Patents by Inventor Kiyoyuki Yokoyama

Kiyoyuki Yokoyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Optical functional devices and integrated optical devices having a ridged multi-quantum well structure
    Patent number: 5689358
    Abstract: An optical functional device includes a semiconductor substrate, an optical functional layer provided on said semiconductor substrate and selected from the group consisting of a light emitting layer, a light absorbing layer, and an optical waveguide layer. The optical functional layer has a multi-quantum well layer. Preferably, the semiconductor substrate is a nonplanar semiconductor substrate having a ridge and two grooves adjacent said ridge, said ridge having a ridge width of from 1 to 10 .mu.m, a ridge height of from 1 .mu.m to 5 .mu.m, and a gap distance of from 1 .mu.m to 10 .mu.m. Such an optical functional device can be fabricated by growing, on a nonplanar semiconductor substrate having a specified dimension of the ridge, a strained multi-quantum well layer by metalorganic vapor phase epitaxy. Integrated optical device or circuit preferably includes an optical functional device on the nonplanar semiconductor substrate of a specified range of ridge shape factors.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: November 18, 1997
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masashi Nakao, Yasuhiro Suzuki, Osamu Mitomi, Kazuo Kasaya, Junichi Nakano, Kiyoyuki Yokoyama
  • Method for producing various semiconductor optical devices of differing optical characteristics
    Patent number: 5585957
    Abstract: An optical functional device includes a semiconductor substrate, an optical functional layer provided on said semiconductor substrate and selected from the group consisting of a light emitting layer, a light absorbing layer, and an optical waveguide layer. The optical functional layer has a multi-quantum well layer. Preferably, the semiconductor substrate is a nonplanar semiconductor substrate having a ridge and two grooves adjacent said ridge, said ridge having a ridge width of from 1 to 10 .mu.m, a ridge height of from 1 .mu.m to 5 .mu.m, and a gap distance of from 1 .mu.m to 10 .mu.m. Such an optical functional device can be fabricated by growing, on a nonplanar semiconductor substrate having a specified dimension of the ridge, a strained multi-quantum well layer by metalorganic vapor phase epitaxy. Integrated optical device or circuit preferably includes an optical functional device on the nonplanar semiconductor substrate of a specified range of ridge shape factors.
    Type: Grant
    Filed: March 23, 1994
    Date of Patent: December 17, 1996
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masashi Nakao, Yasuhiro Kondou, Masanobu Okayasu, Mitsuru Naganuma, Yasuhiro Suzuki, Masahiro Yuda, Osamu Mitomi, Kazuo Kasaya, Junichi Nakano, Kiyoyuki Yokoyama