Abstract: An optical module capable of connecting signal lines to an external substrate easily without causing any degradation of the transmission characteristic is disclosed. The optical module comprises an optical element mounting block having an optical element mounting section and an optical fiber guide, and a wiring lead integrated resin substrate having a ferrule holding section, an optical element mounting block housing section, and wiring leads, where at least a part of the wiring leads are provided by signal lines in a coplanar guide structure entirely formed on the wiring lead integrated resin substrate such that a characteristic impedance does not change when the wiring leads are electrically connected to external wirings.

Abstract: An optical module capable of connecting signal lines to an external substrate easily without causing any degradation of the transmission characteristic is disclosed. The optical module comprises an optical element mounting block having an optical element mounting section and an optical fiber guide, and a wiring lead integrated resin substrate having a ferrule holding section, an optical element mounting block housing section, and wiring leads, where at least a part of the wiring leads are provided by signal lines in a coplanar guide structure entirely formed on the wiring lead integrated resin substrate such that a characteristic impedance does not change when the wiring leads are electrically connected to external wirings.

Abstract: A packaging platform for optically coupling one or more optical waveguides of one or more optical components having the optical waveguide to one or more optical fibers is provided with a reference structure portion for the horizontal and vertical positioning of the optical component. The platform is further provided with one or more fiber positioning portions for inserting and holding the optical fiber and positioning the optical fiber at a position where the optical fiber is optically connected to the optical waveguide. The provided packaging platform and an optical module using the platform can simplify all alignment steps for optical coupling, electrical connection and sealing in the coupling of the optical component and the optical fiber.

Abstract: A plastic split optical alignment sleeve comprising a cylindrical plastic sleeve with a slit in a side surface thereof to be arranged in an adaptor which splices optical fiber chords having inserted therethrough optical fibers and having a ferrule on each end thereof, the sleeve being capable of engaging therein the ferrules on both sides thereof to splice the optical fibers, comprises a resin composition which when injection molded exhibits an anisotropy of 1.5 or less, the anisotropy being expressed in terms of ratio of a physical property, preferably flexural modulus, in a first direction in which a resin in the resin composition flew upon injection molding and that in a second direction which is at right angles to the first direction. The resin composition contains at least one resin selected from polyetherimides, polyethersulfones, and epoxy resins and at least one inorganic substance selected from whiskers and silica powder.

Abstract: A plastic ferrule for an optical connector comprises a cylindrical portion having one insertion hole for fixing an optical fiber and directly related to connection, a holding portion for allowing the cylindrical portion to be stably held in an optical connector, and an guiding portion for allowing an optical fiber to be guided into the ferrule. The ferrule has a hollow, cylindrical hole centering around the insertion hole inside the cylindrical portion. Thus, the ferrule has excellent dimensional accuracy of the outer diameter, and achieves connection of single mode fibers excellent in connection reliability and economy.

Abstract: The present invention provides a second-order nonlinear optical polymer including a polymer backbone and side groups bonded to the polymer backbone, wherein the side groups include one or more of a first nonlinear optical group represented by the following formula (C-1) and one or more of a second nonlinear optical group represented by the following formula (C-2) or (C-2)': ##STR1## wherein .pi..sub.1 to .pi..sub.n, .pi.'.sub.1, .pi.'.sub.2, and .pi.".sub.1 each represent independently a .pi.-conjugated cyclic compound group; X.sub.1 to X.sub.n-1, X'.sub.1, Y.sub.1 to Y.sub.n-1, and Y'.sub.1 each represent independently CH, N, or N.fwdarw.O; A.sub.1, A.sub.2, and A.sub.3 each represent independently an electron attracting group; D.sub.1, D.sub.2, and D.sub.3 each represent independently an electron donating group; and n represents an integer of 3 or greater.

Abstract: In a second-order or third-order organic nonlinear optical material, one of compounds represented by the following formulas (1) and (2) is bonded to a polymer: ##STR1## wherein each of .pi..sub.1 to .pi..sub.n independently represents a cyclic compound of a .pi. electron conjugate system, at least one of R.sub.11 to R.sub.n4 represents an alkyl substituting group derivative and others represent hydrogen, each of X.sub.1 to X.sub.n-1 and Y.sub.1 to Y.sub.n-1 represents one member selected from the group consisting of CH, N, and N.fwdarw.O, A represents an electron acceptor group, D represents an electron donor group, and n is an integer of 3 or more.

Abstract: A coated optical fiber comprising an optical fiber; a first layer of a thermoplastic rubber composition which is disposed around the circumference of the optical fiber, has a Young's modulus of 0.1 GPa or less, and is capable of extrusion coating; and a second layer of a thermoplastic resin composition which is disposed around the circumference of the first layer, has a linear expansion coefficient of 1.times.10.sup.-5.degree. C..sup.-1 or less and a Young's modulus of 5 GPa or more, and is capable of extrusion coating. The coated optical fiber has excellent transmission characteristics at low and high temperatures and is inexpensive.