There is a large opto-galvanic effect (OGE) in CO2-N2-He laser mixtures and this is exploited in laser frequency and power stabilisation systems. Two substantially different theories have been advanced to explain the effect. The two models are compared and it is concluded that the multi-step ionisation model is not adequate to describe the OGE in CO2 lasers, but the temperature perturbation or discharge cooling model describes the phenomenon with considerable precision.
- CO2-laser impedance fluctuations
- opto-galvanic effect