Computer Simulation of Nonlinear Propagation Characteristics of CO2 Laser Pulse

Abstract

The characteristics of pulse propagation through the CO₂ laser system LEKKO II are analysed numerically using a MELCOM COSMO 700 II digital computer. The amplifiers are treated with a Frantz and Nodvik type rate equation model, and the SF₆ saturable absorbers are treated with a phenomenological model based on the measurement of energy transmission. The computed results are compared with the observed data on the pulse energy, the rise time of the pulse and the pulse duration (FWHM). It is found that the pulse peak is delayed when the incident pulse energy is relatively small because of the nonlinear absorption chracteristics of SF₆; but proceeds effectively when the incident pulse energy is relatively large because of the nonlinear amplification characteristics of CO₂ lasers.