Nippon Telegraph and Telephone Corporation

School Juridical Person Kitasato Institute

Takeo Miyazawa

Hidefumi Mori

Fumihiko Kobayashi

Jun-ichi Nakano

Hiroyuki Furukawa

Ryoko Yoshimura

Kimiya Shimizu

Fumiyoshi Kano

Kohji Ohbayashi

Takuji Amano

Hideaki Hiro-Oka

DongHak Choi

Motoi Nakanishi

An OCT technique that permits tomographic observation of biological body parts that are difficult to restrain, and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and thus removes a burden on the biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7&#xd7;10&#x3bc;mand an emitted-light frequency width of no more than 13 GHz, for example, and is capable of changing the wave number stepwise at wave number intervals of no more than 3.1&#xd7;10&#x3bc;mand time intervals of no more than 530 &#x3bc;s.

Wavelength-tunable light generator and optical coherence tomography device

The present invention provides an OCT technique that permits tomographic observation of a biological body parts that is difficult to restrain and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and remove the burden from biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7&#xd7;10&#x3bc;mand an emitted-light frequency width of no more than 13 GHz, for example, and includes means capable of changing the wave number stepwise at wave number intervals of no more than 3.1&#xd7;10&#x3bc;mand time intervals of no more than 530 &#x3bc;s.

An optical semiconductor device includes an optical semiconductor element, a semiconductor region, and a buried layer. The optical semiconductor element is formed on a semiconductor substrate. The semiconductor region opposes the optical semiconductor element and essentially surrounds the optical semiconductor element to form walls. The buried layer is arranged between the walls of the semiconductor region and the optical semiconductor element and formed by vapor phase epitaxy. In this optical semiconductor device, a distance between the wall of the semiconductor region and a side wall of the optical semiconductor element is larger in a portion in which the growth rate of the vapor phase epitaxy in a horizontal direction from the side wall of the optical semiconductor element and the wall of the semiconductor region is higher.

Optical semiconductor device and method of fabricating the same

Optical semiconductor device

Growing community of inventors

Kanagawa, Japan

Takeo Miyazawa