Abstract: An optical module includes a ferrule having a slope end surface and supporting an optical fiber penetrated therethrough, a photodetector attached to the slope end surface and optically coupled directly with the optical fiber, a module substrate supporting the ferrule, and a resin package covering the ferrule so that an end of the ferrule protrudes from the resin package.

Abstract: An optical connector comprises a housing having a ferrule holding portion for holding a ferrule to be connected to an optical fiber, wherein said ferrule is equipped with a split sleeve for implementing an alignment with a ferrule of a mate connector, and said ferrule holding portion has a ferrule holding through passage which allows said ferrule to be received along the direction of ferrule diameter, allows said split sleeve to be inserted along the axial direction of said sleeve, and allows said ferrule to be installed into and held to said housing.

Abstract: An optical module including a plurality of leads, a substrate having a first groove and a plurality of conductor patterns electrically connected to the leads, a ferrule having a center hole in which an optical fiber is inserted and fixed, the ferrule being mounted in the first groove of the substrate so that one end of the ferrule projects from an end surface of the substrate, and an optical element mounted on the substrate for making conversion between light and electricity. The optical module further includes a transparent first resin for covering at least the optical element and the other end of the ferrule, and a second resin for enclosing all of the leads, the substrate, the ferrule, the optical element, and the first resin except the one end of the ferrule and a part of each of the leads.

Abstract: An optical semiconductor module structure comprises a housing which has an optical coupling means comprising an optical semiconductor element and a ferrule accommodating an optical fiber therein, a portion of said housing for holding said ferrule being formed to be a protuberant portion, wherein said optical semiconductor module structure is provided with, for coupling an optical connector with said protuberant portion, a means for regulating said optical connector in the direction of the axis of said ferrule and a means for regulating said optical connector in a direction right to the axis of said ferrule.

Abstract: An optical module has a module case in which an optical device and a circuit unit electrically connected to the optical device are mounted. An optical connector of an optical fiber is detachably connected to the module case so as to be in contact with the optical device. The optical module includes a supporting structure supporting the optical device in a state in which the optical device is movable along a line, a force applying mechanism applying a force to the optical device in a direction parallel to the line along which the optical device is movable, and a locking mechanism releasably locking the optical connector pressing the optical device in a direction parallel to the line so as to be in close contact with the optical device, light passing through a boundary between the optical connector and the optical device.

Abstract: A receptacle optical module including a fixed housing adapted to be fixed to a mother board (substrate); an optical semiconductor assembly having an optical semiconductor chip for performing conversion between an optical signal and an electrical signal; a plurality of lead pins fixed to the fixed housing for mechanically fixing the fixed housing to the mother board and electrically connecting the optical semiconductor chip to the mother board; a movable housing pivotably provided on the fixed housing for supporting the optical semiconductor assembly; and a receptacle mechanism for detachably holding an optical connector in the movable housing so as to optically connect the optical semiconductor chip to the optical connector.

Abstract: A crystal substrate, with an adhesive uniformly applied to its entire rear surface, is fixed to the inner wall of an element housing. By adjusting the thickness of a wall of the element housing, forming grooves in the wall, or fixedly attaching a deadweight to the wall, the resonant frequency of the element housing is adjusted so as to restrain the optical waveguide element from resonating. Further, by mounting the optical waveguide device on a printed board via an elastic member or the like, propagation of the vibration to it is suppressed.

Abstract: An optical semiconductor assembly including a metal stem, a hermetic glass substrate fixed to the stem, and a conductive float pad formed on the hermetic glass substrate. The first to third leads are mounted to the stem so as to be insulated from the stem and pass through the stem. An optical semiconductor element is mounted on a lead head of the third lead, and a bare chip IC is mounted on the stem. By using the float pad, screening of the optical semiconductor element is performed during assembly. After completing the assembly, the characteristics of the assembly are checked to thereby perform screening of the bare chip IC. Thus, two independent steps of screening are performed, so that improvement in yield of the completed products can be expected.

Abstract: An optical semiconductor module including a housing (54), an optical semiconductor assembly (56), a movable ferrule (84), and a sleeve (60). The housing (54) has a hole (80) into which a connector ferrule (76) is inserted. The optical semiconductor assembly (56) is accommodated in the housing (54). An optical fiber (74,82) having a first end (82a) and a second end (82b) is fixed in the movable ferrule (84). The movable ferrule (84) has a thin hole (84a) in which the second end (82b) of the optical fiber (82) is inserted and fixed. The first end (82a) of the optical fiber (82) is supported so as to be optically coupled to the optical semiconductor assembly (36). The sleeve (60) is accommodated in the hole (80) of the housing (54), so as to align the movable ferrule (84) and the connector ferrule (76) with each other. The movable ferrule (84) is biased so as to be pressed against the connector ferrule (76) in the sleeve (60).

Abstract: An optical module has a module case in which an optical device and a circuit unit electrically connected to the optical device are mounted. An optical connector of an optical fiber is detachably connected to the module case so as to be in contact with the optical device. The optical module includes a supporting structure supporting the optical device in a state in which the optical device is movable along a line, a force applying mechanism applying a force to the optical device in a direction parallel to the line along which the optical device is movable, and a locking mechanism releasably locking the optical connector pressing the optical device in a direction parallel to the line so as to be in close contact with the optical device, light passing through a boundary between the optical connector and the optical device.

Abstract: The invention provides an improved simplified waveguide-optical fiber connection structure for connecting a waveguide and an optical fiber. The waveguide-optical fiber connection structure comprises an optical fiber, a waveguide substrate having a waveguide integrally formed thereon and having a first guide groove formed thereon adjacent an end portion of the waveguide for positioning the optical fiber therein, and a fiber substrate provided in an opposing relationship to the first guide groove for cooperating with the first guide groove to hold the optical fiber thereon. The waveguide-optical fiber connection structure can be applied to a waveguide circuit which is employed for optical communication, optical information management and so forth.

Abstract: An optical transmitting/receiving module including a light emitting element, a light receiving element, a transmitting optical communication line for transmitting an optical signal, a receiving optical communication line for receiving an optical signal, and a single aspherical lens for coupling the transmitting light emitted from the light emitting element to the transmitting optical communication line and for coupling the receiving light emergent from the receiving optical communication line to the light receiving element. The light emitting element is arranged so that the center line of a beam of the transmitting light emitted from the light emitting element is inclined with respect to the optical axis of the lens. With this arrangement, the optical transmitting/receiving module can be reduced in size.

Abstract: The method of fabricating an optical waveguide device of the present invention is applicable to an optical waveguide device having at least two asymmetric electrodes for applying an electric field to an optical waveguide formed on a substrate of a ferroelectric crystal. The method is characterized by that annealing at a high temperature is carried out for the substrate and the electrodes after the electrodes have been formed on the substrate. The annealing temperature is 100.degree. C. or over, for example. By carrying out such annealing, the operating characteristic of the optical waveguide device, the operating point of a Mach-Zehnder type optical modulator, for example, can be stabilized.

Abstract: Electric discharge breakdown in an optical waveguide pattern formed on a crystal substrate having pyroelectric effect is substantially extinguished or reduced, so that the yield of optical waveguide devices in the manufacturing process can be increased. A plurality of optical waveguide patterns 5 are formed, in parallel, by means of heat treatment on a substrate 2 of lithium niobate having pyroelectric effect, and the formed waveguide patterns are cut into a predetermined chip-shape. In the manufacturing method of this optical waveguide device, patterns are formed so that both ends of the optical waveguide pattern 5 are respectively communicated at a position where both ends of the optical waveguide pattern 5 are out of an effective chip range. Further, a dummy pattern 26 is formed at a position close to a waveguide pattern 25.

Abstract: An insulating buffer layer of SiO.sub.2 is formed on a substrate of LiNbO.sub.3 crystal in which optical waveguides are formed, and a semiconducting film of Si is formed on the buffer layer. An insulating diffusion suppressing layer of SiO.sub.2 is formed on the semiconducting film, and a pair of electrodes of Au are located on the diffusion suppressing layer. The formation of silicide by solid-phase diffusion of the electrodes into the semiconducting film can be prevented by the diffusion suppressing layer.

Abstract: The invention provides an improved simplified waveguide-optical fiber connection structure for connecting a waveguide and an optical fiber. The waveguide-optical fiber connection structure comprises an optical fiber, a waveguide substrate having a waveguide integrally formed thereon and having a first guide groove formed thereon adjacent an end portion of the waveguide for positioning the optical fiber therein, and a fiber substrate provided in an opposing relationship to the first guide groove for cooperating with the first guide groove to hold the optical fiber thereon. The waveguide-optical fiber connection structure can be applied to a waveguide circuit which is employed for optical communication, optical information management and so forth.

Abstract: An insulating buffer layer of SiO.sub.2 is formed on a substrate of LiNbO.sub.3 crystal in which optical waveguides are formed, and a semiconducting film of Si is formed on the buffer layer. An insulating diffusion suppressing layer of SiO.sub.2 is formed on the semiconducting film, and a pair of electrodes of Au are located on the diffusion suppressing layer. The formation of silicide by solid-phase diffusion of the electrodes into the semiconducting film can be prevented by the diffusion suppressing layer.

Abstract: An optical transmitter having a Mach-Zehnder optical modulator comprising a signal electrode fed with a driving signal for effecting modulation and a bias electrode for operating point control. Because the signal electrode and the bias electrode are independent of each other, a driving circuit and the signal electrode can be connected in a DC setup. This permits stable operating point control and improves waveform characteristics.

Abstract: Operating point trimming methods for an optical waveguide modulator and an optical waveguide switch are disclosed. One operating point trimming method for an optical waveguide modulator comprises, for example, the step of removing, while monitoring the waveform of an intensity modulated light beam, a portion of either one of a first and a second electrode such that the intensity modulated waveform takes on a desired waveform. One operating point trimming method for an optical waveguide switch comprises the step of removing a portion of either one of a first and a second electrode while monitoring output light beams.

Abstract: A polarization-independent optical switch/modulator provides a pair of waveguides having mutually parallel portions spaced apart a distance allowing directional coupling therebetween. A set of first electrodes of an embedded type are disposed in the waveguide substrate in the vicinity of both sides of the optical waveguides for controlling polarized light having the electric field component in the direction parallel to the surface of the waveguide substrate. Further, a set of second electrodes are disposed on the optical waveguides for controlling polarized light having the electric field component perpendicular to the surface of the waveguide substrate. The lengths of the first and second electrodes are set to have a predetermined ratio therebetween and the first and second electrodes are connected to a common power source.