Litton Systems, Inc.

Chin-Lung Chang

John R Feth

Sidney X Huang

Steven C Furlong

A rare-earth doped glass waveguide is optically pumped to produce superfluorescent light. The waveguide is formed in a glass substrate. The pump light is input to a first end of the optical waveguide, and the output is emitted from the other end. A grating formed on the waveguide near the output end reflects the pump light to separate the pump light from the output light.

Broadband light source using rare earth doped glass waveguide

An integrated optics chip eliminates problems caused by polarization cross coupling in fiber optic rotation sensors without requiring time consuming and expensive alignment of the axes of the optical fiber sensing coil and the optical waveguides formed in the integrated optics chip. A substrate formed of an optically active material has slots formed therein for mounting optical fibers to the substrate. An optical waveguide is formed in the integrated optics chip to guide optical signals along a selected axis of propagation such that an end wall of the slot includes an end surface of the optical waveguide. The end surface of the optical waveguide is formed to make an angle with the direction of propagation of light in the optical waveguide to reduce the amount of light reflected at the end surface of the optical waveguide. The angle of the end of the optical waveguide is formed such that light reflected at the interface back into the optical fiber impinges on the core/cladding boundary at an angle that permits refraction from the core into the cladding. The angle of the end of the optical waveguide preferably is in the range of 5.degree. to 25.degree..

Integrated optics chip and method of connecting optical fiber thereto

This invention is a frequency shifter for receiving an optical carrier signal input and producing an output including a sideband that is shifted in frequency from the carrier. The frequency shifter includes an optical waveguide formed in a substrate of an electro-optically active material such as lithium niobate. A plurality of electrodes formed on the substrate cooperate with a signal generator to apply two perpendicular electric fields to the optical waveguide. The resultant of the two fields is a rotating electric field which produces a rotating birefringence in the optical waveguide. The rotating birefringence acts as a rotating wave plate, which shifts the frequency of optical signals input to the optical waveguide. The wave plate is preferably a half wave plate, which converts all of the input optical energy into the sideband.

Guided wave optical frequency shifter

The cladding and a portion of the core of a length of optical fiber are removed to form an interaction region. A form birefringent stack is positioned on the exposed core. The refractive index of the stack for polarizations parallel to the plane of the interaction region is approximately equal to the refractive index of the fiber core so that these polarizations radiate from the fiber. The refractive index of the stack for the polarization normal to the plane fo the interaction region is approximately equal to the refractive index of the cladding so that this polarization remains guided by the fiber. A photodetector forms an error signal from the polarization radiated from the fiber, and control circuitry processes the error signal to drive a polarization controller that adjusts the polarization of light input to the polarizer to minimize the error signal.

Form birefringent cutoff polarizer and method

A polarizing optical fiber has a core formed of a plurality of layers of dielectrics having different refractive indices. The dielectric layers form a composite structure having different refractive indices for light of different polarizations. The differing refractive indices cause the polarization states of light guided by the fiber to be non-degenerate so that energy ordinarily will not couple from one polarization to the other. The fiber includes a cladding that may have a refractive index either less than both core indices to provide a polarization maintaining fiber or greater than or equal to one of the core indices to provide a polarizing fiber. The method of fabrication of the layered core form birefringent optical fiber includes forming a structure of a plurality of layers of the dielectrics, heating the structure to form a monolith, stretching the monolith to form the fiber core, and adding the cladding to the core.

Form polarizing fibers and method of fabrication

The cladding and a portion of the core of apparatus of a length of optical fiber are removed to form an interaction region where the fiber will not guide a light wave. A metal thin layer placed on the exposed core and a portion of the cladding. Polarizations perpendicular to the metal film couple into the metal film to form a surface plasma wave that propagates parallel to the fiber while parallel polarizations radiate through the metal film. The surface plasma wave couples energy back into the fiber so that the throughput of the polarizer is only the perpendicular polarization component. A photodetector forms an error signal from the polarization radiated from the fiber, and control circuitry processes the error signal to drive a polarization controller that adjusts the polarization of light input to the polarizer to minimize the error signal and maximize the intensity of the desired polarization output from the polarizer.

Growing community of inventors

West Covina, CA, United States of America

Chin-Lung Chang