Two-dimensional GaAs photonic switch array with direct gain and high contrast

The fabrication and design of a 4×4 surface-normal reflection photonic switch array, with an operating principle based on the change of the gain coefficient in GaAs, is described. A 3-μm-thick GaAs active layer and carrier confinement layers are sandwiched between a semiconductor multilayer reflector and an antireflection window. The beryllium ion implantation technique is used to make a narrow current path to reduce the operation current. Each photonic switch independently realizes direct amplification and absorption of the optical signal. It features an optical gain of 4 dB and a contrast of 9.6 dB, for an applied voltage of 2.2 V. The array has a simple planar structure