P. G. Eliseev

InGaSbAs injection lasers

Double heterojunction structures of InGaSbAs/GaAl-SbAs emitting at 300 K in the wide wavelength range of 1.8-2.4 \mu m have been prepared by the LPE technique on gallium antimonide

Multicomponent solid-solution semiconductor lasers

Properties of a new hetetrostructure based on quaternary alloys are presented in application to semiconductor lasers. Room temperature laser operation is obtained near 1.06 and 1.8 μm with injection pumping and near 2 μm with electron-beam pumping.

Suppression and spectral splitting of the amplitude noise due to mode beatings in a single-frequency injection laser

Investigations of intensity fluctuations in a single-frequency injection laser showed that they are due to beatings between coherent field and superluminescent spontaneous emission. It has been experimentally found that in the region of developed laser emission, the level of fluctuations is decreased with an increase of the output power, and so the relative spectral shift of external cavity superluminescent mode frequenices is dependent on the laser output power. The explanation of this phenomenon was made on the basis of the mechanism of a nonlinear interaction of a field in the active region of a laser diode. It has been shown that the fluctuation level is over the shot noise level by less than 4 dB when the laser output power is sufficiently large, about 6 mW.

Injection lasers for multichannel optical communication

Injection lasers are suitable sources of radiation for optical communication systems. The output characteristics of III-V compound and mixed crystal III-V compound injection lasers for 0.64-1.1-\mu spectral range are described. In order to improve the spectral output (and to increase the threshold for the appearance of adjacent modes) composite cavities were successfully used. Such a cavity contains the diode and a passive transparent flat plate, which serves as an additional selective component in the feedback circuit of the laser. A 96-channel telephone link was tested in the laboratory using four lasers (wavelengths 0.74, 0.78, 0.85, and 0.91μ) in one beam. The method of combining and separating the four spectral channels at the transmitter and receiver, respectively, as well as the results of the experiments are described.

Degradation of injection lasers during operation and under the influence of fast particles

A study was made of the degradation of injection lasers, some of which were subjected to bombardment with fast particles. It was found that the radiation defects did not accelerate the aging process during prolonged operation of the lasers. The fall of the output power after tests lasting 104 h did not exceed 23%.

STATISTICAL DISTRIBUTION OF THE FAILURE OF INJECTION LASERS

The statistics of the failure of injection lasers was investigated experimentally in the pulsed mode at 300°K and it was compared with the Weibull distribution. A satisfactory agreement was obtained for a form parameter of 2. The influence of the repetition frequency on the average service life was investigated.

EMPIRICAL ESTIMATION OF THE SERVICE LIFE OF INJECTION LASERS FROM SHORT-TERM TESTS

It is shown that an effective method for selecting long-life injection lasers can be based on the initial rate of rise of the threshold current. This gives better results than the selection in accordance with the initial parameters. The aging mechanism is assumed to consist of the formation of new nonradiative recombination centers in the process of recombination of excess carriers.