Measurement of the phase difference between the output beams of two coupled CO2 lasers

Measurements were made of the phase difference between the output beams of two coupled CO₂ lasers operating in a coherent regime. The results of the experiments are in qualitative agreement with calculations performed on the basis of a point model of two coupled lasers, taking the gain dynamics into account. The dependences of the phase difference on the mismatch of the resonator lengths and on the length of the coupling channel should be useful when constructing a phase-matched set of lasers and an optical guidance system linked to it.