A 3 × 2 waveguide switch based on SiGe for C-band operation

Abstract

A waveguide switch structure with three input and two output ports is designed in SiGe/Si material for the operation around 1.55 μm in wavelength. Strained Si 0.96Ge 0.04 layer with a thickness of 2.5 μm is used as the waveguide core layer. Single mode ridge waveguide of 10 μm wide and 1μm deep is formed by plasma etching. The switching functi aaon is realized by total internal reflection. Two separate electrodes are used to control the refractive index change in the intersection region through carrier injection. The switch device can also work as splitter, modulator, or add-drop multiplexer, etc. around wavelength of 1.55 μm. An extinction ratio of about 20 dB is achieved for the modulation state from the two side input ports and about 10dB for the central input port.