Spectroscopy and laser performance of in-band pumped Er:LLF and Er:YLF crystals

Spectroscopic properties and continuous-wave laser performance of in-band pumped Er:LiLuF
₄
and Er:LiYF
₄
crystals were investigated. For Er:LiLuF4 crystal maximum slope efficiency of 44 % was obtained at 1609 nm wavelength. Er:LiYF4 crystal laser operation was demonstrated for the first time under in-band pumping. Output power of 58 mW and slope efficiency of 21 % at 1606 nm were achieved.