Abstract: A method of preparing an optical fiber for fusion splicing comprising the steps of providing an optical fiber having a fiber jacket and an end, removing a predetermined bulk of the fiber jacket from an area adjacent the end while one of substantially simultaneously moving gas over the area and exhausting gas from the area.

Abstract: An optical circuit comprising first and second fiber optic components, an optical fiber having a first end coupled with the first fiber optic component and a second end coupled with the second fiber optic component, and a helical strand of the optical fiber intermediate the first and second components.

Abstract: Aligned birefringent fiber segments are reliably and efficiently rotated approximately 45.degree. relative to each other until the extinction ratio measurement at the output is approximately 0 dB, then birefringent fibers are fused. To determine the extinction ratio, a Wollaston analyzer is placed at the output of the birefringent fiber. Photodetectors placed on each output of the Wollaston analyzer, substantially simultaneously measure the output intensity of each propagation axis.

Abstract: A method for damping an optical fiber on a bias optical phase modulator having two optical fiber leads comprises the steps of securing the bias phase modulator, applying a silicone or acrylate type of substance to an outward facing surface of the fiber wound on the bias phase modulator means, applying the silicone or acrylate type of substance on the two optical fiber leads for at least 0.5 inch (1.28 cm.) along each lead which is apart from the place where the optical fiber wound on the bias phase modulator, frequently brushing or smoothing out the applied silicone or acrylate type of substance until the substance beings to set, and drying the substance on the optical fiber until the substance is cured. The applied damping material significantly reduces an amplitude of a frequency caused by mechanical vibrations in a rotation sensor.

Abstract: A rotation sensor for sensing rotation, particularly about an axis of a coiled optical fiber, wherein the coiled optical fiber has with light waves propagating in opposite directions in the coiled optical fiber, the phase relationship of the counter-propagating light waves providing a basis for indicating rotation of the sensor. A portion of the coiled optical fiber is a part of and affected by a bias optical phase modulator which causes a varying phase relationship between the light waves at a fundamental frequency. However, the varying phase relation ship has at least one harmonic which is due to mechanical vibration of the optical fiber that is a part of the modulator. This harmonic contributes to an erroneous indication of rotation. The amplitude of such harmonic is reduced by lowering the Q of the resonating fiber. This is effected by applying a damping material to the optical fiber and a portion of the modulator.

Abstract: An optical fiber rotation sensor having an ordinary single mode fiber coil with a depolarizer in series therewith configured with component optical path lengths therein and birefringent axes relationships therein chosen with respect to the source autocorrelation. Amplitude related phase errors due to polarization mode coupling can be eliminated or reduced economically, and signal fading can be substantially prevented.

Abstract: An optical fiber rotation sensor having configurations thereof chosen with respect to the source autocorrelation. Both amplitude related and intensity related phase errors due to polarization mode coupling can be eliminated or reduced economically.

Abstract: An error control arrangement for an optical fiber rotation sensor having electromagnetic waves propagating in opposite directions passing through a bias optical phase modulator operated by a phase modulation generator both of which can contribute second harmonic distortion resulting in errors in the sensor output signal which are controlled. Control of the bias optical phase modulator contribution for a modulator having a piezoelectric body wrapped with an optical fiber portion is accomplished by mounting the body utilizing layers having nonlinear stiffness.

Abstract: 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.

Abstract: 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.

Abstract: An optical fiber has an absorbing jacket to absorb cladding modes in a very short distance along the optical fiber to prevent cladding modes from having a significant affect upon signal quality. The absorbing jacket cooperates with a form birefringent polarizing fiber, which radiates light of one polarization out of the core into the cladding, to provide light of a single polarization suitable for use in fiber optic sensing systems and communications systems whose operational characteristics are polarization dependent.

Abstract: 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.