High-efficiency blazed grating couplers

Abstract

High-efficiency blazed grating couplers have been successfully realized by using an ion etching technique. We observed that a guided wave was radiated as the leaky wave which appears selectively either above or below the grating depending on the direction of the propagation of the guided wave. The coupling efficiency from the guided wave into one of the leaky waves was about 97% at the blaze angle of 30°.