Patent ID: 6643063
Filing Date: 2003-11-04
Classification: G02B,H04J

Abstract:
An optical device for interfacing between an optical system in which a light beam contains signals for even and odd channels having channel spacing S, and an optical system in which a light beam contains signals for even channels having channel spacing 2S and a light beam contains signals for odd channels having spacing 2S, the optical device comprising:a dispersion compensator for providing dispersion compensation for light containing signals for even and odd channels; a first polarization interferometer having passbands with channel spacing S, the first polarization interferometer providing filtering for light containing signals for even and odd channels; a second polarization interferometer having passbands with channel spacing S, the second polarization interferometer providing filtering for light containing signals for even channels; a third polarization interferometer having passbands with channel spacing S, the third polarization interferometer providing filtering for light containing signals for odd channels; a first port, the first port being for light containing signals for even and odd channels having channel spacing S; a second port, the second port being for light containing signals for even channels having channel spacing 2S; a third port, the third port being for light containing odd channels having channel spacing 2S; first, second, and third polarization beam splitters; a first polarizer/depolarizer for adding and removing vertical polarization; a second polarizer/depolarizer for adding and removing horizontal polarization; a common polarizer/depolarizer for adding and removing horizontal polarization; a first garnet and a second garnet; a first half wave plate and a second half wave plate; and a quarter wave plate; wherein the first port is optically coupled through the dispersion compensator, the first polarization interferometer, and the second polarization interferometer, to the second port so that there is an optical path between the first port and the second port for light containing signals for even channels; wherein the first port is optically coupled through the dispersion compensator, the first polarization interferometer, and the third polarization interferometer to the third port so that there is an optical path between the first port and the third port for light containing signals for odd channels; wherein the first port is optically coupled to the dispersion compensator via the first polarizer/depolarizer, the third polarization beam splitter by reflection, and the quarter wave plate; wherein the dispersion compensator is optically coupled to the first polarization interferometer via the quarter wave plate, the third polarization beam splitter by transmission, the second polarization beam splitter by transmission, the first half wave plate, the first garnet and the first polarization beam splitter by transmission; wherein the first polarization interferometer is optically coupled to the second polarization interferometer via the first polarization beam splitter by reflection; wherein the second polarization interferometer is optically coupled to the second port via the first polarization beam splitter by transmission, and the second polarizer/depolarizer; wherein the first polarization interferometer is optically coupled to the third polarization interferometer via the first polarization beam splitter by transmission, the first garnet, the first half wave plate, the second polarization beam splitter by reflection, the second garnet, and the second half wave plate; and wherein the third polarization interferometer is optically coupled to the third port via the second half wave plate, the second garnet, the second polarization beam splitter by transmission, and the third polarizer/depolarizer.