Raman generation with resonant periodic nanopatterns.

We provide a new approach to Raman generation in silicon. Thus, we design and fabricate periodic nanophotonic devices incorporating guided-mode resonance to implement and enhance Raman photon generation. We apply one-dimensional gratings located between two distributed Bragg reflectors for feedback and improved efficiency. Operating in a single polarization state, by spectral and angular tuning, two resonance lines exhibit the proper spectral Raman separation for silicon. The efficiency of Raman photon generation can be enhanced by the resonance Q factor of two split resonant modes with proper grating parameter selection. With the pump at 1529 nm, we detect a Raman signal at 1660.4 nm. This wavelength separation corresponds to a Raman shift of 15.527 THz, which is close to the nominal Raman shift in silicon at 15.606 THz. The Raman generation experimental results match well with the theoretical analysis of split resonance modes enabled by the angular tuning technique. These results demonstrate that Raman enhancement using the guided-mode resonance effect is feasible.