Change in the Properties of AlGaN/InGaN/GaN Structures during the Operation of Electron-Beam-Pumped and Optically Pumped Pulse-Periodic Lasers Based on Them

During the operation of lasers based on an AlGaN/InGaN/GaN structure with electron-beam- and optical pumping, a gradual decrease in the output power is observed. In the first minutes of the operation of optical pumping lasers, a certain increase (by 5–10%) in the output power with a successive gradual decrease can be observed. Upon sample cooling, the rate of output-power degradation decreases. A decrease in the output power during operation of the laser is accompanied by changes in the emission spectrum—the line maximum shifts to the short-wavelength region and additional maxima appear. The observed effects can be explained both by the passivation of the initial defects and the diffusion of atoms of the structure during laser operation. The changes in the emission spectra are apparently associated with competition between two different generation channels.