Stray light suppression structures using a waverguide and angled, deep etched trendches filled with an absorbing material

摘要

The present invention relates to an optical waveguide structure comprising a waveguide input section (14) and a waveguide output section (16), at least one of which having a straight geometry, and a single trench (26) formed adjacent to one of said sections (14, 16). The trench is adapted to absorb stray light within said structure and extends obliquely relative to the adjacent section (14, 16).