公开(公告)号：US11212214B2

公开(公告)日：2021-12-28

申请号：US16562742

申请日：2019-09-06

Applicant: NEC CORPORATION ,  PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATION ,  FUJITSU LIMITED

Inventor： Kenji Mizutani ,  Yutaka Urino ,  Tatsuya Usuki

IPC: H04L12/733 ,  H04L12/721 ,  H04L12/18 ,  H04L12/707 ,  H04L12/755

Abstract: A parallel computer system includes: direct links that forms a direct connection between a sending node and a receiving node, one-hop links that forms a connection between a sending node and a receiving node by way of a return node that is other than the sending node and the receiving node, and a communication control unit that, when transferring data from a sending node to a receiving node, selects the link that connects the sending node and the receiving node from among a link that uses only a direct link, a link that uses only a one-hop link, and a link that forms a connection combines and uses the direct link and the one-hop link.

公开(公告)号：US20200235547A1

公开(公告)日：2020-07-23

申请号：US16087961

申请日：2017-03-29

Applicant: PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATION

Inventor： Kenji Mizutani

IPC: H01S5/00 ,  H04B10/50 ,  H04B10/61 ,  G02B6/42

Abstract: Provided is an optical transmitter in which a forward-end surface of a semiconductor laser is set to an effective reflectance with respect to near-end reflection. The optical transmitter is provided with a semiconductor laser and at least one optical function element to which output light from the semiconductor laser is input. The optical transmitter is characterized in that: a signal-to-noise ratio in an optical receiver which receives an optical signal output from the optical transmitter includes a first contribution component caused by re-entry of reflected return light from the at least one optical function element into the semiconductor laser, and a second contribution component caused irrespective of the strength of the optical signal input to the optical receiver; and the reflectance of a forward-end surface of the semiconductor laser is set to a value in a predetermined range including a reflectance that maximizes the signal-to-noise ratio due to the first contribution component and the second contribution component with respect to a change in the reflectance of the forward-end surface.