Mitsubishi Denki Kabushiki Kaisha

Kenzo Fujiwara

Yasunori Tokuda

Norio Takeuchi

Yoshinori Nomura

Teruhito Matsui

Keisuke Kojima

Yuji Nakanishi

Shigeru Murasato

Tsuyoshi Horita

Noriaki Tsukada

Yoji Nakatsuka

A semiconductor optical element having a layer which exhibits a function of diffraction grating between a first cladding layer and a second cladding layer, wherein the layer which exhibits the function of diffraction grating consists of a superlattice layer in which crystal layers are periodically mixed to constitute a semiconductor grating layer.

Process for producing a DFB laser with a diffraction grating superlattice

A semiconductor laser having an active layer of quantum well structure, where the resonator loss is enhanced thereby to conduct an oscillation at a high quantum level.

Semiconductor laser device

At least a portion of the optical waveguide is formed in a superlattice structure or in a quantum well structure, and crystals are mixed in the portions of the superlattice structure or the quantum well structure that divide the resonator to decrease the refractive index of these portions, in order to form two or more laser portions having different cavity lengths. The semiconductor device can be formed easily and precisely without employing cleavage which involves cumbersome manufacturing steps. Further, the crystal need not be grown on the groove but may simply be grown on a flat surface, making it possible to easily and precisely produce the semiconductor laser device.

Composite resonator-type semiconductor laser device

Semiconductor optical element and a process for producing the same

The present invention relates to an armature winding of a split stator having a slotted core divided by at least two circumferentially-spaced split lines to facilitate the disassembly and assembly of the split stator. The armature winding comprises armature coils in the slots of the stator core connected to provide poles and arranged to provide a plurality of armature coils divided at the split lines. Connecting and disconnecting means are provided to connect and disconnect the armature coils when the split stator is assembled and disassembled, respectively.

Armature winding of a split stator

Growing community of inventors

Amagasaki, Japan

Kenzo Fujiwara