Simulation on cross-switching of an all-semiconductor-optical-amplifier nonlinear loop device

Pulsed-signal cross-switching operation of an all-semiconductor-optical-amplifier nonlinear optical loop device is numerically investigated. The device consists of a loop amplifier, a multimode-interference waveguide amplifier (MMIWA), an input leg, and an output leg. With the combined mechanisms including nonlinear coupling in the MMIWA, lateral field redistribution and amplification by the loop, and asymmetric gain/phase modulation between two counterpropagating signals in the loop, the device operates with efficient power-dependent switching. Simulations are conducted using a modified time-domain traveling-wave method for the interplay between the two counter-propagating signals in MMIWA and loop.