Abstract: An optical device that can be used in a range of telecommunications applications including optical multiplexers/demultiplexers and optical routers. The optical device includes an optical processing loop which allows multi-stage performance characteristics to be achieved with a single physical filtration stage. Optical processing on the first leg and second legs of the loop is asymmetrical thereby improving the integrity of the optical signals by effecting complementary chromatic dispersion on the first and second legs. In an embodiment of the invention the optical device includes a fundamental filter cell, a retro reflector and a splitter/combiner. The fundamental filter cell filters optical signals propagating on each of two legs of an optical loop which intersects the fundamental filter cell.

Abstract: The present invention provides optical filters that can be used in a range of telecommunications applications including optical multiplexers/demultiplexers, optical routers, and optical gain scalers. The optical filter is modular, using two or more couplers with a pair of delay paths between each pair of couplers in a sequence to generate a range of optical filter functions. The desired filter profile/function is obtained by proper selection of the coupling ratio for each coupler and by the length of each pair of delay paths. The couplers may be implemented as polarization or intensity beam splitters positioned along the optical path. Each coupler couples in controllable amounts, one or two inputs with the corresponding pair of delay paths.

Abstract: An optical device that can be used in a range of telecommunications applications including optical multiplexers/demultiplexers and optical routers. The optical device splits and combines optical signals of frequency division multiplexed optical communication channels which are evenly spaced apart in frequency from one another. The optical device includes a first filter and a second filter. The first filter splits and combines odd and even channels depending on the propagation direction of the optical signal. The first filter exhibits complementary phase retardations corresponding with odd integer multiples of half a wavelength for each center wavelength associated with a selected one of the odd and even set of channels and with integer multiples of a full wavelength for each center wavelength associated with a remaining one of the odd set and the even set.

Abstract: A method and apparatus for compensating an optical filter is disclosed. The device substantially maintains the selected center wavelength in the optical filter across a range of operating temperatures. In an embodiment of the invention an optical filter is disclosed for filtering a selected channel among a plurality of multiplexed channels of an optical communication. The optical filter includes an optical fiber and an elongate housing. The optical fiber has a first side and a second side and a filter portion intermediate the first side and the second side, and the optical fiber for transmitting the multiplexed optical communication and the filter portion for filtering the selected channel. The elongate housing includes exposed end portions through which the optical fiber extends. The optical fiber is affixed at each exposed end portion.