The description is given of the study and research a modular-type training complex for studying the radiation of semiconductor lasers generated in the region of 400 – 950 nm. Structurally, the complex consists of emitter modules (there are 8 of them in the presented set, but in principle their number is not limited by anything), power and control modules, registration modules, and some additional measuring equipment to provide research on the energy, spectral, spatial, polarization and dynamic characteristics of the output radiation. The modular structure provides high variability of the complex and allows you to implement (in the presented version) more than 40 laboratory works, and also allows students to get skills in working with modern equipment and different data processing methods. This complex is focused on educational activities, but on its basis it is possible to carry out research work up to the second stage of higher education. A number of laboratory works based on the use of the complex have been tested at the department of laser physics and spectroscopy of the physics faculty of the Belarusian State University.

Based on statistical modeling, a numerical analysis of the effects exerted by different factors (fluctuations of the spontaneous emission intensity, nonequilibrium carrier concentration, injection current density) on the statistical characteristics of radiation at the output of surface emitting semiconductor lasers in the region of polarization instability has been performed. In this region the effect of fluctuations is maximal, offering the possibility for substantiated conclusions about relative effects of the parameters. In a theory of semiconductor lasers it is thought that the intensity fluctuations of spontaneous emission represent the dominant source of fluctuations, whereas all other sources may be neglected. As demonstra ted by the results of conducted statistical modeling, this statement is too rigorous; moreover, such a source is not dominant. Taking into consideration fluctuations of the carrier concentration, which result in fluctuations of the amplification factor, we can derive a complete set of the relationships observed experimentally. This result cannot be associated with features our model because in our theory spontaneous emission is a significant factor. If the influence of spontaneous emission would be the dominant factor, it would affect the simulation results. The obtained data make it possible to doubt the key role of the spontaneous emission intensity fluctuations in the process of statistical characteristics formation for the output radiation and to take into account fluctuations of the nonequilibrium carrier concentration.