Abstract: A resonant fiber optic gyro has a tapered polarizer in the ring to produce a single resonant polarization mode. A fused coupler closes the ring and provides inlet and outlet paths, with the entire device fabricated from a single PM fiber, thereby eliminating sources of backscatter and drift. In a preferred embodiment MSR fiber is used, and preferably the fused coupler is fabricated to achieve high finesse and modulation depth with its splitting ratio approximately equal to ring transmission coefficients. Apparatus and methods for forming the polarizer and the coupler are described.

Abstract: A fiber optic coupler and method of manufacture of same in which a single core optical fiber is twisted about a dual core optical fiber and is heated to softening while drawing the melted junction out to form a biconical taper for providing a controlled splitting ratio for light from the single optical fiber into the dual core fiber. In another embodiment two single core fibers are fused to form a dual core fiber without coupling between the cores.

Abstract: A fiber optic laser includes a fiber optic element, and a Bragg grating means in the fiber optic element and defined by a periodic variation in the index of refraction of the element to enhance the narrow band response of the laser and/or increase the loss of unwanted frequencies. A method of making the fiber laser is also disclosed.

Abstract: A fiber is mounted with a bare portion extending between two blocks. Four blocks securing a pair of fibers in this manner are mutually aligned by one or more external sleeves, and the fibers are fused and drawn to form a coupler of defined coupling ratio. One sleeve then slides over all four blocks and is bonded to constitute a rigid housing surrounding the fusion region. A preferred coupling block is a grooved D-rod, and different geometries are shown to provide effective PZ and PM fusion couplings, with fiber stress axes aligned with respect to a flat surface of the rod. Portions of the rod provide fiber support and alignment during fusion, and break away from the assembled coupler when complete.

Abstract: An optical element includes a polarization maintaining fiber, and an Indium film on a lapped region of the fiber that selectively couples light of one polarization out of the fiber. The film bonds to a coupling half block or cover plate, providing an hermetic seal about the fiber coupling region. Polarizers, polarizing couplers, polarization beamsplitters, and single mode resonant fiber ring constructions are described.

Abstract: A spliced fiber is recoated by injection molding a jacket segment over the bare splice region. The dimensions of the recoated fiber approximate those of an undisturbed fiber, and the coating material may be selected to match the physical and mechanical properties of the original fiber jacket. A fixture is shown for performing the recoating.

Abstract: In an optical fiber coupling method and coupling assembly, an optical fiber is secured in a support block which is thermally matched to the fiber material. The fibers are coupled within a homogeneous glass medium, resulting in extreme resistance to ambient chemicals, radiation, temperature and forces. A region of the block is optically worked to form a coupling surface surrounding an exposed central portion of the fiber cladding. First and second such blocks are then positioned with their coupling surfaces aligned, and are placed in optical contact with their opposing counterparts. This produces an optical splice of the fibers within a boundary-free thermally matched medium. The optically-contacted assembly, once aligned, is substantially self-securing, and, due to its homogeneity, does not introduce stresses to the fiber as the temperature of the assembly varies. Preferred forms of fiber mounting and methods of enhancing the formation and quality of optical contact are disclosed.

Abstract: An optical fiber coil is formed by winding successive loops of a fiber in a toroidal helix to form a self-supporting ring. No coilform or adhesives are necessary, resulting in relaxed boundary conditions at the outside of the fiber jacket, and in an overall reduction of thermally-induced strain, as compared to existing coil constructions. One low-stress mounting includes a trellis or spoke-like frame structure which frictionally supports the coil about its circumference. Another mounting includes a bouyant bead support structure. In a third mounting, a filament suspends the coil from a frame. The coil may be suspended within an isothermal enclosure to further reduce thermal effects.

Abstract: A calibration standard simulates predetermined flying characteristics of a magnetic head for calibrating flying height testers. The standard comprises a substrate having a reflective layer supported thereon. A transparent layer is disposed over the reflective layer so that the reflective layer is disposed at a predetermined angle to a surface of the transparent layer, the predetermined angle representative of a predetermined flying angle of a head over a disk, the transparent layer having a thickness representative of a predetermined flying height of a head over a disk. A process for manufacturing and calibrating the calibration standard is also described.