Patent attributes
An optical power monitor comprises: an array waveguide grating comprising first and second optical interaction regions between which an input optical signal propagates from a first position on a first side of the first optical interaction region to a second position on a second side of the second optical interaction region, a correspondence between said first and second positions depending upon a wavelength of the optical signal, there being a plurality of array waveguides coupled between a second side of the first optical interaction region and a first side of the second optical interaction region, and a plurality of output waveguides coupled at one end to the second side of the second optical interaction region for outputting different wavelength channel outputs from the second optical interaction region; and detector for detecting said different wavelength channel outputs at the other ends of the output waveguides: wherein the plurality of output waveguides includes at least two output waveguides for at least one of the wavelength channels.