Abstract: For multichannel optical communications system, an optical communications module comprises a first story in a lower insulating case and a second story in an upper insulating case, allocating either story for an LD set having an optical connector, a silicon bench with lightwaveguides, a WDM (wavelength division multiplexer), LDs and an LD leadframe with leadpins, and the other story for a PD set having PDs and a PD leadframe with leadpins. Another optical communications module comprises a first story in a lower insulating case and a second story in an upper insulating case, allocating either story for an LD set having an optical connector, a silicon bench with lightwaveguides, a beamsplitter, LDs and an LD leadframe with leadpins, and the other story for a monitoring PD set having monitoring PDs and a PD leadframe with leadpins. The both stories are filled with a transparent resin and the both cases are molded with another hard resin.

Abstract: A method of manufacturing an optical communication module, and a mold and a lead frame that are suitable for the method are provided. The method comprises the steps of: placing in a mold the lead frame on which a ferrule and an optical communication facility section are mounted; pressing the ferrule by a moving part that can be stopped at a given position relative to the mold (lower mold tool) such that the distal end of the ferrule is positioned at a proper location within the mold; and filling a resin into the mold, wherein a displacement and a reactive force generated in the lead frame when it is pressed are absorbed by springs provided in the lead frame when it is pressed are absorbed by springs provided in the lead frame such that a catching portion for coupling to a connector is formed with high accuracy at a proper position relative the distal end of the ferrule.

Abstract: An optical transmission module is constructed in a configuration wherein a semiconductor laser is mounted on a stem-side emitter loading portion of a pole provided on a stem and wherein light emitted forward from the semiconductor laser is outputted through a condenser lens and others. A monitor photodiode is mounted on a receiver loading portion of the pole on the forward side of the semiconductor laser and the photodiode detects part of the light emitted forward from the semiconductor laser, to monitor the operating condition of the semiconductor laser. This configuration achieves decrease in the length of a lead pin and thus restrains deterioration of the waveform of the drive current to the semiconductor laser.

Abstract: A producing method an optical module is carried out as shown below. First, an optical-communication functional portion is disposed on a lead frame where each lead is held by an insulating connection leads. A screening test for the optical communication functional portion is performed. A product selected through a screening test process is packaged. In the above-mentioned method, the connection leads which are electrically insulated with one another and the screening test is performed before packaging or encapsulating. Consequently, the waste accompanied by discarding the component elements of the optical module, which has caused an increase in the cost, can be eliminated. Further, an attempt to reduce the cost of products can also be made.

Abstract: An optical receiver comprises (a) an optical fiber, (b) a rear-illuminated type PD for receiving incoming light emerging from the optical fiber, (c) a submount supporting the PD, (d) a coaxial type package housing the submount, and (e) a preamplifier IC for amplifying electric signals from the PD. In particular, the submount is provided with a reflecting face for reflecting the incoming light so that the light can enter the PD. The submount may be provided with an optical path-forming groove having at least one reflecting face for introducing and reflecting the incoming light so that the light can enter the light-receiving portion of the PD mounted on the submount. This structure enables the production of an optical receiver most suitable for high-speed response and excellent in productivity. A method of producing the optical receiver is also offered.

Abstract: The electric circuit unit has a module having an electric or optical signal processing function. Between two parallel circuit boards, the module is bonded thereto and has an electric connection structure or an optical connection structure. This provides a small-size electric circuit unit with component elements mounted at high density.

Abstract: A light emitting device has a fiber stub component, a grating chip, a semiconductor optical amplifier, a photodiode, and a mount member. The fiber stub component is comprised of a ferrule and an optical fiber. The fiber stub component, grating chip, and semiconductor optical amplifier are mounted on the mount member and are optically coupled to each other. An optical cavity is comprised of a light reflecting surface of the semiconductor optical amplifier and a diffraction grating of the grating chip. In this configuration, the light emitting device can provide laser light of a desired wavelength, without use of a pigtail fiber. The light emitting device can be constructed in smaller size than those using the pigtail fiber.

Abstract: The optical communication module comprises a laminated lead frame composed of a plurality of lead frames that are laminated and held by a tie bar made of an insulating material, and an optical communication functional unit that is disposed on at least one layer of the lead frame. The optical communication functional unit comprises at least one of a light emitting element (LD) and a light receiving element and an optical transmission medium (optical fiber).

Abstract: In optical module 1a, substrate 3 has first and second regions 3a, 3b and first and second optical waveguides 3c, 3d. First and second regions 3d, 3e are arranged along a predetermined plane. First and second optical waveguides 3d, 3e are provided in the first region 3a and extend in a direction of a predetermined axis. Semiconductor light emitting device 7 includes a semiconductor light emitting element 7a optically coupled to first optical waveguide 3c and provided in second region 3e. Semiconductor driving element 9 is electrically connected to semiconductor light emitting element 7a. Semiconductor driving element 9 is mounted on mount member 13. Light receiving element 15a reflects a part of incident light and transmits a part of the incident light, and semiconductor light receiving device 17 includes a light receiving element 17a provided in first region 3a so as to be optically coupled to optical element 15a.

Abstract: An optical receiver comprises a PD for receiving an incident light from an optical fiber, a preamplifier IC for amplifying an electrical signal from the PD, a submount on which the PD and the preamplifier IC are mounted on the same plane, and a package on which the submount is mounted. The PD and the preamplifier IC are directly connected to each other by a wire, and these components are both mounted on the same submount. Therefore, the distance between the PD and the preamplifier IC can be reduced, and parasitic inductance, parasitic capacitance, etc. can be greatly reduced. As a result, an optical receiver is provided which has reduced parasitic inductance and parasitic capacitance, and which is optimum for high speed response.

Abstract: An optical communications module in which electrical crosstalk is reduced. The term “optical communications module” represents a surface-mounting-type optical tranceiver, transmitter, or receiver module. The optical communications module has a following structure. (a) An Si substrate carries at least one signal-transmitting section comprising an LD, at least one signal-receiving section comprising a PD, or both together with other components. (b) An insulating substrate is bonded to the back face of the Si substrate. (c) A separating groove separates the Si substrate along the or each boundary line between the sections in order to prevent an AC current flowing through the Si substrate. To attain this object, the separating groove is provided from the top surface of the Si substrate to some midpoint of the insulating substrate.

Abstract: A three-storied structure optical communications module having a top case, a middle case and a bottom case which are piled and coupled in a vertical direction. The middle case has a silicon bench with M (channel number) lightwaveguides, a first WDM1, a second WDM2, M (channel number) laser diodes for generating transmitting signals &lgr;1. The top case has a set of &lgr;2 receiving photodiodes PD1s of the channel number M. The bottom case has another set of &lgr;3 receiving photodiodes PD2s. &lgr;2 signal beams and &lgr;3 signal beams propagating in optical fibers go into the lightwaveguides on the middle case. The &lgr;2 signal beams are reflected midway on the lightwaveguides by the WDM1 upward to the photodiodes PD1s on the top case and are converted into photocurrents by the photodiodes PDs. The &lgr;3 signal beams are reflected halfway on the lightwaveguides by the WDM2 downward to the photodiodes PD2s and are converted into photocurrents by the photodiodes PD2s.

Abstract: Standardized multichannel optical fiber has a pitch 250 &mgr;m (P1). Mounting of optoelectronic device chips requires a pitch P2 larger than P1. The pitch of element fibers should be enlarged for coupling a multichannel ribbon fiber to a multichannel PD or LD module having photodiodes or laser diodes of the channel number M. The module includes a connector maintaining M (channel number) fibers with tails extending backward, a bench having M V-grooves aligning at the pitch P2 larger than the pitch P1 for receiving the tails of the fibers, M lightwaveguides aligning at the pitch P2 following the V-grooves and M photodiodes or laser diodes following the lightwaveguides and a package containing the connector at a front part, the fiber tails at a width enlarging region for converging the pitch from P1 to P2 and the bench at a back part.

Abstract: The object is to provide an optical module for optical transmission which has a double resin structure wherein a transparent resin and a fixing resin are combined, which is low in price, and is easily produced. A package with a inside-and-outside double structure comprising an inner container having barriers filled with a transparent resin and a hard outer container formed of a fixing resin. The inner container stores the highly fluid transparent resin and prevents it from flowing out. The outer container provides mechanical strength and airtightness.

Abstract: An optical communication module having a roughened bottom of a silicon bench for suppressing optical crosstalk. The roughened bottom prevents stray laser beams from reflecting toward a photodiode. The roughened bottom is further covered with a photoabsorbent resin, pigment or adhesive for absorbing the stray laser beams at a bottom. A cladding of a lightwaveguide are narrowed and are painted with a photoabsorbent resin, pigment or adhesive for absorbing horizontally stray beams propagating in the cladding.

Abstract: A method of manufacturing electrode foil for aluminum electrolytic capacitors and an AC power supply unit used therewith are disclosed. An etching is performed on an aluminum foil immersed in an electrolytic solution by applying an AC current to a pair of electrodes in the electrolytic solution. A waveform of the AC current is a deformed sine wave including a period of time (a) when an electric current rises from zero to a peak value, and another period of time (b) when the electric current falls from the peak value to zero. With the periods of time (a) and (b) made different from each other, the surface area of the aluminum foil is efficiently expanded by the etching and an enhancement of electric capacity of the electrode foil is obtained.

Abstract: An optical communication module, such as an optical transmitter used for optical communication incorporating a semiconductor laser (LD) and a monitoring photodiode (MPD), and an optical transceiver including a photodiode (PD), is efficiently and inexpensively provided. As means therefor, two substrates are used, that is, an expensive and high-accuracy first substrate is accommodated in an recess provided in a second substrate that is inexpensive and that needs less accuracy. An optical transmission system is mounted on the first substrate, and the MPD is mounted on the second substrate having an inclined surface provided on an opposite side of the recess in terms of the optical transmission direction. This eases production work and simultaneously allows the decreaseed use of expensive substrates.

Abstract: A transmitting and receiving module helps reduce electrical crosstalk and noise during transmitting and/or receiving signals. Electrical isolation among metallized electrodes in a surface-mounted module with an optical fiber and an optical device can be achieved by using a low resistivity Si substrate, providing ground terminals on the surface of the Si substrate, and grounding the Si substrate. Noise and crosstalk during transmitting and receiving signals can be reduced by providing a copper contact adhered to the bottom surface of the Si substrate and by grounding.

Abstract: An LD/PD module having a main silicon substrate having a cavity, a transmitting portion having an LD and an LD driving IC which is directly mounted upon the main silicon substrate, and a receiving portion having a PD and an amplifier which is indirectly mounted upon the main silicon substrate via an auxiliary insulating substrate embedded in the cavity. The auxiliary insulating substrate suppresses current-induced crosstalk from the transmitting portion to the receiving portion.

Abstract: The electric circuit unit has a module having an electric or optical signal processing function. Between two parallel circuit boards, the module is bonded thereto and has an electric connection structure or an optical connection structure. This provides a small-size electric circuit unit with component elements mounted at high density.