Abstract: A jack module for optical transmission has, on a holder body into which a specified plug is to be inserted, an optical semiconductor device for inputting and outputting an optical signal via the plug. The optical semiconductor device is so constructed that a light-emitting chip and a light-receiving chip are mounted on a one-side surface of a lead frame, where the light-emitting chip and the light-receiving chip are integrally molded with a light-pervious resin. The surface of the lead frame is disposed so as to be inclined with respect to a center axis of the plug inserted into the holder body. The jack module for optical transmission is capable of easily performing communications in the half-duplex method, simple in construction and manufacturable at small size and low cost.

Abstract: A method is provided for measuring a far-end reflectance of a fiber-optic cable. The method comprises the steps of connecting an end face of the fiber-optic cable to a transceiver comprising a transmitter for transmitting an optical signal and a receiver for receiving an optical signal, transmitting an optical signal from the transmitter of the transceiver and receiving the optical signal reflected by the other end face of the fiber-optic cable, and measuring a first amount of light of the reflected optical signal, where the other end face of the fiber-optic cable is open to air, or where the other end face of the fiber-optic cable is made to contact a solid having the same or substantially the same refractive index as that of the fiber-optic cable, and measuring the far-end reflectance of the fiber-optic cable based on the first and second amounts of light.

Abstract: A jack module for optical transmission has, on a holder body into which a specified plug is to be inserted, an optical semiconductor device for inputting and outputting an optical signal via the plug. The optical semiconductor device is so constructed that a light-emitting chip and a light-receiving chip are mounted on a one-side surface of a lead frame, where the light-emitting chip and the light-receiving chip are integrally molded with a light-pervious resin. The surface of the lead frame is disposed so as to be inclined with respect to a center axis of the plug inserted into the holder body. The jack module for optical transmission is capable of easily performing communications in the half-duplex method, simple in construction and manufacturable at small size and low cost.

Abstract: A method is provided for measuring a far-end reflectance of a fiber-optic cable. The method comprises the steps of connecting an end face of the fiber-optic cable to a transceiver comprising a transmitter for transmitting an optical signal and a receiver for receiving an optical signal, transmitting an optical signal from the transmitter of the transceiver and receiving the optical signal reflected by the other end face of the fiber-optic cable, and measuring a first amount of light of the reflected optical signal, where the other end face of the fiber-optic cable is open to air, or where the other end face of the fiber-optic cable is made to contact a solid having the same or substantially the same refractive index as that of the fiber-optic cable, and measuring the far-end reflectance of the fiber-optic cable based on the first and second amounts of light.

Abstract: A polyvinyl acetal sponge sheet of a porous structure having fine continuous pores and a film on the surface thereof. This sponge sheet can be used for a wiping material for car washing which does not leave unwiped portions during wiping after car washing and has a small frictional resistance and a high working factor.