OCIS codes: (230.5298) Photonic crystals; (140.3945) Nanocavities; (140.5960) Semiconductor lasers

Abstract

Abstract: We propose a point-shifted nanocavity based on square lattice photonic crystal, which sustains a lowest-order whispering-gallery (WG) mode. In simulation, the optimized WG mode (quality (Q) factor ~14,000) in point-shifted nanocavity can be with smaller mode volume (~5.5(λ/2n) 3 ) but larger nano-post tolerance than those in single-defect cavity design. From well-fabricated device, single WG mode lasing with measured Q factor of 4,100 and low threshold of 160 µW is obtained. Besides, we also observe the changed polarization of WG mode due to modal symmetry breaking caused by the presence of a nearby dielectric nano-particle, which would be useful in sensing molecule binding or attaching for bio-chemical applications. (C ©2010 Optical Society of Americ