Analysis of Raman effect in chalcogenide and silicon waveguides

• Main Author: Zhou, Hongtao.
• Other Authors: Shum Ping
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Antennas, wave guides, microwaves, radar, radio
• Online Access: http://hdl.handle.net/10356/45809
• Institution: Nanyang Technological University

The development in the monolithic integration of chip-scale photonic devices has been hindered by the lack of efficient light amplification and lasing components. Recently, stimulated Raman scattering (SRS) process has been proposed as a possible solution to obtain optical gain inside waveguides. However, the detrimental nonlinear loss strongly limits the performance of silicon-based active devices such as Raman amplifiers and lasers. As presented by recent experimental and theoretical works, chalcogenide material (As2Se3 in particular) possesses significantly greater Raman gain than silica and negligible free carrier absorption (FCA) nonlinear loss comparing to silicon, which is almost ideal for SRS-based high efficiency light emitting. In this final year project, we conduct a theoretical study on the light amplification, lasing and relative intensity noise (RIN) transfer characteristics of chalcogenide Raman amplifier (CRA) and laser (CRL). Theoretical model with a set of time-independent wave-propagating equations is constructed and RIN is modeled as small amplitude modulation of the mean power. The equations are solved numerically by computer programs for the mean power and the noise level inside the waveguides. A series of analyses regarding key performance parameters including the pump power, waveguide length, noise frequency, etc. are carried out. The obtained results on CRA and CRL are then compared with the well-established silicon Raman amplifier (SRA) and silicon Raman laser (SRL) with the same waveguide dimension and simulation parameters. Based on our comprehensive numerical analysis, we show that CRA and CRL outplay their silicon counterpart in terms of energy efficiency and noise performance. In addition, dual-pumping scheme is proposed and verified to be an effective RIN suppression configuration for CRL and SRL.