Patent ID: 6917730
Filing Date: 2005-07-12
Classification: G02B

Abstract:
1. An arrangement for providing optical coupling between an external light source generating optical signals at a plurality of different wavelengths, the plurality defined by a wavelength range and a center wavelength, and a relatively thin, planar silicon optical waveguide, the arrangement comprising: an evanescent coupling layer disposed over at least a portion of the planar silicon optical waveguide, the evanescent coupling layer exhibiting a refractive index less than the refractive index of silicon and having a substantially constant thickness of an average value selected for minimizing optical loss over the wavelength range associated with the external light source; and a silicon-based prism coupling structure disposed over the evanescent coupling layer, the prism coupling structure including an input facet formed at a predetermined angle with respect to the waveguide surface and an output facet formed at the predetermined angle with respect to the waveguide surface, the prism coupling structure further including a planar lower surface disposed over the evanescent coupling layer.