Abstract: An electronic circuit device includes a negative resistance generating circuit, a second transistor and a path. The negative resistance generating circuit has a first transistor having a control terminal coupled to a resonator. The second transistor has a control terminal coupled to an output terminal of the first transistor and has an output terminal coupled to a DC bias terminal. The path is coupled to between the DC bias terminal and an output terminal of the first transistor through the second transistor and provides a bias to the first transistor.

Abstract: A semiconductor device has an electrode pad, a capacitor and a substrate. The substrate has a given area on which the electrode pad and the capacitor are arranged. The electrode pad and the capacitor are arranged on the substrate so that each of at least two sides of the capacitor and each of at least two sides of the electrode pad is adjacent to each other at a given interval. The capacitor has a connecting side that connects the two sides of the capacitor and faces to the electrode pad. Outside angles of the capacitor formed by the connecting side and the two sides of the capacitor are more than 90 degrees.

Abstract: An optical module includes a light-emitting element, a light-receiving element, and a reflector. The light-emitting element and the light-receiving element are mounted in the optical module, and the reflector composed of a wire or a ribbon reflects and guides an emitted light to a light-receiving surface.

Abstract: A manufacturing method of a light-emitting element includes emitting a laser light to a division region for separating a light-emitting element formed on a substrate, physically dividing the substrate along the division region, and removing a surface layer on at least one of the side faces of the substrate that is exposed by the dividing of the substrate.

Abstract: An optical axis adjusting method for adjusting a tilt angle of an optical axis in two regions optically coupled in a holding member includes the steps of: roughly adjusting the optical axis by irradiating a first region on the holding member with a laser beam; and finely adjusting the optical axis by irradiating a second region on the holding member with a laser beam. One of the two regions is set as a reference point. The first region is located closer to the reference point, while the second region is located further from the reference point.

Abstract: A semiconductor photo detecting element includes a PIN-type photo detecting element and window semiconductor layer. The PIN-type photo detecting element has a semiconductor substrate, a first semiconductor layer, a second semiconductor layer and a third semiconductor layer. The first semiconductor layer is provided on the semiconductor substrate, is lattice-matched to the semiconductor substrate, includes a first conductivity type dopant, and has first band gap energy. The second semiconductor layer is provided on the first semiconductor layer, has the first band gap energy, and has a concentration of the first conductivity type dopant lower than that of the first semiconductor layer or is substantially undoped. The third semiconductor layer is provided on the second semiconductor layer. The window semiconductor layer has second band gap energy larger than the first band gap energy at a light-incoming side with respect to the second semiconductor layer and has a thickness of 5 nm to 50 nm.

Abstract: A semiconductor device includes: a semiconductor substrate having a source region and a drain region; and an offset region that is provided in the semiconductor substrate and extends from an edge of a gate electrode toward the drain region. The offset region includes multiple regions having different impurity concentrations formed by an ion implantation with a mask having an opening ratio that changes from the gate electrode to the drain region and by subsequent thermal treatment. The multiple regions include a concentration gradient region that is interposed between adjacent ones of the multiple regions and has the impurity concentration that gradually changes.

Abstract: A laser device includes a cavity and a control portion. The cavity has an optical amplifier, a wavelength selectable portion having a changeable transmission wavelength range, and a mirror. The control portion controls the wavelength selectable portion so that the transmission wavelength range of the wavelength selectable portion is changed to a given range. The control portion controls the wavelength selectable portion so that the cavity outputs a desirable lasing wavelength light and optical intensity of the desirable lasing wavelength light is a given value, after controlling the wavelength selectable portion so that the cavity outputs the desirable lasing wavelength light.

Abstract: An electronic device includes a first transmission line, a second transmission line and a ground-coupling portion. The first transmission line is composed of a first signal line transmitting a given high frequency wave signal and a first ground. The second transmission line is composed of a second signal line transmitting the high frequency wave signal and a second ground. The ground-coupling portion couples the first ground and the second ground. A phase difference between the high frequency wave signals at both ends of the ground-coupling portion is substantially integral multiple of 180 degrees.

Abstract: A semiconductor light-receiving device includes: a first conduction layer of a first conduction type; a light absorption layer provided on the first conduction layer; a multiplication layer provided on the light absorption layer; a window layer provided on the multiplication layer, the window layer being undoped or having the first conduction type; and a second conduction region provided in the window layer by impurity diffusion, the second conduction region having a band gap wider than that of the light absorption layer and having a second conduction type different from the first conduction type. The following condition is satisfied: X/W?(M?1)2/(2M) where W is a film thickness from a lower surface of the light absorption layer and an upper surface of the multiplication layer, X is a film thickness of the second conduction region, and M is a multiplication factor.

Abstract: A laser module has an optical amplifier, a first etalon and a wavelength selectable mirror. The first etalon has wavelength peaks at a given wavelength interval in transmission characteristics and transmits a light from the optical amplifier. The wavelength peaks are tunable. The wavelength selectable mirror acts as an external mirror of an external cavity laser including the optical amplifier, and has a relatively high reflection intensity at a part of wavelength range in an effective gain range of the optical amplifier. The effective gain range of the optical amplifier includes more than one wavelength peak of the first etalon. A reflection bandwidth where the wavelength selectable mirror has a relatively high reflection intensity is less than twice of the wavelength interval of the wavelength peaks of the first etalon.

Abstract: A semiconductor laser has first and second diffractive grating regions. The first diffractive grating region has segments, has a gain, and has first discrete peaks of a reflection spectrum. The second diffractive grating region has segments combined to each other, and has second discrete peaks of a reflection spectrum. Each segment has a diffractive grating and a space region. Pitches of the diffractive grating are substantially equal to each other. A wavelength interval of the second discrete peaks is different from that of the first discrete peaks. A part of a given peak of the first discrete peaks is overlapped with that of the second discrete peaks when a relationship between the given peaks of the first discrete peaks and the second discrete peaks changes.

Abstract: A testing system includes: a plurality of test applying portions that operate a test device to make an output signal from the test device; a plurality of testing portions that test the output of the test device; and a test applying portion having a test device to output a tested signal; and a switch portion that switches the output signal between the test applying portions and the testing portions. The switch portion includes: (1) a first switch having an input port and a plurality of output ports, and selects the output port for connecting the input port; (2) a second switch having a plurality of input ports and an output port, and selects the input port for connecting the output port; and (3) a connecting portion that has a plurality of transmission parts that connect the output ports of the first switch and the input ports of the second switch.

Abstract: A testing system includes: a plurality of test applying portion that operate a test device to make an output signal from the test device; a plurality of testing portions that test the output of the test device; and a switch portion that switches the output signal between the test applying portions and the testing portions. The test applying portion has a selecting portion that selects the testing portion for testing the output signal through the switch portion under test item information, the test item information including information about a test capability of the testing portion.

Abstract: A testing system includes: a plurality of test applying portions that operate a test device to make an output signal from the test device; a plurality of testing portions that test the output of the test device; and a switch portion that switches the output signal between the test applying portions and the testing portions. The testing portions each have a test information portion that outputs test item information which includes a test capability of the testing portion, and have a test performing portion that receives the output signal from the test applying portion which is selected under the test item information through the switch portion, and performs a test under a designated test item.

Abstract: An electronic device includes a DC/DC converter supplied with an external power supply, and an electronic circuit having a power supply input to which an output of the DC/DC converter is supplied. A converted voltage that is the output of the DC/DC converter is lower than a center value of a recommended operating condition for a voltage of the power supply input of the electronic circuit.

Abstract: An optical semiconductor device has a heater, an optical waveguide layer, a first electrode and a second electrode. The heater is provided on a first semiconductor region and has more than one heater segment coupled or separated to each other. The optical waveguide layer is provided in the first semiconductor region and receives heat from the heater. The first electrode is coupled to a connecting point of the heater segments adjacent to each other. The second electrodes are electrically common and are coupled to other ends of the heater segments in opposite side of the connecting point respectively.

Abstract: A semiconductor device includes: a first FET that is formed with first unit FETs each having a first finger electrode and a second finger electrode provided on either side of a gate finger electrode, the first unit FETs being connected in parallel; and a second FET that is formed with second unit FETs each having a first finger electrode and a second finger electrode provided on either side of a gate finger electrode, the second unit FETs being connected in parallel. In this semiconductor device, the second finger electrode of each of the first unit FETs and the first finger electrode of each corresponding one of the second unit FETs form a common finger electrode, and the first finger electrodes of the first unit FETs, the second finger electrodes of the second unit FETs, and the common finger electrodes are arranged in the gate length direction of the first FET and the second FET.

Abstract: There is provided an optical communication module including a receptacle that has an optical element therein and a brim portion, a chassis on which the receptacle is mounted, and a jig into which the receptacle is inserted, that has an opening smaller than the brim portion, and that presses the brim portion to the chassis.

Abstract: An optical semiconductor device has a semiconductor substrate, an optical semiconductor region and a heater. The optical semiconductor region is provided on the semiconductor substrate and has a width smaller than that of the semiconductor substrate. The heater is provided on the optical semiconductor region. The optical semiconductor region has a cladding region, an optical waveguide layer and a low thermal conductivity layer. The optical waveguide layer is provided in the cladding region and has a refractive index higher than that of the cladding region. The low thermal conductivity layer is provided between the optical waveguide layer and the semiconductor substrate and has a thermal conductivity lower than that of the cladding region.