Period doubling in directly modulated InGaAsP semiconductor lasers

Abstract

We report on period doubling in a directly modulated InGaAsP semiconductor laser at 1.3 μm. This behavior is obtained for modulation frequencies between fr and 1.6fr, where fr is the laser resonant frequency measured under weak current modulation. The domain of period doubling as well as the time responses of the optical output is well interpreted using a rate equation model.