the 7CB liquid crystal host increases as square of the laser tweezers' irradiance. The 2PA cross-section of MBAPB was measured by femtosecond Z-scan method. The polarization and

Naoki Murazawa; Saulius Juodkazis; Hiroaki Misawa; Kenji Kamada

2008-01-01

401

Tunable IR Lasers for Helium Optical Pumping  

Microsoft Academic Search

It has been clear for a number of years that the efficiency of the optical pumping process in helium gas could be improved substantially if a tunable, intense source of radiation were available at the resonance wavelength of the helium triplet metastable atom, 1083 nm. Until recently such sources were unavailable. It was the purpose of this research to develop

Padetha Tin

1990-01-01

402

Pulsed dye laser treatment for viral warts: a study of 120 patients.  

PubMed

A prospective, non-blinded, non-randomized study on 120 wart patients treated with pulsed dye laser was performed to evaluate the efficacy and safety of pulsed dye laser treatment for viral warts and to demonstrate the proper application and effective technique of this method. The overall clearance rate was 49.5%. The clearance rates of flat warts, periungual warts, plantar warts and common warts were 67.6%, 51.1%, 47.6% and 44.3%, respectively. Overall, the response rates of pediatric warts, recalcitrant warts and old warts were superior to those of adult warts, simple warts and non-old warts, respectively; however, those trends were not statistically significant. We concluded that pulsed dye laser treatment is a safe, tolerable and relatively effective treatment method for viral warts. Pulsed dye laser treatment may be a more efficacious method for flat warts and recalcitrant periungual warts, and it can be an effective modality for newly-developed warts. The highest clearance rate was noted at a fluence of 9.5 J/cm2 (P < or = 0.05) and it is recommended that practitioners perform pulsed dye laser treatments for viral warts at the fluences of 9.0-9.5 J/cm2. A replacement of pulsed dye laser treatment should be considered unless prominent improvement is observed after three treatment sessions. PMID:18789068

Park, Hyun Su; Choi, Woo Seok

2008-08-01

403

Scaling studies of blackbody-pumped CO sub 2 lasers using gaussian and waveguide cavities  

Microsoft Academic Search

A large scale pulsed laser system with heated tantalum foils as the blackbody pumping source was built in the laboratory. A deeper understanding of the physics and the scaling factors of the blackbody pumped COâ laser has been achieved through parametric scaling studies using this system. Numerical analysis is also performed for computing pumping power and laser gain. Theoretical analysis

1989-01-01

404

Scaling Studies of Blackbody-Pumped Carbon-Dioxide Lasers Using Gaussian and Waveguide Cavities  

Microsoft Academic Search

A large scale pulsed laser system with heated tantalum foils as the blackbody pumping source was built in the laboratory. A deeper understanding of the physics and the scaling factors of the blackbody pumped CO _2 laser has been achieved through parametric scaling studies using this system. Numerical analysis is also performed for computing pumping power and laser gain. Theoretical

Jim Jih-Chyun Chang

1989-01-01

405

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

406

Rapid prototyping of a micro pump with laser micromaching  

SciTech Connect

A micro electrohydrodynamic (EHD) injection pump has been developed using laser micromaching technology. Two designs have been fabricated, tested, and evaluated. The first design has two silicon pieces with KOH-etched wells which are stacked on the top of each other. The wells am etched on one side of the wafer and gold is deposited on the other side to serve as the pump electrodes. A ND:YAG laser is used to drill an array holes in the well region of both silicon die. This creates a grid distribution with a rectangular pattern. Next the well regions of the die are aligned, and the parts are bonded together using a Staystik thermoplastic. The pump unit is then mounted into a ceramic package over the hole drilled to permit fluid flow. Aluminum ribbon wire bonds are used to connect the pump electrodes to the package leads. Isolation of metallization and wires is achieved by filling the package well and coating the wires with polyimide.When a voltage is applied at the electrodes, ions are injected into the working fluid, such as an organic solvent, thus inducing flow. The second design has the die oriented ``back-to-back`` and bonded together with stayform. A ``back-to-back`` design will decrease the grid distance so that a smaller voltage is required for pumping. Preliminary results have demonstrated that this micro pump can achieved a pressure head of about 287 Pa with an applied voltage of 120 volts.

Wong, C.C.; Chu, D.; Liu, S.L.; Tuck, M.R.; Mahmud, Z.; Amatucci, V.

1995-08-01

407

Rapid prototyping of a micro pump with laser micromachining  

NASA Astrophysics Data System (ADS)

A micro electrohydrodynamic (EHD) injection pump has been developed using laser micromachining technology. Two designs have been fabricated, tested, and evaluated. The first design has two silicon pieces with KOH-etched wells which are stacked on the top of each other. The wells am etched on one side of the wafer and gold is deposited on the other side to serve as the pump electrodes. A ND:YAG laser is used to drill an array holes in the well region of both silicon die. This creates a grid distribution with a rectangular pattern. Next the well regions of the die are aligned, and the parts are bonded together using a Staystik thermoplastic. The pump unit is then mounted into a ceramic package over the hole drilled to permit fluid flow. Aluminum ribbon wire bonds are used to connect the pump electrodes to the package leads. Isolation of metallization and wires is achieved by filling the package well and coating the wires with polyimide. When a voltage is applied at the electrodes, ions are injected into the working fluid, such as an organic solvent, thus inducing flow. The second design has the die oriented 'back-to-back' and bonded together with stayform. A 'back-to-back' design will decrease the grid distance so that a smaller voltage is required for pumping. Preliminary results have demonstrated that this micro pump can achieved a pressure head of about 287 Pa with an applied voltage of 120 volts.

Wong, C. C.; Chu, D.; Liu, S. L.; Tuck, M. R.; Mahmud, Z.; Amatucci, V.

408

Recent Progress of High Power Semiconductor Lasers for EDFA Pumping  

Microsoft Academic Search

Optical fiber communication systems using a WDM (wavelength division multi- plexing) system are being introduced in long-haul networks to manage the explo- sive increase in transmission capacity. Erbium-doped fiber amplifier (EDFA) is one of the key components to support WDM systems. High power lasers emitting at both 980 nm and 1480 nm are essential for pumping sources for EDFA. In

Akihiko Kasukawa; Toshikazu Mukaihara; Takeharu Yamaguchi; Jun' jiro Kikawa

409

A Blackbody Radiation-Pumped CO2 Laser Experiment.  

National Technical Information Service (NTIS)

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

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

1982-01-01

410

Production Engineering Measure for Optical Pumps for Lasers.  

National Technical Information Service (NTIS)

This program is directed toward establishing a capability for manufacturing flashlamps that are to be used as optical pumps for Nd:YAG laser systems. This report describes the work carried out during the fifth quarter of the program. The four synthetic fu...

R. Maynard H. Sowers

1974-01-01

411

Surface Discharge - Pumped XeF(C->A) Laser.  

National Technical Information Service (NTIS)

The focus of this Phillips Laboratory supported research program is the development of a compact, surface discharge device suitable for pumping a variety of atomic and molecular lasers. This effort met all of the goals set forth in the original proposal, ...

J. G. Eden

1996-01-01

412

Single-mode, 980-nm pump lasers for fiber amplifiers  

SciTech Connect

Pump lasers for Er3+-doped silica fiber optical amplifiers must demonstrate excellent spatial mode stability to high output power levels in order to achieve useful gain. 1,2 The pump band at 980 nm is the most efficient of the principle Er3+ absorption bands in terms of gain per input optical power. Pumping at 980 nm is also preferred in comparison to pumping at 1480 nm because it reduces the noise introduced into the amplified optical signal. In this paper we describe the design, fabrication, and characteristics of a high power, MBE-grown 980 nm laser with a simple, weakly-index-guided structure. The geometry of the laser's lateral waveguide is carefully controlled to ensure that all of the power is in the fundamental spatial mode. Far field patterns of these devices are single lobed and stable to the highest measured powers. These Fabry-Perot lasers exhibit single frequency operation to output powers as high as 170 mW, with linewidths as narrow as 5 MHz.

Crawford, F.D.; Sharfin, W.F.; Elman, B.; Lauer, R.B.; Mebrahtu, P.

1992-05-22

413

Flashlamp pumped Cr:LiSrAlF6 laser  

NASA Astrophysics Data System (ADS)

Tunable, flashlamp-pumped laser properties are described for the crystal Cr:LiSrAlF6 (Cr:LiSAF) in both long pulse and Q-switched modes of operation. Slope efficiencies of 5 percent, overall efficiency of 3 percent, and a tuning range from 780 to 1010 nm are reported.

Stalder, Martin; Chai, Bruce H. T.; Bass, Michael

1991-01-01

414

Cs magnetometers optically pumped with radiation of diode lasers  

Microsoft Academic Search

Atomic magnetometers optically pumped with resonance lamps have been explored and used in applications for more than 40 years. After many improvements these devices have reached high level of performance and fundamental limits make further progress difficult. Development of reliable single mode diode lasers (DL) that can be tuned to D lines of alkali atoms opened new possibilities such as

A. V. Klimakov; A. N. Kozlov; V. V. Vassiliev; V. L. Velichansky; V. P. Yakovlev; E. V. Zhivun; A. A. Zhukov; S. A. Zibrov

2009-01-01

415

CW submillimeter wave laser pumped by an RF-excited CO2 waveguide laser  

Microsoft Academic Search

Optical pumping of a submillimeter wave (SMMW) laser with a relatively compact continuous wave CO2 waveguide laser is reported. The CO2 laser beam is directed into the SMMW cavity through a 1.5-mm hole in the mirror of the SMMW laser, which is an unoptimized hole-coupled resonator with a 90-cm long metal waveguide. Part of the beam is reflected off the

M. S. Tobin

1981-01-01

416

Solid state blue-green laser with high efficiency laser pump  

Microsoft Academic Search

A high efficiency, high power blue-green laser is described which is capable of providing short pulses useful for underwater communication and detection systems. To provide the desired blue-green lasing, a solid state laser is pumped by a matched high-efficiency laser having relatively long duration output pulses. Q-switching of the solid state laser is used to shorten the duration and increase

Nicolai

1977-01-01

417

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

418

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

419

Continuously tunable diode-pumped Tm:YAP laser  

NASA Astrophysics Data System (ADS)

Tunable solid-state laser sources emitting in the 2 ?m wavelength region are important for applications in atmospheric monitoring and laser radar because many molecular absorption lines are present there. We report on continuously tunable operation of a diode pumped Tm:YAP laser, which is among the most efficient laser materials emitting in the 1.9-2 ?m spectral band, while continuous tuning of this material has not yet been reported. The 3mm long a-cut (Pbnm) crystal sample with 4% at. doping was used. The 400 ?m fiber was used to deliver up to 17W of pump power to the coupling optics. The differential efficiency in respect to the absorbed pump power reached 57% while the attained optical-to-optical efficiency was 48%. The maximal output of 4.8W was only limited by the available pump power and relatively low sample absorption. The free running wavelength was measured at 1.99 ?m. A 1.5mm thick birefringent plate made from quartz inserted under a Brewster's angle was used as a tuning element. The maximal output power of 3.85W in this set-up was obtained. The laser could be tuned from 1869nm up to 2036nm with a maximum at 1985 nm. The tuning range of over 160nm covers many important atmospheric absorption lines. In this wavelength range, the absorption depth in water changes from 100 ?m (laser wavelength 1.94 ?m) to 400 ?m (wavelength 1.87 ?m) making it potentially attractive for medical applications as a laser scalpel with variable cutting depth.

?erný, Pavel; Šulc, Jan; Jelínkova, Helena

2006-05-01

420

Reducing thermal lensing in diode-pumped laser rods  

NASA Astrophysics Data System (ADS)

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 rod, such that the improvement in a composite-doped rod can be determined. For the Nd:YAG rods used in this work this part of the thermal lens constituted approximately 47% of the total thermal lens in the homogeneously doped rod leading to the maximum pump power being increased by almost 90%, on introduction of composite rods. The laser was demonstrated, giving a maximum output power of over 16 W and an optical efficiency of over 42% in fundamental mode operation.

MacDonald, M. P.; Graf, T.; Balmer, J. E.; Weber, H. P.

2000-05-01

421

2.7-um diode-pumped fiber laser  

NASA Astrophysics Data System (ADS)

The performances of the diode-pumped 2.7 micrometers fiber laser have been studied. From the population inversion estimated for a fluorozircoaluminate (AZF) glass with different ErF3 doping, a higher gain was expected for a higher ErF3 doping. The laser performances were improved by adjusting fiber length. Maximum output power of 18.5 mW and slope efficiency of 7% were obtained by using 10 mol% ErF3 doped, 25 mm long AZF fiber in the 800 nm pumping. A cw lasing was achieved by diode pumping at 0.98 micrometers and the effect of Yb3+ sensitization was discussed to improve the performance.

Yanagita, Hiroaki; Toratani, Hisayoshi; Yamashita, Toshiharu T.; Masuda, Isao

1992-02-01

422

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

423

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

424

Power scaling of a directly diode-laser-pumped Ti:sapphire laser.  

PubMed

Improvements in the output power of a directly GaN diode-laser-pumped Ti:Al2O3 laser are achieved by using double-sided pumping. In continuous wave operation, an output power of 159 mW is reported. A tuning range of over 125 nm with output powers in excess of 100 mW is achieved. Pulses of 111 fs duration and an average power of 101 mW are demonstrated by mode locking the laser with a saturable Bragg reflector. Pumping with GaN diode lasers at wavelengths around 450 nm induces an additional parasitic crystal loss of about 1% per resonator roundtrip that is not observed at the conventional green pump wavelengths. PMID:23037110

Roth, Peter W; Burns, David; Kemp, Alan J

2012-08-27

425

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

426

Raman fiber laser pumped by a semiconductor disk laser and mode locked by a semiconductor saturable absorber mirror.  

PubMed

A 1.6µm mode-locked Raman fiber laser pumped by a 1480nm semiconductor disk laser is demonstrated. Watt-level core pumping of the single-mode fiber Raman lasers with low-noise disk lasers together with semiconductor saturable absorber mirror mode locking represents a highly practical solution for short-pulse operation. PMID:20967123

Chamorovskiy, A; Rautiainen, J; Lyytikäinen, J; Ranta, S; Tavast, M; Sirbu, A; Kapon, E; Okhotnikov, O G

2010-10-15

427

Thermal effects in laser pumped Kerr-lens modelocked Ti:sapphire lasers  

Microsoft Academic Search

Numerical beam propagation simulations are used to demonstrate that the distributed thermal lensing, produced by the absorption of the pump laser in the gain medium, profoundly affects the operation of hard-apertured, Kerr-lens modelocked Ti:sapphire lasers. The pump-induced thermal lensing is shown to shift and distort the resonator stability regions (even allowing the regions to overlap) and severely perturb the modelocking

Manjusha Mehendale; T. R Nelson; F. G Omenetto; W. Andreas Schroeder

1997-01-01

428

Development of a dual-wavelength dye-laser system for the UV and its application to simultaneous multi-element detection  

NASA Astrophysics Data System (ADS)

In this paper, the design and performance characteristics of a pulsed tunable dye laser system for the simultaneous generation of two UV wavelengths are presented. The system is composed of an oscillator and an amplifier stage, pumped by the second harmonic of a commercial Nd:YAG laser. Dual-wavelength operation is achieved with one additional tuning mirror introduced to the prism expanded grazing incidence oscillator. The two obtained wavelengths are independently tunable, their separation is only limited by the gain profile of the dye. Both wavelengths are frequency doubled by Second-Harmonic Generation (SHG) in two KDP or BBO crystals. Performance characteristics such as bandwidth, efficiency, tuning range and wavelength separation are reported. As application two such systems are used for the simultaneous detection of the four elements cadmium, nickel, manganese and lead by Laser-Excited Atomic Fluorescence Spectrometry in a graphite furnace (ETA-LEAFS).

Schütz, M.; Heitmann, U.; Hese, A.

1995-10-01

429

Active frequency stabilization, of diode laser pumped, nonplanar ring oscillators  

NASA Astrophysics Data System (ADS)

Frequency-stabilization and coherent-communication studies are performed on diode-laser pumped nonplanar-ring oscillators (NPRO). The lasers used in the experiments were NPROs with 2-mW output power; Nd:YAG laser crystals were replaced with Nd:GGG crystals optimized for improved resistance to optical feedback, and PZT actuators were bonded directly to the laser to provide fast frequency tuning. The lasers were independently locked to the same interferometer in order to obtain a limited common mode rejection against cavity fluctuations. A spectrum-analyzer trace of the heterodyne beat-note signal is discussed, and it is pointed out that shot noise on the laser beam together with amplifier noise are interpreted by servos as frequency fluctuations. It is also observed that the low noise of diode-laser pumped NPROs and their ability to be easily stabilized as well as used to injection lock high-power oscillators make them candidates for use in coherent communication. An optical phase-locked loop (OPLL) for use in a coherent homodyne receiver is considered.

Day, T.; Gustafson, E. K.; Byer, R. L.

1990-04-01

430

On combined diode pumping of a passively Q-switched solid-state laser  

Microsoft Academic Search

Peculiarities of using combined diode pumping consisting of continuous wave (CW) and pulsed components in a diode-pumped solid-state\\u000a (DPSS) laser with intracavity saturable absorber are studied. The requirements to pumping parameters for Q-switched operation\\u000a are stated. The threshold optical pump energy and the diode-pumping time are investigated.

A. F. Shatalov; F. A. Shatalov

2009-01-01

431

Absorption, luminescent and lasing properties of laser dyes in silica gel matrices and thin gel films  

SciTech Connect

The absorption and emission properties of eight organic compounds in silica gel matrices of different chemical compositions and different types (bulk samples and thin films) are studied upon excitation by a XeCl laser and the second harmonic of a Nd:YAG laser. The mechanisms of the laser-induced changes in the spectral parameters of molecules in silica gel matrices are discussed and the photostability of the laser dyes in silica gel films is estimated. (active media)

Shaposhnikov, A A; Kuznetsova, Rimma T; Kopylova, T N; Maier, G V; Tel'minov, E N [V.D. Kuznetsov Siberian Physical-Technical Institute, Tomsk (Russian Federation); Pavich, T A; Arabei, S M [Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, Minsk (Belarus)

2004-08-31

432

High-power vertical-cavity surface-emitting lasers for solid-state laser pumping  

NASA Astrophysics Data System (ADS)

Vertical-cavity surface-emitting lasers (VCSELs) have emerged as a promising candidate for pumping of solid-state lasers, as they can be configured into high-power two-dimensional arrays and modules of arrays. VCSELs emit in a circular, uniform beam which can greatly reduce the complexity and cost of coupling optics. Their narrow and stable emission spectrum is well suited to the narrow absorption spectrum generally observed for solid-state gain media. The superior reliability of VCSELs greatly enhances the robustness of solid-state laser systems and enables high-temperature operation. In this work, we discuss recent developments on kW-class VCSEL pumps for solid-state lasers. Results on VCSEL modules designed for end-pumping and for side-pumping are presented. More than 4kW in CW operation is demonstrated from a multi-array VCSEL module. We also present results on solid-state lasers using VCSEL modules as pumps. In an end-pumping configuration, more than 250W peak power at 1064nm is demonstrated, and in a sidepumping Q-switched configuration, more than 21mJ at 946nm is demonstrated for an Nd:YAG solid-state laser.

Seurin, Jean-Francois; Xu, Guoyang; Miglo, Alexander; Wang, Qing; van Leeuwen, Robert; Xiong, Yihan; Zou, Wei-Xiong; Li, Daizong; Wynn, James D.; Khalfin, Viktor; Ghosh, Chuni

2012-02-01

433

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

434

Towards shorter wavelength x-ray lasers using a high power, short pulse pump laser  

SciTech Connect

A near-terawatt, KrF* laser system, focussable to power densities >10{sup 18} W/cm{sup 2} has been constructed for use as a pump laser in various schemes aimed at the development of x-ray lasing below 5nm. The laser system along with output characteristics such as the pulse duration, the focal spot size, and the percentage of amplified spontaneous emission (ASE) emitted along with the laser pulse will be presented. Schemes intended to lead to shorter wavelength x-ray emission will be described. The resultant requirements on the pump laser characteristics and the target design will be outlined. Results from recent solid target experiments and two-laser experiments, showing the interaction of a high-power, short pulse laser with a preformed plasma, will be presented. 13 refs., 5 figs.

Tighe, W.; Krushelnick, K.; Valeo, E.; Suckewer, S.

1991-05-01

435

Recombination-pumped triatomic hydrogen infrared lasers  

SciTech Connect

Mid-infrared laser lines observed in hydrogen/rare gas discharges are assigned to three-body recombination processes involving an electron, a rare gas (He or Ne) atom, and the triatomic hydrogen ion (H{sub 3}{sup +}). Calculations of radiative transitions between neutral H{sub 3} Rydberg states support this interpretation, and link it to recent results for hydrogenic/rare gas afterglow plasmas. A mechanism for the population inversion is proposed, and the potential generality and astrophysical implications of such molecular recombination laser systems are briefly discussed.

Saykally, R. J.; Michael, E. A. [Department of Chemistry, University of California, Berkeley, California 94720-1460 (United States); Wang, J.; Greene, Chris H. [Department of Physics and JILA, University of Colorado, Boulder, Colorado 80309-0440 (United States)

2010-12-21

436

Double-Pass-Pumped Tm:YAG Laser with a Simple Cavity Configuration.  

PubMed

For a double-pass-pumped cw Tm:YAG laser, we developed a theoretical model, taking into account reabsorption loss and mode matching between the pumping light and the cavity mode. We also demonstrated that efficient operation can be obtained with a simple cavity configuration by using a dichroic output mirror, highly reflective at the pumping wavelength and partially reflective at the lasing wavelength. Experimental comparisons of this pumping method with single-pass pumping showed that the longitudinally double-pass-pumped Tm:YAG laser performs as well at room temperature as the single-pass-pumped laser performs at -10 degrees C. PMID:18286141

Sato, A; Asai, K; Itabe, T

1998-09-20

437

Femtosecond Cr:LiSAF and Cr:LiCAF lasers pumped by tapered diode lasers.  

PubMed

We report compact, low-cost and efficient Cr:Colquiriite lasers that are pumped by high brightness tapered laser diodes. The tapered laser diodes provided 1 to 1.2 W of output power around 675 nm, at an electrical-to-optical conversion efficiency of about 30%. Using a single tapered diode laser as the pump source, we have demonstrated output powers of 500 mW and 410 mW together with slope efficiencies of 47% and 41% from continuous wave (cw) Cr:LiSAF and Cr:LiCAF lasers, respectively. In cw mode-locked operation, sub-100-fs pulse trains with average power between 200 mW and 250 mW were obtained at repetition rates around 100 MHz. Upon pumping the Cr:Colquiriite lasers with two tapered laser diodes (one from each side of the crystal), we have observed scaling of cw powers to 850 mW in Cr:LiSAF and to 650 mW in Cr:LiCAF. From the double side pumped Cr:LiCAF laser, we have also obtained ~220 fs long pulses with 5.4 nJ of pulse energy at 77 MHz repetition rate. These are the highest energy levels reported from Cr:Colquiriite so far at these repetition rates. Our findings indicate that tapered diodes in the red spectral region are likely to become the standard pump source for Cr:Colquiriite lasers in the near future. Moreover, the simplified pumping scheme might facilitate efficient commercialization of Cr:Colquiriite systems, bearing the potential to significantly boost applications of cw and femtosecond lasers in this spectral region (750-1000 nm). PMID:21997053

Demirbas, Umit; Schmalz, Michael; Sumpf, Bernd; Erbert, Götz; Petrich, Gale S; Kolodziejski, Leslie A; Fujimoto, James G; Kärtner, Franz X; Leitenstorfer, Alfred

2011-10-10

438

Flash-pumped pulsed Cr:LiSAF laser action from a modified conventional solid state laser cavity  

NASA Astrophysics Data System (ADS)

Conventional solid state laser pumping cavities has been used, after proper modification, in order to achieve efficient laser action by Cr:LiSAF crystals. The crystal samples were placed in the laser head, properly supported for efficient pumping to achieve satisfactory laser action. It has been proved that for a successful result a strong flash pumping source and a low output coupling is needed to help the low overall gain of the small Cr:LiSAF samples.

Klinkenberg, Bernhard J.; Papayannis, Alexandros D.; Serafetinides, Alexandros A.

2003-11-01

439

Fiber Raman laser and amplifier pumped by Nd3+:YVO4 solid state laser  

NASA Astrophysics Data System (ADS)

Pumping source is the key technology of fiber Raman amplifiers (FRA) which are important for ultra long haul and high bit rate dense wavelength division multiplexing (DWDM) systems. In this paper the research work of the project, "Fiber Raman Laser and Amplifier pumped by Nd3+:YVO4 Solid State Laser", supported by the National High-tech Program (863-program) of China is introduced, in which a novel 14xx nm pump module with fine characteristics of high efficiency, simplicity, compactness and low cost is researched and developed. A compact 1342 nm Nd3+:YVO4 diode pumped solid state laser (DPSSL) module is developed with the total laser power of 655mW and the slope efficiency of 42.6% pumped by a 2W 808nm laser diode (LD). A special C-lens fiber collimator is designed to couple the 1342nm laser beam into a piece of single mode fiber (SMF) and the coupling efficiency of 80% is reached. The specific 14xx nm output laser is generated from a single stage Raman resonator which includes a pair of fiber Bragg gratings and a piece of Germanic-silicate or Phospho-silicate fiber pumped by such DPSSL module. The slope efficiency for conversion from 1342 to 14xx nm radiation is 75% and the laser power is more than 300mW each. Finally, Raman gain experiments are carried out with 100km SMF. 100 nm bandwidth with 10dB on-off Raman gain and 1.1dB gain flatness is achieved by pumped at 1425, 1438, 1455 and 1490nm.

Liu, Deming; Zhang, Minming; Liu, Shuang; Nie, Mingju; Wang, Ying

2005-04-01

440

Temperature distribution in side- and end-pumped laser crystal rods - Temporal and spatial variations  

Microsoft Academic Search

Knowledge of the temperature distribution of laser rods end pumped by laser diodes or other laser systems is relevant when thermal stress and crystal damage are expected. The temperature of a multipulsed or continuously pumped laser rod is given as a double-series expression and as a function of time. The mathematical model considers all surface cooling rates, the spatial and

Usamah O. Farrukh; Philip Brockman

1993-01-01

441

DPSSL and FL pumps based on 980-nm telecom pump laser technology: changing the industry  

NASA Astrophysics Data System (ADS)

Diode-pumped solid state laser (DPSSL) and fiber laser (FL) are believed to become the dominant systems of very high power lasers in the industrial environment. Today, ranging from 100 W to 5 - 10 kW in light output power, their field of applications spread from biomedical and sensoring to material processing. Key driver for the wide spread of such systems is a competitive ratio of cost, performance and reliability. Enabling high power, highly reliable broad-area laser diodes and laser diode bars with excellent performance at the relevant wavelengths can further optimize this ratio. In this communication we present, that this can be achieved by leveraging the tremendous improvements in reliability and performance together with the high volume, low cost manufacturing areas established during the "telecom-bubble." From today's generations of 980-nm narrow-stripe laser diodes 1.8 W of maximum CW output power can be obtained fulfilling the stringent telecom reliability at operating conditions. Single-emitter broad-area lasers deliver in excess of 11 W CW while from similar 940-nm laser bars more than 160 W output power (CW) can be obtained at 200 A. In addition, introducing telecom-grade AuSn-solder mounting technology on expansion matched subassemblies enables excellent reliability performance. Degradation rates of less than 1% over 1000 h at 60 A are observed for both 808-nm and 940-nm laser bars even under harsh intermittent operation conditions.

Lichtenstein, Norbert; Schmidt, Berthold E.; Fily, Arnaud; Weiss, Stefan; Arlt, Sebastian; Pawlik, Susanne; Sverdlov, Boris; Muller, Jurgen; Harder, Christoph S.

2004-06-01

442

Rotational Energy Transfer in Optically Pumped FIR Lasers.  

NASA Astrophysics Data System (ADS)

Optically pumped far infrared (OPFIR) lasers offer much promise as strong coherent sources in a frequency region where the production, propagation, and detection of radiation has always been fraught with problems. Although the mm/submm spectral region is one which has long been associated with experimental difficulty, it is in fact an excellent place to study the dynamics of these systems. It is the region in which the pure rotational transitions of the light polyatomic molecules used in OPFIR lasers occur and it is therefore possible to probe not only the gain profile of the laser transitions, but also many other transitions, including those directly connected to the pumped state and those only collisionally connected. All of these states are collisionally coupled to one another and play important roles in the energy transfer process. In this spectral region, the interaction of radiation with the molecules is especially strong and it is possible to detect very small concentrations of molecules with good signal to noise, even in the relatively broad bandwidths needed for real time observations. The time resolved experiments described in this work have made possible the extension of a previously developed model to simply, yet accurately describe the rotational and vibrational energy transfer of one of these lasers. The model was substantially improved by including a more physical pumping process, completely separating thermal and non -thermal molecules, and adding an additional vibrational state. The time dependent population in states both directly connected to the pump and those only collisionally connected was monitored by using a Q-switched pump laser and the sensitive, tunable mm/submm spectroscopic techniques described herein. The data collected verified the existence of a fast process for rotational and vibrational deexcitation, thus providing a rapid pathway for emptying the lower laser state and preventing vibrational bottlenecking. It would appear that the approach outlined in this work is very general and that it should be applicable to a wide range of OPFIR lasers, including some that might operate in physical regimes quite different from those commonly employed. In particular, the simulation should be useful for any OPFIR laser system and should require a minimum of additional diagnostic data.

McCormick, Rodney Ivan

1987-09-01

443

Diffractive photonic-crystal pumping of power lasers  

NASA Astrophysics Data System (ADS)

In the present report a novel diffractive technique for effective optical pumping of power chemical lasers by external coherent radiation is proposed. This technique utilizes a bicomponent diffraction system coupled structurally to the unstable telescopic cavity of the laser. The space localization of the electromagnetic field inside the proposed optical scheme represents a periodic structure of diffractive maxima in the near field-zone and a narrow paraxial diffraction channel with high intensity in the far-field zone. In the Fresnel diffraction zone, the optical effect of multifocal diffractive focusing of the radiation is observed. Here the intensity in the central peaks can exceed by a factor of six (for spherical waves) to ten (for plane waves) the value of the incident wave intensity. The diffractive focusing of the input radiation opens the possibility to create a narrow diffraction initiation channel inside the laser cavity with a given space distribution and a high intensity. This technique provides a high efficiency for optical pumping and makes it possible to get a huge value of the laser energy gain. Calculations show that the ignition of laser-chemical reactions in the diffraction initiation channel under the condition of diffractive focusing of input radiation allows the laser energy to reach a gain of up to 109.

Letfullin, Renat R.; Arnoldus, Henk F.; Foley, John T.

2003-06-01

444

Electron beam pumped tunable excimer lasers  

SciTech Connect

Laser characteristics were studied extensively for the broadband rare gas halide excimers Xe/sub 2/Cl, Kr/sub 2/F, and XeF (C ..-->.. A). The trimer Kr/sub 2/F was first observed to lase during these investigations, while Xe/sub 2/Cl and XeF (C ..-->.. A) had been previously demonstrated. Since all three excimers have unbound ground states, a spectrally wide emission bandwidth is available for wavelength tuning. Several system parameters were studied for each of the lasers. These included mixture optimization, variation of optical resonator configuration, and influence of different halogen donors and buffer gases. Tuning was accomplished by using cavity mirrors with different center wavelengths. The trimer Xe/sub 2/Cl had a nominal peak wavelength of 518 nm, with a tuning range of approx. 15 nm and a ..delta..lambda of 20 nm (FWHM). Laser pulse widths were about 36 nsec, and were delayed by 35 nsec from the e-beam excitation current pulse. Kinetics of Xe/sub 2/Cl* were also studied, with the following results: a radiation lifetime of 135 (+75-60) nsec; a CCl/sub 4/ quenching constant of 6 +- 1 x 10/sup -10/ cm/sup 3/ sec/sup -1/; a xenon quenching constant of < 5 x 10/sup -13/ cm/sup 3/ sec/sup -1/; an argon quenching constant of 3 +- 1 x 10/sup -14/ cm/sup 3/ sec/sup -1/; and a formation constant (from XeCl* via Xe and Ar collisions) of 1.5 + -0.5 x 10/sup -31/ cm/sup 6/ sec/sup -1/. The triatomic excimer Kr/sub 2/F lased at 436 nm with a ..delta..lambda of 25 nm. The pulse duration was approx. 50 nsec, with a delay of 35 nsec for the onset of laser action. Atomic absorptions by krypton metastables were identified in the laser spectrum. The dimer XeF (C ..-->.. A) had the largest laser output intensity. The peak wavelength was 486 nm, with a ..delta..lambda of 10 nm and a tuning range of 30 nm. Pulse duration was approx. 30 nsec.

Smayling, M.C.

1981-01-01

445

Photo-pumped x-ray laser research on Saturn  

NASA Astrophysics Data System (ADS)

Using Saturn as a driver, we are pursuing both photoresonantly pumped and photoionization/recombination lasers. Our lasing targets are gas cells with thin windows that are pumped by a z pinch 2 cm away radiating 10 TW. In both schemes the lasant and gas fill is neon. We will present evidence for inversion in the sodium/neon photoresonant scheme but we have yet to detect the lasing transition itself. To increase our chances of measuring this line we have introduced potassium into a sodium z-pinch and have eliminated oxygen from the gas cell windows.

Nash, Tom J.; Spielman, Rick B.; Vargas, M.; Ruggles, L.

1994-02-01

446

Laser pumping in the scheme of an Mx-magnetometer  

NASA Astrophysics Data System (ADS)

This paper describes the construction of a single-mode diode laser having an external resonator, stabilized by the resonance of saturated absorption in the D(1)-line of the K atom, and presents the results of investigation of its fluctuation characteristics and efficiency of pumping K-39 vapors. Results show that a hitherto unattainable sensitivity of the magnetometric sensor of 1.8 x 10(exp -15) T Hz(exp 1/2), and that in the range of intensities need for optical pumping of (sup 39)K, amplitude fluctuations are reduced to shot fluctuations.

Aleksandrov, E. B.; Balabas, M. V.; Vershovskii, A. K.; Ivanov, A. E.; Yakobson, N. N.; Velichanskii, V. L.; Senkov, N. V.

1995-02-01

447

Intracavity laser diode pumped and modulated Er3+-doped fiber lasers  

Microsoft Academic Search

We reported on a pulsed compound Er3+-doped laser that simultaneously uses an intracavity laser diode for optical pumping, gain or phase modulation, and as a bandwidth control etalon. We demonstrate a simple method to produce high-energy pulses with peak powers up to 100 times the average power, and with durations on the order of 1 ?s using the synchronization of

O. G. Okhotnikiov

1994-01-01

448

2.7mW output of emerald laser pumped by laser diode  

NASA Astrophysics Data System (ADS)

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.

Chen, Z. Q.; Zhang, G.

2005-12-01

449

Efficient, frequency-stable laser-diode-pumped Nd:YAG laser  

Microsoft Academic Search

We have designed and tested a laser-diode-pumped monolithic Nd:YAG oscillator. The electrical-to-optical slope efficiency was 6.5%. The frequency jitter was less than 10 kHz over a 0.3-sec period, the best frequency stability reported for a Nd:YAG laser to date.

Bingkun Zhou; Thomas J. Kane; George J. Dixon; Robert L. Byer

1985-01-01

450

Cr:LiSrAlF6 laser pumped by visible laser diodes  

NASA Astrophysics Data System (ADS)

A Cr:LiSrAlF6 (Cr:LiSAF) laser has been diode pumped. Both CW and long pulse diode pumping were demonstrated with pump power levels as high as 300 mW CW and 1 W pulsed. Polarization combination of pump diodes to reach threshold was demonstrated with two low power lasers. The maximum output power obtained was 26.5 mW CW and 175.8 mW pulsed. Analysis of the data show the passive loss level of the crystal is less than 0.1 percent/cm. Details of the Cr:LiSAF crystal growth and high power diode architecture are presented, along with optical characterization data for the laser resonator.

Scheps, Richard; Myers, Joseph F.; Serreze, Harvey B.; Rosenberg, Ari; Morris, Robert C.; Long, Marge

451

An investigation of solvent effects on the optical properties of dye IR-140 using the pump supercontinuum-probing technique  

NASA Astrophysics Data System (ADS)

The effects on the optical properties of an organic tricarbocyanine dye, IR-140 (5,5'-dichloro-11-diphenylamine-3,3'-diethyl-10,12-ethylene-thiatricarbocyanine-perchlorate), in different polar solvents, have been investigated using the pump supercontinuum-probing technique. Solvent-induced spectral shifts of the absorption and emission spectra of IR-140 have also been observed in a variety of solvents. The dependence of the spectral features on the nature of the solvent has been explained by the conformational change because of different interactions between the dye molecule and the solvent.

Wang, Danling; Jiang, Hongbing; Wu, Songjiang; Yang, Hong; Gong, Qihuang; Xiang, Junfeng; Xu, Guangzhi

2003-09-01

452

Electron Beam Pumped Tunable Excimer Lasers  

Microsoft Academic Search

Laser characteristics were studied extensively for the broadband rare gas halide excimers Xe(,2)Cl, Kr(,2)F, and XeF (C(--->)A). The trimer Kr(,2)F was first observed to lase during these investigations, while Xe(,2)Cl and XeF (C(--->)A) had been previously demonstrated. Since all three excimers have unbound ground states, a spectrally wide emission bandwidth is available for wavelength tuning. Other excimers with wide band

Michael C. Smayling

1981-01-01

453

Electric-discharge-pumped nitrogen ion laser  

Microsoft Academic Search

The routine operation is described of an N2(+) laser oscillating on the first negative band system of N2(+) which is produced in a preionized transverse discharge device. The discharge design incorporates features which favor the efficient production of the excitation transfer reaction of He2(+) with N2. A capacitive discharge switched by means of a high-current grounded grid thyratron is used

J. B. Laudenslager; T. J. Pacala; C. Wittig

1976-01-01

454

Efficient sintering of nanocrystalline titanium dioxide films for dye solar cells via raster scanning laser  

NASA Astrophysics Data System (ADS)

By identifying the right combination of laser parameters, in particular the integrated laser fluence ?, we fabricated dye solar cells (DSCs) with UV laser-sintered TiO2 films exhibiting a power conversion efficiency ?=5.2%, the highest reported for laser-sintered devices. ? is dramatically affected by ? and a clear trend is reported. Significantly, DSCs fabricated by raster scanning the laser beam to sinter the TiO2 films are made as efficient as those with oven-sintered ones. These results, confirmed on three batches of cells, demonstrate the remarkable potential (noncontact, local, low cost, rapid, selective, and scalable) of scanning laser processing applied to DSC technology.

Mincuzzi, Girolamo; Vesce, Luigi; Reale, Andrea; di Carlo, Aldo; Brown, Thomas M.

2009-09-01

455

Highly efficient passive Q switches for a neodymium laser based on thiopyrylotricarbocyanine dyes  

SciTech Connect

The spectral, photochemical and nonlinear optical properties of a group of thiopyrylotricarbocyanine dyes in a polyurethane matrix are studied and compared with well-known materials for passive Q-switching such as nickel BDN and BDNII complexes. Passive laser Q switches based on these dyes feature the high modulation efficiency (up to 76%) in neodymium lasers and high photochemical stability. It is shown that the service life of Q switches can be considerably increased by removing oxygen from a polymer matrix. (elements of laser setups)

Bezrodnyi, V I [Institute of Physics, National Academy of Sciences of Ukraine, Kiev (Ukraine); Derevyanko, Nadezhda A; Ishchenko, Aleksandr A; Kropachev, A V [Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev (Ukraine)

2009-01-31

456

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

457

Femtosecond-laser-written diode-pumped Pr:LiYF4 waveguide laser.  

PubMed

Waveguides were fabricated in a 5 mm long Pr(0.5?at%):LiYF4 (YLF) crystal with a femtosecond Ti:sapphire laser system. Waveguiding was achieved inside a core surrounded by eight single modified tracks building a rhombic structure. The waveguide was pumped at a wavelength of 444 nm with an InGaN laser diode. Orange and deep red laser oscillation were realized. Maximum output powers of 25 mW at 604 nm and 12 mW at 720 nm with respect to the incident pump power were achieved. PMID:23258059

Müller, Sebastian; Calmano, Thomas; Metz, Philip; Hansen, Nils-Owe; Kränkel, Christian; Huber, Günter

2012-12-15

458

System for end-pumping a solid state laser using a large aperture laser diode bar  

NASA Astrophysics Data System (ADS)

An optical system for end-pumping the gain medium of a three-level or a self-terminating solid state laser with the optical output from a wide aperture laser diode bar is disclosed. In a preferred embodiment, the optical system includes: a laser diode bar for emitting from an elongated emissive area thereof a bright light having a lateral divergence and a transverse divergence; and an optical assembly disposed between the laser diode bar and the three-level solid state laser for collecting and focusing the bright light into a relatively small high-intensity spot to end-pump the gain medium of the three-level or self-terminating solid state laser.

Esterowitz, Leon; Stoneman, C.; Lynn, James G.

1993-12-01

459

High-power laser-diode-pumped Nd:YAG laser and its frequency conversion  

NASA Astrophysics Data System (ADS)

A high power intracavity frequency doubled Nd:YAG laser with KTP crystal and A-O Q-switcher pumped by 1600 Watt-808 nm laser diodes and its thermal effect are discussed. Also we proved that the title angle of KTP crystal can be to compensate for the phase mismatching and to solve the problem of the drop of green laser output power along with the increasing temperature of KTP crystal. Then based on optical parametric oscillator (KTP-OPO) pumped by 532 nm laser and their frequency doubling (with KTP and BBO) a Watt-level red and blue laser system which would be provided as RGB laser projection display are described.

Yao, Jianquan; Yu, Yizhong; Zhang, Fan; Chen, Jin; Zhang, Baigang; Xu, Degang; Wang, Peng

2002-09-01

460

Femtosecond Cr:Colquiriite lasers pumped by a single tapered diode laser  

NASA Astrophysics Data System (ADS)

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 alternative, Cr :Colquiriites (Cr:LiCAF, Cr:LiSAF, Cr:LiSGaF) also possess broad gain bandwidths and their total cw tuning range cover the 720-1110 nm region. Moreover, their broad absorption bands around 650 nm enable direct diode pumping by low-cost red laser diodes. However, so far the limited brightness of red diodes required combination of four to six pump diodes to reach reasonable output power levels from Cr :Colquiriites. This complex pumping geometry increases cost and causes stability issues in long-term operation. In this study, we report compact, low-cost and efficient Cr:Colquiriite lasers pumped by a single 1.2 W tapered laser diode at 675 nm. In continuous wave laser operation, output powers of 500 mW and 410 mW together with slope efficiencies of 47% and 41% were demonstrated from Cr:LiSAF and Cr:LiCAF, respectively. In cw mode-locked operation, sub-100-fs pulse trains with average power between 200 mW and 250 mW were obtained at repetitions rates around 100 MHz. These results indicate that tapered diodes in the red spectral region are likely to become the standard pump source for Cr:Colquiriite lasers in the near future. Moreover, the simplified pumping scheme might facilitate efficient commercialization of these low-cost systems, bearing the potential to significantly boost applications of cw and femtosecond lasers in this spectral region.

Demirbas, Umit; Schmalz, Michael; Sumpf, Bernd; Erbert, Götz; Petrich, Gale S.; Kolodziejski, Leslie A.; Fujimoto, James G.; Kärtner, Franz X.; Leitenstorfer, Alfred

2012-05-01

461

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

462

Indication of Local Laser Pump Depletion via Transmitted Self-Guided Laser Light  

SciTech Connect

In recent experiments it has been shown that an ultra-intense, ultra-short laser pulse can be self-guided over tens of Rayleigh lengths in an underdense plasma where {tau}(FWHM of the laser pulse) is on the order of the plasma wavelength ({lambda}{sub p}). Using an imaging spectrograph, the frequency of the transmitted laser pulse was spatially and spectrally resolved at the exit of 3, 5, and 8 mm long plasmas. The mechanism of laser pump depletion was studied by observing the amount that the transmitted laser pulse's spectrum was red shifted in wavelength through the interaction with the self-guiding plasma wave.

Pak, A. E.; Marsh, K. A.; Ralph, J. E.; Lu, W.; Clayton, C. E.; Joshi, C. [Electrical Engineering, University of California Los Angeles, Los Angeles, CA. 90095 (United States)

2009-01-22

463

Intracavity laser spectroscopy with a semiconductor disk laser-pumped cw Cr2+ : ZnSe laser  

NASA Astrophysics Data System (ADS)

Absorption spectra of the air have been measured near 2.31 ?m using intracavity laser spectroscopy with a semiconductor disk laser-pumped cw Cr2+ : ZnSe laser. It is shown that, at lasing times of at least 3 ms, the sensitivity of the laser to intracavity absorption increases. This allows one to reach an effective path length of 900 km and enables detection of weak lines with absorption coefficients down to 1 × 10-9 cm-1.

Kozlovsky, V. I.; Korostelin, Yu V.; Okhotnikov, O. G.; Podmar'kov, Yu P.; Skasyrsky, Ya K.; Frolov, M. P.; Akimov, V. A.

2013-09-01

464

Diode pumped operation of tm, Ho:YAP microchip laser  

NASA Astrophysics Data System (ADS)

Single-wave length operation of a c-cut Tm (5%), Ho (0.3%):YAP microchip laser pumped by a fiber-coup led diode-laser was reported. Under cryogenic temperature, the output power of 188 mW was obtained under the incident power of 2230 mW, corresponding to the slope efficiency was 12.2%. As much as 168 mW output and slope efficiency of 5.7% was obtained under the pump power of 3400 mW at 291 K. In addition, a maximum single-wave length output power of 60 mW at wavelength of 2130.2 nm and 14 mW at wavelength of 2102.4 nm is demonstrated under 77 and 291 K, respectively.

Yao, B. Q.; Chen, F.; Meng, P. B.; Zhang, C. H.; Wang, Y. Z.

2011-04-01

465

Cladding-pumped passive harmonically mode-locked fiber laser.  

PubMed

A passive harmonically mode-locked fiber laser cladding pumped by a broad-area diode-laser array is described. Harmonic mode locking is obtained in a frequency range from 33.3 to 128.6 MHz, where the higher frequency limit is imposed because of insufficient available pump power. The maximum pulse jitter in one cavity roundtrip time is between 300 and 50 ps in the whole frequency range, and the sidebands in the frequency domain are suppressed by as much as 50 dB. 600-fs bandwidth-limited pulses with pulse energies of as much as 20 pJ are obtained, giving rise to an average output power as great as 2.5 mW. PMID:19876221

Fermann, M E; Minelly, J D

1996-07-01

466

Effect of dye laser pulse duration on selective cutaneous vascular injury  

SciTech Connect

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 volunteers received 577 nm dye laser exposures at pulsewidths of 1.5-350 microseconds to their skin. Clinical purpura threshold exposure doses were determined in each volunteer, and biopsies of threshold and suprathreshold doses were examined in each volunteer. The laser exposure dose required to produce purpura increased as pulsewidth increased in all 9 subjects (p less than 0.001). This finding corresponds to laser pulsewidths equal to or exceeding the thermal relaxation times for dermal blood vessels. Histologically, vessel damage was selectively, but qualitatively, different for short vs long pulsewidths. Pulsewidths shorter than 20 microseconds caused vessel wall fragmentation and hemorrhage, whereas longer pulsewidths caused no significant hemorrhage. The purpura noted clinically appears to be due to a coagulum of intralumenal denatured erythrocytes. At 24 h, there was marked vessel wall necrosis at all pulsewidths. The short pulsewidths may cause erythrocyte vaporization, rapid thermal expansion, and mechanical vessel rupture with hemorrhage. Long pulsewidths appear to cause thermal denaturation with less mechanical vessel damage. The selective, nonhemorrhagic, vascular necrosis caused by the long-pulsewidth dye laser may lead to a more desirable clinical outcome in the therapy of blood vessel disease processes.

Garden, J.M.; Tan, O.T.; Kerschmann, R.; Boll, J.; Furumoto, H.; Anderson, R.R.; Parrish, J.A.

1986-11-01

467

10-W-level diode-pumped compact 2.78 microm ZBLAN fiber laser.  

PubMed

We report on >9W transverse-fundamental-mode CW output near 3 mum from a 4m heavily erbium-doped ZBLAN double-clad fiber laser pumped by a collimated 100 W 975 nm laser diode array. The pump threshold of the fiber laser was about 1W, and the slope efficiency was 21.3%. The peak wavelength of free running was about 2708 nm at low pump power and moved to around 2785 nm at high pump power. Output of 9W was obtained when the launched pump power was 42.8W. The output, however, fluctuated intensively like a pulsed laser, and the operation broke down with optical damage of the pumping end facet when the pump was increased beyond 42.8 W. Therefore, alleviation of the operation fluctuation, heat management, and strengthening the pumping fiber are crucial considerations for the stable operation of 10-W-level mid-IR ZBLAN fiber lasers. PMID:17167572

Zhu, Xiushan; Jain, Ravi

2007-01-01

468

Anatomical differences in response to treatment of port-wine stains by the pulsed dye laser  

NASA Astrophysics Data System (ADS)

Two-hundred and fifty-seven patients (136 adults and 121 children) with port-wine stains of the head and neck were treated with the flashlamp-pumped pulsed dye laser. The head and neck was subdivided into 8 anatomical regions (forehead/temple, periorbital, medial cheek, nose, upper cutaneous lip, lateral cheek, chin and neck) which were independently evaluated for response. Response to treatment was found to be associated with the anatomical location of the lesion; in both adults and children the mid-facial region (medial cheek, nose and upper cutaneous lip) responded less favorably to treatment than the other regions of the head and neck (periorbital, forehead/temple, lateral cheek, neck and chin). In adults and children, mean percent lesional lightening of the mid-facial regions was 70.7% compared to 82.3% of the other regions of the head and neck with an estimated difference of 11.6% (95% confidence interval: 8.7% - 14.6%). The mean number of treatments for adults was 3.7, while this number in children was 3.9. All side effects were transient, and included cutaneous depressions, hypopigmentation and hyperpigmentation.

Renfro, Lisa; Geronemus, Roy G.

1992-06-01

469

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

SciTech Connect

This paper reports on the lasing properties of chromium-aluminum-doped forsterite that 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 pump beam energies. Laser rate equations are developed to model the lasing center as a four-level system and applied to the case of 746 nm pumping.

Behrens, E.G.; Jani, M.G.; Powell, R.C. (University Center for Laser Research, Oklahoma State Univ., Stillwater, OK (US)); Verdun, H.R. (Fibertek, Inc., Herndon, VA (US)); Pinto, A. (US Center for Night Vision and Electro-Optics, Fort Belvoir, VA (US))

1991-08-01

470

Highly efficient and stable doped hybrid organic–inorganic materials for solid-state dye lasers  

Microsoft Academic Search

Significant enhancement on the laser action of Rhodamine 6G (Rh6G) has been obtained for solid-state dye lasers based on hybrid matrices obtained by simultaneous polymerisation of 2-hydroxyethyl methacrylate with different weight proportions of tetraethoxysilane or tetramethoxysilane. Lasing efficiencies of up 28% and high stabilities, with no sign of degradation, albeit with some oscillations, in the initial laser output after 100000

Angel Costela; Inmaculada Garc??a-Moreno; Clara Gómez; Olga Garc??a; Leoncio Garrido; Roberto Sastre

2004-01-01

471

Optical pump-terahertz probe spectroscopy of dyes in solutions: probing the dynamics of liquid solvent or solid precipitate?  

PubMed

The optical pump-terahertz probe spectroscopy was used together with ab initio calculations and molecular dynamics simulations to investigate ultrafast dynamics following electronic excitation of Coumarin 153 and TBNC (2,11,20,29-tetra-tert-butyl-2,3-naphtalocyanine) dyes in polar solvents. By scanning the terahertz waveform for different pump-probe delays this experimental technique allows us to obtain two dimensional spectra directly reflecting the temporal response of the system. A distinct signal was obtained for TBNC in chloroform, 2-propanol, and n-butanol, while no signal was recorded for Coumarin 153 in either of these solvents. We explain the nonequilibrium signal detected in TBNC solutions by the presence of a solid, polycrystalline phase of the dye resulting from irradiating the solution by intense optical pulses. PMID:15267927

Kadlec, Filip; Kadlec, Christelle; Kuzel, Petr; Slavícek, Petr; Jungwirth, Pavel

2004-01-01

472

A microwave-pumped slab CO{sub 2} laser  

SciTech Connect

The radiation parameters of a diffusion-cooled compact slab CO{sub 2} laser pumped by microwave discharge at a frequency of 2.45 GHz are studied. A magnetron from a domestic microwave oven is used as the pump source. An average output power of 25 W and an efficiency of {approx}13% are obtained at a wavelength 10.6 {mu}m. A peak output power of 580 W is achieved for 20-{mu}s pulses emitted at a pulse repetition rate of 400 Hz. The dependence of parameters of the CO{sub 2} laser on the input pulse power in the range 0.8-8 kW, the composition and pressure of the working mixture and the pump pulse duration and repetition rate are studied experimentally. Optimal relations between these parameters are determined for the given design of the laser. (special issue devoted to the 25th anniversary of the a.m. prokhorov general physics institute)

Mineev, A P; Nefedov, S M; Pashinin, P P [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2007-10-31

473

Upper hybrid wave pumped free electron laser  

SciTech Connect

A large upper hybrid wave has potential to be employed as a wiggler for the generation of high frequency coherent radiation via free electron laser (FEL) instability. At a density fluctuation level of a few percent, due to the upper hybrid wave, the growth time of FEL instability, with electron beam current of a few kilo ampere, turns out to be of the order of a nanosecond. The growth rate of FEL instability depends sensitively on {omega}{sub 1} and this dependence comes through v{sub osc}, the beam oscillatory velocity. However, this scheme of FEL operating suffers from a severe limitation due to the parametric instability of the upper hybrid wave. The process of parametric decay into lower hybrid and upper hybrid waves may have growth rate comparable to that of the FEL instability.

Sharma, S.C.; Tripathi, V.K. [Indian Inst. of Tech., New Delhi (India). Dept. of Physics

1995-08-01

474

Ion acoustic wave pumped free electron laser  

SciTech Connect

A large amplitude ion acoustic wave has potential as a wiggler to produce short wavelength coherent electromagnetic radiation in a free electron laser (FEL). The frequency of radiation is given as {omega}{sub 1} {approx_equal} 2{gamma}{sub 0}{sup 2}({omega}{sub 0}/c{sub s})v{sub b}cos{theta}{sub 0}, where {gamma}{sub 0} is the frequency of the ion acoustic wave propagating at angle {theta}{sub 0} with the electron beam and c{sub s} is the sound speed. The growth time of the instability at 10 {micro}m turns out to be in the submicrosecond range at beam voltage {approximately}1 MV and beam current {approx}1.5 A.

Agarwal, R.N. [Opto-Electronics Factory, Dehradun (India); Tripathi, V.K. [Indian Inst. of Tech., New Delhi (India). Dept. of Physics

1995-08-01

475

Exploding-type pumping of plasma for high-efficiency x-ray laser  

Microsoft Academic Search

A new pumping scheme named exploding pumping is proposed for realizing recombination x-ray lasers with high excitation efficiency. In the new scheme, a very thin membrane is employed as a target and it is heated instantaneously before the plasma starts to move by a high peak power sub- picosecond pumping laser. In the scheme, the plasma heating efficiency is improved

Toshihisa Tomie; Hidehiko Yashiro; Eisuke Miura; Peixiang Lu; Isao Matsushima

1997-01-01

476

Laser rods with undoped, flanged end-caps for end-pumped laser applications  

DOEpatents

A method and apparatus for achieving improved performance in a solid state laser is provided. A flanged, at least partially undoped end-cap is attached to at least one end of a laserable medium. Preferably flanged, undoped end-caps are attached to both ends of the laserable medium. Due to the low scatter requirements for the interface between the end-caps and the laser rod, a non-adhesive method of bonding is utilized such as optical contacting combined with a subsequent heat treatment of the optically contacted composite. The non-bonded end surfaces of the flanged end-caps are coated with laser cavity coatings appropriate for the lasing wavelength of the laser rod. A cooling jacket, sealably coupled to the flanged end-caps, surrounds the entire length of the laserable medium. Radiation from a pump source is focussed by a lens duct and passed through at least one flanged end-cap into the laser rod.

Meissner, Helmuth E. (Pleasanton, CA); Beach, Raymond J. (Livermore, CA); Bibeau, Camille (Danville, CA); Sutton, Steven B. (Manteca, CA); Mitchell, Scott (Tracy, CA); Bass, Isaac (Castro Valley, CA); Honea, Eric (Sunol, CA)

1999-01-01

477

Study of the chemical hf laser pumped by phototriggered discharge  

NASA Astrophysics Data System (ADS)

The non-chain reaction HF laser energized by an x-ray photo- triggered discharge has been studied for Ne/SF6/C2H6 and Ne/SF6H2 gas mixtures. For an active volume of 312 cm3, a high specific output laser energy of 10 J/l has been reached with an electric efficiency of 4.7% for the mixture with ethane, whereas only 6 J/l is obtained with an efficiency of 3.1% for the mixture with hydrogen. The study of the discharge development shows that the total production of HF molecules weakly depends on the gas mixture type, so that the plasma kinetic is not responsible for the difference observed between the laser performances obtained with the two mixtures. Time and spatially resolved measurements of the plasma fluorescence shows that discharge instabilities occur in the Ne/SF6 discharge, which are responsible for the HF laser emission disruption when hydrogen is added. But addition of ethane at about 3% of the total pressure induces the discharge stabilization, and allows the laser emission to occur in an homogeneous medium. As a result, this work clearly establishes the physical reason of the observed laser performance improvement when hydrogen is replaced by some hydrocarbons in discharge pumped HF laser.

Richeboeuf, L.; Doussiet, F.; Legentil, M.; Pasquiers, S.; Postel, C.; Puech, Vincent

1996-08-01

478

Performance comparison of optically pumped type-II midinfrared lasers  

NASA Astrophysics Data System (ADS)

We report a comparative study on the performance of three optically pumped, type-II quantum well lasers with differing quantum well (QW) confinement. One of the active regions emphasized hole confinement, another emphasized electron confinement, while the third incorporated both electron and hole confinements. In all cases the wells were inserted in a thick InxGa1-xAsySb1-y waveguide/absorber region. The lasing wavelengths at 84 K were 2.26, 3.44, and 2.37 ?m, respectively. The maximum peak output powers and differential quantum efficiencies ? at 84 K were similar for the hole well and W lasers (~13 W,?~0.55), but significantly reduced in the electron-well-only laser (2.3 W,?=0.14). Waveguide loss measurements via the traditional quantum efficiency versus cavity length method and by a Hakki-Paoli method revealed that all three lasers had low waveguide loss that either increased slowly or not at all with increasing temperature. However, the laser's internal efficiency, ?i, showed a linear decline with increasing temperature, with the ?i of the electron-well-only laser significantly less than the other two. The data suggest that for antimonide-based type-II designs, strong hole confinement is essential for improved performance. The data further suggest that it is hole leakage from the QW and/or hole dilution that is largely responsible for the degradation in laser performance.

Ongstad, A. P.; Kaspi, R.; Tilton, M. L.; Chavez, J. R.; Dente, G. C.

2005-08-01

479

End-pumped continuous-wave alkali vapor lasers: experiment, model, and power scaling  

NASA Astrophysics Data System (ADS)

End-pumped alkali vapor lasers excited on their D2 transition and lased on their D1 transition offer a pathway to high average power that potentially competes with diode-pumped solid-state lasers in many applications that require cw or quasi-cw laser operation. We report on the first experimental demonstration of an end-pumped Cs laser using a Ti:sapphire laser for pump excitation. Detailed experimental and model results are presented that indicate our understanding of the underlying physics involved in such systems is complete. Using an extrapolation of our developed model, a discussion is given on power scaling diode-pumped alkali lasers, indicating a potential efficiency advantage over power-scaled diode-pumped solid-state lasers.

Beach, Raymond J.; Krupke, William F.; Kanz, V. Keith; Payne, Stephen A.; Dubinskii, Mark A.; Merkle, Larry D.

2004-12-01