Optically induced pulse delay in a solid-state Raman amplifier

Abstract
The pump-induced group velocity reduction of subnanosecond pulses is calculated and measured in a Ba(NO3)2 solid-state Raman amplifier. 1.197 μm probe pulses with 90 ps duration were generated using a Raman-shifted mode-locked and Q-switched Nd:YAG laser, and propagated through a Ba(NO3)2 crystal synchronously pumped by 7-ns-long 1.06 μm pulses. The time delay of the pulse peak was measured with varying pump intensity and was compared with theoretical calculation up to the point where amplified spontaneous Raman emission becomes dominant. The maximum time delay was found to be 105 ps.