High-Q resonant modes in a photonic crystal heterostructure nanocavity and applicability to a Raman silicon laser

When a heterostructure is created at the center of a photonic crystal line-defect cavity to form a nanocavity, the photonic band gap contains several high-quality (Q) factor resonant modes. We have studied the optical properties of these modes to examine their applicability to Raman silicon lasers, which require two high-Q resonant modes with a frequency spacing of 15.6 THz. Our experimental and numerical analyses reveal four types of resonant modes. We demonstrate that pairing the resonant mode originating from the first-order propagation mode with that arising from the second-order propagation mode is the most promising approach toward the realization of Raman silicon lasers.