Low-loss photonic crystal defect waveguides in InP

Abstract
We have fabricated high-quality planar photonic crystal defect waveguides in InP/InGaAsP material. Using Fourier analysis of the Fabry-Pérot fringes obtained in transmission, we derive the propagation losses. Values as small as 1.8 dB/mm for waveguides consisting of three rows of missing holes (W3) were measured. We believe that the reduction in losses is due to the high quality of etching carried out using a high beam voltage–current ratio regime of chemically assisted ion-beam etching.