Patent ID: 7424223

Claim:
A reconfigurable wavelength blocking apparatus, comprising: a first arrayed waveguide grating demultiplexing an input WDM signal and outputting demultiplexed signals on respective outputs; an array of optical shutters optically coupled to the outputs from said first arrayed waveguide grating, each of the optical shutters in said array having a control input, wherein said array of optical shutters have a default state that is substantially transparent to the demultiplexed signals when no power is supplied to said array of optical shutters to minimize power consumption; a second arrayed waveguide grating optically coupled to said array of optical shutters, said second arrayed waveguide grating multiplexing optical signals output from said array to form a WDM signal; a common optical shutter optically coupled to either an input of said first and an output of said second arrayed waveguide gratings, said common optical shutter having a control input; said common optical shutter having a default state that is substantially opaque to the WDM signal when no power is supplied to said common optical shutter; and a controller operatively coupled to said array of optical shutters, said controller supplying control signals to the control inputs of said array in order to selectively drive each of the optical shutters in said array into a substantially transparent or opaque state in order to thereby select which WDM channels pass through and which WDM channels are blocked by said array; wherein said default state of said array of optical shutters and said default state of said common optical shutter are operable to prevent duplication of a wavelength channel and provide fault isolation and signaling while minimizing power consumption.