Abstract: An optical multiplexer comprises a signal energy divider, such as a directional coupler, for dividing optical signal energy received by way of a multiplexer upstream port into a control portion and a utilization portion, and an optical switch having a first switch port connected to receive the utilization portion of the optical signal energy and having a plurality of additional switch ports connected to repsecive multiplexer downstream ports. A decoder extracts a control message from the control portion of the optical signal energy, and a controller is responsive to the control message for selectively setting the switch to interconnect the first switch port and a selected one of the additional switch ports. In this manner, at least part of the utilization portion of the optical signal energy received by the multiplexer by way of the multiplexer upstream port is emitted from the multiplexer by way of the multiplexer downstream port that is connected to the selected one of the additional switch ports.

Abstract: An electrooptic directional coupler having first and second electrodes for influencing coupling between a segment of a first optical waveguide and a segment of a second optical waveguide, is operated by varying the potential of the first electrode relative to the second electrode during a first interval in accordance with a first function such that the first electrode remains at a first polarity relative to the second electrode, and varying the potential of the first electrode relative to the second electrode during a second interval in accordance with a second function such that the first electrode remains at a second polarity, opposite the first polarity, relative to the second electrode. The integral with respect to time over the first and second intervals of the potential of the first electrode relative to the second electrode is essentially zero.

Abstract: An optical time domain reflectometer comprises a detector device for detecting optical energy received at an end of a fiber under test, an amplifier having an input terminal connected to the detector device, and a photoconductive switch connected between the amplifier input terminal and a reference potential level. The photoconductive switch is selectively illuminated.