Abstract: In a fiber optic coil arrangement for use in rotation sensors, for example, axial or radial errors can be reduced or substantially eliminated by negatively trimming the fiber optic coil. As a result of the negative trimming, a sufficient amount of the predictable turns of the optical fiber is removed from the fiber optic coil so as to interrupt the predetermined pattern with which the fiber optic coil is wound in order to thereby reduce axial or radial related errors which would have otherwise resulted. Alternatively, the fiber optic coil may be negatively trimmed by terminating winding of the fiber optic coil before the predetermined pattern of the fiber optic coil has been completed. The point at which winding is terminated may be selected so as to reduce axial or radial related errors to a desired level.

Abstract: 1.times.2 and more complex switching operations use routing corresponding with guides produced by heating with a laterally-homogeneous layer. Strip heaters, in contact with a silica-based sandwich structure, thermally increase refractive index to define laterally-constrained cores within the center layer.

Abstract: A fiber optic module includes a connector connected to a mother board of a host computer, an LD semiconductor IC for converting serial data received from the mother board to an LD electric signal for a laser diode, an LD module for converting the LD electric signal to an LD optical signal, a PD module for converting a photodiode optical signal to a PD electric signal, a PD semiconductor IC for converting the PD electric signal to PD serial data, a circuit board having the connector and carrying LD semiconductor IC and PD semiconductor IC, an LD shielding plate and a PD shielding plate for electrically shielding the LD module and the PD module, respectively, a first frame and a second frame for holding the circuit board, LD module and PD module.