Patent ID: 7542686

Claim:
A process for operating on an incoming optical signal having a first state of polarization to produce an outgoing optical signal having a second state of polarization different from said first state and further processing said outgoing signal, said process comprising the steps of: introducing said incoming signal having said first state of polarization to a series of physically coupled sequences, wherein: (i) said series comprises at least two Type I sequences, at least two Type II sequences or at least one each of a Type I sequence and a Type II sequence; (ii) each Type I sequence comprises two waveguiding structures, wherein said two waveguiding structures are arranged to form a sequence of a first variable phase shifter, a variable optical coupler, and a second variable phase shifter, wherein each said variable phase shifter comprises two electrodes, wherein said variable optical coupler is physically coupled between the two electrodes of said first variable phase shifter and the two electrodes of said second variable phase shifter, wherein a coupling strength of said variable optical coupler is variable in proportion to the phase shift of said first variable phase shifter and the phase shift of the second variable phase shifter, wherein the phase shift of said first variable phase shifter and the phase shift of the second variable phase shifter are substantially equal; and (iii) each Type II sequence comprises two waveguiding structures, wherein said two waveguiding structures are arranged to form a sequence of a first variable optical coupler, a variable phase shifter, and a second variable optical coupler, wherein said variable phase shifter is coupled between said two variable optical couplers, wherein said variable phase shifter comprises two electrodes, wherein the two electrodes of said variable phase shifter is physically coupled between said first variable optical coupler and said second variable optical coupler, wherein a phase shift of said variable phase shifter is variable in proportion to the coupling strength of said first variable optical coupler and the coupling strength of said second variable optical coupler, wherein the coupling strength of said first variable optical coupler and the coupling strength of said second variable optical coupler are substantially equal; controlling said sequences to operate without reset as allowed by said variable coupling strength of said variable optical coupler of said Type I sequence or said variable phase shift of said variable phase shifter of said Type II sequence, generating said outgoing optical signal having said second state of polarization from a combination of an output of said two waveguiding structures of said at least two Type I sequences, said at least two Type II sequences or said at least one each of a Type I sequence and a Type II sequence; and further processing said outgoing signal.