Novel ultrasmall Si-nanowire-based arrayed-waveguide grating interleaver with spirals

A novel layout is presented to achieve an ultrasmall arrayed-waveguide grating (AWG) interleaver based on Si-nanowire waveguides. Spiral waveguides are inserted in the middle of arrayed-waveguide to obtain a large lightpath (required for the ultra-high diffraction order) in a small occupied area. A designed ultrasmall AWG interleaver with a free spectral range of 0.8 nm has a total size of only about 73 μm × 372 μm (0.027 mm2).