Abstract

Silicon photonics offers the potential for low-cost integration of optoelectronic components for a wide range of applications, from telecommunications and interconnects to optical sensing and biomedical applications. Recently, stimulated Raman scattering has been studied as a means to achieve light amplification and lasing in silicon, and a continuous-wave silicon Raman laser was developed using a silicon waveguide with a p-i-n diode to reduce nonlinear optical loss associated with two-photon absorption induced free carrier absorption [1], Single frequency operation can be achieved in silicon Raman lasers with high spectral purity [2], which is particularly useful in high resolution laser spectroscopy applications. In addition, the lasing wavelength is 15.6 THz red-shifted from the pump wavelength, which allows the silicon Raman laser to access wavelengths which are important for trace gas analysis and toxic gas monitoring but for which room-temperature semiconductor lasers are not widely available. Here we demonstrate continuous (mode-hop free) tuning of a single-mode silicon Raman laser over more than 20 GHz range which is broad enough to cover typical molecular transitions in gasses at room temperature, and allows us to perform absorption spectroscopy measurements of methane.

© 2007 IEEE