Methods for switching radiation polarization in GaAs laser diodes

Operation modes of laser structures with controlled polarization of light have been studied and the results of measuring polarization characteristics are presented. The possibility of controlling both the linear and circular polarizations of light with corresponding modification of the laser design is shown. In particular, stable lasing at two orthogonally polarized modes in the near-IR range with the intensity ratio of radiation components $I_{\mathrm{TE}}/I_{\mathrm{TM}}\approx$ 4.5 is implemented. The possibility is confirmed of generation of circularly polarized radiation in edge-emitting laser diodes by magnetization of a combined semitransparent mirror with a ferromagnetic CoPt layer deposited on the end face of the laser cavity. The degree of polarization is $\pm$1.25% in the CoPt layer saturation magnetization mode.