Experimental Verification of Numerically Optimized

Abstract—We present the experimental measurement of a photonic crystal (PhC) device comprising an injector, Y-splitter, and 60 bend. The complete device consists of a 9- m-long in-jector tapering down from 5 m into a triangular-lattice-of-holes single-line defect waveguide with period = 430 nm and 36.2% air filling factor (corresponding to a radius over period (r/a) ratio of 0.30), an optimized Y-junction, 60 bend and output injectors, with a total device footprint of 30 m. This is etched into a GaAs/AlGaAs heterostructure using chlorine/argon chemically assisted ion beam etching (CAIBE). An erbium-doped fiber am-plifier (EDFA)-based source and Fabry–Perot technique are used to characterize the device. The device displays a bandwidth of approximately 110 nm in the 1.55 m window, and a transmission of 70 % relative to the same length of 5- m-wide waveguide. This is compared with three-dimensional finite-difference time-domain (3-D FDTD) results, which have a bandwidth and transmission of 120 nm and 75%, respectively. The highlight of this paper is the close agreement of the numerically optimized complete microcircuit with its experimental equivalent, and the significant improvement in bandwidth over previous work on Y-junctions. Index Terms—Chemically assisted ion beam etching (CAIBE), Fabry–Perot resonance, input coupling, numerical optimization, photonic crystals (PhCs). I