J. Arnaud

Optic communications, Vol 68, n°6, novembre 1988

ABSTRACT

Yamamoto and others are shown when the pump (or injected current) fluctuations of a laser diode are suppressed, the optical power fluctuations are much reduced, but the laser linewidth remains essentially unchanged. We find that for a realistic extended laser model, the linewidth may in fact be importantly reduced. Our finding is based on a semiclassical theory. With full shot-noise in the injected current, the linewidth is proportional to (1 + α2) av, where α (z) denotes the phase-amplitude factor, and the average is evaluated along the diode z-axis. Without injected current fluctuations, one must substract from this expression half the variance (α2) av – (αav)2 of α. The linewidth reduction thus occurs only if α varies significantly along the diode.

LIEN VERS  L’ARTICLE : CONTRIBUTION OF SHOT NOISE TO LASER DIODE LINEWIDTH