An experimental investigation was made of the dependence stimulated emission threshold GaAs–AlAs injection lasers on duration pumping pulses in 2–100 nsec range. The effective lifetime injected electrons determined for with one diffused p–n junction (~1 nsec), heterojunction (~2.5 and two heterojunctions (3–6 nsec).

An investigation was made of the spectral composition radiation emitted from a cw stripe AlGaAs–GaAs injection heterolaser operating at room temperature in an external dispersive resonator. Narrow-band (Δλ≤0.15 nm) stimulated emission with output power up to 20 mW obtained. The tunable range ~10 nm centered on wavelength 884 and this case maximum single-frequency 4 mW. Excitation several longitudinal external-resonator modes (within limits narrow band) accompanied by rf intensity...

The results are given of an experimental investigation the catastrophic and slow degradation heterojunction lasers. It is shown that failure occurs when average density optical energy flux (2–4)106 W/cm2 local 107 W/cm2. Depending on this density, service life lasers can range from several minutes to 100 h or longer: be regarded as extreme case under action radiation. Heterojunction emitting pulses ≥ 10 W power, nsec duration, 6 kHz repetition frequency work for more than without suffering a...

Reaction of lithium oxide with solutions uranium tetrachloride was studied in LiCl (at 750 °C) and LiCl– KCl 550 based melts. The effect the initial Li2O : UCl4 molar ratio on degree precipitation, phase composition particle size precipitates determined.

Results are presented of an experimental investigation the radiative characteristics single-channel semiconductor injection lasers operated under cw conditions (77°K) with different active region widths (1.5–11μ). It is shown that two-sided horizontal confinement region, using Ge-doped layers AlxGa1–xAs solid solution, makes it possible to produce a structure exhibiting good waveguide properties and low leakage currents. A study was made threshold, spectral, watt-ampere radiation field...

Solubility of rare earth oxides in mixtures alkali or alkaline halides was determined by the method isothermal saturation at temperatures up to 1400 o C. The melts studied included CaCl 2 –CaF (20 75 mol. % CaF ), BaCl –BaF (15 73 BaF equimolar and eutectic NaCl–NaF mixtures. Melting points salt were differential thermal analysis effect added oxide on melting point considered. yttrium, lanthanum, cerium, praseodymium, neodymium, samarium determined. temperature, melt composition, presence a...

The rare earth oxides (REO) have emerged as important insulating materials. Thin films are used in a wide variety of components optical and electronic devices. REO exhibit good dielectric properties, thermal chemical stability. electrical resistivity the is order 10/sup 14/-10/sup 16/ /spl Omega/ cm constant range 12-13. Knowledge breakdown mechanism can be for design thin film capacitors, varactors, transistors switching elements with memory. In present report we discuss results study...

Interaction between metallic uranium and rare earth oxides, i.e. neodymium oxide, were investigated using thermodynamic modeling experimental exposures at 1300–1500 °C. It was shown that partly reduced oxide resulting in formation of dioxide film prevented a uniform ingot formation. Increasing temperature led to higher degree reduction further complicated the separation from metal. Direct smelting cannot be used for fissile materials extraction mixture components obtained during nuclear fuel...

Solubility of neodymium oxide was determined in molten salt systems based on CaF2–BaF2 (50 mol. %), CaCl2–CaF2 (20 (75 BaCl2–BaF2 (15 (73 %) and NaCl–NaF (34 mixtures at 700–1400 °C. Temperature dependencies the solubility were calculated. Maximum observed melts.

The results are given of an experimental investigation the principal parameters active regions injection lasers with diffused or epitaxial p–n junctions and GaAs–AlAs heterojunctions. It is shown that heterojunction region bounded on both sides have better characteristics: Their gain factor 10−2 cm/A, inversion current density 2.1 kA/cm2, losses amount to 26 cm−1.

An investigation was made of the dependence threshold current density and differential quantum efficiency AlAs-GaAs heterojunction lasers on width active region. It found that excitation higher modes reduced when region increased.

An investigation was made of the operation a YAG:Nd$sup 3+$ laser excited by pulse-injection semiconductor lasers emitting at wavelengths 0.81 and 0.88 $mu$. The flat end an active rod pumped. room-temperature thresholds rods 1 mm dia 20 long 2 were 1times10$sup -4$ 3.7times10$sup J, respectively. A study emission when rate pumping twice threshold value. stimulated from Nd$sup ions spiky nature: duration each spike did not exceed $mu$sec power carried could reach 100 mW.

Results are presented of an experimental investigation the polarization characteristics radiation from single-channel GaAs injection lasers. It is shown that cw lasers operated at T=77°K emit linearly polarized over a broad range currents. On application uniaxial pressure perpendicular to p-n junction plane, plane oscillations vector E rotated through 90° and in which this rotation occurs depends on width emitting area.

Objective: To improve the integrity of running and dynamic testing results force impact on track, basis modern facilities data logging wireless transmission from rotary elements a car, as well change indirect to direct methods measurement. Methods: Comparative tests track were held simultaneously same section using three vertical side forces, that is Schlumpf (State Standard R 55050-2012), “RZhD-2016” “NVTs-TKP” methods. The key difference third method was application strain-gauge set wheels...

Initial results are presented on the fabrication of laser diodes for wavelength range 0.9 to 1.1 μm based 9- and 11-layer InxGa1–xAs/GaAs/AlGaAs heterostructures grown by hydride-MOCVD technology. Calculations show that a prespecified (e.g., λ =0.98 μm) can be obtained over wide ranges compositions (0.1≤X≤0.4) active-layer thickness (4 nm≤Lz≤25 nm). We discuss choice optimal parameters as function reproducibility growth. Emitters fabricated λ=0.95–1.016 promise development. They exhibit no...

A study was made of the operation an injection heterolaser at high pulse repetition frequencies. It found that such possible up to 5 MHz for pulses 0.02–0.05 μsec duration. An average output power 200 mW (in one direction) obtained. The thermal resistance (15–30 deg/W) and overheating active region (up 150°C) were determined.