In this paper, a model program has been established to investigate the amplified spontaneous emission (ASE) in the nd: glass disk amplifier with the Monte Carlo method and rays tracing.

After analyzing all the factors which determine gain of a laser diode array (LDA) pumped Nd glass rod amplifier, the optimum parameters are presented.

Allowances are made for the effects of multiple reflections on the reflector and laser rod, Xe flashlamp emission spectrum and absorption spectrum of nd doped laser glass.