The photocurrent effect in pin silicon waveguides at 1550 nm wavelength is experimentally investigated. The photocurrent is mainly attributed to surface-state absorption,defect-state absorption and/or two-photon absorption.Experimental results show that the photocurrent is enhanced by the avalanche effect.A pin silicon waveguide with an intrinsic region width of 3.4μm and a length of 2000μm achieves a responsivity of 4.6 mA/W and an avalanche multiplication factor of about five.
A magneto-optical(MO)metal-sandwiched multilayered structure composed of metal,MO medium and dielectric buffer layers is presented and investigated by finite-element-method-based-mode solver and perturbation theory.The results show that this structure exhibits large nonreciprocal phase shift,strong mode confinement in the narrow buffer layers as well as very low propagation loss.The propagation length with 1dB loss is much longer than the required length of𝜌π/2 nonreciprocal phase shifts in this structure.The modal area is smaller than half of the conventional MO waveguides.This phenomenon can be used to achieve a compact plasmonic isolator based on the Mach–Zehnder interferometer.
