Characteristics of delayed amplification of free-oscillation pulses of an iodine photodissociation laser. Control of pulse duration

An experimental study was made of nonlinear amplification of free-oscillation pulses of an iodine photodissociation laser when pump pulses were applied to the amplifier either synchronously or in advance of the iodine laser pulses. The duration of the amplified pulses decreased strongly and the peak output power jose from 10³ W/cm² to over 10⁶ W/cm² when the input pulse reaching the amplifier was delayed by a time interval close to the duration of the amplifier pump pulses. A considerable part of the trailing edge of the amplified pulse became strongly attenuated and this was due to nonpyrolytic transition of the active medium of the amplifier to an absorbing state, which was attributed to the quenching of the excited atoms by molecular iodine.