Nonlinear dynamics of a CO2laser with current modulation and cavity detuning

A detailed numerical study of the dynamic behaviour of a CO2 laser under current modulation and cavity detuning has been performed on the basis of the complete laser model which takes into account vibrational–vibrational and vibrational–rotational energy exchanges in the active medium. We have shown that due to a relatively fast decrease in the laser response with increasing modulation frequency, nonlinear regimes (period doubling and chaos) can be obtained with cavity detuning either from the line centre or near the laser threshold. Comparison is made with a two-level equation model for the active medium.