Tm: Y2SiO5 Crystal: Effective Material for the Generation of Eye-Safe Laser Sources.

We report on continuous-wave and passively Q-switched Tm: Y2SiO5 (YSO) crystal lasers. For continuous-wave operation, a maximum output power of 3.23 W is achieved at 1969.8 nm with slope efficiency of 34.3%. The results represent the best laser performance that ever obtained in Tm3+-doped oxyorthosilicate materials. Effective continuous-wave lasers have been also obtained at 1976.0, 1972.9, and 2044.6 nm by using differently coated output couplers. Using Cr: ZnSe saturable absorber, passively Q-switched Tm: YSO lasers are realized at 1944 and 2022 nm, for the first time to our knowledge. The maximum average output power has reached 0.74 W with pulsewidth of 78.3 ns and the corresponding pulse energy is 71.8 μJ. The present results indicate that Tm: YSO lasers could be very potential as sources for 2-μm eye safety related applications. [ABSTRACT FROM AUTHOR]