Abstract: Systems, methods, and structures for overcoming Rayleigh backscatter in wavelength division multiplexed fiber optic systems and in particular fiber optic sensor systems along with method(s) for detecting faults in optical networks employing the intentional temporal separation of share wavelength noise and demarcation signals in conjunction with the use of accumulated Rayleigh noise signal(s) to detect a fault location.

Abstract: Systems, methods, and structures for overcoming Rayleigh backscatter in wavelength division multiplexed fiber optic systems and in particular fiber optic sensor systems along with method(s) for detecting faults in optical networks employing the intentional temporal separation of share wavelength noise and demarcation signals in conjunction with the use of accumulated Rayleigh noise signal(s) to detect a fault location.

Abstract: An optical fiber connection monitor has a detector adjacent the connection which detects light scattered from the connection. The detector signal is converted to a voltage and applied to a comparator circuit which gives an indication that the connection is not dangerously emitting radiation or an indication that it is dangerously emitting radiation. In another embodiment of the invention, a finite amount of light is fed from the end or ends of the ferrule or ferrules of the connection components to the detector to insure that the monitor circuitry is functioning properly in the presence of optical signals. A further embodiment includes passing light past the ferrule end to the detector, further checking the operation of the monitor system.

Abstract: Embodiments of the invention include an optical fiber system and method for separating the different wavelengths of transmitted light transmitted therethrough and for monitoring the respective optical power in the separated spectral components. More specifically, embodiments of the invention scan or modify the physical parameters of in-fiber gratings that couple light between spatially different modes of light within a wavelength-division-multiplexed (WDM) optical fiber system, separate the spatial modes using a mode-discriminating device (MDD) and monitor or detect the separated spectral components using a conventional or other suitable detector. By scanning the in-fiber gratings, the peak wavelength of coupling between two dissimilar modes is modified, thus allowing control of the coupling within the fiber optic system. Scanning the grating is performed, e.g., by changing the temperature or modifying the physical dimensions of the grating.

Abstract: The present invention is an optical monitoring and test access interconnection module especially adapted for use with a fiber optic distribution frame for a fiber optic communications system. The interconnection module provides a combination of monitoring and test access for two fiber lines, typically a transmit/receive pair, where wavelength division multiplexer (WDM) test access is provided to both the transmit and receive fibers. In one embodiment of the present invention, the interconnection module monitors only the receive fiber line where a power monitoring circuit receives a monitor level optical signal via an optical tap and converts the optical signal to an electrical output. Processing electronics and firmware within the module are operable to generate alarms and other control signals when changes in the power level of the received signal are detected. A test access path is provided on the module for use, for example, with an optical time domain reflectometer (OTDR).

Abstract: A lightwave communication monitoring system has a monitoring member to which are applied signals extracted from one or more fibers in a transmission system. The monitoring member detects the signal and applies a signal derived therefrom to a control or processing unit. When the strength of the derived signal is below a predetermined minimum, the control unit is adapted to activate a fault location member which applies a fault location signal to the fiber circuit in which the signal, or lack thereof, is transmitted. The system is capable of handling a plurality o fiber circuits simultaneously. In another embodiment of the invention, a test signal is launched on the first fiber, or, simultaneously launched on a plurality of first fibers of fiber pairs, and the test signal is simultaneously extracted from one or more of a plurality of corresponding second fibers of the fiber pairs.

Abstract: A mapping system and method for mapping optical fiber communication networks which have several stages has switches at each stage which have an input, a home position stage, and a plurality of outputs. An optical signal is applied to the input of one of the switches and the energy appearing at its home port is measured and applied to a CPU. The switch is then stepped to apply the optical energy to the output ports, and the optical energy appearing at the home ports of the switches in the next stage affords an indication of which output port of the first stage switch is connected to the input of which switch in the second stage. The same procedure is performed for the switches in the third stage, until the network, or a portion thereof, is mapped.

Abstract: An optical switch device has a plurality of fixed optical fiber terminations supported in a fixed array, and a terminated fiber movable by means of a stepping motor into registry with each of the terminations. Opposite the fixed array is a second array of optical devices oriented such that each termination defines a unique light path with each of the optical devices, with the light paths thus formed being parallel to each other.