A.2.5 GHz-spaced 1080-channel tandem multi/demultiplexer covering the. S-, C-, and L-bands using an arrayed-waveguide grating with Gaussian passbands as a primary filter

We describe a low-loss 25-GHz-spaced multi/demultiplexer with more than 1000 channels that covers the S-, C-, and L-bands of optical fiber amplifiers. It was achieved by cascading a 2.5-THz-spaced arrayed-waveguide grating (AWG) with Gaussian passbands as a primary filter and ten 25-GHz-spaced 1/spl times/200 AWGs as secondary filters in a tandem configuration.