Patent ID: 6614947
Filing Date: 2003-09-02
Classification: G02B

Abstract:
A Mach-Zehnder interferometer comprising:a first arm having a first optical path; a second arm having a second optical path; and an optical phase shifter for introducing a phase into an optical signal passing through the second optical path, said optical phase shifter comprising; a first waveguide having a core having an associated index of refraction, the first waveguide being part of the second optical path; a second waveguide having a core having an associated index of refraction, the second waveguide being part of the second optical path, the first and the second waveguides being separated from each other by a predetermined distance across a trench that contains a medium with an associated index of refraction; a phase shift element disposed in the trench between the first and second waveguides and selective movable relative to the first and second waveguides between a first position in which the optical signal passing from the first waveguide to the second waveguide does not pass through the phase shift element, and a second position in which the optical signal passing from the first waveguide to the second waveguide passes through the phase shift element to shift the optical signal in phase relative to an optical signal passing along the first optical path.