An 1GW high power iodine photodissociation laser amplifier series is designed. The amplifier series consists of oscillator, first pre-amplifier, second pre-amplifier, and main amplifier. The characteristic output of the first preamplifier is investigated and analyzed. In order to investigate the characteristics of the first pre-amplifier the oscillator is made to operate with $TEM_{00}$ mode and 80 torr $i-C_3F_7I$. The multiple firing performance of a single $i-C_3F_7I$ filling in the first pre-amplifier is made, and a quasi-equilibrium state appears to be possible after 20 to 30 firings. The maximum output energy from the first pre-amplifier is 540mJ when the pressure of $i-C_3F_7I$ is 80 torr.
Pulse propagation in an amplifier is investigated both experimentally and by computer calculation. Computer calculation is based on a simple two level model, and the pulse form of the oscillator output is assumed to be square-top, Gaussian, and modified Gaussian. A 50nsec modified Gaussian pulse is sharpened to 42nsec by calculation and 43nsec by experiment.
In this research the pressure broadening coefficient of argon buffer gas is measured using laser gain technique. For small signal measurements, the length and the operating voltage of amplifier are fixed to 10cm and 18.0KV, respectively. The result obtained from 6 independent measurements is (6.89±0.44)MHz/torr.
