Observations of Spontaneous Raman Scattering in Silicon Slow-light Photonic Crystal Waveguides

TL;DR

This paper demonstrates enhanced spontaneous Raman scattering in silicon photonic crystal waveguides, showing significant nonlinear enhancement due to slow-light effects, with detailed measurements of wavelength and power dependence.

Contribution

It reports the first observation of Raman scattering enhancement in silicon photonic crystal waveguides utilizing slow-light effects for the first time.

Findings

Stokes emission increased up to five times in slow-light regions

Enhanced Raman scattering observed at the Bragg gap edge

Nonlinear enhancement confirmed in silicon photonic crystal waveguides

Abstract

We report the observations of spontaneous Raman scattering in silicon photonic crystal waveguides. Continuous-wave measurements of Stokes emission for both wavelength and power dependence is reported in single line-defect waveguides in hexagonal lattice photonic crystal silicon membranes. By utilizing the Bragg gap edge dispersion of the TM-like mode for pump enhancement and the TE-like fundamental mode-onset for Stokes enhancement, the Stokes emission was observed to increase by up to five times in the region of slow group velocity. The results show explicit nonlinear enhancement in a silicon photonic crystal slow-light waveguide device.