Abstract
We demonstrated laser operation at 2.8 μm in a monolithic Er, Cr: YSGG laser pumped by a laser diode
with a silica optical fi ber. Under a condition where the pumping beam spot sizes ranged from 90 μm to
140 μm using a 100-μm or a 200-μm core diameter fiber, we achieved maximum slope efficiency.
During continuous operation, the output power reached 1.09 W at an incident power of 4.5 W without
any active cooling. When the laser diode is driven by a square wave current where the repetition
frequency ranged from 10 Hz to 10 kHz, the average output power of the higher frequency with a lower
duty ratio decreases because of the delay of the pulse start timing.
