Theoretical stability analysis of single-mode operation in uncontrolled mode-selection semiconductor lasers

An uncontrolled mode-selection laser is a laser containing an intracavity filter under which the cavity mode alignment is uncontrolled. We present a theoretical stability analysis of the single-mode operation of uncontrolled mode-selection semiconductor lasers. We find that to maximize the stability the cavity length and intracavity filter bandwidth must be minimized, and a specific, nonzero, linewidth enhancement parameter must be chosen. For a given cavity mode spacing to filter bandwidth ratio, a shorter cavity is more stable.