A tunable optical wavelength demultiplexer (10) has a plurality of
demultiplexer units (113, 114, 115, 116) formed on a planar waveguide
(111). Every demultiplexer unit comprises a plurality of input waveguide
channels, a plurality of output waveguide channels, and a Bragg grating,
said each input waveguide channel coupling with the Bragg grating at a
different angle, and each output waveguide channel being a mirror image of
a corresponding input waveguide channel. Bragg gratings of demultiplexer
units are parallel each other. Corresponding input waveguide channels are
parallel to each other. An adjustable mechanism (100) adjusts an input
port (25) and output ports (271, 272, 273, 274) to couple with a desired
input waveguide channel and corresponding output waveguide channels.
