Patents by Inventor Togo NAKATANI

Togo NAKATANI 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).

  • Publication number: 20230387662
    Abstract: A semiconductor laser element includes a substrate and a semiconductor stack. The semiconductor stack includes an N-side semiconductor layer, an active layer, a P-side semiconductor layer, and a P-type contact layer. The semiconductor stack includes two end faces. Laser light resonates between the two end faces. The semiconductor stack includes: a ridge portion; and a bottom portion surrounding the ridge portion in a top view of the semiconductor stack. The ridge portion protrudes upward from the bottom portion, is spaced apart from the two end faces, and includes at least a portion of the P-type contact layer. A current injection window is provided only on the ridge portion out of a top face of the semiconductor stack, the current injection window being a region into which a current is injected. A distance from a top face of the active layer to the bottom portion is constant.
    Type: Application
    Filed: July 25, 2023
    Publication date: November 30, 2023
    Inventors: Yasumitsu KUNOH, Atsushi YAMADA, Hiroki NAGAI, Togo NAKATANI, Naoto YANAGITA, Masayuki HATA
  • Publication number: 20230021325
    Abstract: A semiconductor laser device includes an N-type cladding layer, an active layer, and a P-type cladding layer. The active layer includes a well layer, a P-side first barrier layer above the well layer, and a P-side second barrier layer above the P-side first barrier layer. The P-side second barrier layer has an AI composition ratio higher than an AI composition ratio of the P-side first barrier layer. The P-side second barrier layer has band gap energy greater than band gap energy of the P-side first barrier layer. The semiconductor laser device has an end face window structure in which band gap energy of a portion of the well layer in a vicinity of an end face that emits the laser light is greater than band gap energy of a central portion of the well layer in a resonator length direction.
    Type: Application
    Filed: September 28, 2022
    Publication date: January 26, 2023
    Inventors: Toru TAKAYAMA, Togo NAKATANI, Hiroki NAGAI, Takashi YUMOTO, Takeshi YOKOYAMA, Shoichi TAKASUKA