Laser linewidth narrowing induced by amplifier gain saturation.
We demonstrate that temporal broadening of transform-limited nanosecond pulses during gain saturation in a Nd:YAG amplifier can produce substantial linewidth narrowing. Measurements of linewidths with two-color Doppler-free saturated spectroscopy in I(2) show reductions in linewidth by more than a factor of 2.5 from 58 to 20 MHz when a double-pass amplifier is used. The observed temporal broadening is described well by a simple gain saturation theory.
G W
GW
Faris
M J
MJ
Dyer
W K
WK
Bischel