A watt-level efficient continuous wave Er:YAP laser at 2.92 μm

A watt-level continuous wave (CW) operation at 2.92 μm with near quantum defect slope efficiency was demonstrated by the diode-pumped Er doped YAlO3(YAP) laser. The high slope efficiency of 30% was achieved with the maximum output power of 0.95 W. This value is the 91 % of theoretical quantum defect efficiency. Those results show that an Er:YAP laser has the great potential to achieve the high power mid-IR laser.