Arrayed waveguide grating having a reflective input coupling

An arrayed waveguide grating for spatially separating an optical signal including a plurality of wavelength channels comprising:

• a substrate for supporting an integrated arrayed waveguide grating formed therein including:
• an input planar waveguide, having an input plane at an edge of the substrate and an output plane, for propagating a wavefront from an input point on the input plane to an output plane;
• a grating comprising an array of waveguides optically coupled to the output plane of the input planar waveguide for receiving the wavefront, an optical length of the waveguides differing by a substantially equal amount from a first waveguide to an nth waveguide;
• and,
• an output planar waveguide for focusing separated wavelength signals on an output plane of the output planar waveguide for coupling to output waveguides;
• an input assembly for launching a signal into the integrated arrayed waveguide grating including:
• at least one input waveguide disposed on a plane substantially parallel to the input planar waveguide having a waveguide end for launching a signal into an input point on the input planar waveguide;
• a lens assembly including lens means symmetrically disposed between the coupled input point and the waveguide end of a selected one of the at least one waveguide, and a reflective element optically coupled to the lens means, the lens assembly for providing a lateral offset to a signal propagating from the input waveguide to the planar waveguide, and for focusing a reflected input signal at the input point of the input planar waveguide.