Tunable laser utilizing LiF : $F_2^+$ color centers in LiF and a holographic selector

An efficient and continuously tunable laser was constructed utilizing $F_2^+$ color centers in LiF crystals. The laser had a holographic total-internal-reflection selector and it operated at room temperature at a high pulse repetition frequency. The tuning range was 0.85–1 $\mu$ for a line less than 0.06 nm wide. The efficiency of conversion of the energy absorbed in a crystal was about 10%.