Phase-locking of semiconductor injection lasers

The problem of phase-locking of several semiconductor injection lasers via mutual coupling was investigated. The equations of motion of the parameters of both individual lasers and an array of lasers were derived considering both coupling via field overlapping and interactions via the active media. The solution of the equations was outlined and the conditions for obtaining phase-matching were derived. The sign of the coupling constraints must be negative, and its magnitude must be greater than the standard deviation of the laser transition frequency deviations. The actual magnitude of the coupling coefficients in several configurations were calculated, and the results indicate that is possible, although not trivial, to achieve the coupling conditions.