Patent ID: 6285500
Filing Date: 2001-09-04
Classification: G02B,G02F,H04J,H04Q

Abstract:
An optical device for selectively directing a first signal and a second signal to a selected output, said optical device comprising: a birefringent optical system having a system input that receives the first signal and the second signal, and a system output to which said birefringent optical system transmits a superimposed signal formed by superimposing a first polarized signal and a second polarized signal, wherein said first polarized signal and said second polarized signal are polarized versions of the first signal and the second signal, respectively; and a polarization modulator coupled to said system output, whereby said polarization modulator selectively rotates a polarization state of said superimposed signal, wherein the polarization modulator is selected from the group consisting of a birefringent crystal switch, a twisted nematic liquid crystal switch, a ferroelectric liquid crystal switch, a cholesteric liquid crystal switch, a magneto-optical Farady rotator, an acousto-optic rotator, or an electro-optical rotator and wherein an optical distance of the first polarized signal from the system input to the polarization modulator is substantially equal to an optical distance of the second polarized signal from the system input to the liquid crystal switch.