Qd Laser, Inc.

Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Mirise Technologies Corporation

University of Sheffield

Keizo Takemasa

Kenichi Nishi

Koichi Oyama

Yuki Kamata

Yutaka Ohnishi

Hiroyuki Tarumi

Mitsuru Sugawara

Richard Hogg

Siming Chen

Yutaka Onishi

Takeo Kageyama

Hitoshi Yamada

An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers include: a first quantum dot layer doped with a p-type impurity; and a second quantum dot layer doped with an n-type impurity and having an emission wavelength different from that of the first quantum dot layer.

Optical semiconductor device

In a semiconductor device, a quantum dot group includes a stack of plural quantum dot layers having different central wavelengths at which respective gains are maximum. A part of or all of the quantum dot layers are stacked so that the central wavelengths sequentially shifts along a stacking direction. The quantum dot group includes a longest wavelength layer group composed of some quantum dot layers including a longest wavelength layer having a longest central wavelength and at least one quantum dot layer stacked on the longest wavelength layer. The longest wavelength layer or the longest wavelength layer group has a larger gain at the central wavelength than the gain at the central wavelength of each of the other quantum dot layers.

Semiconductor device

The semiconductor laser device includes: an activation layer having at least one first quantum dot layer and at least one second quantum dot layer having a longer emission wavelength than the first quantum dot layer. The gain spectrum of the active layer has the maximum values at the first wavelength and the second wavelength longer than the first wavelength corresponding to the emission wavelength of the first quantum dot layer and the emission wavelength of the second quantum dot layer, respectively. The maximum value of the gain spectrum at the first wavelength is defined as the first maximum value, and the maximum value of the gain spectrum at the second wavelength is defined as the second maximum value. The first maximum value is larger than the second maximum value.

Semiconductor laser device

A semiconductor light-emitting element includes: a lower clad layerthat is provided on a substrate; an active layerthat is provided on the lower clad layerand includes a quantum well layerand a plurality of quantum dotssandwiching a second barrier layertogether with the quantum well layer; and an upper clad layerthat is provided on the active layer, wherein a distance D between the quantum well layerand the plurality of quantum dotsis smaller than an average of distances X between centers of the plurality of quantum dots

Semiconductor light-emitting element

Growing community of inventors

Kawasaki, Japan

Keizo Takemasa