Kokusai Denshin Denwa Kabushiki Kaisha

Other

Kokusai Denshin Denwa Co., Ltd.

Kokusai Denshin Denwa K.k.

Yukitoshi Kushiro

Shigeyuki Akiba

Yukio Noda

Masatoshi Suzuki

Katsuyuki Utaka

Kazuo Sakai

Chuichi Ota

Fujio Tanaka

Kohsuke Nishimura

Yasuyuki Okamura

Hideaki Tanaka

A light emitting semiconductor device which emits blue and/or green light has an active layer and a pair of clad layers which sandwich the active layer, and which are deposited on a semiconductor substrate. The substrate is made of one of GaAs, GaP, InP, Si, Ge, ZnSe and mixed crystals of GaAsP. The active layer is made of at least one of II-VI group compound semiconductor, I-III-VI.sub.2 group compound semiconductor, and II-IV-V.sub.2 group compound semiconductor. The clad layer is made of II-transition metal-VI group compound semiconductor, which is lattice-matched to the active layer.

Light emitting semiconductor device

A semiconductor external modulator is disclosed in which the mode of polarization of incident light, the crystal plane of the substrate (the direction of application of an electrical field), the energy gap of the optical waveguide layer, and the direction of travel of light are determined so that, of variations in the real and imaginary parts of the refractive index of the optical waveguide layer which are caused by the application of the electric field to the semiconductor external optical modulator, the variation in the real part of the refractive index may be reduced to substantially zero.

Semiconductor external optical modulator

A method for manufacturing a semiconductor optical integrated device in which a semiconductor element A having an optical waveguide region and a semiconductor element B having another optical waveguide region are integrated on a single substrate. In accordance with the present invention, there is provided steps of growing the optical waveguide region of the semiconductor element A and a protective layer therefor are grown on the entire area of the substrate surface, selectively removing them from the substrate surface in the region to be ultimately occupied by the semiconductor element B, and forming in the region the optical waveguide region of the semiconductor element B through crystal growth.

Method for manufacturing semiconductor optical integrated device with

A semiconductor integrated light emitting device is disclosed which comprises a light emitting waveguide including a light emitting layer, and an external waveguide directly coupled to the light emitting waveguide. In accordance with the present invention, the light emitting waveguide and the external waveguide are mutually laminated in the vicinity of a region where they are directly coupled together.

Semiconductor integrated light emitting device

A semiconductor optical modulator is disclosed which is capable of high-speed modulation without the necessity of increasing the modulating voltage. The present invention has its feature in that the carrier density of the clad layer adjoining the optical waveguide layer 3 is gradually raised toward the p-n junction or Schottky junction, thereby increasing the width of the depletion layer to decrease the junction capacitance.

Semiconductor optical modulator

An optical modulation element is disclosed in which a diffraction grating is formed along a waveguide for guiding unmodulated incident light and inclined to the direction of travel of the light, and a structure is provided for changing the refractive index of the waveguide portion where the diffraction grating is formed. the refractive index of the waveguide portion can be effected by voltage application, by current injection or by light irradiation.

Optical external modulation semiconductor element

A semiconductor light emitting element is disclosed, which is provided with a light emitting region having a diffraction grating formed by periodic corrugations, a modulation region having an external waveguide layer optically connected directly to the light emitting region and a pn junction separated from a pn junction of the light emitting region and a window region formed of a semiconductor having a larger energy gap than that of a light emitting layer of the light emitting region and extending from at least one end of the light emitting region and the external waveguide layer. The refractive index of the external waveguide is varied through utilization of the electrooptic effect so that the frequency or phase of light stably oscillating at a single wavelength is precisely controlled or modulated. In particular, when the window region is formed only outside the light emitting region, frequency modulation is carried out, and when the window region is formed at least outside the modulation region, phase modulation takes place.

Integrated semiconductor light emitting element with oscillation

A semiconductor laser, which comprises a substrate of InP, an active layer, and two clad layers holding therebetween the active layer, and which is constructed so that the refractive index of the active layer may be larger than the refractive indexes of the two clad layers. In one of the two clad layers, the refractive index of a region adjacent to a radiation region in the active layer is larger than the refractive index of a region adjacent to a non-radiation region in the active layer. The refractive index of the other clad layer is equal to the refractive index of that region of said on clad layer adjoining the radiation region or the non-radiation region. The thickness and width of the radiation region of the active layer are selected so that the semiconductor laser may oscillate in the fundamental transverse mode. A buffer layer may be further provided between the active layer and one of the two clad layers.

Growing community of inventors

Tokyo, Japan

Yukitoshi Kushiro