Inverse Raman Scattering in Silicon
Abstract
Stimulated Raman scattering is a well-known nonlinear process that can be harnessed to produce optical gain in a wide variety of media. This effect has been used to produce the first silicon-based lasers and high-gain amplifiers. Interestingly, the Raman effect can also produce intensity-dependent nonlinear loss through a corollary process known as inverse Raman scattering (IRS). Here, we demonstrate IRS in silicon--a process that is substantially modified by the presence of optically-generated free carriers--achieving attenuation levels >15 dB with a pump intensity of 4 GW/cm^2. Ironically, we find that free-carrier absorption, the detrimental effect that suppresses other nonlinear effects in silicon, actually facilitates IRS by delaying the onset of contamination from coherent anti-Stokes Raman scattering. The carriers allow significant IRS attenuation over a wide intensity range. Silicon-based IRS could be used to produce chip-scale wavelength-division multiplexers, optical signal inverters, and fast optical switches.
Cite
@article{arxiv.0810.1939,
title = {Inverse Raman Scattering in Silicon},
author = {D. R. Solli and P. Koonath and B. Jalali},
journal= {arXiv preprint arXiv:0810.1939},
year = {2008}
}