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The performance characteristics of semiconductor lasers based on quantum wells (QWs) are theoretically studied as functions of the thickness of the waveguide region [optical confinement layer (OCL)]. The maximum modal gain, optical-confinement factor (in QWs, OCLs, and emitters), threshold current density, electron and hole densities (in QWs and OCLs), internal optical loss (in QWs, OCLs, and cladding layers), internal differential quantum efficiency, currents of stimulated and spontaneous recombination and the output optical power of the laser are calculated as functions of the OCL thickness. It is shown that up to pump current densities of 50 kA/cm2 the dependence of the output power of the considered lasers on the OCL thickness is weak in the thickness range of 1.5–2.8 μm. This result is important for the development of high-brightness lasers, since such lasers use a wide waveguide to ensure low radiation divergence. It is shown that, at very high pump-current densities, the output power has a maximum as a function of the OCL width. [ABSTRACT FROM AUTHOR]

Photo- and electroluminescence in p–i–n structures with compensated GaAs/AlGaAs quantum wells have been studied. Two structures with different doping profiles were studied: with spatial separation of donors and acceptors (donors are localized in quantum wells, while acceptors are localized in barriers) and without it (both donors and acceptors are localized in quantum wells). The studies were carried out in the near-IR range at helium temperatures. Luminescence lines due to electron transitions from donor states to the first heavy-hole subband (D–hh1) and from the first electron subband to acceptor states (e1–A) have been identified. At large electric currents, the near-IR lasing due to these transitions was observed in the electroluminescence spectra. It has been found that the integrated lasing intensity related to the D–hh1 transitions in the structure without a spatial separation of donors and acceptors was three times higher than in the structure with the spatial separation. It is these transitions that ensure effective depletion of donor levels, which is important for the donor-assisted terahertz emission at e1–D electron transitions. The results of the work can be used in the development of electrically pumped terahertz emitters. [ABSTRACT FROM AUTHOR]

Radiative characteristics of microstripe laser diode bar in an external resonator based on an aspherical lens and a flat dielectric mirror were Investigated. The bar had total emitting aperture of 185 μm, formed by 10 stripes with a width of 6 μm separated by mesa-grooves. Operation in the external resonator of the entire emitting aperture was characterized by a multimode generation regime with a peak power of 3 W/6 A. Selection of lateral modal structures and transition to a single-mode regime is possible by limiting the number of stripes involved in optical feedback. Dependences of optical mode reconfiguration were studied by introducing limiting slits into the external cavity. It was shown that limiting the emitting aperture involved in the feedback to 65 μm allows us to demonstrate high-order single-mode operation with far-field divergence for the central lobe of 1°. [ABSTRACT FROM AUTHOR]

The possibility of realizing single-mode emission in quantum-cascade lasers due to modulation of output optical losses in a Fabry–Perot cavity is demonstrated. For the active region of the 7.5–8.0 μm spectral range, the two- phonon resonance design was used, thus, 50 stages and waveguide layers based on indium phosphide made it possible to realize single-mode 7.765 μm lasing at the temperature of 292 K. Side-mode suppression ratio was about 24 dB and remained the same with an increase in the current pumping up to 1.2 of the threshold current values. The coefficient of wavelength shift with temperature (temperature tuning) in the single-mode lasing regime was 0.56 nm/K. [ABSTRACT FROM AUTHOR]

The possibility of fabrication of 4.6 μm spectral range quantum-cascade laser heterostructures by molecular-beam epitaxy technique with non-selective overgrowth by the metalorganic vapour-phase epitaxy is shown. The active region of the laser was formed on the basis of a heteropair of In0.67Ga0.33As/In0.36Al0.64As solid alloys. The waveguide claddings are formed by indium phosphide. The results of surface defects inspection and X-ray diffraction analysis of quantum-cascade laser heterostructures allow to conclude that the structural quality of the heterostructures is high and the estimated value of the root mean square surface roughness does not exceed 0.7 nm. Lasers with four cleaved facets exhibit lasing at room temperature with a relatively low threshold current density of the order of 1 kA/cm2. [ABSTRACT FROM AUTHOR]

The results of studies of 7.5–8.0 μm range surface-emitting ring quantum-cascade lasers are presented. A second- order diffraction grating with a calculated coupling coefficient of ~9 cm–1 is formed on the entire surface of the ring cavity by focused ion beam milling. Surface-emitting lasing at room temperature near 7.75 μm with a threshold current density of ~8 kA/cm2 and an outer radius of the ring cavity of 202 μm is demonstrated. The results of studying the intensity distribution in the far-field near the normal to the surface showed the presence of two maxima. It is shown that the implemented coupling coefficient is not sufficient to ensure single-mode lasing in the studied ring quantum-cascade lasers. [ABSTRACT FROM AUTHOR]

The results of studies of ring quantum-cascade lasers with surface emission due to a second-order grating formed in the top cladding layers are presented. Surface emission near 7.85 μm with a low threshold current density (3.8 kA/cm2), in comparison with ridge quantum-cascade lasers of the same cavity length is demonstrated. The results of measurements of the intensity distribution of the near and far fields at different pumping levels are presented. The estimated value of the angle of beam extraction relative to the surface normal is in the range 5.7°–6.7°. [ABSTRACT FROM AUTHOR]

An experimental technique for measuring internal optical loss in high-power edge-emitting semiconductor lasers is demonstrated. The technique is based on coupling a probe beam into the waveguide of a pulse-pumped laser diode. It allows measuring free-carrier absorption (FCA) in a laser heterostructure at different temperatures and at pump current levels up to 30 kA/cm2. Measurement results are presented for two laser heterostructure designs, which vary in the waveguide doping level and material. For both heterostructures, the pump current increase induces a significant rise in FCA and a corresponding increase in internal optical loss, from 0.4–0.7 cm−1 at the threshold current to 2–2.5 cm−1 at 15 kA/cm2. At higher temperatures, the dependence is even stronger and the internal optical loss rises to 6 cm−1 (65 °C, 27 kA/cm2). The gradient of the FCA current dependence is lower for the laser heterostructure with a doped GaAs waveguide, while the heterostructure with an undoped AlGaAs waveguide displays a larger increase in FCA but better internal quantum efficiency at high currents. These results show that the proposed experimental method has significant potential. [ABSTRACT FROM AUTHOR]

Uncooled bridge photodetectors based on InAs/InAsSbP heterostructures for the mid-IR region of the spectrum are presented. The bridge structure is distinguished by the fact that the contact pad is placed outside the photosensitive mesa and is connected to it only by an air bridge contact. This design makes it possible to reduce the area of the p–n junction and the capacitance of the device, which leads to an increase in speed without loss of detectivity. The InAs/InAsSbP heterostructures were grown by vapor-phase epitaxy on InAs substrates with (111) orientation. The developed photodetectors have maximum spectral sensitivity in the range of 2.8–3.1 μm and differential resistance at zero shift R0 = 1.0–5.6 kΩ. The capacitance of the best devices is C = 3.4–3.6 pF at Urev = 0 V. The speed of the photodetectors was studied with an InGaAsP/InP laser with emission wavelength of 1.55 μm. The response time determined from the leading edge of the photoresponse is 200 ps. The created bridge photodetectors can be used to detect laser pulses in the range of 1.1–3.8 μm. [ABSTRACT FROM AUTHOR]

The results of studying a ring surface-emitting quantum-cascade laser with radiation emission through a textured layer formed in the layers of the upper cladding of the waveguide by ultrahigh-vacuum ion-beam milling are presented. The far-field profile shows that the radiation is emitted through windows with a textured layer in the range of angles ~63°–75° to the surface normal. [ABSTRACT FROM AUTHOR]

We continue the comparative studies of high-power AlGaAs/InGaAs/GaAs semiconductor lasers with different waveguide designs. In this work, measurements were carried out for a continuous-wave mode of operation: lightâ€"current and currentâ€"voltage characteristics, threshold characteristics and their temperature dependences and crystal temperature depending on the pump current. The data obtained made it possible to reconstruct the dependences of internal optical losses and internal quantum efficiency using calculations. It was shown that the main factor affecting the power characteristics in the continuous mode of operation is the temperature stability of the laser and its relationship with internal optical losses and internal quantum efficiency. Thus, lasers based on a heterostructure with a doped GaAs waveguide with characteristic temperatures T 0 and T 1 of 120 K and 170 K, respectively, demonstrated an increase in internal optical losses to 2 cmâˆ'1 and a drop in the quantum efficiency to 90%, which led to saturation of the output power by high pump currents. Lasers based on the heterostructure with an AlGaAs waveguide, which are characterized by higher temperature stability (T 0 = 161 K and T 1 = 280 K), had lower internal optical losses and a higher quantum efficiency. This made it possible to obtain optical power 1 W higher than that for lasers with GaAs waveguides. [ABSTRACT FROM AUTHOR]

Quantum-cascade lasers with surface emission of radiation by means of a grating formed in the upper waveguide cladding layers by ion-beam milling are fabricated and studied. The active region of the laser heterostructure is based on the In0.53Ga0.47As/Al0.48In0.52As alloy alloys and uses a design with two-phonon resonance emptying of the lower level in the cascade. Room-temperature lasing near 7.9 μm is demonstrated for a laser with a ring-cavity diameter of 191 μm. The mode spacing in the lasing spectra corresponds to whispering-gallery modes. [ABSTRACT FROM AUTHOR]

Characteristics of semiconductor lasers based on asymmetric heterostructures with broadened lateral waveguide of mesa-stripe design have been studied at ultrahigh levels of pulsed current pumping. A peak power of 5.1 W was demonstrated at a drive current amplitude of 10 A. Three types of spatial dynamics of laser emission were determined: slow (~200 ns) rearrangement of the intensity along the lateral near field is characteristic of the initial level of drive currents, fast processes of mode competition (~10 ns) are characteristic of moderate drive currents, and rearrangements are not repeated from pulse to pulse, being of chaotic nature, at maximum drive currents. [ABSTRACT FROM AUTHOR]

The threshold conditions and operating efficiency of a semiconductor laser emitter with a large rectangular cavity (1 × 1 mm) based on an AlGaAs/GaAs/InGaAs heterostructure for high-power stripe lasers, which operate on high-Q internally circulating structures are estimated. Two designs of emitters with different characteristics of the laser-radiation propagation regions are proposed, and the possibility of achieving a differential efficiency that is characteristic of high-power stripe lasers (more than 70%) is shown. [ABSTRACT FROM AUTHOR]

Semiconductor lasers with a 10-μm-wide lateral mesa-stripe waveguide are developed, and their radiative characteristics are studied. It is shown that the continuous wave (cw) optical power of lasers with a 4.6-mm-long cavity reaches 2.6 W at a heat-sink temperature of 25°C. Lasers with shorter cavities (<3 mm) showed lower maximum optical powers due to thermal rollover of the light–current characteristic. [ABSTRACT FROM AUTHOR]

The purpose of the study is to investigate the effect of a new type of compliant substrates based on an AlGaAs superstructure layer (SL) and a protoporous Si (proto-Si) layer formed on a crystalline Si (c-Si) layer on the optical properties of an epitaxial GaAs layer grown by metal–organic chemical vapor deposition. It is for the first time shown that the low-temperature growth of high-quality epitaxial GaAs films can be conducted using SL/proto-Si compliant substrates. The introduction of a SL layer in addition to proto-Si into the composition of the compliant substrate makes it possible to mitigate a number of negative effects of low-temperature growth, to reduce the level of strains in the epitaxial layer, to protect it from self-doping with Si atoms, to reduce the number of technological operations of the growth of transition buffer layers, to improve the structural and morphological characteristics of the epitaxial layer, and to attain good optical characteristics of the layer. The GaAs/Si heterostructures are studied by Raman spectroscopy, photoluminescence measurements, and optical transmission–reflection spectroscopy. The data will serve as an important material for understanding the fundamentals of the physics and technology of integrated III–V/Si heterostructures and for facilitating their use in optoelectronic devices. [ABSTRACT FROM AUTHOR]

The purpose of the study is to investigate the effect of a new type of compliant substrate based on an AlGaAs superstructure layer (SL) and a protoporous Si (proto-Si) layer formed on a crystal Si (c-Si) layer on the practical implementation and specific features of the epitaxial growth of GaAs layers by metal–organic chemical vapor deposition. It is for the first time shown that the low-temperature growth of high-crystal-quality epitaxial GaAs films can be implemented due to the use of compliant SL/proto-Si substrates. The introduction of a SL into the composition of a compliant substrate in addition to proto-Si makes it possible to neutralize a number of negative effects of low-temperature growth, to reduce the level of stresses in the epitaxial layer, to protect it from self-doping with Si atoms, to reduce the number of technological operations of the growth of transition buffer layers, and to improve the structural and morphological characteristics of the epitaxial layer. [ABSTRACT FROM AUTHOR]

We have created a quantum-cascade laser with 7–8 μm wavelength and surface radiation output through a lattice formed by focused ion beam etching of the upper cladding of the waveguide. The active area of the quantum-cascade laser heterostructure was formed on the basis of the solid alloy heteropair In0.53Ga0.47As/Al0.48In0.52As with two-phonon depletion of the cascade lower level. We demonstrate laser generation in the spectral band 7–8 μm for the created lasers with the selective ring resonator. The studies of the generation spectra for the temperatures in 8–77 K range have shown, that the mode spacing in the generation spectra of these lasers correspond to the whispering-gallery modes. [ABSTRACT FROM AUTHOR]

Near- and far-fields of quantum-cascade lasers emitting in the spectral range near 8 μm have been studied. For all laser samples with a ridge width of 20 and 50 μm, lasing on the fundamental waveguide mode with a divergence of ~50° was observed for all laser samples with a ridge width of 20 and 50 μm along the "fast" axis. Along the "slow" axis, a multimode lasing and a competition between the fundamental and higher waveguide modes, which is manifested for lasers with a ridge width of 50 μm in an increase in the emission divergence from ~10° near the threshold to >50° when the lasing threshold is exceeded by a factor of 2–3. The divergence along the "slow" axis for lasers with ridge width of 22 μm remained invariable in the whole range of pumping currents and equaled ~50°. That there is a substantial contribution from the fundamental mode to the total emission intensity of quantum-cascade lasers, which is apparent from the far-field intensity distribution pattern, cannot be established exclusively on the basis of results obtained in near-field measurements. [ABSTRACT FROM AUTHOR]

We have studied the spectral and dynamic characteristics of quantum cascade lasers emitting in the long-wavelength infrared range. It is shown that lasers with a short cavity (~1 mm) make it possible to obtain frequency combs in a very wide spectral range. We have investigated the spectral dynamics in the frequency comb generation regime. It is demonstrated that the intensity of longitudinal laser modes varies during a pump pulse propagation. We have observed simultaneous generation of all longitudinal modes of a frequency comb over a pump pulse segment with a constant amplitude. [ABSTRACT FROM AUTHOR]

A cavity scheme based on a half-ring with different radii is proposed and fabricated for 7–8 μm quantum-cascade lasers. A quantum-cascade laser with a half-ring cavity radius of 191 μm demonstrated lasing with a spectral width of 474 nm (82 cm–1) at low temperatures. The free spectral range in these lasers was determined by the whispering gallery modes typical for ring cavities. The laser bandwidth at room temperature was 190 nm (31 cm–1), which may be related to an increase in the internal losses with increasing temperature. An increase in the cavity radius to 291 μm made it possible to achieve room-temperature lasing with whispering gallery modes and a bandwidth of 249 nm (40 cm–1) by reducing losses on the mirrors. [ABSTRACT FROM AUTHOR]

The spatial and temporal dynamics of the optical loss and carrier density in the heterostructure of a semiconductor laser with a segmented contact are studied using an optical pump–probe technique based on the injection of probe radiation with a wavelength of 1560 nm into a semiconductor laser chip under study that is based on an AlGaAs/InGaAs/GaAs heterostructure and emits at wavelength of 1010 nm. It is demonstrated that employing probe light at a wavelength of 1560 nm enables sensitivity in measuring an internal optical loss of no less than 1 cm–1. The segmented design of the current pumping region made it possible to estimate the absolute internal optical loss. It is shown that changing the configuration of the Fabry–Perot eigenmodes of the laser affects the carrier distribution and the internal optical loss both in the current pumping region and in the passive, current unpumped part of the laser chip. [ABSTRACT FROM AUTHOR]

The temperature characteristics of arched-cavity quantum-cascade lasers with different geometrical dimensions emitting in the spectral range of 7–8 μm are studied. The laser heterostructure was grown by molecular-beam epitaxy. The active region consisted of 50 cascades based on a heteropair of In0.53Ga0.47As/Al0.48In0.52As solid alloys. Single-mode lasing is demonstrated for lasers with the semicircular cavity segment 100 μm in diameter and the linear segment 1 mm long. The maximum side-mode suppression ratio at a temperature of 290 K was 26 dB, and the emission wavelength was 7.73 μm. [ABSTRACT FROM AUTHOR]

The method of molecular-beam epitaxy was used to fabricate an elastically balanced heterostructure of a quantum-cascade laser for the spectral range of 4.6 μm based on a heteropair of solid alloys, In0.67Ga0.33As/In0.36Al0.64As, and indium phosphide layers serving as waveguide cladding layers. An X-ray diffraction analysis demonstrated the high uniformity of the composition and thickness of layers in cascades of the heterostructure over the substrate area. Lasers with four cleaved facets show lasing at room temperature at a wavelength close to 4.6 μm with a comparatively low threshold current density of 1.1 kA/cm2. [ABSTRACT FROM AUTHOR]

A 2D carrier transport model to be used in studying the spatial current dynamics in laser thyristors is presented. The model takes into account such features as optical feedback, impact ionization, and drift velocity saturation in strong electric fields. It is shown that there is current localization during laser-thyristor switch-on. A relationship is demonstrated between the distribution nonuniformity of the control current and its amplitude and position of the initial switch-on region. The time of laser-thyristor switch-on is 13 ns at a feed voltage of 26V, with a time of switch-on spreading over the entire 200-μm stripe width of ~65 ns. These parameters remain invariable irrespective of the switch-on spatial dynamics. [ABSTRACT FROM AUTHOR]

A lumped model of the dynamics of the controlled switching of high-Q closed-mode structures in rectangular large cavities (up to 1 × 1 mm and larger) based on AlGaAs/InGaAs/GaAs laser heterostructures is presented. The model considers the modulation of the useful power of a closed-mode structure due to controlled generation switching to an alternative closed mode. Generation-switching control between closed mode structures is implemented due to a variation in the optical loss of one structure. A variation in the optical loss occurs due to an increase in interband optical absorption due to the quantum-confined Stark effect upon the application of voltage to a laser crystal segment in the closed-mode propagation region. [ABSTRACT FROM AUTHOR]

The emission characteristics of single-mode lasers based on an AlGaAs/GaAs heterostructure with an ultra-narrow waveguide are studied. It is shown that using an ultra-narrow waveguide (100 nm) and thin (70 nm) wide-gap barriers at the waveguide/cladding interface makes narrower the vertical divergence of far-field emission. The lateral and vertical divergences are 5° and 18.5°, respectively, for the narrow-stripe (5.1 μm) single-mode lasers developed in the study. The lasers demonstrate efficient single-mode operation up to a power of 200 mW. Raising the current further gives rise to higher order modes, the maximum optical power in continuous-wave lasing being limited to 550 mW by overheating. Passing to the pulsed operation mode (pulse width 200 ns) makes it possible to raise the maximum peak optical power to 1500 mW. [ABSTRACT FROM AUTHOR]

The emission characteristics of narrow mesa-stripe (5.5 μm) lasers based on asymmetric AlGaAs/GaAs heterostructures are studied. It is shown that the maximum optical power achieved in the continuous-wave (CW) operation mode is limited by heating and reaches a value of 1695 mW at a current of 2350 mA at +25°C, with the maximum efficiency reaching 54.8%. Reducing the working temperature to –8°C makes it possible to raise the maximum low-mode CW power to 2 W. A peak power of 2930 mW is obtained under pumping with current pulses (width 240 ns, amplitude 4230 mA). It is shown that the power profile has in the pulsed mode an "optical dip" region in which low-efficiency lasing occurs with the generation of a train of subnanosecond pulses. [ABSTRACT FROM AUTHOR]

We have studied the generation of frequency combs by quantum cascade lasers (QCLs) emitting in the 8-μm wavelength range. Results showed the presence of a self-pulsation regime near the lasing threshold. Further increase in the pumping current led to a sharp increase in width of the lasing spectrum, which allowed us to obtain frequency combs with a spectral width exceeding 1.5 THz. This behavior of QCLs can be explained by radiation absorption at the stripe edge that is related to the penetration of waveguide mode into unpumped regions. [ABSTRACT FROM AUTHOR]

Molecular beam epitaxy techniques were used to grow a quantum-cascade laser (QCL) heterostructure based on an In0.53Ga0.47As/Al0.48In0.52As heteropair lattice-matched with an InP substrate. InP layers were used to form an optical waveguide. The obtained QCL heterostructure ensured room-temperature lasing in the 8-μm wavelength range at a maximum output optical power of 0.45 W from one facet in a standard ridge geometry of the Fabry–Pérot cavities formed by cleaved facets. [ABSTRACT FROM AUTHOR]

This study is concerned with the specific features of how high-Q closed modes operating on the total-internal-reflection effect in large-size (up to hundreds or thousands of wavelengths) rectangular resonators based on InGaAs/GaAs/AlGaAs laser heterostructures are formed. The specific features of the spectral composition and spatial configurations of closed-mode configurations are experimentally examined. The presence of frequency combs in the spectra is demonstrated and their correspondence to the separate spatial configurations of closed modes is shown. The effect of changing the pumping level and the temperature on the mode composition of the emission is also considered. [ABSTRACT FROM AUTHOR]

A method of determining the spatiotemporal dynamics of current in semiconductor heterostructures is proposed that is based on the modulation of external probing radiation transmitted through the crystal. The proposed method has been verified on semiconductor laser thyristors based on AlGaAs/InGaAs/GaAs heterostructures. The results of this experiment qualitatively coincide with the results of previous measurements of the device on-state dynamics. [ABSTRACT FROM AUTHOR]

Abstract: The characteristics of semiconductor chip modulators providing the angular deflection of a laser beam due to all-electric modulation of the optical characteristics of a semiconductor heterostructure are theoretically studied. Designs for quantum-confined semiconductor waveguide heterostructures with a distributed Bragg reflector integrated on the heterostructure surface are developed. The design of a waveguide structure including 20 periods of coupled asymmetric quantum wells, which provide an optical confinement factor of the waveguide mode of 20%, and an optimized doping profile allowing a uniform electric-field distribution to be maintained in the quantum-well region in the entire range of operating voltages are proposed. In this waveguide structure, the change in the refractive index due to the quantum-confined Stark effect reaches 0.086 when the control signal changes from 0 to 6 V. It is shown that the spatial (angular) scanning of the laser beam emitted from the surface of a distributed Bragg mirror with a divergence of less than 0.1° in the range of 1°-2° is feasible for the proposed waveguide structure design. [ABSTRACT FROM AUTHOR]

Single-mode lasing at room temperature in quantum-cascade lasers (QCLs) with arched cavity design has been demonstrated. The output optical power in single-mode lasing regime at ~7.7-μm lasing wavelength was above 6 mW with a side-mode suppression ratio of up to 25 dB. The QCL heterostructure for the arched cavities was grown by molecular-beam epitaxy (MBE) based on a heterojunction of In0.53Ga0.47As/Al0.48In0.52As solid alloys, lattice-matched with InP substrate, and InP layers performing the function of waveguide claddings. [ABSTRACT FROM AUTHOR]

Abstract: Lasing of quantum cascade lasers is demonstrated at a radiation wavelength of 8100 nm at room temperature. Analysis of oscillograms of optical pulses is used to determine dependence of mean and peak radiation intensities on current. A delay of turn-on of quantum cascade lasers is experimentally estimated at a level of two times higher than the lasing threshold to be greater than theoretically estimated delay by several orders of magnitude. [ABSTRACT FROM AUTHOR]

Design parameter optimization of a chip based on a heterostructure with a surface diffraction grating for laser beam angle modulation was carried out. It was found that the widest field of view is achieved at outcoupling angles close to the total internal reflection. The highest energy efficiency is provided by using epitaxy Bragg reflector on the substrate side. It is shown that using a multiple quantum well that gives electro-optic refractive index modulation by 0.007 and second-order surface diffraction grating with a period of 317 nm provides laser beam steering in a range of 5°, with resolution of 130 points at a wavelength of 782 nm.

It is shown that the use of low-voltage GaAs/AlGaAs thyristors as high-speed and high-current switches in vertical stacks with semiconductor lasers ensures the efficient generation of high-power ns-duration laser pulses. The lasing and current dynamics in vertical stacks based on laser diode mini bar emitting at 1060 nm and a single as well as a double thyristor switch is studied. The possibility is demonstrated that a laser diode mini bar (with 3 laser emitters) together with a single thyristor switch can generate laser pulses with a peak power of 6 W with a duration of 950 ps and a peak current of 12 A for an operating voltage of 28 V. The use of a double thyristor switch leads to a broadening of the current pulse due to different delays in turn-on of the thyristor switches, while the peak power and duration of laser pulses increase to 8 W and 1.4 ns, respectively. It is found that the stage of low-speed turn-on of the thyristor limits the efficient generation of current and laser pulses of ns duration at low operating voltages (less than 21V). An efficient generation of current and laser pulses by low-voltage thyristors at control currents of 2-320 mA is ensured by efficient impact ionization in the region of the reverse biased p-n junction at high values of operating voltages (more than 21V).