Patent ID: 6607313
Filing Date: 2003-08-19
Classification: G02B,H04J

Abstract:
A circuit for receiving two streams of data and for polarization time-division-multiplexing the two streams of data onto a single waveguide such that one of the data streams is delayed by a time td from the other data stream, comprising:a first modulator having an input port and an output port for modulating input light and for providing a first modulated data stream; a second modulator having an input port and an output port for modulating input light and for providing a second modulated data stream; a first lens for collimating light provided by the first modulator; a second lens for collimating light provided by second modulator, the first and second lenses each for providing a substantially collimated substantially unguided beam of light to at least another component; a polarization beam splitter/combiner having two input ports at one end optically coupled to receive the substantially collimated, substantially unguided beams of light, said polarization beam splitter/combiner having a combining port at another end for combining the data streams wherein optical path from one input port of the splitter/combiner to the combining port is different than optical path from the other input port of the splitter/combiner to the combining port such that one data stream is delayed by a time td from the other data stream, whereby the block has both a light combining function and a time delay function, light traversing parallel paths from the first and second lenses respectively to the polarization beam splitter/combiner being substantially unguided, so that light traversing at least one of said parallel paths will have a polarization state which is substantially unchanged.