Abstract: Laser diodes containing aluminum at high concentration in an active layer have been usually suffered from remarkable facet deterioration along with laser driving operation and it has been difficult for the laser diodes to attain high reliability. An aluminum oxide film lacking in oxygen is formed adjacent to the semiconductor on an optical resonator facet, by which facet deterioration can be minimized and, accordingly, the laser diode can be operated with no facet deterioration at high temperature for long time and a laser diode of high reliability can be manufactured at a reduced cost.

Abstract: The prior art distributed feedback laser having an InGaAlAs active layer involves a problem that its laser characteristics are deteriorated at high temperature due to the high device resistance. According to the present invention, a ridge type laser is fabricated by: forming an InGaAlAs-MQW layer 104 on a n-type InP substrate 101; growing a p-type InGaAlAs-GRIN-SCH layer 105, a p-type InAlAs electron stopping layer 106 and a p-type grating layer 107 in this order on the InGaAlAs-MQW layer 104; forming a grating; and regrowing a p-type InP cladding layer 108 and a p-type InGaAs contact layer in this order. The concave depth of the grating is smaller than the thickness of the p-type grating layer 107.

Abstract: The present invention provides a highly reliable ridge-waveguide semiconductor laser diode and an optical module. The p-side electrode of the ridge-waveguide laser diode has a first conductor layer region and a second conductor layer region formed on the first conductor layer region. At least one of facets of the second conductor layer region is recessed inward from a reflection facet. Thus, the ridge-waveguide semiconductor laser diode has a structure in which strain which is caused by the electrode stress to be applied on the diode facet is reduced and the saturable absorption does not occur. The ridge-waveguide semiconductor laser diode thus obtained is highly reliable, and the optical module using the same is remarkably high in reliability.

Abstract: The present invention relates to an optical transmission module comprising two substrates, each of which has an electronic part mounted on the substrate and a terminal area for inputting/outputting an electric signal into/from the electronic part, wherein an electrical connection is made between the terminal areas of said two substrates by use of a flexible substrate having a structure constituted of at least three layers, and thereby a high frequency signal is transmitted between the electronic part mounted on one substrate and the electronic part mounted on the other substrate through the flexible substrate while confining an electromagnetic field. In addition, the present invention provides an optical transmission module characterized in that a slit formed in a ground plane on a connection section of a three-layer flexible substrate reduces a disturbance in electromagnetic field, making it possible to improve the transmission characteristic of a high frequency signal.

Abstract: A sample & hold type phase detector is used in a CDR IC and, in jitter transfer bandwidth adjustment, VCO output waveforms 90° out of phase with each other can be inputted to the phase detector, whereby a jitter transfer bandwidth can be calculated by only the measurement of frequency and of a DC voltage and it is possible to make a jitter transfer bandwidth adjustment in DC test for IC.

Abstract: For preventing an optical axis from shifting due to a heat cycle in a semiconductor laser module, or in a optical transmitter, the semiconductor laser module comprises, a semiconductor laser element, a frame for storing the semiconductor laser element therein, an optical fiber fixing portion being connected to the frame; and a flange being connected to the frame, and having a fixing portion for fixing the frame on a substrate, wherein the flange has a narrow width region between a fixing region, including a foxing portion with the substrate therein, and the frame, and the narrow width region is narrower than width of the fixing region.

Abstract: In a semiconductor laser module, in order to sufficiently reduce the thermal stress arising in a due to the bonding of elements when they are packaged and to improve the yield of production, the semiconductor laser module is provided with a semiconductor laser element, a submount bonded to the semiconductor laser element with a solder layer in-between and thereby mounted with it, and a base mounted with this submount with another solder layer in-between. Herein, T/W?0.15 holds, where W is the width of the submount in the direction orthogonal to the optical axis of the semiconductor laser element and T is the thickness of the submount.

Abstract: A standard pattern of a differential value of an interference light is set with respect to a predetermined film thickness of a first member to be processed. The standard pattern uses a wavelength as a parameter. Then, an intensity of an interference light of a second member to be processed, composed just like the first member, is measured with respect to each of a plurality of wavelengths so as to obtain a real pattern of an differential value of the measured interference light intensity. The real pattern also uses a wavelength as a parameter. Then, the film thickness of the second member is obtained according to the standard pattern and the real pattern of the differential value.

Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.

Abstract: A semiconductor laser device which ensures high yield, high reliability and high power output by reduction in tensile strain in its active region for improvement in the COD level. The device comprises: a semiconductor crystal-growing portion having an active layer for conversion of electric energy into light energy and a mesa structure protruding on the one side; and an electrode film which is electrically connected with the top face of the mesa structure. The electrode film has a tensile strain and stretches sideward from the mesa structure. In the device, there is a strain control film which is polymerized with the electrode film part stretching sideward from the mesa structure and has a compressive stress.

Abstract: The present invention provides an optical module and a method for manufacturing the optical module, in which a V-shaped or trapezoidal groove having a first slope and a second slope facing to the first slope is formed at the surface of a silicon substrate by anisotropic etching, an adhesive is applied to a portion of at least the second slope in a region except the first slope of the groove, and lens is fixedly put in the groove.

Abstract: There is provided a thin and small size connector-less optical transmission module M which assures excellent high frequency characteristic. This optical transmission module comprises transmission line substrates and a coaxial cable for connecting these transmission line substrates and is connected to the transmission line substrate via a contact sleeve which is provided with projections fixed to the external conductor of the coaxial cable and projected in the extending direction of the coaxial cable. Since an electromagnetic field mode alleviating portion formed of a dielectric material is provided to the core wire of the coaxial cable, the thin and small size optical transmission module M can assure less amount of radiation of an interference electromagnetic wave, high frequency characteristic through connection with the coaxial cable.

Abstract: An optical transmission module includes a housing with a heat radiating fin and a receptacle for being connected to an external optical fiber. The module also includes a coaxial can stem for mounting an optical element and a ceramic printed circuit board. The signal transmission lines are provided on one side of the board, and heat from the coaxial can package is radiated from the radiating fin.

Abstract: An optical transmitter for use in an optical transmitting system based on PDS (Passive Double Star) technology, does not erroneously output an optical signal when the optical transmitter is powered on/off. The optical transmitter has a current source 1 for outputting a drive current having a magnitude corresponding to an input control signal, a Laser diode (LD) for generating an optical output signal based on the received drive current, a modulator 9 for controlling the supply and cutoff of the drive current to the Laser diode (LD), a source voltage detector 3 for monitoring a source voltage to detect whether the source voltage is lower than a predetermined voltage, and a switch circuit 4 for outputting a control signal to the current source 1 to stop the supply of the drive current when the source voltage is determined to be lower than the predetermined voltage.

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: An optical transmitter for use in an optical transmitting system based on PDS (Passive Double Star) technology, does not erroneously output an optical signal when the optical transmitter is powered on/off. The optical transmitter has a current source 1 for outputting a drive current having a magnitude corresponding to an input control signal, a Laser diode (LD) for generating an optical output signal based on the received drive current, a modulator 9 for controlling the supply and cutoff of the drive current to the Laser diode (LD), a source voltage detector 3 for monitoring a source voltage to detect whether the source voltage is lower than a predetermined voltage, and a switch circuit 4 for outputting a control signal to the current source 1 to stop the supply of the drive current when the source voltage is determined to be lower than the predetermined voltage.

Abstract: A control apparatus for stabilizing optical wavelength output by a laser module in which a laser element, temperature sensor and cooling/heating element are installed, comprises a temperature deviation detecting circuit comprising a temperature monitor for detecting a laser temperature, and a first comparator for outputting a first control signal indicating a difference between the laser temperature and a control target value, a wavelength deviation detecting circuit comprising a wavelength monitor for detecting light output from the laser element, and a second comparator for outputting a second control signal indicating a difference between the wavelength of the detected output light and a control target value, a selector circuit for selecting either of the detecting circuits according to the external conditions of the laser element, and a current controller for controlling the current supplied to the cooling/heating element based on the output signal from the selected detecting circuit.

Abstract: There is provided a communications-type car navigation system including a vehicle-mounted terminal and a server. When transferring, to the terminal, the result of a route searching which the server has performed, the server transfers the data that will satisfy the requirements of a route guiding method which the user wishes. Also, the server transfers the route data that has been compressed. Concerning the map data as well, the server transfers only the necessary attributes thereof. Moreover, the following conditions allow the operability to be enhanced: the selection of a map transferring method and the route guiding method where the driving state has been taken into consideration, and the selection of a guiding unit which the user wishes.

Abstract: In the application of the optical transmitter to any system for the compensation of passing degradation, the invention provides the optical transmitter which maintains constant modulator output and the highly reliable optical transmission by tuning, the alpha parameter for given systems. As the optical element back-face output power detected by PD6 depends on the optical element driving current amount, the electronic absorption amount of the EA optical modulator monitored by the electronic absorption monitor depends on the optical output of the optical element 5 and the EA optical modulator driving point of the driving part 8. It is possible to detect a change in the driving point in the EA optical modulator by taking a difference between the amount monitored by the PD 6 and the amount monitored by the electronic absorption monitor.

Abstract: An optical transmitter receiver module and an apparatus incorporating the same module are provided, which realizes the reduction of power consumption and the enlargement of the operating temperature range.