Abstract: In an optical transmit-receive module, an optical fiber plug connected with an optical fiber for optical transmission is removably inserted in a housing. Within the housing, there are provided a branching type light guide, and an optical semiconductor device giving an optical signal to the branching type light guide and receiving an optical signal from the branching type light guide. When the optical fiber plug is inserted in the housing, it is optically connected with the branching type light guide through a light-permeable member having a refractive index approximately equal to refractive indices of the optical fiber and the branching type light guide.

Abstract: An optical transmission and receiving module includes a light source; a light receiving element; and a light branching element for causing signal light from the light source to be incident on an optical fiber and causing signal light output from the optical fiber to be incident on the light receiving element. The light branching element includes a prism array including a plurality of triangular prisms arranged at substantially an identical pitch on a plane extending substantially perpendicular to an imaginary line connecting the light source and the light receiving element.

Abstract: A plug-jack type transfer device includes: at least seven electric terminals for connecting a mini single-head electric plug to the transfer device and exchanging an electrical signal therewith; a container body for containing and supporting the electric terminals and receiving the mini single-head electric plug; and a switch mechanism which completes electrical connection between a fourth electric terminal and a sixth electric terminal when the mini single-head electric plug is inserted into the container body. The mini single-head electric plug includes at least seven regions. A region farthest from a plug tip electrode corresponds to a first region.