Reflection efficiency and response relaxation time in degenerate four-wave mixing in the active media of TEA CO2 lasers

An experimental investigation was made of the reflection by a nonlinearity from gain saturation in the active medium of a TEA CO₂ laser under degenerate four-wave mixing conditions. A new mechanism of relaxation of the response to such a nonlinearity was identified and processes with submicrosecond and subnanosecond relaxation times were found in CO₂. The saturation intensities for these processes and the conditions for achieving high reflection intensities as a result of such a mixing were determined.