S.V. Boritko, I.B. Kutuza, U.P. Konstantinov, А.Е. Otlivanchik

The results of studies of the active element of the system and semiconductor pump of solid state lasers are presented. The acousto-optical spectrometer is used. Raman spectra of active elements used in neodymium-doped YAG lasers allowed us to estimate spatial distribution of the mean concentration of the activator ions and its heterogeneity (the deviation from the mean). Spectral and spatial distribution of radiation intensity of diode array Silver Bullet ASM06C020 «NORTHROP GRUMMAN» (sample was taken out from the laser system which didn-t satisfy spectral characteristics) showed that although the longitudinal distribution of spectral intensity is constant, but angle distribution varies. This leads to different efficiency of pumping along the active element and therefore inhomogeneous heating produces thermal lens and birefringence. So, single-mode, single-frequency generation with a small width of the emission spectrum are difficult to achieve.