Abstract: A method for adjusting the position of two ends of a pair of aligned optical fibers during formation of a connection or a splice between the two ends either to repair a break in a fiber or to add another fiber characterized by coupling a light pulse into a free end of one of the pair of fibers, measuring the intensity of a back-scattering of the light pulse received at the free end, determining an abrupt change in the intensity of the back-scattered light at the free end corresponding to the point of the connection to be made for the pair of fibers, and adjusting the position of the two ends of the pair of fibers to decrease the amount of the abrupt change in the intensity being determined to the smallest determined value.

Abstract: Solid state relay with a full-wave rectifier bridge having d-c output terminals, a thyristor, the anode and cathode of which being respectively connected to the output terminals of the rectifier bridge, a first and a second transistor, the load circuits of which being shunted across the gate-cathode path of the thyristor, the control terminal of the first transistor being connected to a first and a second resistor, the first resistor being, in turn, connected to the anode of the thyristor, and the second resistor being, in turn, connected to the cathode of the thyristor, the control terminal of the second transistor being connected to a third resistor and to a control transistor, the third resistor being, in turn, connected to the anode of the thyristor, and the control transistor being connected to the cathode of the thyristor, including a Zener diode connected in series with the first resistor.

Abstract: A communication cable is composed of a number of optical fibers with an outer coating, loosely twisted together to form basic groups, provided with tension-relieving wires and sheathed to form a cable while filling the interspaces with lubricants.

Abstract: A method and apparatus for measuring the distance of a discontinuity in a glass fiber from one end of the fiber characterized by coupling a pulse into the one end, sensing a pulse of light reflected by a discontinuity as it leaves the one end and measuring the time lapse between the pulse to determine the distance of the discontinuity from the one end.