Broadly Tunable and Passively Mode-Locked Operations of Yb3+,Gd3+:SrF2 Laser

Both tunable and passively mode-locked laser oscillators based on an efficient Yb,Gd:SrF
₂
crystal are reported for the first time. Charge compensation ions of Gd
³⁺
enhanced the emission and absorption cross section of Yb,Gd:SrF
₂
crystal markedly. With the aid of birefringent filter, a 61.1-nm continuous-wavelength-tunable laser from 1020.2 to 1081.3 nm was obtained, making it a potential candidate for ultrafast lasers. Based on a semiconductor saturable absorber mirror, a diode-pumped passively mode-locked laser with the pulse width of 951 fs was realized. The oscillator operated at a repetition rate of 92 MHz.