Silicon-on-Insulator Spectral Filters Fabricated With

Abstract—We give an overview of recent progress in passive spec-tral filters and demultiplexers based on silicon-on-insulator pho-tonic wire waveguides: ring resonators, interferometers, arrayed waveguide gratings, and echelle diffraction gratings, all benefit from the high-index contrast possible with silicon photonics. We show how the current generation of devices has improved crosstalk levels, insertion loss, and uniformity due to an improved fabrica-tion process based on 193 nm lithography. Index Terms—Arrayed waveguide grating (AWG), echelle grat-ing, nanophotonics, photonic wire, planar concave grating (PCG), ring resonator, silicon-on-insulator (SOI), silicon photonics. I