Raman silicon laser based on a nanocavity fabricated by photolithography

Abstract

Fabricating silicon photonics devices by CMOS-compatible processes is important for applications. Here, we demonstrate a Raman silicon laser based on a heterostructure nanocavity that was fabricated by immersion photolithography using an argon fluoride excimer laser. The Raman laser confines the pump light and the Stokes Raman scattered light in two resonant modes of the nanocavity. By using the presented CMOS-compatible approach, sufficiently high quality-factors can be obtained for both modes. The sample whose frequency spacing of the two resonant modes closely matches the Raman shift of silicon, achieves continuous-wave oscillation with a lasing threshold of 1.8 µW at room temperature.