Programmable wavelength router
AssigneeChorum Technologies LP
InventorsKuang-Yi Wu, Jian-Yu Liu
Life of this patent
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Abstract
A programmable wavelength router having a plurality of cascaded stages where each stage receives one or more optical signals comprising a plurality of wavelength division multiplexed (WDM) channels. Each stage divides the received optical signals into divided optical signals comprising a subset of the channels and spatially positions the divided optical signals in response to a control signal applied to each stage. Preferably each stage divides a received WDM signal into two subsets that are either single channel or WDM signals. A final stage outputs optical signals at desired locations. In this manner, 2.sup.N optical signals in a WDM signal can be spatially separated and permuted using N control signals.
Claims17
A wavelength router comprising:
- a first birefringent element positioned to receive a wavelength division multiplexed (WDM) optical signal, the outputs of the first birefringent element defining a first optical path and a second optical path wherein the first and second optical paths have opposite polarization and are spatially separated;
- a polarization converter coupled to receive the first and second optical paths from the first birefringent element, wherein the polarization converter rotates the polarization state of at least one of said first and second optical paths;
- a wavelength filter coupled to receive the first and second optical paths from the polarization converter, the wavelength filter having a polarization dependent optical transmission function such that the filtered first optical path comprises a first set of frequencies with vertical polarization and a second set of frequencies with horizontal polarization, and the filtered second optical path comprises the first set of frequencies with horizontal polarization and the second set of frequencies with vertical polarization, wherein the first and second sets of frequencies are substantially complementary;
- a second birefringent element coupled to receive the first and second optical paths from the wavelength filter and spatially separate each of the first and second optical paths into horizontally polarized and vertically polarized components;
- means for combining the horizontal component of the first path with the vertical component of the second path into a first output signal;
- and
- means for combining the vertical component of the first path with the horizontal component of the second path into a second output signal.
A wavelength router for routing an input wavelength division multiplexed (WDM) signal having a plurality of channels, said router comprising:
- a plurality of cascaded stages wherein each stage receives one or more optical signals comprising a plurality of WDM channels, each of said stages filter and divides the received optical signals into a plurality of divided optical signals, each of said divided optical signals comprising a subset of at least one and less than all of the received channels for the stage so that up to 2.sup.N optical signals in the input WDM signal can be spatially separated, where N is the number of said stages.
A wavelength router comprising:
- a plurality of cascaded stages wherein each stage receives one or more optical signals comprising a plurality of wavelength division multiplexed (WDM) channels, divides the received optical signals into divided optical signals comprising a subset of the channels, and spatially positions the divided optical signals, and wherein at least one of said stages includes:
- (a) means for spatially separating each received optical signal into a horizontally polarized component along a first optical path and a vertically polarized component along a second optical path;
- (b) means for rotating the polarization of at least one component of the separated optical signal;
- (c) a wavelength filter coupled to receive the rotated components, the wavelength filter having a polarization-dependent optical transmission function such that the filtered first optical path comprises a first set of channels with vertical polarization and a second set of channels with horizontal polarization, and the filtered second optical path comprises the first set of channels with horizontal polarization and the second set of channels with vertical polarization, wherein the first and second sets of channels are substantially complementary;
- (d) means for spatially separating each of the first and second optical paths into horizontally-polarized and vertically-polarized components;
- (e) means for combining the horizontally-polarized component of the first optical path with the vertically-polarized component of the second optical path to output said second set of channels;
- and
- (f) means for combining the vertically-polarized component of the first optical path with the horizontally-polarized component of the second optical path to output said first set of channels.
Dependencies are inferred from the claim text.