Showing papers on "Ruby laser published in 1977"
TL;DR: In this paper, a plano-concave Fabry-Perot cavity containing ruby was used to perform differential gain, discriminator, clipper, and limier actions with room-temperature operation.
Abstract: Bistability, differential gain, discriminator, clipper, and limier actions were observed using a plano‐concave Fabry‐Perot cavity containing ruby. Input powers were approximately 20 mW from a cw ruby laser. Operation wa anticipated near 77 °K where the R1 transition was nearly resonant with the laser. However, the device functioned at room temperature. The refractive index of ruby depends on the fractional ground‐state population. Driving the R lines leads to a nonlinear refractive index due to dispersive contributions from nonresonant pump and charge‐transfer bands, which explains the room‐temperature operation.
102 citations
TL;DR: In this article, high energy electron diffraction was used to investigate the amorphous to polycrystalline structure transition in silicon induced by laser pulse, and depth analysis was carried out in 〈100〉 silicon crystal using the channeling effect technique.
Abstract: Reflection high energy electron diffraction has been used to investigate the amorphous to polycrystalline structure transition in silicon induced by laser pulse. The power density of the ruby laser pulse, in the free generation mode, has been maintained below the threshold to induce surface damage. Depth analysis has been carried out in 〈100〉 silicon crystal using the channeling effect technique.
45 citations
TL;DR: A total of eight teeth from two rhesus monkeys were exposed to various amounts of neodymium laser radiation and the pulp response was found to be much less severe than that in a study of nineteen teeth previously reported for exposure to similar amounts of ruby laser radiation.
42 citations
TL;DR: In this article, the dependence of the molecular weight distribution on the parameters of the initiating radiation was studied for the polymerization of methylmethacrylate under the influence of the second harmonic of a ruby laser.
Abstract: An expression is found for the function describing the molecular-weight distribution of a polymer formed by pulse-periodic initiation of polymerization. A study is made of the dependence of the molecular-weight distribution on the parameters of the initiating radiation. Experimental results are reported on the polymerization of methylmethacrylate under the influence of the second harmonic of a ruby laser. It is shown that the dependence of the reaction rate on the repetition frequency of the laser pulses and their energy is logarithmic. Viscometric measurements of the average molecular weight of the polymer samples are in satisfactory agreement with the theoretical predictions.
31 citations
TL;DR: In this article, the authors reported measurements of the parameters of shock waves and cavities generated as a result of laser breakdown in water, glycerin, and benzene (focusing by a lens with F = 2 cm).
Abstract: Experimental results are reported of measurements of the parameters of shock waves and cavities generated as a result of laser breakdown in water, glycerin, and benzene (focusing by a lens with F = 2 cm. The results are reported as a function of the optical energy (0–1 J) and duration (10–70 nsec) of ruby laser pulses. It is shown that the efficiency of conversion of radiation into mechanical energy as a result of breakdown in liquids increases when the duration of laser pulses is reduced.
31 citations
TL;DR: In this article, the frequency-tunable generation by means of F2+ and F2− color centers in a LiF crystal is reported. But the frequency tuning is obtained in the range of 0.88-1.25 μm.
Abstract: Frequency-tunable generation by means of F2+ and F2− colour centers in a LiF crystal is reported. Colour centers were created by illuminating LiF crystals with electrons of 3 meV energy at the electron current density of 1 μA/cm2. The pumping source was a ruby laser with a peak power of 20 MW, a pulse duration of 20 ns, and a repetition rate of 1 Hz. The frequency tuning is obtained in the range of 0.88–1.25 μm. Discussed are the ways of pumping of colour centers and the possibility of lasing in the spectral region of 0.85 to 2 μm in the type of colour centers under investigation.
29 citations
TL;DR: In this article, a multiply Q -switched ruby laser is used to produce the series of coherent light pulses for hologram exposure, and image separation of different holograms is achieved by spatial multiplexing using a rotating disk with apertures directly in front of the holographic plate.
27 citations
TL;DR: In this paper, the reflectivities of copper and aluminium have been measured at high temperatures up to the melting points using a pulsed ruby laser of moderate power to avoid surface disruption, and the results compare reasonably well with Ujihara-Drude theory.
25 citations
TL;DR: In this paper, an experimental investigation has been made of laser-induced breakdown thresholds in rare gases, using single picosecond pulses from a ruby laser with time durations of 18+or-4 ps.
Abstract: An experimental investigation has been made of laser-induced breakdown thresholds in the rare gases, using single picosecond pulses from a ruby laser with time durations of 18+or-4 ps. Breakdown threshold intensity measurements, carried out at pressures below approximately 7000 Torr, were always pressure-dependent. The results show important differences from those already obtained on picosecond timescales at the same wavelength of 0.694 mu m, but are in general agreement with similar measurements made at laser wavelengths of 1.064 and 0.53 mu m. They support the view that present multiphoton ionization theory is inadequate for describing ionization in high ( gamma approximately=1) radiation fields.
18 citations
TL;DR: In this paper, a free running ruby laser was used as the source of Raman scattering in a flame and the density and the vibrational temperature of N2 were investigated with accuracies in the percent range and with a response time of about 10 μs.
18 citations
01 Feb 1977
TL;DR: In this paper, the intensity dependence and pulse shape of photocurrent transient excited by either a high-power frequency-doubled Nd laser (λ 1 = 530 nm) or a ruby laser(λ 2 = 694 nm) are analyzed.
Abstract: Intensity dependence and pulse shape of photocurrent transient excited by either a high-power frequency-doubled Nd laser (λ 1 = 530 nm) or a ruby laser (λ 2 = 694 nm) are analysed. While the 694 nm transients are easily interpreted on the basis of a conventional kinetic scheme, this treatment fails to account for a short photocurrent pulse which appears superimposed on the normal transient upon excitation with 530 nm radiation at an intensity 1 ⪢ 4 × 10 25 photons cm −2 s −1 . The results are interpreted in terms of interaction between free conduction electrons and singlet excitons in course of which the electron is temporarily excited into a high mobility state.
TL;DR: In this article, a 16μm source based upon the combined effects of stimulated rotational Raman scattering and four-wave mixing in gaseous para-hydrogen has been experimentally demonstrated.
Abstract: A 16‐μm source based upon the combined effects of stimulated rotational Raman scattering and four‐wave mixing in gaseous para‐hydrogen has been experimentally demonstrated. The input beams were synchronized pulses from a ruby laser and a CO2 TEA laser. Pulses with ∼2 μJ of energy were generated at 627.8 cm−1.
TL;DR: In this paper, the blue and red fluorescence of cryptocyanine solutions was observed under conditions of steady-stay light excitation and during Q-switched ruby laser excitation.
TL;DR: The dye DDI (1,1'-diethyl 2,2'-dicarbocyanin iodid) dissolved in DMSO (dimethyl sulphoxid) was used in giant pulse ruby laser pumped DFB laser configuration as discussed by the authors.
TL;DR: In this article, the main characteristics of a parametric converter of middle-infrared radiation in a silver thiogallate crystal pumped with ruby laser radiation were reported, and a description was given of experimental conversion of CO2 laser radiation to the visible range in an AgGaS2 crystal, confirming the results of calculations.
Abstract: A computer calculation is reported of the main characteristics of a parametric converter of middle-infrared radiation in a silver thiogallate crystal pumped with ruby laser radiation. A description is given of experimental conversion of CO2 laser radiation to the visible range in an AgGaS2 crystal, confirming the results of calculations. The conversion efficiency is found to be 10% for Q-switched pump-laser radiation of 2.2×105 W/cm2 power density in a crystal 3.3 mm long.
01 Jan 1977
TL;DR: Retinal damage accompanied lenticular damage in all cases and energy consideration as well as histologic investigation of the lesions indicate a mechanical damage process following a light-induced absorption in the focus.
Abstract: Results on Q-switched ruby laser damage to lenses of Chinchilla grey rabbits are reported. Threshold irradiances of about 10(10)W/cm2 are shown to be necessary for lens damage. The minimal lesions consist of empty bubbles about 1 mm in diameter. Energy consideration as well as histologic investigation of the lesions indicate a mechanical damage process following a light-induced absorption in the focus. Retinal damage accompanied lenticular damage in all cases
TL;DR: In this article, an optically induced magnetization precessing at a frequency corresponding to the energy separation near the level anticrossing points of the ground state 4 A 2 in ruby at room temperature was detected by a pick-up coil.
Abstract: Using excitation by ultrashort light pulses from a mode-locked ruby laser, we have observed optically induced magnetization precessing at a frequency corresponding to the energy separation near the level anticrossing points of the ground state 4 A 2 in ruby at room temperature. The motion of the magnetization is detected by a pick-up coil. The decay time of the signal is 5∼6 ns. The analysis is made by using the model of fictitious spin 1/2 and the agreement with the experiment is satisfactory.
TL;DR: In this article, an intracavity nonlinear loss element based on the ellipse rotation effect in liquid crystals EBBA and MBBA was used for stretching of Q-switched laser pulses.
TL;DR: The double-pulsed holographic interferometry operation with short pulse separation avoids many temporal aberrations seen in single-pulse systems and allows time differential interferograms of transient phenomena such as seen in theta-pinch plasmas.
Abstract: A unique method for double-pulsed holographic interferometry has been developed and employed in a meter-long theta-pinch experiment. Q-switching of two orthogonally polarized ruby laser beams, using the same lasing medium but different laser cavities, allows pulse separations of 0.2–100 μsec. The double-pulse operation with short pulse separation avoids many temporal aberrations seen in single-pulse systems and allows time differential interferograms of transient phenomena such as seen in theta-pinch plasmas. Orthogonal polarization of the two beams permits background fringe construction without the need for a mechanically introduced planar phase shift.
TL;DR: In this paper, the output of a Q-switched ruby laser irradiated a freely expanding jet of nitrogen gas and the remaining energy within the laser pulse heated the plasma and drove forward-travelling waves through the orifice and into the plenum of the jet.
Abstract: The output of a Q‐switched ruby laser irradiated a freely expanding jet of nitrogen gas. The laser optical axis was collinear with that of the jet. Gaseous breakdown occurred and the remaining energy within the laser pulse heated the plasma and drove forward‐travelling waves through the orifice and into the plenum of the jet. The temperature of the electrons within the plasma was measured using relative transmittance of x rays through thin metal‐foil spectrometers. The temperature varied as the square of the wave velocity from 60 to 160 eV. Measurements were also made of the spontaneous magnetic field generated in the vicinity of the plasma.
TL;DR: A simple CW ruby laser pumped by a 514.5-nm argon ion laser, utilizing an uncoated ruby rod (no external mirrors), was described in this article, where the output does not exhibit spiking, but does show a low amplitude ∼1 percent.
Abstract: A simple CW ruby laser pumped by a 514.5-nm argon ion laser, utilizing an uncoated ruby rod (no external mirrors), is described. The output does not exhibit spiking, but does show a low amplitude ∼1 percent) of modulation.
TL;DR: In this paper, a CO2 laser induced breakdown in argon has been studied using a pulsed ruby laser and complete mappings of the density gradient profiles at different temporal stages of the plasma are obtained.
TL;DR: In this paper, the characteristics observed for the stationary case are analyzed in terms of a spatial distribution of carriers governed by diffusion and interband Auger recombination in tellurium C = 1.5 × 10−28 cm6 s-l.
Abstract: Photoconductivity (p.c.) and photomagnetoelectric effect (p.m.e.) are observed in tellurium at high levels of optical excitation by means of a Q-switched ruby laser. The characteristics observed for the stationary case are analysed in terms of a spatial distribution of carriers governed by diffusion and interband Auger recombination. The coefficient of Auger recombination in tellurium C = 1.5 × 10−28 cm6 s-l is obtained.
[Russian Text Ignored]
01 Jan 1977
TL;DR: In this article, it was shown that it is possible to generate monochromatic (+0.05 nm) electromagnetic radiation with peak intensities and average intensities thousands of orders of magnitude higher than obtainable with the older classical sources.
Abstract: Not more than 5 years ago, it was common to refer to the laser as an “instrument in search of a problem.” Here was this marvelous device that could generate electromagnetic radiation that was naturally monochromatic (+0.05 nm) anywhere from 250 nm through the visible and infrared regions of the spectrum, and both the peak intensities and the average intensities were thousands of orders of magnitude higher than obtainable with the older classical sources. In addition, it was possible to generate ultrashort pulses (below 10-12 s) of this intense, monochromatic radiation. Furthermore, because of the physical mechanism involved in stimulated emission of radiation, and the design of laser cavities, the output beam was always plane polarized and virtually nondivergent.
TL;DR: In this article, a pulsed ruby laser was used as the light source and techniques to improve its coherence properties were described, and procedures for the formation and reconstruction of the hologram, fringe interpretation, and data reduction and presentation were detailed.
Abstract: Holographic interferometry was utilized to determine the three orthogonal components of displacement in elastic surface waves. A pulsed ruby laser was used as the light source and techniques to improve its coherence properties are described. Procedures for the formation and reconstruction of the hologram, fringe interpretation, and data reduction and presentation are detailed. The elastic-wave velocities and material constants for pink westerly granite were obtained. Solutions for an explosively generated Rayleigh wave in a half space and its reflection from a free edge are presented.
01 Aug 1977
TL;DR: In this article, an experimental system based upon a singlemode ruby laser and a ruby-pumped dye laser has been developed to investigate coherent anti-Stokes Raman scattering (CARS) of molecular gases.
Abstract: : An experimental system based upon a single-mode ruby laser and a ruby-pumped dye laser has been developed to investigate coherent anti-Stokes Raman scattering (CARS) of molecular gases. The CARS system is capable of both broad- and narrow-band operation. Theoretical and experimental results obtained using this system for such gases as H2, HF, CO, N2, and CH4 are given. In particular, real-time CARS spectra of these gases have been obtained for rotational temperature estimations and the pressure dependence of integrated CARS intensity has been determined. In addition, the effect of media turbulence upon laser-beam propagation and upon the CARS process has been investigated. Results of CARS measurements on a laboratory rocket-engine plume are also presented.
TL;DR: In this article, an argon laser pumped ruby laser system was described, which provided 300 mW in several modes using 2 W of single mode 5145 A argon LM pump power.
Abstract: We describe an argon laser pumped ruby laser system which provides 300 mW in several modes using 2 W of single mode 5145 A argon laser pump power. By filtering the output with a stabilized Fabry–Perot cavity, single mode outputs of 75 mW or more were obtained. The laser is tunable over a frequency width of 60 GHz about the R1 line at LN2 temperatures, with single mode powers between 10 and 100 mW.
TL;DR: In this article, single crystals, placed within a confocal optical resonator, were pumped with ruby laser fundamental and second-harmonic nanosecond pulses, in both cases laser oscillations at 1.05 μm exceeding in duration many times the pumping pulse were obtained.
Abstract: NdxLa1−xP5O14 (0.25≦x≦1) single crystals, placed within a confocal optical resonator, were pumped with ruby laser fundamental and second-harmonic nanosecond pulses. In both cases laser oscillations at 1.05 μm exceeding in duration many times the pumping pulse were obtained.
TL;DR: In this article, the power dependence of the frequency sweeping of a Q-switched ruby laser with saturable dyes, DDI and DCI, is experimentally studied by means of the holographic method of a rotating object.