Optical waveguide device

Abstract

In An optical waveguide device, an output light reflected by a reflective groove can be monitored with a phase identical to a signal light. The optical waveguide device includes a substrate; an optical waveguide formed in a plane of the substrate and having a normal line with a predetermined angle relative to an optical axis of the optical waveguide; a reflective groove formed on the optical waveguide; and a monitor device to monitor an output light reflected by the reflective groove, wherein the reflective groove has as much depth as approaching a half or less of a mode field of a waveguided light propagated through the optical waveguide, to reflect a portion of the waveguided light.

Dependencies are inferred from the claim text.