Patent ID: 6407835
Filing Date: 2002-06-18
Classification: G02B

Abstract:
An apparatus for monitoring and controlling transmissions of signals comprising:a fluid-manipulable chamber having a transmissive state in which fluid resides in a first region of said chamber, said chamber having a reflective state in which said fluid is absent from said first region, a first one of said transmissive and reflective states being selected for application during fault-free conditions with respect to signal transmissions, a second one of said transmissive and reflective states being selected for application during fault conditions; first and second input waveguides separately coupled to receive optical signals, said first and second input waveguides intersecting said chamber such that said optical signals propagate into said chamber when said chamber is in said transmissive state and reflect from said chamber when said chamber is in said reflective state; first and second output waveguides that are responsive to said transmissive and reflective states of said chamber such that said first and second output waveguides are respectively in signal-transfer engagement with said first and second input waveguides during said fault-free conditions and such that said first and second output waveguides reverse said signal-transfer engagements during said fault conditions; a signal traffic detection subsystem connected to detect incidentally reflected light from said chamber when said chamber is in said transmissive state, said incidentally reflected light being leakage light energy and being indicative of a fault-free condition; and a switch controller responsive to said signal traffic detection subsystem to establish said first one of said transmissive and reflective states during said fault-free conditions and to establish said second one during said fault conditions, wherein determinations of said fault-free and fault conditions are at least partially based on detections of said incidentally reflected light by said signal traffic detection subsystem.