AlGaAs-based two-dimensional photonic crystal slab with defectwaveguides for planar lightwave circuit applications

摘要

An AlGaAs-based near-infrared 2-D photonic crystal (PC) with annair-bridge structure featuring defect waveguides has been developed. Fornthe sample without defect waveguides, measurements of the opticalntransmission characteristics in the wavelength range from 850 nm to 1100nnm showed a deep attenuation due to a bandgap with 30-35 dB attenuationnand transmittance of nearly 100% for the guided modes. Opticalnpropagation properties of defect waveguides were obtained by twonmethods: measurements of transmission spectra and plan-view observationsnof the optical beam trace along the waveguide with an infrared-vidiconncamera. 3-D finite-difference time-domain simulations for the bandnstructure and transmission spectra in the air-bridge slab with andnwithout defect waveguides have revealed the appearance of four defectnpropagation modes specific to the defect waveguide, between two slabnmodes for the defect-free photonic crystal slab. These defect modes werenexperimentally identified in the measured transmission spectra