Coherence multiplexing of optical sensors

An optical sensor system, comprising:

• a common optical bus;
• one or more optical sources, each source having a coherence length;
• a plurality of sensors, each sensor comprising a sensor interferometer formed in substrate, the sensor interferometer comprising a sensing arm and a reference arm, each arm comprising an optical waveguide having first and second ends, the sensor interferometer further comprising means for coupling radiation from an associated one of the sources into the first ends of the arms and means for coupling sensor modulated radiation from the second ends of the arms into the optical bus, the arms of each sensor interferometer (i) having an optical path length difference LS(i) that is greater than the coherence length of the associated source and that differs from the path length difference LS(j) of the sensor interferometer of each other sensor by an amount greater than the coherence length of the source associated with path length difference LS(i), each sensor further comprising means for varying the optical path length of the sensing arm based on a sensed input parameter;
• and
• a detection subsystem coupled to receive the sensor modulated radiation from the optical bus, the detector subsystem comprising detector interferometer means for causing separate portions of the sensor modulated radiation, for each path length difference LS(i), to travel along first and second optical paths that have a path length difference LD(i) that differs from LS(i) by an amount not substantially greater than the coherence length of the source associated with path length difference LS(i), and for combining the sensor modulated radiation that has traveled along the first and second optical paths to produce an optical output signal having an intensity that varies as the sensed parameter of the associated sensor varies.