Abstract: Providing an optical transceiver module that reduces electric crosstalk between a light emitting device and a photodetector while providing an excellent high-frequency characteristic, and an optical transceiver including the same. According to the invention, a first metal plate having a first substrate for mounting a light emitting device and a at second metal plate having a second substrate for mounting a photodetector are provided separately and independently of each other in a resin package, thus reducing the parasitic capacitance. This provides an optical transceiver module capable of suppressing electric crosstalk where part of a high-frequency signal causes a variation in the potential at a terminal of a photodetector while improving the high frequency characteristic in driving the light emitting device with a high-frequency signal, and an optical transceiver including the same.

Abstract: Optical transmission apparatus 100 is provided with laser element 101 and optical fiber 102 and has an optimum position where the efficiency of optical coupling between laser element 101 and optical fiber 102 becomes a maximum. Laser element 101 and optical fiber 102 are fixed at positions shifted from the optimum position in the direction of the optical axis by a value within a range from 10 ?m to 150 ?m. It is possible to construct the apparatus such that outgoing light of laser element 101 is not parallel to the optical axis of outgoing light from an end face of optical fiber 102 and the outgoing light of laser element 101 is not parallel to the optical axis of light reflected on the end face of optical fiber 102.

Abstract: In a bidirectional optical module, a technique for attaining a miniaturization and a lower cost of a bidirectional optical module in which one optical fiber propagation path can be bused in two ways is disclosed. According to this technique, a molded product 12 is made of a transparent material, and a beam splitter layer 121 is inclined and embedded. A sub carrier 15 has a stage portion constituting an upper stage and a lower stage and is mounted on a flat top plane of a carrier 19. A semiconductor laser 14 is mounted on the upper stage of the sub-carrier, and a light receiving device 13 is mounted at a lower position of the molded product on the lower stage, and a side of the molded product is mounted on the side, and the respective planes are consequently bonded.

Abstract: A technique to improve degree of freedom in mounting an electrode of an optical device on a wiring substrate without being affected by an angle in the optical fiber circumferential direction of the optical device provided for an optical module is disclosed. According to the technique, an optical device 5, from which a plurality of electrodes 61 to 64 protrude; and a wiring substrate 7, in which a plurality of electrical wirings 10 to connect to the respective plurality of electrodes are formed approximately concentrically are included. Respective ends of the electrodes are connected to the respective plurality of electrical wirings so that distances between the respective ends of the plurality of electrodes and the center of the optical device are different from each other.

Abstract: A laminated piezoelectric element (1) comprises a laminated piezoelectric element (1) piezoelectric layers (11) composed of a ceramic capable of expanding and contracting upon application of a voltage, and internal electrode layers (21a and 21b) that supply voltage to the piezoelectric layers, the internal electrode layers and piezoelectric layers being alternately provided, a first external electrode layer (31) provided on a side of the laminated piezoelectric element (1) and electrically connected with the internal electrode layers (21a and 21b), and a second external electrode layer (32) provided on a side of the laminated piezoelectric element (1) and electrically connected with the internal electrode layers (21a and 21b) via the first external electrode layer (31); wherein, when the maximum width of the laminated piezoelectric element (1) in the direction perpendicular to the direction of lamination is taken to be W0, the width of the first external electrode layer (31) is taken to be W1, and the width o

Abstract: A laminated-type piezoelectric element 1 is provided, which comprises a first external electrode layer 33, which is located at a side area of the laminated-type piezoelectric element 1, is electrically continuous to internal electrode layers 21, and comprises plural expansible and contractible opening portions 33a in a stacking direction of the laminated-type piezoelectric element 1. As the first external electrode layer 33 is connected to the laminated-type piezoelectric element 1 with an electrically conductive adhesive member 32 and the electrically conductive adhesive member 32 is narrower than the first external electrode layer 33, the electrically conductive adhesive member 32 penetrates into the opening portions 33a of the first external electrode layer 33 to form connections in a shape of an anchor. Therefore, the first external electrode layer 33 is firmly connected to the laminated-type piezoelectric element 1.

Abstract: This invention discloses an optical burst transmission system in which an optical generator generates Type 1 lightwaves having different wavelengths corresponding to transmission lines and having undergone intensity modulation with obtained data; a broad spectrum optical generator generates, by incorporating Type 2 lightwaves, a Type 3 lightwave using a fewer light emitting devices than the number of the Type 1 lightwaves, each Type 2 lightwaves having a corresponding wavelength apart from Type 1 lightwave's wavelength with an FSR interval and having undergone the intensity modulation with clock signals; an optical multiplexer multiplexes the Type 1 and Type 3 lightwaves to output the combination to each transmission line; and an optical routing unit extracts, from the combination, pairs of one Type 1 lightwave and one Type 2 lightwave having the corresponding wavelength, and guides pairs to each transmission line corresponding to the Type 1 lightwave's wavelength in each pair.

Abstract: A small-sized optical transceiver module, wherein any stress attributable to the differences in coefficient of thermal expansion between a transmission section optical system, a receiving section optical system, and the components which integrate and fix them and the like is not applied therebetween, and which is not influenced by any stress at the time of attachment/detachment of the optical connector is disclosed.

Abstract: A circuit construction for maintaining a constant extinction ratio of a laser diode for converting a high-speed burst signal to an optical signal is disclosed. In this construction, control is made so that a difference between average optical power of burst #1 wherein a modulation current Im is set to a regular value and average optical power of burst #2 wherein a modulation current is slightly increased becomes equal to a reference value, and further control is made so that average optical power of burst #3 wherein the modulation current Im is set to the regular value is equal to a reference value.

Abstract: A two-input logic gate circuit suitable for extremely high-speed operation, which operates on two differential signal pairs expressing respective logic inputs, includes a control signal generating circuit which converts the input differential signal pairs to two sets of differential control signal pairs respectively having first and second level ranges, to be supplied to a current switching section.

Abstract: A power converter apparatus converts electricity supplied from a power source into a different form and outputs the electricity to an output line. The apparatus includes a ground-fault detector and a simulated ground fault generator. When the ground fault detecting signal is output within an predetermined time and the output of the ground fault detecting signal is stopped as the simulated ground fault generator stops operating, a control section causes the power section to continue outputting electricity. When the signal is not output within the predetermined time or when the output of the signal is not stopped as the generator stops operating, the control section stops the power section. Therefore, the apparatus detects abnormality in the ground fault detector and continues supplying electricity without interruption when the detector is in a normal state.

Abstract: The present invention discloses an optical transmitting/receiving module designed in small size and produced at low cost without the need to use an optical waveguide, which requires complicated process and larger area, and the invention also discloses a method for manufacturing such an optical transmitting/receiving module. According to the present invention, a V-groove running in linear direction and a vertical groove (a groove having vertical side surfaces) crossing obliquely said V-groove at the end of the V-groove, an optical fiber core is arranged to the end of the V-groove, a wavelength selective filter is arranged in the vertical groove, and a light emitting element and a light receiving element are arranged respectively in transmitting direction and reflecting direction of the wavelength selective filter.

Abstract: The invention provides a bidirectional optical module which can enable bidirectional utilization of one optical fiber transmission channel with low-cost, and an optical transmission device using it. This optical module comprises a light receiver, wherein a photo acceptance unit is optically coupled with a light output part obtained by cutting an optical fiber in the middle thereof aslant an optical fiber core, and inserting a filter/half mirror between obtained cross sections of the core; and a light transmitter, wherein a light emitting device is optically coupled with one end of the optical fiber. The light receiver is set to have a receptacle structure having a ferrule in which the other end of the optical fiber is inserted from inside, and which can physically contact with an optical connector.

Abstract: The present invention provides a piezoelectric actuator with excellent durability. In the present invention, a piezoelectric element 2 in which a plurality of piezoelectric layers that expand in accordance with an applied voltage, and internal electrode layers for supplying an applied voltage, are alternately laminated, and at least a part of the side surfaces 201 and 202 thereof is covered by an external packaging resin 25, the piezoelectric element 2 being housed in a sealed container 11 that substantially isolates it from the external atmosphere, and in which the internal atmosphere 19 is replaced by an inert gas. Alternatively, the piezoelectric element 2 is housed in a sealed container 11 that substantially isolates it from the external atmosphere, and the external packaging resin 25 includes an antioxidant.

Abstract: In an optical transmitter comprising a laser module including a laser diode and a monitor photodiode, a laser drive circuit for supplying a drive current to the laser module and an APC circuit for applying a bias current to the laser module on the basis of a detection signal from the monitor photodiode so that the output level of the laser module becomes constant, there is further provided an extinction ratio control circuit including an RF signal generating circuit, a low-pass filter and a peak detecting circuit. The extinction ratio control circuit superimposes an RF signal on an input data signal to the laser drive circuit to control the amplification degree of the laser drive circuit on the basis of the RF signal of the detection signal from the monitor photodiode so that the extinction ratio of the output light from the laser module becomes constant.

Abstract: The present invention provides a one-core bidirectional optical transmitting/receiving module for wavelength multiplexing, which does not require optical waveguide fabricated with high precision and which has superb high frequency characteristics and has very low optical and electrical crosstalks and available at low cost. At the middle of an optical fiber 1 buried in a glass substrate 3, a light irradiating portion is provided, which has a wavelength selection filter 2 placed obliquely to the optical fiber. The light irradiating portion is fixed immediately above a backside entrance type photodetection element 4 mounted on a ceramic substrate 6 by flip-clip bonding, and only optical signals with specific wavelength are received. An optical fiber extra portion 7 between a photodetection unit and a light emitting unit has sufficient length, and an end of the optical fiber is optically coupled with the light emitting element.

Abstract: This invention discloses an optical burst transmission system in which an optical generator generates Type 1 lightwaves having different wavelengths corresponding to transmission lines and having undergone intensity modulation with obtained data; a broad spectrum optical generator generates, by incorporating Type 2 lightwaves, a Type 3 lightwave using a fewer light emitting devices than the number of the Type 1 lightwaves, each Type 2 lightwaves having a corresponding wavelength apart from Type 1 lightwave's wavelength with an FSR interval and having undergone the intensity modulation with clock signals; an optical multiplexer multiplexes the Type 1 and Type 3 lightwaves to output the combination to each transmission line; and an optical routing unit extracts, from the combination, pairs of one Type 1 lightwave and one Type 2 lightwave having the corresponding wavelength, and guides pairs to each transmission line corresponding to the Type 1 lightwave's wavelength in each pair.

Abstract: The present invention discloses an optical transmitting/receiving module designed in small size and produced at low cost without the need to use an optical waveguide, which requires complicated process and larger area, and the invention also discloses a method for manufacturing such an optical transmitting/receiving module. According to the present invention, a V-groove running in linear direction and a vertical groove (a groove having vertical side surfaces) crossing obliquely said V-groove at the end of the V-groove, an optical fiber core is arranged to the end of the V-groove, a wavelength selective filter is arranged in the vertical groove, and a light emitting element and a light receiving element are arranged respectively in transmitting direction and reflecting direction of the wavelength selective filter.

Abstract: A technique for driving a laser diode on the basis of automatic power control (APC) is disclosed. The technique uses, for the bottom level feedback control, a constant reference voltage instead of a variable intermediate signal generated in the peak level feed back control. The constant reference voltage may be either a reference voltage for the peak level control or a separately generated voltage. A technique for setting the extinction ratio to 1/n is also disclosed.

Abstract: A technique for driving a laser diode on the basis of automatic power control (APC) is disclosed. The technique uses, for the bottom level feedback control, a constant reference voltage instead of a variable intermediate signal generated in the peak level feed back control. The constant reference voltage may be either a reference voltage for the peak level control or a separately generated voltage. A technique for setting the extinction ratio to 1/n is also disclosed.