Showing papers on "Tunable laser published in 1972"
TL;DR: A pulsed tunable dye laser with a bandwidth of less than 0.004 A, repetitively pumped by a nitrogen laser, is described and output peak powers in the kilowatt range at 5-100 nsec pulse width and repetition rates up to 100 pps can be generated from the near-ultraviolet throughout the visible spectrum.
Abstract: A pulsed tunable dye laser with a bandwidth of less than 0.004 A, repetitively pumped by a nitrogen laser, is described. An intracavity beam expanding telescope together with a diffraction grating in Littrow mount and a tilted Fabry-Perot etalon provide convenient, very reproducible wavelength tuning and good stability. Output peak powers in the kilowatt range at 5–100 nsec pulse width and repetition rates up to 100 pps can be generated from the near-ultraviolet throughout the visible spectrum.
598 citations
TL;DR: In this article, a method to compensate the astigmatic distortions introduced by both the internal mirror and the cell is described, which allows the formation of a tight intracavity focus as required in applications such as CW dye lasers.
Abstract: An analysis is given of folded 3-mirror laser resonators with an internal cell set at Brewster's angle. A method is described to compensate the astigmatic distortions introduced by both the internal mirror and the cell. This compensation is achieved for a specific relation between cell thickness and folding angle. It allows the formation of a tight intracavity focus as required in applications such as CW dye lasers. A discussion is given of the mode characteristics of compensated cavities and of the limitation on beam concentration set by the thickness of the Brewster cell.
430 citations
TL;DR: In this article, the EH 11 lowest order waveguide mode as a function of mirror position and mirror radius was analyzed and it was shown that some mirror positions and radii are optimum, in that they provide low coupling loss and are relatively insensitive to mirror position.
Abstract: Hollow waveguide gas lasers of the type described by Smith have some inherent loss in coupling radiation from the guide into free space and back into the guide. This paper calculates that loss for the EH 11 lowest order waveguide mode as a function of mirror position and mirror radius. It is shown that some mirror positions and radii are optimum, in that they provide low coupling loss and are relatively insensitive to mirror position.
220 citations
TL;DR: Experimental results are given for the photoionization of rubidium vapor using a ruby-laser-pumped dye laser and a doubled ruby laser radiation, and photodissociation of HCl using the Raman-shifted output and the fourth harmonic output of a tunable Nd-glass laser.
Abstract: The general considerations for two-step photoionization of atoms and photodissociation of molecules using tunable laser sources are discussed. Experimental results are given for the (1) photoionization of rubidium vapor using a ruby-laser-pumped dye laser and a doubled ruby laser radiation, and (2) photodissociation of HCl using the Raman-shifted output and the fourth harmonic output of a tunable Nd-glass laser. The possibilities for other laser systems are also discussed.
182 citations
01 Apr 1972
TL;DR: This is a tutorial review on the subject of mode selection in lasers that discusses some systems for frequency stabilization of single-frequency lasers, and concludes with examples of laser applications where mode-selection techniques are required.
Abstract: This is a tutorial review on the subject of mode selection in lasers. We begin with a historical review. After an introduction to the subject of modes in laser resonators and a brief review of the theory of laser gain saturation, the main body of the paper is devoted to a discussion of various mode-selection techniques, many which can be used to produce single-frequency laser operation. We discuss some systems for frequency stabilization of single-frequency lasers, and conclude with examples of laser applications where mode-selection techniques are required.
179 citations
TL;DR: In this paper, a tunable dye laser has been used to observe resonant two photon photodetachment of electrons from C − 2, and these measurements definitely establish the fact that the Herzberg-Lagerquist band system belongs to C−2, and that the ground state of C− 2 is a 2 σ + g state.
112 citations
Patent•
01 Sep 1972TL;DR: In this paper, a rotatable mirror is used as one portion of the laser cavity and a diffraction grating is positioned with respect to the rotatable mirro such that the laser beam can scan the grating and thereby change the effective wavelength of the output laser beam.
Abstract: A tunable laser having a rotatable mirror as one portion of the laser cavity and a diffraction grating positioned with respect to the rotatable mirro such that the rotatable mirror causes the laser beam to scan the diffraction grating and thereby change the effective wavelength of the output laser beam.
103 citations
TL;DR: In this article, a kind of resonator was found, the radiation of which is insensitive to thermal distortions, and reproducible material processing was achieved in industrial use with a high-precision laser drilling machine.
Abstract: Optical pumping of solid-state lasers induces thermal lensing in the laser crystal. This lansing determines the beam properties in the resonator; the TEM 00 -mode radiation is limited to a small laser rod volume and it depends on the pump power. Especially with pulse-pumped systems, the generation of stable fundamental mode radiation could only be obtained with low efficiency. Laser resonators with optimum TEM 00 mode output were studied considering the thermal lensing. A kind of resonator was found, the radiation of which is insensitive to thermal distortions. The following is determined by parameters g_{1}, g_{2} : \frac{1}{g_{1}}=2g_{2} +^{1} (\frac{a}{b})^{2} + 2\frac{a}{b} , where a and b are distances between rod ends and mirrors, a and b being the distances between the two mirrors and the lens. The predicted beam behavior was verified experimentally with a high repetition rate YAG laser. A high-precision laser drilling machine was constructed with this design. Because of the insensitive properties, reproducible material processing was achieved in industrial use.
86 citations
TL;DR: In this paper, the deflection of a sodium atomic beam by the radiation pressure of the light of a cw dye laser was investigated, and it was deduced that the linear momentum trasferred corresponds to an average of 60 excitations per atom.
85 citations
TL;DR: In this article, individual transitions of the ν1 vibration-rotation band of SO2 in the 8.7μm-wavelength region have been observed, using tunable semiconductor diode lasers, and compared with theoretical calculations based on pure−rotation data from microwave absorption measurements.
Abstract: Individual transitions of the ν1 vibration‐rotation band of SO2 in the 8.7‐μm‐wavelength region have been observed, using tunable semiconductor diode lasers, and compared with theoretical calculations based on pure‐rotation data from microwave absorption measurements. A new value of 1151.71 ± 0.01 cm−1 has been found for the ν1‐band center. Pressure‐broadening coefficients and intensities of individual lines were determined from the high‐resolution data, and a value was obtained for total band intensity.
75 citations
TL;DR: In this article, the spectral dependence of the first order Raman scattering cross section of Ge at room and liquid nitrogen temperatures in the energy region containing the E 1 and E 1 + Δ 1 optical gaps was studied.
TL;DR: In this article, the coupling coefficients between two guided modes that are coupled by ripples in the tube wall are derived based on the model of a slab waveguide, and expressions for the leaky mode losses and scattering losses inevitably introduced by the coupling mechanism are also presented.
Abstract: Hollow dielectric waveguides with gas-filled core and a dielectric tube seem promising as laser structures. The tube fulfills the dual role of a guidance structure for the electromagnetic radiation as well as that of a container for the plasma of the gas laser. Feedback for laser oscillation is achieved by providing coupling between forward- and backward-traveling modes by means of periodic ripples of the inner surface of the hollow dielectric tube. This paper is devoted to the derivation of the coupling coefficients between two guided modes that are coupled by ripples in the tube wall. The calculation is based on the model of a slab waveguide. Expressions for the leaky-mode losses and the scattering losses inevitably introduced by the coupling mechanism are also presented.
TL;DR: In this paper, results obtained with TEA CO 2 lasers in both single-pulse and high-repetition-rate operation are described, with output energy of more than 18 J/1 of excited volume, with overall efficiency of 17 percent without arcing.
Abstract: Results obtained to date with TEA CO 2 lasers in both single-pulse and high-repetition-rate operation are described. The special cathode arrangement for triggered discharge permits output energy of more than 18 J/1 of excited volume, with overall efficiency of 17 percent without arcing. Preliminary results obtained with a gas recirculating loop are 100 pulses/s at a 20-J/pulse level.
TL;DR: In this article, the authors used a simple nozzles to provide flowing thin streams of dye solution having excellent optical quality and stability over substantial areas, used in CW dye lasers instead of confined flows through thin cells, yield reduced lasing thresholds and superior longterm stability.
Abstract: Dyes dissolved in viscous solvents can be pumped through simple nozzles to provide flowing thin streams of dye solution having excellent optical quality and stability over substantial areas. Such free flows, used in CW dye lasers instead of confined flows through thin cells, yield reduced lasing thresholds and superior long-term stability.
TL;DR: In this article, a pulsed tunable dye laser was used to induce quantum beats in the triplet resonance line of ytterbium, which may improve the possibility of determining relaxation times and splitting factors.
TL;DR: In this paper, an output power of 1 W was reported from a tunable CW dye laser pumped by 3.5 W of argon laser radiation, which was achieved by using a very low-loss folded 3-mirror cavity and by pumping through a Brewster-angle dispersing prism.
Abstract: An output power of 1 W is reported from a tunable CW dye laser pumped by 3.5 W of argon laser radiation. The nearly 30 percent conversion efficiency is achieved by using a very low-loss folded 3-mirror cavity and by pumping through a Brewster-angle dispersing prism.
TL;DR: In this article, a calorimeter is described that can measure megajoules of laser energy from CW lasers whose output wavelength is in the region from 1 to 11?m. The calibration of this device is traceable to NBS electrical standards.
Abstract: A calorimeter is described that can measure megajoules of laser energy from CW lasers whose output wavelength is in the region from 1 to 11 ?m. The calibration of this device is traceable to NBS electrical standards. This calorimeter can measure total energies from 3 × 104 to 107 J. The laser power range this device can handle ranges from 300 to 100 000 W.
TL;DR: In this paper, the authors used a 10-cm-long gas cell to measure high-resolution absorption spectra for SF6, NH3, and C2H4 at 10.6, SO2 at 8,6, CO at 4.7, and NO at 5.2.
Abstract: Optical techniques have opened up new possibilities in air pollution monitoring because of their remote-sensing capability, very high specificity, and short observation time. Techniques involving the use of lasers include Raman scattering, emission either from resonantly excited or from hot gases, and resonant absorption. Unique advantages in these applications are provided by the recently developed tunable lasers, including organic dye lasers, parametric oscillators, spin-flip Raman lasers, and semiconductor lasers. The absorption technique which promises to have the widest range of application has been tested in the laboratory by using tunable diode lasers. High-resolution absorption spectra have been measured for SF6, NH3, and C2H4 at 10.6 ?m, SO2 at 8,6 ?m, CO at 4.7 ?m, and NO at 5.2 ?m, and the C2H4 (ethylene) content of automobile exhausts has been measured by means of a derivative technique. A sensitivity sufficient to detect one ppm of NH3 in air has been achieved in a 10-cm-long gas cell. The 50 to 100-kHz resolution achievable with diode lasers is about four orders of magnitude better than the resolution of conventional spectrometers and more than adequate to resolve Doppler broadened gas absorption lines which are on the order of 100 MHz wide.
TL;DR: The effects of self-broadening and broadening by nitrogen to a pressure of 760 Torr are presented, and some characteristics of the laser source such as stability and reproducibility are discussed.
Abstract: Current tunable semiconductor lasers of Pb1−xSnxTe have been used to investigate the ir spectrum of sulfur dioxide at high resolution near 1130 cm−1. The diode lasers emit radiation in a line of width <10−5 cm−1 thus providing much higher resolution than has been possible with the best grating spectrometer. The effects of self-broadening and broadening by nitrogen to a pressure of 760 Torr are presented, and some characteristics of the laser source such as stability and reproducibility are discussed.
TL;DR: In this paper, an improved resonator configuration for CW dye lasers is described, permitting minimum circular waist areas and compensation for comatic and astigmatic aberration, and a minimum waist area is required.
Abstract: An improved resonator configuration for CW dye lasers is described, permitting minimum circular waist areas and compensation for comatic as well as astigmatic aberration.
TL;DR: High power continuous and pulsed coherent radiation generation by gas lasers, discussing transmission by proton generators and transforming engines was discussed in this article, where the authors also discussed transmission by Proton Generators and Transformers.
Abstract: High power continuous and pulsed coherent radiation generation by gas lasers, discussing transmission by proton generators and transforming engines
TL;DR: In this paper, experimental evidence is given in support of a dielectric-waveguide model for filaments in gallium-arsenide lasers. But this model is not suitable for the case of a single-heterojunction galliumarasenide laser.
Abstract: Experimental evidence is given in support of a dielectric-waveguide model for filaments in gallium-arsenide lasers. Measurements of the variation with current of the spectral-mode frequencies of a single-heterojunction gallium-arsenide laser have been carried out both below and above threshold. It is suggested that the frequency shifts above threshold are due to the formation of filaments in the laser. Changes in the far-field pattern support this theory.
TL;DR: In this article, a junction laser fabricated from the IV-VI alloy Pb1−xGexTe was used to detect high-resolution spectra of nitric oxide near 5.3 μm.
Abstract: cw operation at liquid‐helium temperatures of junction lasers fabricated from the IV‐VI alloy Pb1−xGexTe is reported. These lasers are current tunable and emit in the infrared between 4 and 6 μm. Preliminary high‐resolution spectra of nitric oxide recorded near 5.3 μm by using these lasers are reported.
TL;DR: In this paper, a transversely excited helium-xenon discharge was used to obtain 5.2 W of average power from an 80 cm-long closed-cycle device in which the flow velocity is 30 m/s.
Abstract: Pulsed laser action has been obtained in neutral xenon in the infrared at a repetition rate of 1.4 kHz by using a transversely excited helium-xenon discharge. This high PRF was made possible by the use of a transverse gas flow to remove the residual ions from the discharge region. We have been able to obtain 5.2 W of average power from an 80-cm-long closed-cycle device in which the flow velocity is 30 m/s. The xenon pressure is 0.1-1 torr, which is 10-100 times greater than that for CW xenon lasers. Pulses of 104W peak power and 0.5 μs duration are obtained with spectral components at 2.027, 3.508, and 3.652 μ.
TL;DR: In this paper, the coupledmode equations are solved for homogeneously broadened lasers modulated near the axial mode separation frequency, and the character of the oscillations changes rapidly when the modulation period is tuned through the round-trip delay at the group velocity.
Abstract: The coupled-mode equations are solved for homogeneously broadened lasers modulated near the axial mode separation frequency. The character of the oscillations changes rapidly when the modulation period is tuned through the round-trip delay at the group velocity. Specifically, this is the region in which phase modulation leads to pulsing and loss modulation leads to pulsing at normal power. The present method agrees with the results of Kuizenga and Siegman for this region, but gives a countable set of supermodes in addition. There is some reason to believe that these other modes have already been observed. When the group velocity condition is not satisfied, a more complete description is given than has been previously reported. Most importantly, the dependence of laser power on modulator drive and frequency can be predicted.
TL;DR: In this paper, the magnetic field tuning in conjunction with the conventional current tuning is shown to significantly increase the versatility of diode lasers in high-resolution spectroscopy, and details of the tuning characteristics for fields up to 90 kG are presented.
Abstract: Tunable laser spectroscopy measurements on low‐pressure gases have been performed using magnetic‐field‐tuned lead‐salt semiconductor diode lasers in the 4‐ to 7‐μm region. Use of magnetic field tuning in conjunction with the conventional current tuning is shown to significantly increase the versatility of diode lasers in high‐resolution spectroscopy. Details of the tuning characteristics for fields up to 90 kG are presented.
TL;DR: In this article, a tunable dye laser system pumped by a ruby laser was used to generate IR radiation from 4.1 to 5.2 μm. But the IR radiation was obtained as output in the spectral region.
TL;DR: In this paper, an organic dye laser has been employed which is pumped by a nitrogen laser and produces continuously wavelength-variable light pulses of ∼10 kW peak power, which is attributed to the light absorption induced by intense electronic excitation of the material.
Abstract: Second-order Raman effect has been investigated in CdS and ZnO at liquid He temperature by using a tunable exciting light source. An organic dye laser has been employed which is pumped by a nitrogen laser and produces continuously wavelength-variable light pulses of ∼10 kW peak power. Measured frequency dependence of the scattering cross-section near the resonance region is compared with existing theory. The result indicates that the dominant scattering mechanism in this region is successive scattering of the virtually created A exciton by two longitudinal optical phonons. With high density excitation (∼0.6 MW/cm 2 ), the intensity ratio of the Raman line to the incident laser light has been found to decrease remarkably under the nearly resonant condition in CdS. This effect is attributed to the light absorption induced by intense electronic excitation of the material.
TL;DR: In this paper, the effects of chemical quenching on the efficiency of a protonic exciplex laser were investigated, and the effect of quenched solutions of 4 methylumbelliferone pumped by a second harmonic of ruby was investigated.