Patent ID: 7336365
Filing Date: 2008-02-26
Classification: G01D

Abstract:
1. A method of interrogating sensor interferometers of an optical network comprising multiple optical pathways from a transmitter unit to a receiver unit, wherein pairs of optical pathways form the sensor interferometers, each sensor interferometer having a sensor imbalance, the method comprising: defining a plurality of transmission time intervals; dividing the plurality of transmission time intervals into a sequence of time-division multiplexing (TDM) repetition periods; transmitting optical pulses from the transmitter unit during a portion of the transmission time intervals such that corresponding optical pulses are positioned equally in each TDM repetition period; and modulating a phase of the optical pulses between different TDM repetition periods such that unwanted interference signal components reaching the receiver unit are distributed to frequency bands that do not affect a demodulated sensor signal.