Kabushiki Kaisha Toshiba

Masaki Tohyama

Shinya Nunoue

Shinji Saito

Yasushi Hattori

Yuzo Hirayama

Rei Hashimoto

Jongil Hwang

Nobuo Suzuki

Maki Sugai

Motoyasu Morinaga

Masahisa Funemizu

Kazuhiro Inoue

Masaaki Onomura

Hung Hung

Keiji Takaoka

Takayuki Matsuyama

Makoto Okada

Hirokazu Nishimura

Tattee Khayim

Makoto Ohashi

Osamu Horiuchi

Tomoaki Yamaguchi

A semiconductor laser device in an embodiment includes a compound semiconductor layer and a silicon layer. The compound semiconductor layer includes an active layer emitting laser light and has a first mesa structure. The silicon layer is bonded with the compound semiconductor layer. A diffraction grating is provided on a surface of the silicon layer which faces the compound semiconductor layer, and includes a main diffraction grating and two sub-diffraction gratings. The main diffraction grating extends in a longitudinal direction of the first mesa structure; the sub-diffraction gratings are disposed on both sides of the main diffraction grating.

Semiconductor laser device

According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a well layer, a barrier layer, an Al-containing layer, and an intermediate layer. The p-type semiconductor layer is provided on a side of [0001] direction of the n-type semiconductor layer. The well layer, the barrier layer, the Al-containing layer and the intermediate layer are disposed between the n-type semiconductor layer and the p-type semiconductor layer subsequently. The Al-containing layer has a larger band gap energy than the barrier layer, a smaller lattice constant than the n-type semiconductor layer, and a composition of AlGaInN. The intermediate layer has a larger band gap energy than the well layer, and has a first portion and a second portion provided between the first portion and the p-type semiconductor layer. A band gap energy of the first portion is smaller than that of the second portion.

Semiconductor light emitting device with an aluminum containing layer formed thereon

The semiconductor light emitting device according to an embodiment includes an N-type nitride semiconductor layer, a nitride semiconductor active layer disposed on the N-type nitride semiconductor layer, and a P-type nitride semiconductor layer disposed on the active layer. The P-type nitride semiconductor layer includes an aluminum gallium nitride layer. The indium concentration in the aluminum gallium nitride layer is between 1E18 atoms/cmand 1E20 atoms/cminclusive. The carbon concentration is equal to or less than 6E17 atoms/cm. Where the magnesium concentration is denoted by X and the acceptor concentration is denoted by Y, Y&#x3e;{(&#x2212;5.35e19)&#x2212;(X&#x2212;2.70e19)}&#x2212;4.63e19 holds.

Semiconductor light emitting device and manufacturing method of the same

According to one embodiment, a semiconductor laser device with high reliability and excellent heat dissipation is provided. The semiconductor laser device includes an active layer, a p-type semiconductor layer on the active layer, a pair of grooves formed by etching into the p-type semiconductor layer, a stripe sandwiched by the pair of grooves and having shape of ridge, and a pair of buried layers made of insulator to bury the grooves. The bottom surfaces of the grooves are shallower with an increase in distance from the stripe.

Embodiments describe a semiconductor laser device driven at low voltage and which is excellent for cleavage and a method of manufacturing the device. In one embodiment, the semiconductor laser device includes a GaN substrate; a semiconductor layer formed on the GaN substrate; a ridge formed in the semiconductor layer; a recess formed in the bottom surface of the GaN substrate. The recess has a depth less than the thickness of the GaN substrate. The device also has a notch deeper than the recess formed on a side surface of the GaN substrate and separated from the recess. In the semiconductor laser device, the total thickness of the GaN substrate and the semiconductor layer is 100 &#x3bc;m or more, and the distance between the top surface of the ridge and the bottom surface of the recess is 5 &#x3bc;m or more and 50 &#x3bc;m or less.

Semiconductor laser device and method of manufacturing the same

According to one embodiment, a semiconductor laser device includes stacked layers and a light output layer. The stacked layers include an active layer. The light output layer is provided in contact with a light output end face of an optical cavity made of the stacked layers. The light output layer includes a dielectric layer having a non-amorphous film, and a conductor portion provided at least one of on a surface of the dielectric layer and inside the dielectric layer.

An embodiment of the invention provides a light emitting device in which a semiconductor laser diode is used as a light source to emit visible light in a wide range. The light emitting device includes a semiconductor laser diode that emits a laser beam; and a luminescent component that is provided while separated from the semiconductor laser diode and absorbs the laser beam to emit the visible light. In the light emitting device, the luminescent component includes an optical path through which the laser beam is incident to a center portion of the luminescent component.

Light emitting device

A laser transmitter device includes a laser light source, first and second optical elements, and first and second detection elements. The first optical element has a first optical characteristic with wavelength dependency, whose light transmissivity or reflectivity shows a monotone increase or decrease within a wavelength range over channels. The second optical element has a second optical characteristic with wavelength dependency, whose transmissivity or reflectivity changes in a cycle corresponding to intervals of the channels or two times the intervals. The first detection element detects an intensity of light emitted from the laser light source and coming via the first optical element, and generates a first electric signal reflecting the first optical characteristic. The second detection element detects an intensity of light emitted from the laser light source and coming via the second optical element, and generates a second electric signal reflecting the second optical characteristic.

Laser transmitter device

The ridge waveguide type photo semiconductor device includes: a first cladding layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type; an active layer formed on the first cladding layer; a second cladding layer of a second conductivity type formed on the active layer; a third cladding layer of the second conductivity type formed on the second cladding layer and being worked so as to have a ridge shape; and an impurity diffusion region formed in the second cladding layer and the active layer on both sides of the ridge-shaped third cladding layer and which has a higher resistance value than that of the second cladding layer below the ridge shape.

Ridge waveguide type photo semiconductor device and method for fabricating same

In order to realize an optical semiconductor device having a window structure promising high-speed operation and highly efficient coupling with optical fibers and to realize its manufacturing method, the device has a window structure in which an optical guide layer is partly removed near the emission facet to decrease the facet reflectivity. Since a cladding layer has a narrow mesa structure also in a window region, the parasitic capacitance can be reduced, and high-speed modulation is ensured. Although light runs through the window region in spread directions from one end of the optical guide layer toward the emission facet, the cladding layer changes its width or thickness in accordance with the spread angle of light. Therefore, light is not reflected or scattered by side surfaces of the cladding layer, and prevents a decrease in optical output due to a scattering loss, or a deterioration in distribution of emitted light. As a result, the device has a high coupling efficiency with optical fibers, and is operative for high optical output.

Optical semiconductor device and its manufacturing method

A grating coupled surface emitting laser has a diffraction grating of a second or higher order for guided-mode light part of a waveguide region, and extract a beam in a direction perpendicular to the waveguide region. By narrowing a stripe of the waveguide region around the center, the phase of the diffraction grating is shifted to attain a Gaussian distribution for radiation-mode light in a cross section along the waveguiding direction.

Grating coupled surface emitting device

This invention provides an optical semiconductor device including a semiconductor substrate having a mesa stripe in which at least an optical waveguide layer is formed, a major surface of the semiconductor substrate being a crystal plane, a semiconductor buried layer formed on the two side surfaces of the mesa stripe, and a stripe cladding layer formed on the mesa stripe region and the semiconductor buried layer and having a shape whose section is substantially trapezoidal and whose side surfaces are crystal planes.

Optical semiconductor device and method of fabricating the same

An optical transmission apparatus characterized by comprising a transmission system for transmitting an optical frequency-division multiplex signal, and an optical reception system which contains a semiconductor laser as a light source for reception and receives the optical signal, wherein the semiconductor laser contains first oscillation wavelength control device for controlling its oscillation wavelength according to temperature and second oscillation wavelength control device for controlling its oscillation wavelength according to carrier density, causes the first oscillation wavelength control device to scan oscillation wavelengths over a range from a first frequency to a second wavelength and simultaneously, causes the second oscillation wavelength control device to change the oscillation frequency, and selects wavelengths in the range from the first wavelength to the second wavelength stepwise sequentially.

Optical transmission apparatus

A semiconductor optical device includes a n-clad layer, an active layer formed on the n-type clad, a carrier reservoir layer formed on the active layer, and a p-clad layer formed on the carrier reservoir layer. The thickness of the carrier reservoir layer is in a range where the oscillation wavelength shifts in a short wavelength direction with increasing driving current.

Growing community of inventors

Kanagawa, Japan

Masaki Tohyama