The authors present the results of research on the use of bireftingent filter as a spectral selector in the laser cavity, especially in the short-pulse lasers. The study was carried out on the tunable ultraviolet solid-state Ce:LiCAF (280-320 nm) and inftared Cr:LiSAF (780-900 nm) lasers. As a result, the obtained results showed clearly the dynamics of spectral narrowing in narrow-band laser emissions, and therefore, provided better understanding of the solid-state lasers in broadband and tunable laser operations. Additionally, it is also indicates the characteristics when using bireftingent filter as a spectral selector in laser technology.