Abstract

The experiments discussed in this paper were designed to verify the theory of two coupled lasers as developed by Spencer and Lamb. The experiments employed a pair of coupled half-symmetric unstable resonators which shared a common flat coupling mirror. The use of half-symmetric unstable resonators results in a compact coupling configuration with a minimum number of mirrors as well as single-mode operation. A beam splitter-coupled configuration was used to verify the theoretical predictions, which included measurements of the near- and far-field outputs, measurement of the mutual coherence of the output beams, and measurements of the locking range as a function of the coupling strength. The width and characteristic shape of the tuning curves and the observed rf beats outside the phase-locked operating region were in excellent agreement with the theoretical predictions. Additional experiments were then performed with hole-coupled resonators to provide a more complete picture. In both experiments, single supermode operation was obtained with a locking range that increased with coupling strength.

© 1985 Optical Society of America