Abstract: In a conventional EA/DFB laser, since the temperature dependence of the operation wavelength of the EA portion is substantially different from that of the DFB portion, the temperature range over which a stable operation is possible is small. In the case of using the EA/DFB laser as a light emission device, an uncooled operation is not possible. An EA/DFB laser which does not require a temperature control mechanism is proposed. A quantum well structure in which a well layer made of any one of InGaAlAs, InGaAsP, and InGaAs, and a barrier layer made of either one of InGaAlAs or InAlAs is used for an optical absorption layer of an EA modulator. By properly determining detuning at a temperature of 25° C. and a composition wavelength of the barrier layer in the quantum well structure used for the optical absorption layer, it can be realized to suppress the insertion loss, maintain the extinction ratio, and reduce chirping simultaneously over a wide temperature range from ?5° C. to 80° C.

Abstract: In a multi-beam semiconductor laser device, relative difference in shear strain applied to each of light-emitting portions of a laser chip mounted on a submount is suppressed, thereby reducing relative difference in polarization angle. A semiconductor laser element array mounted on a submount has a structure in which a semiconductor layer having two ridge portions is stacked on a substrate, and Au plating layers are formed on the surfaces of p type electrodes formed on the ridge portions. In each of the ridge portions, a central position of the Au plating layer in a width direction is intentionally displaced with respect to a central position of the underlying light-emitting portion in a width direction, so that shear strain is applied to each of the light-emitting portions at a stage before the semiconductor laser element array is mounted on the submount.

Abstract: An optical module having a flexible substrate having, even after actual manufacturing steps, excellent transmission characteristics of high-frequency signals and an advantage that electromagnetic field radiation is reduced even when it is connected with a package. The flexible substrate used in external connection of the package of the optical module uses a flexible substrate having a coplanar line to which a lead pin is fixedly attached, a grounded coplanar line which is in contact with the coplanar region, and a microstrip line which is in contact with the grounded coplanar line. The flexible substrate has an electrode layout in which an electromagnetic field component of a surface ground line and a signal line is more dominant than an electromagnetic field component of a back-surface ground line and the signal line in a region of the coplanar line adjacent to the grounded coplanar line.

Abstract: There is provided a pluggable module having grooves, on lateral faces, for latching with a cage and engaging portions for detachment, wherein the module body is detached from the cage by using a module detaching unit which is inserted along the grooves and which locks the engaging portions of the module body in the length direction. Further, there is provided a detaching jig including: latch release portions which are inserted between the pluggable module and the cage; lock portions which allow the pluggable module to be locked in the detaching direction; and a handle portion for detaching the pluggable module from the cage.

Abstract: The invention aims at realizing a 1300-nm-band direct modulation laser, having a single lateral mode, in which a chip light power of several milliwatts and a low current operation are simultaneously realized. Also, the invention aims at realizing a laser light source excellent in economy as well by realizing output characteristics of a vertical cavity surface light emitting laser. A distributed Bragg reflector laser is constructed in the form of a semiconductor laser having a multilayer structure formed on a predetermined semiconductor substrate. The multilayer structure includes an active region for emitting a laser beam, and a distributed Bragg reflector layer. A length of the active region falls within the range of 10 to 100 ?m, and a laser light beam is generated in accordance with ON/OFF of current injection to the active region.

Abstract: A semiconductor laser diode device with small driving current and no distortion in the projected image.

Abstract: In an InGaN-based nitride semiconductor optical device having a long wavelength (440 nm or more) equal to or more than that of blue, the increase of a wavelength is realized while suppressing In (Indium) segregation and deterioration of crystallinity. In the manufacture of an InGaN-based nitride semiconductor optical device having an InGaN-based quantum well active layer including an InGaN well layer and an InGaN barrier layer, a step of growing the InGaN barrier layer includes: a first step of adding hydrogen at 1% or more to a gas atmosphere composed of nitrogen and ammonia and growing a GaN layer in the gas atmosphere; and a second step of growing the InGaN barrier layer in a gas atmosphere composed of nitrogen and ammonia.

Abstract: A super-lattice structure is used for a portion of a laser device of a self-aligned structure to lower the resistance of the device by utilizing the extension of electric current in the layer, paying attention to the fact that the lateral conduction of high density doping in the super-lattice structure is effective for decreasing the resistance of the laser, in order to lower the operation voltage and increase the power in nitride type wide gap semiconductor devices in which crystals with high carrier density are difficult to obtain and the device resistance is high.

Abstract: Disclosed are a wavelength tunable filter and a wavelength tunable laser module that are of a codirectional coupler type whose characteristics do not significantly vary with a process error. They are structured so as to include a semiconductor substrate which has a first optical waveguide and a second optical waveguide. The first and the second optical waveguide are extended from a first side of the semiconductor substrate to an opposing second side thereof. The first optical waveguide includes a first core layer, which has a planar layout having periodic convexes and concaves, and a pair of electrodes, which vertically sandwich the first core layer. The second optical waveguide includes a second core layer, which has a lower refractive index than the first core layer. Further, a layer having the same composition and film thickness as the second core layer is placed under the first core layer.

Abstract: Included are: a gain chip having a gain unit and a phase control region; a current supply for causing a positive current to flow to the phase control region; a voltage supply for applying a bias voltage to the phase control region; and a control unit for selectively driving the current supply or the voltage supply depending on a direction of the wavelength shift. The control unit drives the current supply when a laser wavelength is to be shifted to a shorter wavelength side from a wavelength with the current supply and the voltage supply being turned off, and drives the voltage supply when the laser wavelength is to be shifted to a longer wavelength side from a wavelength with the current supply and the voltage supply being turned off.

Abstract: A wavelength tunable laser module for DWDM is used, in which a single electroabsorption modulator integrated laser is mounted and an oscillation wavelength is made tunable by temperature control. Driving conditions of a laser and a modulator are determined such that they have approximately the same modulation and transmission characteristics in a temperature control range. Such an electroabsorption modulator integrated laser is used and the driving conditions are incorporated, thereby a small, inexpensive wavelength tunable optical transmitter can be provided.

Abstract: An opto-semiconductor device. An opto-semiconductor element includes a semiconductor substrate, a multilayered semiconductor layer formed on a first surface of the semiconductor substrate and having a resonator, a first electrode with multiple conductive layers formed on the multilayered semiconductor layer, and a second electrode formed on a second surface of the semiconductor substrate. A support substrate has a first surface formed with a fixing portion having a conductive layer for fixing the first electrode connected thereto through a bonding material. Bonding material and conductive layers forming the first electrode react to form a reaction layer. The difference in thermal expansion coefficient between semiconductor substrate and support substrate is not more than ±50%. A second barrier metal layer not reactive with bonding material is formed inside the first electrode uppermost conductive layer, while uppermost layer reacts with the bonding material to form the reaction layer.

Abstract: The optical module comprises a device mounted with a photoelectric element and a receptacle to optically connect this device and an optical fiber is provided. The receptacle comprises a device holder at its one end, allows the device holder to be fitted to the top end side of the device, and fixed and held through the interposition of the ultraviolet curing resin. The device holder comprises a window area relatively large in an amount of ultraviolet transmission dispersedly arranged on the entire periphery of the fitted portion with the device.

Abstract: An optical transmission module mounted pluggably to a cage having an opening. The optical transmission module comprises a gasket on at least a part of an outer periphery of the module. The gasket is deformed depending on temperature change. The gasket is deformed according to temperature rise in a direction toward an inner wall of the cage to push the inner wall and deformed according to temperature drop in an opposite direction to the direction.

Abstract: In the optical integrated devices with ridge waveguide structure based on the conventional technology, there occur such troubles as generation of a recess in a BJ section to easily cause a crystal defect due to the mass transport phenomenon of InP when a butt joint (BJ) is grown, lowering of reliability of the devices, and lowering in a yield in fabrication of devices. In the present invention, a protection layer made of InGaAsP is provided on the BJ section. The layer has high etching selectivity for the InP cladding layer and remains on the BJ section even after mesa etching.

Abstract: Provided is a metal casing structure capable of avoiding a cavity resonance at 10 GHz and 20 GHz by controlling an eigenmode frequency in an inner space of a casing without involving an increase in cost, and a 10 Gbit/s optical transceiver module which achieves reduction in unnecessary electromagnetic waves and cost. In the optical transceiver module, a metal casing having a cavity therein is formed by an upper casing (100) and a lower casing (101), a metal partition wall (103, 104) is provided on at least one of the upper casing (100) and the lower casing (101) near a central portion of the casing in a direction parallel to a direction connecting a front and a rear thereof, and a length of a gap between the partition wall (103, 104) and a printed circuit board (102) is adjusted.

Abstract: In an optical semiconductor device that emits or receives light substantially perpendicularly to or in parallel to an active surface formed on a semiconductor substrate, the optical semiconductor device, an electrode that is formed on the active surface side and connected to the active surface is stepped or tapered at an end of the electrode. The electrode of the optical semiconductor device is formed of three layers including an adhesive layer, a diffusion prevention layer, and an Au layer, and the stepped configuration or the taped configuration is formed by a difference of the thickness of the Au layer or the thickness of the adhesive layer/diffusion prevention layer/Au layer.

Abstract: In a mesa type PIN-PD formed using a heavily doped semiconductor material, a high frequency response is degraded as slow carriers occur in a heavily doped layer when light incident into a light receiving section transmits through an absorbing layer and reaches the heavily doped layer on a side near the substrate. In a p-i-n multilayer structure, a portion corresponding to a light receiving section of a heavily doped layer on a side near a substrate is previously made thinner than the periphery of the light receiving section by an etching or selective growth technique, over which an absorbing layer and another heavily doped layer are grown to form the light receiving section of mesa structure. This makes it possible to form a good ohmic contact and to realize a PIN-PD with excellent high frequency response characteristics.

Abstract: Provided are an optical transceiver and a projection covering member that can suppress EMI noise radiated from a pig-tail part. An elastic covering member for covering a projection which includes an optical coupler of an optical sub assembly is made of a conductive elastic material having predetermined resistivity. At least a part of an outer circumference surface of the elastic covering member comes into intimate contact with an outer periphery of a conductive opening part of a case while an inner circumference surface of the elastic covering member contacts with the projection.

Abstract: A fabrication process for a semiconductor device including a plurality of semiconductor layers, the plurality of semiconductor layers including at least a nitrogen-containing alloy semiconductor AlaGabIn1-a-bNxPyAszSb1-x-y-z (0?a?1, 0?b?1, 0<x<1, 0?y<1, 0?z<1), and a method of making the semiconductor device and apparatus. For at least two semiconductor layers out of the plurality of semiconductor layers, a value of lattice strain of said at least two semiconductor layers is set at less than a critical strain at which misfit dislocations are generated at an interface between said two adjacent semiconductor layers.