LOW-LOSS, SINGLE-MODE, OPTICAL-PHASE MODULATOR IN SIMOX MATERIAL

This paper reports results of the simulation of an optical phase modul ator. The proposed modulator consists of an elongated p-i-n structure fabricated in a silicon-on-insulator material such as SIMOX. It utiliz es the free-carrier effect to produce the desired refractive index cha nge in a single-mode optical rib waveguide. The MEDICI two-dimensional semiconductor device simulation package has been employed to optimize the overlap between the injected free carriers and the propagating op tical guided mode. Although the device is designed to support a single optical guided mode, it measures several micrometers in cross section al dimensions, thereby simplifying fabrication and allowing efficient coupling to/from other single-mode devices. Furthermore, the device ha s an extremely high figure of merit, predicting over 200 degrees of in duced phase shift per volt per millimeter, as well as a low drive curr ent of less than 10 mA. This is approximately an order of magnitude lo wer than most other reported devices in silicon.