A series of low-voltage thyristor current switches based on (Al)GaAs/GaAs homo- and heterostructures with a volume charge region formed in the lightly doped p-GaAs base layer have been developed. The transient processes characteristics in pulse generation mode of nanosecond duration have been studied. It has been shown that the use of a wide-bandgap barrier based on AlGaAs at the n‑emitter/p-base junction allows reducing the minimum control current amplitude from 30 to 3 mA, and the turn-on delay time can be shortened to 6 ns. For the developed thyristor switches, a minimum transition time of 3.7–3.9 ns was demonstrated when operating in a circuit with a 1 nF capacitive load. In a circuit with a nominal 1 Ω resistive load, the thyristor switches provided a peak current of 17.5 A with a pulse duration of 3.7 ns.

A comparison is made of conventional pin photodetectors and modern uni-traveling-carrier photodetectors based on InGaAs/InP heterostructures. The differences in the designs of heterostructures of these photodetectors are considered and the resulting features of their functioning are analyzed. It is shown that with comparable photosensitivity, the saturation photocurrent of uni-traveling-carrier photodetectors is approximately four times greater than that in conventional pin photodetectors. Devices with a photosensitive area 40 mu m in diameter reach the saturation current at an input optical power of 10-12 and 60-70 mW for pin and uni-traveling-carrier photodetectors, respectively (reverse bias voltage of 5 V).

A comparison is made of conventional pin photodetectors and modern uni-traveling-carrier photodetectors based on InGaAs/InP heterostructures. The differences in the designs of heterostructures of these photodetectors are considered and the resulting features of their functioning are analyzed. It is shown that with comparable photosensitivity, the saturation photocurrent of uni-traveling-carrier photodetectors is approximately four times greater than that in conventional pin photodetectors. Devices with a photosensitive area 40 μm in diameter reach the saturation current at an input optical power of 10–12 and 60–70 mW for pin and uni-traveling-carrier photodetectors, respectively (reverse bias voltage of 5 V).

We report the fabrication of 1.5–1.6 μm light-emitting modules based on an AlGaInAs/InP heterostructure with strain-compensated quantum wells in new, smaller, thermally stabilized housings. Their performance is tested under extreme operating conditions. The reliability of such modules and stability under the influence of climatic factors is studied.

Current switches based on low-voltage InP heterothyristors with a maximum blocking voltage of 20 V were developed and studied. In current pulse generation mode, the efficient operation of InP heterothyristors with a low-resistance load in the form of a capacitor was demonstrated. It has been shown that the minimum turn-on delay time is about 6 ns at a control current amplitude of 60 mA. The possibility of generating current pulses with a duration of 53–154 ns and amplitudes of 38–130 A was demonstrated when the capacitor values were changed in the range of 56–1000 nF.

Current switches based on low-voltage InP heterothyristors with a maximum blocking voltage of 20V were developed and studied. In current pulse generation mode, the efficient operation of InP heterothyristors with a low-resistance load in the form of a capacitor was demonstrated. It has been shown that the minimum turn-on delay time is about 6 ns at a control current amplitude of 60 mA. The possibility of generating current pulses with a duration of 53–154 ns and amplitudes of 38–130 A was demonstrated when the capacitor values were changed in the range of 56–1000nF.

The influence of a thin AlInAs energy barrier on the efficiency of 1550 nm high-power semiconductor lasers efficiency has been experimentally studied. It was shown that the position and number of barriers in an asymmetric laser heterostructure based on a 1.8-1.9 mu m thick waveguide has a significant effect on the output optical power. It is shown that in a barrierless structure, the main reason for radiative efficiency decrease is internal quantum yield drop due to the absence of an energy barrier for the type-II heterojunction at the waveguide-pcladding interface and electron leakage to the p-emitter layer. It is demonstrated that the implementation of single AlInAs energy barrier layer on waveguide-p-cladding heterojunction allows significantly increase laser diode maximum output power. 2 W maximum CW optical power has been achieved from 40 mu m aperture laser diode at heatsink temperature 25 degrees C.

A UTC photodetector based on InGaAs/InGaAsP/InP heterostructures grown by MOCVD is demonstrated. A model of the band diagram of the photodetector is proposed. Energy barriers that reduce the rate of hole removal from the absorbing layer are shown. A solution to reduce these barriers and increase the holes velocity is proposed.

The output characteristics of $1.3-1.6\ \mu \mathrm{m}$ high-power single-frequency DFB-lasers with a laterally coupled Bragg diffraction grating were experimentally studied.

Compact superluminescent diodes based on AlGaInAs/InP separate-confinement double heterostructures with strain-compensated quantum wells are studied. The characteristics of these diodes that allow their application for development of fibre-optic gyroscopes in a temperature range from – 55 °C – +70 °C are demonstrated. The devices demonstrate an acceptable reliability and a potential for further improvement.

High-power semiconductor lasers based on AlGaInAs/InP heterostructures and emitting in the spectral range 1.9−2.0 μm are developed. Strain compensation in the active region makes it possible to use InGaAs quantum wells with a compressive strain of about 2.0 %−2.5 %. The operation of a laser with an ultra-narrow waveguide at wavelengths increasing from 1.4−1.6 to 2.0 μm is studied. At room temperature, the semiconductor lasers with a stripe contact width of 100 μm demonstrates a cw output optical power of 1.0 W with a wavelength of 1.91 μm at a pump current of 6.5 A and with a wavelength of 1.98 μm at a pump current of 7.2 A.

Semiconductor lasers based on AlGaInAs/InP heterostructures with ultra-narrow and asymmetric waveguides are comparatively studied. It is shown that the use of these waveguides with a simultaneous increase in the quantum well depth makes it possible to increase output powers. Such lasers based on both strongly asymmetric and ultra-narrow waveguides with a stripe contact width of 100 μm demonstrate an output power of 5 W (at pump currents of 11.5 and 14 A, respectively) in a continuous-wave regime at room temperature and a wavelength of 1450 – 1500 nm.

Исследованы выходные характеристики мощных одночастотных лазеров с распределенной обратной связью с боковой брэгговской дифракционной решеткой. Приведены рекордные значения энергетических и спектральных характеристик одночастотных РОС-лазеров.

High-power 1.5-1.6-mu m semiconductor lasers with an asymmetric periodic optically coupled waveguide are developed and their current-voltage, light-current, and spectral characteristics are experimentally studied. The characteristics of these lasers are compared with the characteristics of traditional lasers based on double separate-confinement heterostructures. It is shown that the developed lasers have lower divergence and almost the same threshold and power characteristics as conventional lasers with Fabry-Perot resonators. The developed lasers with a cavity length of 1.6 mm and a mesa-stripe contact width of 3 mu m mounted in a housing 11 mm in diameter have a power no lower than 200 mW at a pump current not exceeding 700 mA with a divergence of 25-35 degrees versus 45 degrees typical for conventional lasers.

High-power laser diodes based on Al x Ga y In 1-x-y As/InP heterostructures emitting in the region of 1.5 - 1.6 μm are actively used in various fields of human activity. This requires continuous improvement of their performance in the considered spectral range. The use of an strain-compensated active region with a compression stress in the quantum well corresponding to +1.4 % and tensile stress in the barrier layer corresponding to -0.8 % allowed to increase of internal and external differential quantum efficiency and obtain laser diodes with cw output power 4.2 W at 15 A. The output power in a pulsed regime reached 20 W (100 ns, 5 kHz) at a pump current 80 A.

Semiconductor lasers based on AlGaInAs/InP heterostructures with an ultra-narrow waveguide and an increased electron barrier layer are developed. It is shown that the use of this waveguide in conjunction with profiled doping ensures a balance between internal optical losses and heat resistance. Additional use of strained wide-bandgap layers as blocking barriers limiting electron leakage from the active region makes it possible to increase the output power at the same pump current. The developed lasers with a stripe contact 100 μm wide demonstrate at room temperature an output optical power of 4.0 – 4.4 W (pump current 14 A) in a continuous-wave regime and 15 – 17 W (100 A) in a pulsed regime (100 ns, 1 kHz) at wavelengths of 1450 – 1500 nm.

Superluminescent diodes based on AlGaInAs/InP separate-confinement double heterostructures with strain-compensated quantum wells are investigated. The influence of elastic strains in the active region on the output characteristics of the devices is analysed. It is shown that such a design of a superluminescent diode allows an optical power of more than 5 mW, a radiation spectrum width of more than 60 nm, a degree of output radiation polarisation up to 30 dB to be obtained at the output of a single-mode fibre, and has a great potential for further improvement.

This paper presents an experimental study of AlGaInAs/InP semiconductor lasers with different barrier layers. The use of strained layers with an increased band gap as blocking barriers limiting carrier leakage is shown to increase the output power of the lasers at a given pump current.

The compositions of epitaxial layers forming quantum-well heterostructures AlxGayIn1-x-yAs / InP for laser diodes with the radiation wavelength of 1.55 μm are calculated. When carrying out the calculations, the problem was to provide the maximum height of the energy barriers for effective limitation of charge carriers in the quantum wells. Along with taking care of the effects of the dimensional quantization of the energy of free charge carriers in allowed zones, the effect of elastic stress in epitaxial layers on the displacement of the edges of the energy bands were taken into account in the calculation. It is shown that in order to solve the posed problems it is necessary to form heterostructures with elastic compression stress in a quantum well and elastic tensile stress in the barrier layers. As a result of the calculations the authors suggest a structure that includes a barrier layer of Al0.28Ga0.30In0.42As with a thickness of 110 Å and a quantum well Al0.03Ga0.23In0.74As in a layer with a thickness of 55Å (with the mismatch between the parameters of the crystal lattice and the InP substrate - 0.8% and + 1.4 %, respectively). According to the calculation results, the indicated thicknesses of epitaxial layers do not exceed the critical values that can lead to the formation of imperfect dislocations at heterointerfaces.

Выполнены расчеты составов эпитаксиальных слоев, формирующих низкоразмерные гетероструктуры Al x Ga y In 1-x-y As/InP для лазерных диодов с длиной волны излучения 1.55 мкм.При проведении расчетов ставилась задача обеспечения максимальной высоты энергических барьеров для эффективного ограничения носителей заряда в квантовых ямах.Наряду с эффектом размерного квантования энергии свободных носителей заряда в разрешенных зонах, учитывалось влияние упругих напряжений в эпитаксиальных слоях на смещение краев энергетических зон.Показано, что для решения поставленных задач необходимо формирование гетероструктур с напряжениями упругого сжатия в квантовой яме и напряжениями упругого растяжения в барьерных слоях.Предложена структура, включающая барьерный слой Al 0.28 Ga 0.30 In 0.42 As толщиной 110 Å и квантовую яму Al 0.03 Ga 0.23 In 0.74 As в слое толщиной 55 Å со степенями рассогласования параметров кристаллической решетки с подложкой InP -0.8% и +1.4%, соответственно.По результатам расчетной оценки, указанные толщины эпитаксиальных слоев не превышают критических значений, способных привести к образованию дислокаций несоответствия на гетерограницах.