Tunable Cr/sup 4+/:YSO Q-switched Cr:LiCAF laser

Tunable passive Q-switching (781 nm to 806 nm at 300 K) of a flash-lamp pumped Cr/sup 3+/:LiCaAlF/sub 6/ (Cr:LiCAF) laser with a Cr/sup 4+/:Y/sub 2/SiO/sub 5/ (Cr/sup 4+/:YSO) broad-band solid-state saturable absorber has been realized. Typical pulse widths of the Q-switched laser output ranged from 40 ns to 80 ns, depending on the lasing wavelength. Spectral narrowing and reduced beam diameter with the use of the saturable absorber were observed. The ground state and the excited state absorption cross sections of the Cr/sup 4+/:YSO absorber were found by bleaching experiments to be (7.0/spl plusmn/1.4)/spl times/10/sup -19/ cm/sup 2/ and (2.3/spl plusmn/0.5)/spl times/10/sup -19/ cm/sup 2/ at 694 nm, respectively. Numerical simulation was utilized to simulate the Cr:LiCAF passive Q-switching with Cr/sup 4+/:YSO solid-state saturable absorber.>