A novel design of devices based on the thermo-optic effect in silicon on insulator (SOI) waveguides is presented. In order to evaluate accurately the temperature distribution and speed of the device, the heat transfer equation is to be solved numerically. It will be shown in this paper how the new thermo-optic waveguide structure, in which air trenches are made, can improve the performance of the thermo-optic device. In addition, a new formula for calculating the phase shift induced by the thermo-optic effect is proposed. | TẠP CHÍ KHOA HỌC VÀ CÔNG NGHỆ Tập 48, số 6, 2010 Tr. OPTIMAL DESIGN OF THERMO-OPTIC DEVICES ON THE SILICON-ON-INSULATOR PLATFORM LE TRUNG THANH ABSTRACT A novel design of devices based on the thermo-optic effect in silicon on insulator (SOI) waveguides is presented. In order to evaluate accurately the temperature distribution and speed of the device, the heat transfer equation is to be solved numerically. It will be shown in this paper how the new thermo-optic waveguide structure, in which air trenches are made, can improve the performance of the thermo-optic device. In addition, a new formula for calculating the phase shift induced by the thermo-optic effect is proposed. Keyword. Thermo-optic effect, silicon on insulator, optical devices 1. INTRODUCTION In recent years, silicon on insulator (SOI) technology has been used for the design and implementation of various integrated-optic devices. It is because the fabrication of such devices requires only small and low cost modifications to existing fabrication processes. SOI technology is compatible with existing complementary metal–oxide–semiconductor (CMOS) technologies for making compact, highly integrated and multifunction devices [1]. The SOI platform uses silicon both as the substrate and the guiding core material. The large index contrast between Si ( n Si = at wavelength 1550 nm) and SiO 2 ( n SiO2 = ) allows light to be confined within submicron dimensions and single mode waveguides can have core cross-sections with dimensions of only few hundred nanometers and bend radii of a few micrometers with minimal losses. Moreover, SOI technology offers potential for monolithic integration of electronic and photonic devices on a single substrate. A variety of photonic devices have been designed and realized on the SOI platform, including lasers [2], high speed optical modulators [3] and optical switches [4]. Active devices on the SOI platform such as optical switches, filters and modulators rely on either
