Electrooptic modulation of multisilicon-on-insulator photonic wires

This paper proposes and analyzes electrically modulated submicrometer-size high-index-contrast waveguides (photonic wires) based on a multisilicon-on-insulator (MSOI) platform. Metal-oxide-semiconductor junctions are used to control the effective refractive index of the waveguides. The electrooptic structures are electrically and optically modeled. The performances of the studied configurations are analyzed and compared in terms of phase modulation efficiency, optical losses, and operation speed, and the feasibility of their fabrication is discussed. Calculations indicate that the proposed schemes can be used to achieve highly efficient phase shifters (V/sub /spl pi//L/sub /spl pi//<1 V-cm) based on photonic wires on MSOI, with data transmission rates ranging from 3 to 10 Gb/s.

I. Introduction

Micro (nano) photonics is a promising candidate to overcome limitations of micro(nano) electronics, particularly those concerning speed of processing and transmission of information on a chip. The use of a proper photonic material is essential for microphotonic circuits to be commercially competitive. Silicon is transparent in the range of optical telecommunications wavelengths (1.3 and 1.55 ) and has a high-refractive index, which permits the miniaturization of photonic devices [1]. In addition, Si-based materials are process compatible with standard fabrication techniques (bipolar or complementary metal–oxide–semiconductor (CMOS) technology), which facilitates the fabrication and commercialization of Si-based integrated optoelectronic circuits. For this purpose, Si-on-insulator (SOI) substrates provide an excellent platform. The use of crystalline Si (c-Si) instead of polysilicon (poly-Si) or amorphous Si for light guiding reduces scattering and absorption losses [2]. Besides, the importance of SOI is increasing in the microelectronics field for high-speed and low-power applications [3], making it ideal for the simultaneous integration of electronic and photonic components on the same chip.