Abstract

We demonstrate optically bistable (light switching light) operation in a room-temperature InGaAsP Fabry-Perot amplifier. The amplifier is an InGaAsP/InP laser structure biased at ~95% of its lasing threshold. It is switched with <3 μW of optical power provided by the mechanically chopped output of a quasi-single-mode InGaAsP/InP laser. The experimental apparatus is depicted in Fig, 1. A change in the refractive Index in the amplifier of only 5 × 10⁻⁴ is sufficient to cause switching. Input and output pulses from the nonlinear amplifier are shown in Fig. 2 when the source frequency is initially detuned by 14 GHz from the closest Fabry-Perot mode of the amplifier. Smaller switching powers are required at lesser detunings. The physical mechanism of the intensity-dependent change of the refractive index is thought to be the change in carrier density resulting from stimulated recombination of free carriers.

© 1985 Optical Society of America