Infrared laser performance and self-frequency-doubling of ytterbium doped yttrium calcium oxyborate crystal pumped by a fiber-coupled laser diode

Summary form only given. As a novel ytterbium laser material and nonlinear optical crystal, Yb:Ca/sub 4/YB/sub 3/O/sub 10/ (Yb:YCOB) has the advantage of easy growth, long radiative lifetime, high quantum efficiency, low quantum defect, and the possibility of self-frequency-doubling. Previously we reported over 10 mW of laser output using a polarisation coupled pump scheme with a 100 /spl mu/m pump spot size. According to the quasi-three-level laser model of Taira (1977), a high power/high brightness pumping source should be used to decrease the pumping threshold and increase the slope efficiency. We report the low threshold, high slope efficiency infrared laser output of a Yb:YCOB crystal pumped by a 1.6 W 50 /spl mu/m fiber-coupled 977 nm laser diode for the first time. Self-frequency-doubling green light was also observed.