Abstract

Slab optical waveguides are well suited for the monolithic achievement of various sensing and optical preprocessing functions.¹ They are of practical usefulness only if free-space beams can easily be coupled to/from the waveguide. Grating coupling is the only access technology compatible with the symmetry and technology of planar waveguides. In the main two noncommunication applications of integrated optics (opto-chemical sensors² and displacement sensors³), there is a need for coupling a single freespace beam to two guided sensing modes² and conversely.³

© 1994 IEEE