Abstract: An optical connector comprises an optical fiber connector ferrule which comprises a substrate plate having at least one optical fiber groove and pin grooves each being formed at one surface thereof, and a cover plate joined to the substrate plate to form at least one optical fiber groove holes into which an optical fiber is inserted; a guide pin means to be inserted into the pin grooves for coupling the optical fiber connector ferrule with another; and means for absorbing the variation in the diameter of the guide pin means.

Abstract: An optical recording/reproducing apparatus capable of accurately estimating the remaining service life of an optical disk without the need for recording large amounts of information on the disk beforehand. At the time of manufacture, the reflection factor in a specified blank portion of the disk is detected and the detected value recorded in a predetermined position on the disk. To estimate the remaining lifetime at a later time, the reflection factor is again detected and compared with the recorded value.

Abstract: A fiber optic sensor useful, for example, in intrusion detection systems for sensing seismic or pressure disturbances produced by an intruder, comprises a cable having an optical fiber core for transmitting the output of a laser, a hard preferably electrically nonconductive strand wound helically on and coextensive with the fiber, and a compliant tubular sleeve over the fiber and strand. The coils of the strand are axially spaced apart and circumferentially engage the fiber. The sleeve fits snugly over the strand and fiber and transmits through the strand coils to the fiber forces resulting from disturbances to be detected, subjecting the fiber to bending stresses. With cable connected at one end to the laser output, the polarization of light transmitted by the fiber is changed by the induced stresses and is detected at the other end of the cable to indicate the occurrence of the disturbance.

Abstract: A fiber optic recirculating memory is disclosed which utilizes dual couplers to form a splice-free recirculating memory device from a length of single mode optical fiber forming a loop which acts as a delay line and a second length of single mode optical fiber which provides an input end and an output end for the device. A single signal supplied as an input to the device will result in a series of output signals identical to the input signal, although at smaller, decreasing amplitudes; the invention prevents the first output signal from being substantially larger than the rest of the output signals, thus eliminating the need for protective circuitry on the output end or the rejection of the first output signal.