Optical Y-junctions and S-bends formed by preferentially etched single-mode rib waveguides in InP

Abstract

Single-mode optical Y-junctions are demonstrated in epitaxial n−/n+ InP. The rib waveguides with rectangular cross-section have been made using wet chemical etching in an HCI:H3PO4 preferential etchant. The minimum measured loss due to the branching point is approximately 1 dB for Y-junctions with a branching angle of 0.9° at the tip.