Wavelength filter that operates on sets of wavelength channels
View Patent ↗A wavelength filter, for filtering a WDM signal, comprises a demultiplexer, a multiplexer, and a control array connecting the demultiplexer and the multiplexer, where the demultiplexer and the multiplexer have a free spectral range (FSR) smaller than their wavelength channel span.
1. An optical device for demultiplexing an input WDM signal into a plurality of output signals, the optical device comprising:
a single input waveguide;
a plurality of output waveguides, and
a grating having a free spectral range smaller than a wavelength channel span of the input WDM signal, said grating including an input coupler, an output coupler, and an array of unequal-length waveguides connecting the input and output couplers, wherein the input and output couplers are respectively connected to the input waveguide and the plurality of output waveguides,
characterized in that;
upon receiving the input WDM signal at the input waveguide the optical device demultiplexes the input WDM signal into the plurality of output signals, wherein each output signal has multiple channels each one at a different wavelength, and wherein each output signal is carried by a respective plurality of in-concert output waveguides,
such that each output signal is not carried by output waveguides other than its respective in-concert output waveguides.
2. The optical device of claim 1 wherein the number of wavelengths in each output signal is the same.
3. An optical device for producing an output WDM signal by multiplexing a plurality of input signals, the optical device comprising:
a plurality of input waveguides;
a single output waveguide, and
a grating having a free spectral range smaller than a wavelength channel span of the output WDM signal, said grating including an input coupler, an output coupler, and an array of unequal-length waveguides connecting the input and output couplers, wherein the input and output couplers are respectively connected to the plurality of input waveguides and the output waveguide,
characterized in that each input signal has multiple channels each one at a different wavelength, and wherein each input signal is carried by a respective plurality of in-concert input waveguides,
such that each input signal is not carried by input waveguides other than its respective in-concert input waveguides.
4. The optical device of claim 3 wherein the number of wavelength in each input signal is the same.