Passive Q-switching and nonlinear spectroscopy of Cr4+: (Ca,Sr)Gd4(SiO4)3O crystals

Abstract

Cr4+-doped crystals are known as lasing media for tunable solid state lasers in the near infrared spectral range as well as useful passive Q-switches for several solid-state lasers. These applications motivate an active search for new crystal hosts doped with the Cr4+ ion. Recently, room temperature laser action have been demonstrated for Cr4+-doped SrGd4(SiO4)3O (Cr4+:SrGdSOAP) and CaGd4(SiO4)3O (Cr4+:CaGdSOAP) crystals at 1.44 µm and 1.37 µm, respectively.