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Optical loss and polarization characteristics of the photonic crystal stick waveguide resonator modes were investigated using both theory and experiment. A stick waveguide resonator with 12 missing air holes was found to have a very high Q(>3 800 000) mode originating from the lossless guided mode below the light line. Photoluminescence spectra show sharp resonance peaks at regular intervals in k space, satisfying the resonant condition. Linear polarizations parallel or perpendicular to the waveguide were observed, depending on the mode symmetry. This polarization selection is explained in terms of the far-field cancellation effect of the in-plane field components.

Square lattice photonic crystal single defect nanocavity structures are formed in free-standing slab InGaAsP materials emitting near 1.55 μm. Laser operations are achieved from two types of resonant modes, a degenerate dipole mode and a nondegenerate whispering-gallery-like mode. Each laser mode is identified by the measurement of mode shapes, quality factors, and polarization. The threshold absorbed pump power is estimated to be less than 0.2 mW for the whispering gallery mode. It is found, by rate equation analyses, that nonradiative surface recombination, which takes >60% of carrier recombination near threshold, is one of the main limiting factors for the low-threshold operation of photonic crystal single defect lasers.

This work is supported by the National Research Laboratory Project, Nano Research and Development program of Korea and NICOP program of the Office of Naval Research.