Mitsubishi Denki Kabushiki Kaisha

Takushi Itagaki

Yutaka Mihashi

Mikio Deguchi

Masaaki Usui

Daisuke Suzuki

Kazuhiko Sato

Tatsuya Kimura

Tadashi Kimura

Tohru Takiguchi

Norio Hayafuji

Masayoshi Takemi

Akira Takemoto

Genshiro Nakamura

Katuhiko Goto

An optical semiconductor device includes an n-type InP substrate having top and bottom surfaces; a stripe-shaped mesa structure including an n-type cladding layer, a multi quantum well layer, and a p-type first upper cladding layer disposed on the top surface of the substrate; a first layer of a semi-insulating material, an n-type InP hole blocking layer having a carrier concentration equal to or less than 4.times.10.sup.18 cm.sup.-3 and more than 1.times.10.sup.18 cm.sup.-3, and a second layer of the semi-insulating material disposed burying the mesa structure; a second p-type cladding layer and a p-type contact layer disposed on the mesa structure and on the second layer of the semi-insulating material, and p side electrodes spaced from each other in a stripe direction of the mesa structure, disposed on the p-type contact layer; and an n side electrode disposed on the bottom surface of the substrate. Therefore, an optical semiconductor device is available which has superior element isolation characteristics and broad modulation bandwidth, and enables the individual elements to operate with the utmost performance.

Optical semiconductor device with InP

A method of making a semiconductor optical device, including an integrated laser diode and optical waveguide lens with a continuous resonator extending along a resonator length direction between a pair of resonator facets, includes forming a pair of dielectric films disposed on a surface of a substrate on which a semiconductor layer of the optical waveguide is to be grown, the dielectric films having a linear symmetry about a hypothetical line extending in the resonator length direction, having edges opposing each other and parallel to the hypothetical line, and widths perpendicular to the resonator length direction that gradually narrow toward one facet from a position in the resonator length direction of the films. A mask pattern that produces a precise layer thickness profile is easily designed.

Method of fabricating semiconductor optical device

A method for forming a film by selective area growth by MDCVD technique includes forming a mask on a semiconductor substrate having a (100) plane, the mask having a mask opening to selectively growing a compound semiconductor layer, and a slit which is narrower than the mask opening in width and controls the growth rate of the compound semiconductor layer at the mask opening; and selectively growing the compound semiconductor layer at a growth rate which is on the mask in the mask opening and the slit.

Method for forming a film by selective area MOCVD growth

A surface-emitting LD array includes a plurality of surface-emitting LDs respectively including secondary diffraction gratings produced at the same pitch. These LDs are radially arranged on the substrate with a prescribed point on the substrate as the center of the radial arrangement so that the secondary diffraction gratings face to the center point. In this structure, the laser oscillation regions of the adjacent surface-emitting LDs are spaced apart from each other, so that the respective surface-emitting LDs are operated individually with high stability. As the result, when these surface-emitting LDs are oscillated with the same driving current, a high power laser light comprising a plurality of laser lights that are emitted from the respective LDs and have the same phase and the same wavelength is output stably in a prescribed direction. On the other hand, when these surface-emitting LDs are oscillated with different driving currents, a phase composite wave in which a plurality of laser lights having the same phase and different wavelengths are compounded is output stably in a prescribed direction.

Surface-emitting laser diode array and driving method thereof,

An apparatus for producing a linear pattern having a width less than 100 microns and a resistivity of the order of 10.sup.-6 .OMEGA..multidot.cm on a substrate includes a tank for maintaining a low melting point metal in a fused state and having a narrow passage for flow of the fused metal, a drawing head having a fine groove connected to the narrow passage of the tank, and a tip close to or in contact with a substrate, the fused metal flowing to the tip of the drawing head through the groove by capillary action for application to the surface of the substrate.

Apparatus for applying narrow metal electrode

In a method of fabricating an integrated semiconductor light modulator and laser device, a semiconductor layer having first and second regions of different crystal compositions is produced on each chip region of a semiconductor wafer by a selective crystal growth using, as a mask, a dielectric film having a prescribed pattern. Thereafter, a semiconductor laser and a light modulator that modulates laser light emitted from the semiconductor layer are produced in a first semiconductor region and a second semiconductor region, respectively, of each chip region. In this method, the shape of the dielectric mask pattern and the shape of the opening of the mask pattern on each chip region is symmetrical with the dielectric mask pattern and opening of an adjacent chip region along the optical waveguide direction of the semiconductor laser. The semiconductor layer is grown on the wafer so that the first and second semiconductor regions of different crystal compositions on each chip region are in contact with semiconductor regions having the same crystal composition of an adjacent chip region. As the result, at opposite edges of the chip region in the optical waveguide direction, the crystal compositions of the first and second semiconductor regions are the same.

Method of fabricating an integrated semiconductor light modulator and

A method for producing a linear pattern having a width less than 100 microns and a resistivity of the order of 10.sup.-6 .OMEGA..multidot.cm on a substrate includes maintaining a low melting point metal in a fused state, applying the fused metal to a tip of a drawing head disposed close to or in contact with a substrate by capillary action, applying the fused metal to the substrate in a line with a width less than 100 microns while moving the tip of the drawing head relative to the substrate, and cooling and solidifying the fused metal as a linear pattern on the substrate.

Method of making narrow metal electrode

A method for producing a linear pattern having a width less than 100 microns and a resistivity of the order of 10.sup.-6 .OMEGA..multidot.cm on a substrate includes maintaining a low melting point metal in its fused state, applying the fused metal to a tip of a drawing head disposed close to or contacting a substrate by capillary action, applying the fused metal to the substrate in a line with a width less than 100 microns while moving the tip of the drawing head relative to the substrate, and cooling and solidifying the linear pattern of fused metal. Therefore, a linear pattern having a width less than 100 microns and a resistivity of the order of 10.sup.-6 .OMEGA..multidot.cm is directly formed on the substrate in a simple process with high efficiency and the production yield is significantly improved.

Solar cell with low resistance linear electrode

An electrode structure of a solar cell includes a metal wire fixed to the light incident surface of the solar cell with an electrically conductive adhesive. An electrode production method of a solar cell includes applying an electrically conductive adhesive to at least one of a portion of a metal wire and a portion of the light incident surface of the solar cell, pressing the metal wire into a predetermined position of the light incident surface of the solar cell, and solidifying the conductive adhesive to fix the metal wire.

Method of making a solar cell electrode

Solar cell and solar cell array with adhered electrode

An amorphous solar cell including an amorphous SiGe film which is produced by a glow discharge method using a mixed gas obtained by mixing Si.sub.2 H.sub.6 and GeH.sub.4 or obtained by diluting Si.sub.2 H.sub.6 and GeH.sub.4 with a predetermined dilution gas such that the ratio of GeH.sub.4 to (Si.sub.2 H.sub.6 +GeH.sub.4) is 0.1 to 0.4.

Growing community of inventors

Itami, Japan

Takushi Itagaki