Abstract: A device for retaining a wire-like optical wave-guide for an optical connector includes a cylindrical plug made of an elastic material for gripping the outer peripheral surfaces of a wire-like optical wave-guide with at least one end portion of the plug, having a predetermined length, being divided into a plurality of portions in a circumferential direction. The cylindrical plug has an expanded form in which a distance from an axis of the plug to each of the divided portions gradually increases toward the one end of the plug, with a tightening member pressing a vicinity of a free end of the cylindrical plug, which is in a state where the wire-like optical wave-guide is passed through the plug along the axis of the plug so as to allow the wire-like optical wave-guide to be retained by the cylindrical plug, in a direction substantially perpendicular to the axis of the plug from the outside of the plug.

Abstract: A connector comprises a plug and a socket. The plug has a main plug body, a plurality of contact pins projecting from the main plug body and including a contact pin for grounding, and a shielding member surrounding the plurality of contact pins. The socket has a main socket body, a plug receiving part provided on the main socket body for receiving the shielding member, a plurality of contact portions provided within the plug receiving part for making contact with corresponding ones of the plurality of contact pins and including a first contact portion for making contact with the contact pin for grounding, and a second contact portion provided on the main socket body for making contact with the shielding member. The plug is detachably coupled to the socket by inserting the shielding member into the plug receiving part. The first and second contact portions are made of a single contact member.

Abstract: In a device for coupling optically a light source with an optical transmission path, the present invention interposes an optical transmission path structure at the center of the distance between them in order to improve the optical coupling efficiency. The optical transmission path structure consists of a plurality of light transmitting elements arranged so that the light from the light source is received by the structure as incident light and is sent out therefrom as outgoing light at an outgoing angle which is equal to the angle of incidence. The light transmitting elements are arranged in parallel with the optical path of the light emitted from the light source and according to this arrangement, the system of the present device becomes equivalent to a system in which the positions of the light source are located at points of .+-.l.sub.1 from the light outgoing surface of the optical transmission path structure.

Abstract: An opto-electric transformation connector is provided, which can be used, as if it were an electric connector, without consideration of optical transmission of devices connected therewith, in a connecting system for connecting different devices by means of optical fibers. The connector includes an electronic circuit board, on which not only a light emitting element for transmitting optical signals and a light receiving element for receiving optical signals are disposed, but also a driving circuit for driving the light emitting element and an amplifier circuit for amplifying the light signals received by the light receiving element are mounted.

Abstract: An optical switch having a small number of optical connections includes a substrate in which are provided a first light path for conducting optical signals and a second light path consisting of a photosensitive element and light emitting element in pairs. An optical fiber cable is interrupted by the substrate, and optical signals in the fiber cable are transmitted through the first light path or intervened by an electrical system through the second light path in response to the switching movement of the substrate.