Low Dispersion On-Chip Hollow Waveguide for High Data Rate Applications

Abstract

Low loss structures for guiding light pulses for on chip communication is the major challenge for the application of high data rate. As time is moving ahead high data rates are becoming the un-escapable for transfer of large data on chip and to overcome the interconnection bottle-neck. In an effort to move this important issue along, the thesis work mainly concentrates on the analysis of engineering of hollow waveguides for being used at higher data rates. Hollow waveguides engineered with high contrast gratings (HCG) have been comprehensively studied over the years due to its diverse application in optoelectronics devices. One of the innovative forms of grating is high-index contrast grating (HCG). It is possible to control the dispersion loss of light in waveguide by optimizing the HCG parameters. Review of the recent advances in HCG grating and its application for high data rate optoelectronic devices is done. From application point of view the dissertation pave the way for realizing low dispersion for high data-rate transmission. A proficient structure of HCG based hollow waveguide (HWG) on SOI is proposed. The presence of three material i.e. silicon-air-silicon oxide grating on top silicon layer in SOI allows a strong interaction between the guided mode and the grating. The design of high data rate hollow waveguide is presented by optimizing the various grating parameters like grating thickness (tg), grating period (˄), waveguide core thickness (d) and refractive index contrast of grating. Optimizing all the parameters the design is then analysed over a wide range of data rates. Design and simulation of waveguide is done in MATLAB using RCWA (Rigorous Coupled wave analysis) and SVFD (Semei-Vectorial Finite Difference) method. Dispersion of 15.14 ps/nm/km is observed at data rate of 40 gbps. The proposed characteristics of the device arise from the engineered structure of hollow waveguide.