Abstract: An optical transmission module includes a beam spot size expanding waveguide and a beam spot size reducing waveguide adjoining in the light propagating direction, or includes a beam spot size expanding waveguide, a beam spot size retaining waveguide and a beam spot size reducing waveguide aligning in the light propagating direction. Each waveguide has laminated core layers which are formed of materials of different refractive indexes.

Abstract: A ceramic substrate is provided through a stem of a can-package, the desired number of wirings including the high speed signal wirings are formed on this ceramic substrate and the necessary electronic components other than a light-emitting/photosensitive element such as driver LSI and amplifying LSI or the like are also accommodated within the can-package.

Abstract: The incident angle of the beam with regard to an etalon is arranged finely tunable by either rotating the etalon provided with a plane of incidence inclined with regard to the rotational axis thereof in the vicinity of the optical axis or rotating a lens whose edge surface is obliquely ground around the optical axis, which allows the incident angle of the laser beam with regard to the etalon to be adjusted and fixed with high precision.

Abstract: The present invention provides an optical transmission module comprising: a laser diode; a lens for condensing a laser beam from the laser diode; a fiber ferrule which is placed so that the laser beam condensed by the lens can enter a fiber core; and a lens aperture or a lens aperture portion which is provided at one of the lens itself, a position before the lens and a position after the lens.

Abstract: According to the present invention there are provided a transmission line and an optical module having the transmission line, the transmission line having on a dielectric substrate a first signal wiring conductor, a second signal wiring conductor insulated from the first signal wiring conductor, a first electrode disposed near the first and second signal wiring conductors, a second electrode disposed near the second signal wiring conductor, and a ground wiring conductor disposed in adjacency to the second electrode, wherein a passing frequency band can be changed by changing the connection of conductor wires.

Abstract: A method of manufacturing an optic transmission module assures a high reliability for the module by inspecting the character of a low bit error rate (BER) of the module quickly and accurately. The module is employed in an optical communication system (light transmission system) required to cope with information communication systems that are becoming faster and faster in operation and larger and larger in capacity. Also disclosed is a system and a method for inspection of the BER character which uses a rectangular wave pulse as an interference light to calculate a degradation quantity of a signal-to-noise ratio (S/N) on the basis of a simple theory, thereby inspecting the BER character by extrapolating a case in which there is no interference light (S/X=∞ or X=0) with use of a sign error rate theoretical value according to a bit error rate of a light signal measured according to the degradation quantity.

Abstract: A transmission line with a bending portion is provided, which line comprises any one of a coplanar line, another coplanar waveguide line formed on the dielectric substrate under which a ground layer is provided and a coplanar strip line. A chamfered portion is provided on the outer angular portion of the bending portion of the signal wiring conductor and a triangular conductor is disposed to an inner angular portion thereof. Given that length of the chamfered portion is defined as a, and length of the wiring edge side of the triangular conductor is defined as b and width of the signal wiring conductor is defined as c, it is arranged such that a is greater than b+c×square root of 2. Thereby, a transmission line or an optical module of smaller reflection loss at the bending portion thereof and of improved high-frequency characteristics is provided.

Abstract: An electronic device, in which terminals of a semiconductor integrated circuit chip and terminals of a circuit substrate are mounted with solder so as to face one another. The electronic device includes a first resin, which is disposed between the circuit substrate and a terminal formation face of the semiconductor integrated circuit chip and a second resin, which is disposed at the outer perimeter of the semiconductor integrated circuit chip or is disposed laterally thereon. The modulus of elasticity of the second resin is smaller than the modulus of elasticity of the first resin, the modulus of elasticity of the second resin is at least 0.5 GPa but not more than 28 GPa at room temperature.

Abstract: A PD (20) is mounted to a position offset (23) as viewed in the direction orthogonal to the center of an optical axis (14) of backward light (13) of an LD (11) in such a manner that a light receiving plane (21) thereof becomes substantially parallel to the center of the optical axis. Alternatively, the PD (20) is mounted thereto so that the light receiving plane of the PD is inclined at angles ranging from about 0° to about 30° to the center of the optical axis of the backward light. Further, the PD whose side face on the LD side is inclined, is used to repeatedly reflect the backward light between the PD and an LD mounting substrate, after which the backward light is launched on the light receiving plane 21.

Abstract: An optical transmission module with an optical device mounted in a substrate provided with an optical waveguide is provided wherein respective metallic electrodes in pair are symmetrically disposed in each side of an optical device divided by a centerline parallel to an optical axis such that those electrodes have an error of 60 &mgr;m or less and said metallic electrodes are soldered to a metallic electrode as disposed on a substrate, which electrode has a size enough to cover those electrodes as disposed in the optical device.

Abstract: In a wavelength locking optical system, a resonator is formed between a wavelength deviation detection device and a facet of the laser diode, which makes a control signal unstable. A solution to this problem is to arrange polarization controlling elements between a wavelength deviation detection filter and a laser diode to stabilize the deviation signal, and to perform wavelength-locking with the stabilizer signal.

Abstract: In aiming at cost lowering of an optical module and an optical transmission apparatus and with the objective of providing a semiconductor light receiving element that has a good coherence with the other edge emitting/incidence type optical devices and is capable of performing the positioning easily and with a high accuracy, in the edge emitting/incidence type light receiving element in which the light absorbing layer 19 has been formed, the space region is formed so as to provide at least 100 &mgr;m2 of the marker detecting region 24, thereby facilitating detection of marker 23 on the optical device 26 and executing the positioning of the light receiving element with a high accuracy, the space region resulting from eliminating a part of the light absorbing layer 19 that absorbs the detection light of the light receiving element, the transmission amount of the detection light toward the marker detecting region that is parallel to a primary plane being equal to 30% or higher, the detection light having penetrat

Abstract: An optical module for use in detecting a plurality of different wavelengths by making use of the multiple wavelength selectivity of an etalon. The optical module includes a semiconductor laser, a lens for converting a beam emitted from the semiconductor laser into a substantially parallel beam, a beam splitter for splitting the converted beam into a reflected beam and a transmitted beam, and a light-receiving element disposed such that one of the split beams is incident thereupon through an etalon, wherein a center of the reflected beam from the etalon occurring as the beam is incident upon the etalon is arranged to return to a region other than a beam-emitting portion of the semiconductor laser.

Abstract: The incident angle of the beam with regard to an etalon is arranged finely tunable by either rotating the etalon provided with a plane of incidence inclined with regard to the rotational axis thereof in the vicinity of the optical axis or rotating a lens whose edge surface is obliquely ground around the optical axis, which allows the incident angle of the laser beam with regard to the etalon to be adjusted and fixed with high precision.

Abstract: A semiconductor laser and an optical fiber are optically coupled via a first lens and a second lens, the second lens is previously fixed to a module package and these parts are mounted to the module package, when focal lengths of the first lens and the second lens are respectively designated by f1 and f2, an optical distance between a principal plane of the first lens on its side of the second lens and a principal plane of the second lens on its side of the first lens, is made substantially equal to f1+f2. Thereby, there is provided an optical transmission module having low price capable of achieving a high coupling efficiency with high yield.

Abstract: The problem of the disclosed technology is that, in a wavelength locking optical system, a resonator is formed between a wavelength deviation detection device and a facet of a laser diode, which makes a control signal unstable.

Abstract: An optical transmission module includes at least one of a light emitting element and a light receiving element, an optical fiber and an optical wave-guide provided between the light emitting element or the light receiving element and the optical fiber. The optical wave-guide has a z-axis in a direction of light propagation, an x-axis in a vertical direction on a cross-sectional plane perpendicular to the z-axis, and a y-axis in horizontal direction thereon. The optical wave-guide includes a core portion formed so that light is transmitted in the direction of the z axis, around at a center of an origin of the x axis and y axis, and a crud layer which surrounds the core portion and is lower in refractive index than a refractive index of the core portion. The core portion includes a plural number of segments, and at least one of the segments has a recess portion.

Abstract: An electronic device, in which terminals of a semiconductor integrated circuit chip and terminals of a circuit substrate are mounted with solder so as to face one another. The electronic device includes a first resin, which is disposed between the circuit substrate and a terminal formation face of the semiconductor integrated circuit chip and a second resin, which is disposed at the outer perimeter of the semiconductor integrated circuit chip or is disposed laterally thereon. The modulus of elasticity of the second resin is smaller than the modulus of elasticity of the first resin, the modulus of elasticity of the second resin is at least 0.5 GPa but not more than 28 GPa at room temperature.

Abstract: An optical transmission module includes a beam spot size expanding waveguide and a beam spot size reducing waveguide adjoining in the light propagating direction, or includes a beam spot size expanding waveguide, a beam spot size retaining waveguide and a beam spot size reducing waveguide aligning in the light propagating direction. Each waveguide has laminated core layers which are formed of materials of different refractive indexes.

Abstract: An optical transmission module includes at least one of a light emitting element and a light receiving element, an optical fiber and an optical wave-guide provided between the light emitting element or the light receiving element and the optical fiber. The optical wave-guide has a z-axis in a direction of light propagation, an x-axis in a vertical direction on a cross-sectional plane perpendicular to the z-axis, and a y-axis in horizontal direction thereon. The optical wave-guide includes a core portion formed so that light is transmitted in the direction of the z axis, around at a center of an origin of the x axis and y axis, and a crud layer which surrounds the core portion and is lower in refractive index than a refractive index of the core portion. The core portion includes a plural number of segments, and at least one of the segments has a recess portion.