Optical frequency comb source for fiber sensor interferometer arrays

An interrogation system, comprising:

• an optical frequency comb including a plurality of optical carriers evenly spaced to transmit the plurality of optical carriers to a plurality of optical sensors positioned on a fiber-optic cable along an outer surface of a casing string and a plurality of coupling bands extendable around the casing string to secure at least a portion of the fiber-optic cable against the outer surface of the casing string in a wellbore of a wellbore environment;
• a de-interleaver device positionable between the fiber-optic cable and at least two electro-optical devices to separate optical reflection signals received from the plurality of optical sensors and route the optical reflection signals to the at least two electro-optical devices;
• and
• a data processing system couplable to the at least two electro-optical devices, the data processing system including a processing device couplable to a data storage device having instructions for causing the processing device to perform optical phase measurements of a signal based on the optical reflection signals received from the plurality of optical sensors and received from the at least two electro-optical devices.

A method, comprising:

• transmitting, via an optical frequency comb source, a plurality of optical frequencies to a plurality of sensors coupled to a fiber-optic cable along an outer surface of a casing string, at least a portion of the fiber-optic cable secured against the outer surface of the casing string by a plurality of coupling bands extending around the casing string;
• separating, using a de-interleaver, optical reflection signals received from the plurality of sensors into a first set of reflection signals corresponding to a first set of wavelengths and a second set of reflection signals corresponding to a second set of wavelengths;
• routing the first set of reflection signals to a first opto-electrical device;
• routing the second set of reflection signals to a second opto-electrical device;
• generating a plurality of interference signals from the plurality of sensors using the first opto-electrical device and the second opto-electrical device, an interference signal based on the optical reflection signals from the plurality of sensors;
• and
• performing optical phase measurements using the plurality of interference signals.