2-D array wavelength demultiplexing by hybrid waveguide and free-space optics

We demonstrate wavelength demultiplexing into a raster-scanned 8×9 array by combining a 1×8 arrayed waveguide grating with a free-space grating multiplexer. 9 diffraction orders from each AWG output are separated onto a 2D array on an InGaAs camera or coupled into a scanned output fiber. This first proof-of-principle device had 0.2 nm channel -20 dB width, >35 dB spectral extinction and 15 to 25 dB insertion loss over the 70 nm operating range.