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Showing papers in "IEEE Journal of Quantum Electronics in 1973"


Journal ArticleDOI
TL;DR: In this article, the problem of propagation and interaction of optical radiation in dielectric waveguides is cast in the coupled-mode formalism, which is useful for treating problems involving energy exchange between modes.
Abstract: The problem of propagation and interaction of optical radiation in dielectric waveguides is cast in the coupled-mode formalism. This approach is useful for treating problems involving energy exchange between modes. A derivation of the general theory is followed by application to the specific cases of electrooptic modulation, photoelastic and magnetooptic modulation, and optical filtering. Also treated are nonlinear optical applications such as second-harmonic generation in thin films and phase matching.

1,952 citations


Journal ArticleDOI
TL;DR: In this article, the authors considered third-harmonic generation in phase-matched mixtures of alkali metal vapors and inert gases and showed that the combination of near-resonant nonlinear susceptibilities, the ability to phase match, and the relatively high UV transparency of these vapors should allow high conversion efficiency for picosecond laser pulses with a peak power of 108-109W.
Abstract: This paper considers third-harmonic generation in phase-matched mixtures of alkali metal vapors and inert gases. Calculations show that the combination of near-resonant nonlinear susceptibilities, the ability to phase match, and the relatively high UV transparency of these vapors should allow high conversion efficiency for picosecond laser pulses with a peak power of 108-109W. Calculations of the nonlinear susceptibility and of the ratio of xenon atoms to metal vapor atoms which is necessary to achieve phase matching are given for each of the alkalies as a function of incident laser wavelength. Processes that limit the allowable peak power density and energy density are discussed and guides for determining the metal vapor pressure, cell length, and beam area are given.

253 citations



Journal ArticleDOI
TL;DR: In this paper, the first experimental measurements of intensity induced changes of optical polarization (ellipse rotation) in a cubic crystalline medium, YAG, for which they obtained the nonlinear susceptibilities = 6.34 \times 10-15} ESU and \frac{1}{2} (
Abstract: Using a TEM 00q near Gaussian mode ruby laser system we report the first experimental measurements of intensity induced changes of optical polarization (ellipse rotation) in a cubic crystalline medium, YAG, for which we obtain the nonlinear susceptibilities \chi_{3}^{1221} (- \omega, \omega, \omega, -\omega) = 6.34 \times 10^{-15} ESU and \frac{1}{2} (\chi_{3}^{1111} + \chi_{3}^{1221} - 2\chi_{3}^{1212}) = 7.18 \times 10^{-15} ESU, accurate to better than ±7 percent relative to \chi_{3}^{1221} (- \omega,\omega,\omega, -\omega) for liquid CS 2 . These values are compared with further results obtained for fused quartz and two laser glasses. Moreover, by time resolving the ellipse rotation data we demonstrate the capability to plot ellipse rotation versus input power on a single laser shot, thus increasing the practical feasibility of the technique and introducing the possibility of resolving transient contributions to the measurement.

202 citations


Journal ArticleDOI
F. Stern1
TL;DR: In this paper, the optical gain coefficient as a function of the nominal current density is given for GaAs lasers with compensated n-type active layers and with undoped active layers. And the results suggest that n type layers may give lower threshold currents near room temperature than do comparable p-type layers.
Abstract: Results for the optical gain coefficient as a function of the nominal current density are given for GaAs lasers with compensated n-type active layers and with undoped active layers. The results suggest that n-type layers may give lower threshold currents near room temperature than do comparable p-type layers.

147 citations


Journal ArticleDOI
TL;DR: In this article, a perturbation analysis of etched or deposited grating couplers based upon both the transmission line and the Green's Function approach is presented, which predicts the coupling efficiency, the output radiation beamwidth, the angular dependence of excitation, and the intensities of the other orders of the diffracted beams as functions of the grating periodicity, grating groove depth, and excitation direction.
Abstract: Grating couplers provide an attractive method for the excitation of optical thin-film waveguides. We present here a perturbation analysis of etched or deposited grating couplers based upon both the transmission line and the Green's Function approaches, which predict the coupling efficiency, the output radiation beamwidth, the angular dependence of excitation, and the intensities of the other orders of the diffracted beams as functions of the grating periodicity, grating groove depth, and excitation direction. It is found that the maximum excitation efficiency is 81 percent, that high efficiency can be achieved by excitation from the substrate, and that higher efficiency is obtained when the radiation leakage to the side orders is minimized.

127 citations


Journal ArticleDOI
Dietrich Marcuse1
TL;DR: In this paper, an analysis of the TE modes of a slab waveguide with a graded refractive-index distribution is presented, where the refractive index is approximated by a piecewise-linear distribution for which exact solutions of the guided-wave problem can be obtained.
Abstract: An analysis of the TE modes of a slab waveguide with graded refractive-index distribution is presented. The refractive index is approximated by a piecewise-linear distribution for which exact solutions of the guided-wave problem can be obtained. For multimode guides, useful approximate solutions can be worked out with the help of the Wentzel-Kramers-Brillouin (WKB) approximation. A formula is given for the total number of guided TE modes supported by the waveguide. The coupling efficiency of a prism coupler is investigated by studying the radiation losses of the guided modes escaping from the waveguide through the coupling prism. It is found that the radiation losses of the modes of the graded-index waveguide are more nearly constant than those of the asymmetric slab waveguide.

120 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented gain and output power of sealed-off waveguide CO 2 lasers as a function of gas mixtures and total gas pressure. But the authors did not consider the effects of the optical properties of the waveguide wall material on the loss of waveguide losses.
Abstract: Gain and output power of sealed-off waveguide CO 2 lasers are presented as a function of gas mixtures and total gas pressure. Experimental data on circular-bore and square-channel waveguide lasers are presented. Output power per unit length of 0.2 W/cm is achieved for both types of lasers in agreement with gas-discharge scaling laws which are presented. Saturation intensities as high as 24 kW/cm2are inferred from the data. The effects of the optical properties of the waveguide wall material on the waveguide losses are discussed and theoretical waveguide loss versus wavelength is presented for BeO, Al 2 O 3 , and fused silica.

119 citations


Journal ArticleDOI
TL;DR: In this article, the voltage obtained from metal-barrier-metal (MBM) diodes by phase-sensitive detection when illuminated with optical and near-infrared radiation, modulated at 880 Hz, has been studied as a function of an applied dc bias.
Abstract: The voltage obtained from metal-barrier-metal (MBM) diodes by phase-sensitive detection when illuminated with optical and near-infrared radiation, modulated at 880 Hz, has been studied as a function of an applied dc bias. The detected voltage is a nonlinear function of the bias voltage for high junction impedances, and linear for low junction impedances. The nonlinearity in the junction has been shown to be consistent with electron tunneling theory.

118 citations


Journal ArticleDOI
TL;DR: In this article, a general theory of finite-aperture waveguide-laser resonators is developed which represents the external reflectors by matrices which couple linearly polarized waveguide modes having the same azimuthal symmetry.
Abstract: A general theory of finite-aperture waveguide-laser resonators is developed which represents the external reflectors by matrices which couple linearly polarized waveguide modes having the same azimuthal symmetry. The theory allows the determination of resonator efficiency, resonator frequencies, and laser near- and far-field patterns. Computations of the coupling loss for the fundamental waveguide mode as a function of mirror curvature, separation, and aperture are in good agreement with recent infinite-aperture calculations in the limit of large apertures and indicate three low-loss configurations: 1) large radius of curvature mirrors close to the guide; 2) "large" radius of curvature mirrors centered at the guide entrance: and 3) generally smaller curvature mirrors separated by half their curvature from the guide entrance. The importance of higher order waveguide modes in determining laser output power and far-field patterns is demonstrated experimentally and compared to theoretical predictions. Design guidelines for the construction of high-efficiency CO 2 , CO, and He-Ne waveguide-laser resonators are summarized in tabular form.

112 citations


Journal ArticleDOI
TL;DR: In this paper, the linear coupled-wave analysis of a distributed feedback laser is presented for nonzero reflectivity at the ends of the lasing medium, and the results for the case of real coupling coefficients and the threshold behavior, as the reflectivity effects dominate, are described.
Abstract: The linear coupled-wave analysis of a distributed-feedback laser is presented for nonzero reflectivity at the ends of the lasing medium. Numerical results are given for the case of real coupling coefficients and the threshold behavior, as the reflectivity effects dominate, is described.

Journal ArticleDOI
Clyde G. Bethea1
TL;DR: Oscillation at 1.318 μ in Nd3+:YAG, at a peak power level of 1 MW in a 50-ns pulse is reported in this paper, and simultaneous laser oscillation was achieved in the same laser cavity at both 1.06 and 1.34 μ.
Abstract: Oscillation at 1.318 μ in Nd3+:YAG, at a peak power level of 1 MW in a 50-ns pulse is reported. In addition, simultaneous laser oscillation was achieved in the same laser cavity at both 1.06 and 1.318 μ.

Journal ArticleDOI
TL;DR: In this article, a weak volumetric preionization of the active gas region produced by UV radiation has been used to generate atmospheric-pressure CO 2 laser discharges between electrodes separated by 30 cm, having total cross sections of ∼600 cm2.
Abstract: Large aperture high-pressure gas laser discharges are a prerequisite for the development of high-energy gas lasers of sufficient power for the production of plasmas of thermonuclear interest. Of the several approaches being followed toward the attainment of such discharges, one utilizing weak volumetric preionization of the active gas region produced by UV radiation is described. The use of this technique has resulted in the successful generation of atmospheric-pressure CO 2 laser discharges between electrodes separated by 30 cm, having total cross sections of ∼600 cm2. With input energies of ∼200 J/1 small signal gain values of 4-5 percent cm-1were measured in 1 : 1 : 3 gas mixtures of CO 2 , N 2 , and He, respectively. It is thus concluded that this excitation technique could be incorporated into the fabrication of large volume gas laser amplifiers having beam cross sections in excess of 103cm2and total output-energy capabilities of \sim 10^{4} J.

Journal ArticleDOI
TL;DR: In this article, a transverse electric discharge scheme has been proposed for large volumes of CO 2, N 2, and He mixtures with beam cross sections up to 60 cm2in area.
Abstract: The development of a new transverse electric discharge scheme has permitted the excitation of large volumes of CO 2 , N 2 , and He mixtures with beam cross sections up to 60 cm2in area. The scheme utilizes as a preionizer a sheet of small arc discharges produced prior to the main discharge and situated behind a perforated anode. Time-resolved photography establishes that rapid volumetric ionization of the gas between the electrodes occurs concurrent with the formation of these arcs. This behavior is consistent with a preionization mechanism depending upon UV photo-excitation of the gas. A parametric study has shown that reproducible discharge conditions in 30 percent CO 2 gas mixtures are obtained with input energies of >300 J.I-1, resulting in energy extraction efficiencies of ∼10 percent and an average small-signal gain of ∼4.3 percent cm-1. The laser is modular in construction and, when a number of discharge modules are employed in series in a simple oscillator configuration, energies of ∼300 J with peak powers of several gigawatts are obtained.

Journal ArticleDOI
TL;DR: In this paper, a superluminescent diode (SLD) which simultaneously generates incoherent optical radiation and amplifies this radiation has been made from double-heterostructure (DH) Al x Ga 1-x As-GaAs material previously used to make lasers and light-emitting diodes having superior characteristics.
Abstract: A superluminescent diode (SLD) which simultaneously generates incoherent optical radiation and amplifies this radiation has been made from double-heterostructure (DH) Al x Ga 1-x As-GaAs material previously used to make lasers and light-emitting diodes having superior characteristics. The device configuration was similar to that of the stripe-geometry DH injection laser, except that optical feedback was suppressed by providing absorption for the backward waves in the cavity. A single-pass gain device resulted. The stripe contacts were 12.5 μm or 25 μm in width, and from 0.125 to 1.5 mm in length. The single-pass gain was found to be proportional to ( e^{\betaL} -1)/\beta , where β is a gain coefficient depending on the pump current and L is the stripe length. The structure was found to favor low-order modes, and the half-power radiation beam angle in the junction plane was measured to be 6-10\deg . The radiation field was slightly TE polarized, and it exhibited a spectral width of 50-85 A. When operated in the pulsed mode, the longest diodes (1.5 mm) radiated 60-mW peak power at a peak-current density of 6.5 kA/cm2(2.5-A current) and about 10 mW at 3 kA/cm2. The external differential quantum efficiency was 3.5 percent. Due to the relatively narrow radiation pattern of the SLD, more than 80 percent of the radiation from this source has been coupled into a multimode optical fiber with a numerical aperture of 0.63. These measured characteristics were found to conform to those calculated on the basis of a simple model.

Journal ArticleDOI
C. L. Tang1, P. Bey1
TL;DR: In this paper, the use of artificial periodic structures, consisting of spatial modulations of the linear and nonlinear susceptibilities of a nonlinear optical medium, to achieve phase matching in second-harmonic generation is analyzed.
Abstract: The use of artificial periodic structures, consisting of spatial modulations of the linear and nonlinear susceptibilities of a nonlinear optical medium, to achieve phase matching in second-harmonic generation is analyzed. Dispersion relations and approximate formulas for the second-harmonic fields generated under various conditions are obtained and used to evaluate the experimental situation.

Journal ArticleDOI
TL;DR: In this paper, the time evolution of the CO vibrational distribution function in electrically pumped CO-N 2 -He mixtures is revealed through a time-dependent solution of the coupled rate equations for the first 50 vibrational levels of CO considering spontaneous and stimulated emission, electron impact excitation, and deexcitation as well as kinetic heating of the lasing medium.
Abstract: We report here calculations of pulsed CO laser operation by revealing the time evolution of the CO vibrational distribution function in electrically pumped CO-N 2 -He mixtures. This is accomplished through a time-dependent solution of the coupled rate equations for the first 50 vibrational levels of CO considering V-V and V-T processes, spontaneous and stimulated emission, electron impact excitation, and deexcitation as well as kinetic heating of the lasing medium. The electron excitation rates as a function of E/N are obtained from calculations of the steady-state electron distribution function in the appropriate gas mixtures. In addition to following the time dependence of pulsed operation, CW calculations have been performed for the purpose of comparison with the results of other investigators. Comparisons between the predicted time of appearance of lasing lines and experimental data is quite good for both the free-running and single-line modes of operation.

Journal ArticleDOI
TL;DR: In this paper, an antiresonant ring-mirror configuration, the optical analog of a microwave reentrant hybrid tee, is suggested for several potential laser applications including coupled laser cavities, variable laser output coupling, intracavity harmonic output coupling and cavity dumping, and pulse code modulation.
Abstract: An antiresonant ring-mirror configuration, the optical analog of a microwave reentrant hybrid tee, is suggested for several potential laser applications including coupled laser cavities, variable laser output coupling, intracavity harmonic output coupling, mode locking, cavity dumping, and pulse code modulation.

Journal ArticleDOI
TL;DR: In this article, it was shown that the small-scale filaments generated by laser pulses in nonlinear media are the natural consequence of moving foci, and the results of many controlled experiments performed with singlemode Q-switched laser pulses agree very well with the predictions of the moving focus model.
Abstract: It is shown that the small-scale filaments generated by laser pulses in nonlinear media are the natural consequence of moving foci. Results of many controlled experiments performed with single-mode Q -switched laser pulses agree very well with the predictions of the moving focus model. The earlier experimental results on filaments reported in the literature are also shown to be consistent with the moving focus model. In the picosecond case, this model appropriately modified, gives essentially the same description as the so-called dynamic trapping model, which explains qualitatively the observed filament characteristics in that limit.

Journal ArticleDOI
TL;DR: In this article, the optical gain due to stimulated transitions between the lowest-bound diatomic states of xenon (Xe) and the repulsive ground state of ground states was reported.
Abstract: Experimental measurements are reported of optical gain due to stimulated transitions between the lowest-bound diatomic states of xenon (Xe) and the repulsive ground state. The optical gain was greatest at a wavelength of (1730 ± 10) A, where the effective gain cross section is estimated to be 7 \times 10^{19} cm2.

Journal ArticleDOI
TL;DR: In this paper, a light deflector consisting of arrayed electrooptic prisms was proposed, and the resolving power of this deflector was shown to be N times larger than that of a single EO prism.
Abstract: A type of light deflector that shows ultrahigh resolving power is proposed. This light deflector consists of arrayed electrooptic prisms. The resolving power of this deflector is N times larger than that of a single electrooptic prism, where N is the number of arrayed prisms. If the voltages applied on each crystal are all the same, the deflecting angle is discontinuous. But if the voltages are not equal to each other, it can be continuous. Experiments were done using a simple deflector. The experimental results agreed with the theory. The experimental deflector showed 50 resolved individual spots when maximum applied voltages were ± 600 V. It is clear that we can have a light deflector that shows over 600 resolvable spots easily. Current techniques are sufficient to manufacture such deflectors.

Journal ArticleDOI
TL;DR: In this paper, a single-mode strip double-heterostructure laser is investigated with a high-time resolution (10-10s) spectrometer apparatus, and the properties of a laser with such a cavity are described.
Abstract: Single-mode (SM) laser radiation from a GaAs diode is obtained using a composite cavity which can be tuned to select a desired spectral mode. The properties of a laser with such a cavity are described. The kinetics of the spectra of the single-mode strip double-heterostructure laser is investigated with a high time resolution (10-10s) spectrometer apparatus. At sufficiently high currents above threshold a transition from SM to multimode operation occurs with breaks in the stable SM oscillation. Such an event is accompanied by a frequency self-modulation of the oscillation with a self-induced intensity pulsation at the same microwave frequency. Multimode oscillation appears simultaneously with the pulsation of the radiation, and the SM output power is limited due to such pulsations.

Journal ArticleDOI
TL;DR: Laser action has been observed for the following rare-earth ions in YAlO 3 :Ho3+(sensitized with Er3+and Tm3+), Er3+, and Tm 3+ at wavelengths of 2.123, 0.851, and 1.861 μm, respectively as mentioned in this paper.
Abstract: Laser action has been observed for the following rare-earth ions in YAlO 3 :Ho3+(sensitized with Er3+and Tm3+), Er3+, and Tm3+(sensitized with Er3+) at wavelengths of 2.123, 0.851, and 1.861 μm, respectively. Measurements of spectroscopic properties, fluorescence kinetics, and laser performance of these ions in YAlO 3 are reported.

Journal ArticleDOI
TL;DR: In this article, an optical device exhibiting both a time versus frequency and a space versus frequency dispersion has made possible the performance of 1) the pulse by pulse spectrum analysis of mode-locked Nd-glass laser trains and 2) the shaping of these pulses by a completely passive process.
Abstract: An optical device exhibiting both a time versus frequency and a space versus frequency dispersion has made possible the performance of 1) the pulse by pulse spectrum analysis of mode-locked Nd-glass laser trains and 2) the shaping of these pulses by a completely passive process. The relatively poor performance of this spectrum analyzer (7 spectral lines resolved) is essentially due to the rise time of the photodetection setup utilized in the experiments. The shaping consists in a preliminary pulse expansion (from picoseconds to nanoseconds), which gives linear FM long pulses whose envelopes are then modulated with a rise time of 50 ps by a spectral filtering simply obtained by diaphragms and neutral filters.

Journal ArticleDOI
R. Smith1
TL;DR: In this article, the performance characteristics of a continuously pumped doubly resonant optical parametric oscillator have been studied in detail using barium sodium niobate as the nonlinear material threshold for oscillation.
Abstract: The performance characteristics of a continuously pumped doubly resonant optical parametric oscillator have been studied in detail. Using barium sodium niobate as the nonlinear material threshold for oscillation, as low as 3 mW has been observed. At higher pump power levels an efficiency exceeding 50 percent and a tunable output power of nearly 80 mW (signal plus idler), have been achieved. The effect of frequency stability of the pump on oscillator performance has been studied with single-mode operation and ±20-percent amplitude stability attained. The effects of cavity-length perturbations on oscillator performance have also been studied. It is found that cavity-length changes of \frac{1}{4} wavelength (250 nm in this case) can produce tunability of the output frequency by as much as 100 cm-1. These results as well as their interpretation and implications on the design of doubly resonant optical parametric oscillators are discussed.

Journal ArticleDOI
TL;DR: In this article, a Gaussian pulse consisting of 1-5 10.6-\mu transitions and one line at 9.6 μ was used to extract energy from an atmospheric-pressure CO 2 amplifier.
Abstract: The ability of a nanosecond or shorter CO 2 -laser pulse consisting of a single vibrational-rotational transition to extract energy from an atmospheric-pressure CO 2 amplifier is limited owing to the finite rotational thermalization time in CO 2 and the larger number of rotational states which share the stored energy. Theoretical studies are reported which indicate that utilizing an incident pulse consisting of several vibrational-rotational lines within the 10.6-μ band substantial improvements can be obtained over single-line extraction. Even more dramatic improvements are possible if the pulse contains vibrational-rotational transitions at both the 10.6- and 9.6-μ bands. Quantitative energy-extraction results are presented for an input Gaussian pulse consisting of 1-5 10.6-\mu transitions, and for a pulse containing one line at 9.6 μ and one at 10.6 μ, traversing a 1-m amplifier, for a wide range of input energies, pulsewidths, and gas pressures. Possibilities of using multiband techniques for pulse shaping are also discussed.

Journal ArticleDOI
TL;DR: In this article, the design advantages of using four-and five-layer heterostructure lasers in order to separately optimize the optical distribution and carrier confinement for a particular application were discussed, given an arbitrary gain/carrier density relationship the parameters can be optimized for minimum threshold current.
Abstract: This paper shows the design advantages of using four- and five-layer heterostructure lasers in order to separately optimize the optical distribution and carrier confinement for a particular application. Given an arbitrary gain/carrier density relationship the parameters can be optimized for minimum threshold current. Theoretical results for both wide optical cavity and close confined lasers are given. These show the optical distributions for four- and five-layer lasers and how the threshold current varies with the active region width. Experimental results report a reduction from 55° half-power polar diagram width to 32° by the addition of a fourth layer to increase the optical cavity width of a double-heterostructure laser. The threshold current against reciprocal length characteristics for three- and four-layer devices are considered in terms of the theory given and hence a plot of gain against injected carrier density is obtained that extends over an order of magnitude of gain.

Journal ArticleDOI
TL;DR: In this paper, the authors considered a band-to-level transition model of semiconductor laser gain and showed that the gain exhibits a spectral hole-burning in the vicinity of oscillation frequency as well as a decrease from the corresponding linear gain over the entire spectral region.
Abstract: Frequency characteristics of a nonlinear lasing gain under the condition that a laser oscillation exists at a fixed frequency are theoretically obtained on the basis of a band-to-level transition model (without the k - selection rule) of semiconductor lasers This nonlinear gain exhibits a spectral hole-burning in the vicinity of oscillation frequency as well as a decrease from the corresponding linear gain over the entire spectral region The analysis uses a semiclassical density-matrix formalism and a perturbation method The lasing transitions are assumed to occur between a conduction-band Bloch state and a localized acceptor level The above-defined nonlinear gain is obtained from a third-order perturbation calculation In the neighborhood of a lasing frequency, a narrow spectral region where the gain is burned is theoretically found (hole-burning effect) The width of this "hole" increases with the relaxation rate at acceptor states, and is almost independent of excitation level The gain decrease over the entire spectral region results from the absence of the k -selection rule, and corresponds to the saturation of spontaneous emission after the onset of lasing Rapid relaxations in the conduction band and lower acceptor concentrations make more significant gain decreases at a frequency sufficiently apart from the lasing frequency This effect makes possible a single axial-mode operation in some cases

Journal ArticleDOI
TL;DR: In this paper, the relative contributions of the Kerr, electrostrictive, and thermal effects to the self-focusing thresholds of borosilicate crown glass, fused silica, and dense flint glass have been estimated from an analysis of damage-threshold data for linearly polarized and circularly polarized radiation.
Abstract: The relative contributions of the Kerr, electrostrictive, and thermal effects to the self-focusing thresholds of borosilicate crown glass, fused silica, and dense flint glass have been estimated from an analysis of damage-threshold data for linearly polarized and circularly polarized radiation. The measurements were made with a Nd:glass laser operating in the TEM 00 mode with a temporal pulsewidth of 25 ns. The Kerr effect appears to be the largest effect. The thermal effect is also significant. The electrostrictive effect is smallest. Reasonable values of the absorption coefficient are calculated from the thermal contribution. The results are in qualitative agreement with the work of others.

Journal ArticleDOI
TL;DR: In this article, a Nd-glass disk-disk-laser amplifier has been constructed at the Naval Research Laboratory (NRL) to achieve 320-J output in a 1-ns pulse with 110-J input.
Abstract: The details of the analysis, design, and operation of a Nd-glass-disk-laser amplifier which has been constructed at the Naval Research Laboratory are presented. Gain and fluorescence measurements have been compared to theoretical predictions; these show that 0.6-J/cm3energy storage is achieved in the disk (assuming a cross section of 3.0 \times 10^{-20} cm2). The effects of unsuppressed parasitic oscillations are demonstrated and an effective method of preventing their occurrence is shown. The disk amplifier has demonstrated 320-J output in a 1-ns pulse with 110-J input.