Showing papers on "Ruby laser published in 1973"
TL;DR: In this paper, a ruby laser beam mixed in AgGaS 2 with the output of various ruby-pumped dye lasers has provided down-converted infrared radiation tuned from 4.6 to 12 μm.
58 citations
TL;DR: In this paper, the authors analyzed the kinetics and spectral distribution of the recombination radiation during and after the injection pulse by a theoretical model which takes into account the heating of the sample by the laser pulse as well as the decrease of the band gap due to the high carrier concentration.
Abstract: High concentrations of electrons and holes in silicon and germanium have been achieved by optical injection by a giant pulse ruby laser. The kinetics and spectral distribution of the recombination radiation during and after the injection pulse have been analyzed by a theoretical model which takes into account the heating of the sample by the laser pulse as well as the decrease of the band gap which is due to the high carrier concentration. The decay of the recombination radiation signal shows that a third-order recombination process (band-to-band impact or Auger recombination) is predominant at high concentrations. The value of the Auger recombination coefficient γ3 10-31 - 4 × 10-30 cm6/s is obtained for silicon in the temperature interval 300 K-800 K.
41 citations
TL;DR: In this paper, the amplitude, velocity, and damping of ultrasonic waves were examined by Debye Sears diffraction of argon laser pulses, and the sound waves were excited by two light beams of equal intensity derived from a modelocked ruby laser.
Abstract: A temporally and spatially periodic light intensity distribution generates thermally in an absorbing sample a corresponding density variation which can be considered a standing sound wave. This thermal excitation of ultrasonic waves by modulated laser light has been investigated theoretically and experimentally. The sound waves were excited by two light beams of equal intensity derived from a mode‐locked ruby laser. The amplitude, velocity, and damping of the sound waves were examined by Debye Sears diffraction of argon laser pulses.
37 citations
TL;DR: In this paper, the frequency dependence of the optical nonlinear susceptibility has been determined using linear optical constants calculated by a Kramers-Kr\"onig analysis of reflectivity.
Abstract: Using a pulsed tunable dye laser pumped by a $Q$-switched ruby laser, the frequency dependence of second-harmonic generation has been measured in the region of the first and second $1s$ excitons of CuCl from about 3.18 to 3.34 eV and the region of the $C$ exciton of ZnO from about 3.38 to 3.48 eV. From the data, the frequency dependence of the optical nonlinear susceptibility has been determined using linear optical constants calculated by a Kramers-Kr\"onig analysis of reflectivity. The results for the single nonzero term of the nonlinear susceptibility of CuCl and the two terms ${d}_{\mathrm{zzz}}$ and ${d}_{\mathrm{zxx}}$ of ZnO have been fit theoretically by an anharmonic-oscillator model employing two oscillators.
37 citations
TL;DR: In this paper, a thermally tuned Q-switched ruby laser with moderate power, with emission wavelength at 6939 A, has been used to selectively excite the 4^{2}P{3/2}-6^{2]S_{1/2}) transition in the atoms of a pure potassium plasma of low degree of ionization produced in a hot cathode diode.
Abstract: A thermally tuned Q -switched ruby laser of moderate power, with emission wavelength at 6939 A, has been used to selectively excite the 4^{2}P_{3/2}-6^{2}S_{1/2} transition in the atoms of a pure potassium plasma of low degree of ionization produced in a hot cathode diode. A pulse of intensified spontaneous emission has been observed at 6939 A, 6911 A, and at a number of other wavelengths. The possibility of using this type of interaction for localized plasma diagnostics has been studied experimentally. It has been found that the intensified signal decay time decreases with increasing electron density, thereby providing a potential means for measurement of this parameter. In particular, it is shown that because of a saturation effect, the recorded signal characteristics depend to some extent on the laser parameters. A specially tailored laser performance is suggested as essential in order to overcome these problems and obtain signals which depend unambiguously on the plasma conditions.
31 citations
TL;DR: In this article, the second harmonic of a mode-locked ruby laser was used to obtain a superradiant picosecond laser emission from dye solutions transversely pumped with the second harmonics of a binary mode.
31 citations
TL;DR: In a separate set of experiments, the temporal development of coating breakup and plasma formation is investigated and the experimental results are discussed in the context of possible damage mechanisms.
Abstract: Laser induced damage characteristics have been studied for twelve, multiple-layer dielectric, 95% reflecting mirrors irradiated with single ruby laser pulses of 20-nsec and 20-psec duration and Gaussian beam radii ranging from 0.06 mm to 0.24 mm. During measurements to determine damage threshold the pulse energy, an oscilloscope trace of the pulse, and the beam’s transverse energy density profile at the surface being damaged are recorded for each shot. In a separate set of experiments, the temporal development of coating breakup and plasma formation is investigated. The experimental results are discussed in the context of possible damage mechanisms.
25 citations
TL;DR: In this article, the intrinsic bulk damage in nine alkali-halide crystals was reported, and for all of these crystals the damage field was greater than or equal to that measured at 1.06 μm and dc.
Abstract: Ruby‐laser‐induced intrinsic bulk damage in nine alkali‐halide crystals is reported. Within experimental error and for all of these crystals the damage field is greater than or equal to that measured at 1.06 μm and dc. The trend in breakdown fields among these crystals at 0.69 μm differs from that at longer wavelengths and suggests that, even though electron avalanche breakdown is the likely damage mechanism, the first signs of a frequency dependence to this process appear by 4.3×1014 Hz.
25 citations
TL;DR: This paper is an attempt to evaluate the clinical application of laser iridotomy from the results of treating more than forty eyes.
Abstract: Extensive experience with animals has shown that it is possible to irradiate the iris with a ruby laser without damage to the cornea, lens, or retina (Hallman, Perkins, Watts, and Wheeler, I 968, I969). The possible use of a laser to make an iridotomy for therapeutic purposes was appreciated by Flocks and Zweng (i964), and Zweng, Flocks, Kampany, Silbertrust, and Peppers (I964) reported two attempts to perform this in human eyes. In neither case was a complete iridotomy produced, but holes were produced in two pigmented irides by Zweng, Paris, Vassiliadis, Rose, and Hayes (I970). Some success in treating a small series of cases of closed-angle glaucoma and secondary glaucoma due to iris bombe has been reported (Perkins, I970, I971), and this paper is an attempt to evaluate the clinical application of laser iridotomy from the results of treating more than forty eyes.
23 citations
TL;DR: In this article, the difference frequency between the output from a tunable narrow-linewidth ruby-pumped infrared dye laser and a Q-switched ruby laser in a proustite crystal was calculated.
Abstract: High‐power wavelength‐tunable coherent radiation has been produced by generating the difference frequency between the output from a tunable narrow‐linewidth ruby‐pumped infrared dye laser and a Q‐switched ruby laser in a proustite crystal. Peak infrared powers in the kilowatt range and wavelength tunability from 3.20 to 5.65 μ have been achieved. The experimentally determined infrared power tuning curves are compared to those predicted by theory for interacting Gaussian light beams.
21 citations
TL;DR: In this paper, an oscillator-amplifier dye laser pumped by a single giant-pulse ruby laser is described, which allows production of a tuneable 5 MW, 30 nsec pulse without damaging the intra-cavity echelle which is used to achieve the 0.05 nm linewidth.
TL;DR: In this article, self-focusing of ruby laser light is studied as a function of sample length and temperature in the isotropic phase of nematic liquid-crystal MBBA.
Abstract: Self‐focusing of ruby laser light is studied as a function of sample length and temperature in the isotropic phase of nematic liquid‐crystal MBBA. The critical power for self‐focusing, 0.36 kW, observed near the phase transition temperature is a factor of 20 times less than that for CS2. The corresponding nonlinear index 4.4 × 10−10 esu is the largest value known so far for any material.
TL;DR: In this paper, the Stokes parameters of dye laser light at a wavelength of 0.6328 pm were measured experimentally by measuring the second harmonic of a ruby or neodymium-doped laser.
Abstract: The degree of polarization of dye laser light (Rhodamine B) under excitation by a beam of linearly polarized light (second harmonic of a ruby or neodymium-doped laser) has been studied experimentally by measuring the Stokes parameters of dye laser light at a wavelength of 0.6328 pm. The sign of degree of polarization is negative in the case of the ruby second harmonic (0,3471 pm), whereas it is positive in the case of the neodymium second harmonic (0.53 pm). Even in the case of illumination with the ruby second harmonic, the magnitude of the degree of polarization increases with the intensity of unconverted ruby laser light. The experimental fact that the degree of polarization of dye laser light is nearly as high as unity has been explained fairly well on the basis of the theory proposed by the authors.
TL;DR: In this article, it was shown that undamped spikes in the output of multimode pulsed lasers were due to an inhomogeneous depletion of the inverted population in the bulk of an active rod.
Abstract: The results of an experimental investigation were combined with the published work to show that undamped spikes in the output of multimode pulsed lasers were due to an inhomogeneous depletion of the inverted population in the bulk of an active rod. A quasicontinuous output was obtained from a ruby laser with plane mirrors. It was found that the mechanical and thermal distortions of the resonator, which could suppress the laser action, were essentially misalignments. A new feature of the stimulated emission, called inertia, was observed for a ruby laser with spherical mirrors when the spatial inhomogeneities of the population inversion were smoothed out.
Patent•
09 Apr 1973TL;DR: Vanadyl phthalocyanine sulfonamides of the formula: Pc is a phhalocyanin moiety, R and R'' are lower alkyl and x is an integer from 1 to 4; are incorporated into plastics to provide plastic compositions suitable for fabrication into devices, such as goggle lenses, capable of protecting the eye against laser radiation of from about 620 to 720 nanometers as mentioned in this paper.
Abstract: Vanadyl phthalocyanine sulfonamides of the formula: WHERE Pc is a phthalocyanine moiety, R and R'' are lower alkyl and x is an integer from 1 to 4; are incorporated into plastics to provide plastic compositions suitable for fabrication into devices, such as goggle lenses, capable of protecting the eye against laser radiation of from about 620 to 720 nanometers, e.g. the ruby laser (694 nm), the krypton laser (671 nm) and the helium-neon laser (633 nm). A typical composition consists of 75 parts poly(methyl methacrylate) syrup, 25 parts methyl methacrylate, 0.03 parts vanadyl phthalocyanine di-nbutylsulfonamide having 2.8 dibutyl sulfonamide radicals per mole of phthalocyanine, 0.2 part 2,2''-dihydroxy-4-methoxybenzophenone and 0.03 part azobisisobutyronitrile. A plate, 0.1 in. thick, cast-molded from said composition, exhibited an optical density at 694.3 nm of 5.5+ and a luminous transmittance of 47 percent. When exposed to a Q-switched ruby laser of 300 kilowatts per cm2 for 20 nanoseconds, the plate remains undamaged.
TL;DR: In this paper, the expansion of sparks produced in various gas mixtures by a helical TEA CO 2 laser of modest power (∼ 0.5 MW) was examined using time-resolved photography and two-wavelength interferometry.
Abstract: The expansion of sparks produced in various gas mixtures by a helical TEA CO 2 laser of modest power (∼ 0.5 MW) has been examined using time-resolved photography and two-wavelength interferometry. The latter was accomplished with the aid of a synchronized ruby laser, the fundamental and second-harmonic frequencies of which illuminated a Mach-Zehnder interferometer. The interferograms have been analyzed using Abel inversion techniques and two-dimensional profiles of the electron density within the sparks obtained.
TL;DR: In this article, a hole-burning effect was observed spectroscopically in a solution of cryptocyanine in methanol, when excited by a mode-locked ruby laser.
TL;DR: In this paper, a LiIO3 crystal, placed inside a doubly resonant oscillator, was pumped with the second harmonic of a Q•switched ruby laser, and a 0.415 to 2.1μm tuning range for both signal and idler was obtained.
Abstract: A LiIO3 crystal, placed inside a doubly resonant oscillator, was pumped with the second harmonic of a Q‐switched ruby laser. A 0.415‐ to 2.1‐μm tuning range for both signal and idler was obtained. The conversion efficiency from pump to signal power amounts to 8%. The peak power of the signal radiation was 10 kW and the pulse duration was 5 nsec.
TL;DR: In this article, it was shown that the lifetimes of molecules which give a reasonably strong absorption (molar decadic extinction coefficient ∈ > 10 4 M −1 cm −1 ) at the frequency of the ruby laser can be determined from the saturation of the optical transitions.
TL;DR: In this article, the long-lived transient absorption which is observed when solutions of cryptocyanine and DDI in methanol and other alcohols are exposed to nanosecond ruby laser pulses arises from a photoproduct whose formation requires consecutive absorption of two photons.
TL;DR: In this article, an efficient organic dye laser with a linewidth of less than 2 A was developed as a source of tunable high power radiation in the wavelength range 7500-9200 A.
TL;DR: In this article, the photochemical yield was found to depend on the temperature and the temporal substructure of the laser pulse, leading to a dependence of the photon yield on the pumping conditions of a laser.
TL;DR: In this paper, the two-photon photochromism of spiropyran solutions subjected to ruby laser radiation was investigated and the absorption cross-section of the twophoton absorption cross section was calculated.
Abstract: An investigation was made of the two-photon photochromism of spiropyran solutions subjected to ruby laser radiation. The two-photon absorption cross section of spiropyran was calculated. At high laser radiation intensities the dependence of the optical density of the photoinduced form of spiropyran on the incident radiation intensity deviated from the square law. The cause of this deviation was considered.
TL;DR: In this paper, the breakdown region was observed by recording infinite fringe, interferometric, diffuse holograms with a singlemode ruby laser of 100 ns FWHM pulse length.
Abstract: Air breakdown at pressures of 300 and 753 torr was produced by a 28J, 40 ns FWHM neodymium glass laser focused with a 100 mm focal length lens. The breakdown region was observed by recording infinite fringe, interferometric, diffuse holograms with a single-mode ruby laser of 100 ns FWHM pulse length. The two lasers were synchronized to examine the time region from R-t diagram was found to be in excellent agreement with the weak spherical blast wave theory of Sakurai. The radial density profile of the shock wave was determined by an Abel inversion of the fringe pattern. Both the R-t function and the density profile were calculated using a one-dimensional, hydrodynamic model and good agreement was obtained.
TL;DR: In this article, four individually Q-switched laser cavities have been established sharing a common ruby laser rod, and single giant pulses have been emitted with a time duration of ≈ 30 ns (half width) and energies of 0.16 J from each cavity apertured by a 2.54mm-diameter hole.
Abstract: Four individually Q -switched laser cavities have been established sharing a common ruby laser rod. Single giant pulses have been emitted with a time duration of ≈ 30 ns (half-width) and energies of 0.16 J from each cavity apertured by a 2.54-mm-diameter hole. The spacing of the pulses was continuously variable in time from 0 to 1.25 ms plus or minus a jitter time of approximately 13 ns. This multiple-cavity laser light source can be used as a stroboscopic illuminator for photographic or holographic recording of fast events.
TL;DR: In this paper, the forward-scattered spectrum of the light from a giant-pulse ruby laser, which was focused into liquids to which absorbers were added, was examined and it was found that almost all of the non-absorbed light is transmitted, but at the shifted frequency.
Abstract: This investigation has examined the forward-scattered spectrum of the light from a giant-pulse ruby laser, which was focused into liquids to which absorbers were added. Anti-Stokes shifts of about one-half of the incident linewidth were observed, the same shift as that for back-scattered light. The shift has a small dependence upon the liquid used but does not depend upon the kind of absorber, or the amount of absorption above a critical value, and, except for the lowest powers used, is independent of incident laser power. It is found that almost all of the non-absorbed light is transmitted, but at the shifted frequency. The intense, shifted, forward-scattered light is explained as an interaction of the stimulated back-scattered light with the incident light which preferentially amplifies certain frequencies of the incident laser profile at the expense of the back-scattered light. It is concluded that forward scattering is an important technique for additional observations of stimulated thermal scattering.
TL;DR: In this paper, a short (2nsec) pulse ruby laser has been used to make holographic interferograms of exploding wire events, which exhibit both shock waves and ionization.
Abstract: A short (2‐nsec) pulse ruby laser has been used to make holographic interferograms of exploding‐wire events. At atmospheric pressure the interferograms exhibit both shock waves and ionization. In a vacuum the vaporization and subsequent ionization of the wire are evident. At selected times after initiation, spatial electron density profiles have been calculated via an Abel inversion, with peak densities approaching 1019 cm−3.
TL;DR: A Pockels cell having all surfaces at Brewster's angle is described, and the possibility of using the cell to obtain high contrast ratio, low loss selection of pulses from mode-locked pulse trains is discussed.
Abstract: A Pockels cell having all surfaces at Brewster's angle is described. A simple analysis is presented to show that the extinction ratio of a quarter-wave mode Q-switch using this design is limited to 180:1 by the presence of Brewster faces on the crystal when the cell is closed by one window and one resonator mirror, whereas the ratio is limited to 28:1 if two Brewster windows are used to close the cell. The measured extinction ratio of an experimental cell based on the design requiring a single window is 150:1. Operation of a ruby laser using the Q-switch is described, and the possibility of using the cell to obtain high contrast ratio, low loss selection of pulses from mode-locked pulse trains is discussed.
TL;DR: In this paper, the authors report laser action in some organic compounds when pumped by the second harmonic of a ruby laser: αNPD or 2-(1-naphtyl)-5-phenyl, 1,3,4, oxadiazole; αNBE or trans -1-(4-biphenyl)-2-(1)-naphthyl)-ethylene; 1, 3, 4,8,8 tetraphenyl-pyrene; 1.1, 4.4, 4.
TL;DR: The single pass gain of a 4 × 10−5 M/l solution of 3,3′−diethylthiatricarbocyanine iodide in methanol optically pumped by a giant pulse ruby laser was measured as a function of pump power, wavelength, and time.
Abstract: The single‐pass gain of a 4 × 10−5 M/l solution of 3,3′‐diethylthiatricarbocyanine iodide in methanol optically pumped by a giant‐pulse ruby laser was measured as a function of pump power, wavelength, and time Pump power was varied over a range of 0–7 MW and the wavelength range was 7850–8075 A The gain is seen to have strong dependence on the instantaneous pump power The dependence of gain on pump power is plotted from the experimental data for six wavelengths in the region investigated, and is also discussed theoretically The spontaneous decay rate from the excited state and the cross section for stimulated emission are also obtained from the theory The low signal gain coefficient and the gain saturation value are tabulated for each wavelength investigated