Systems and methods for optically generated trigger multiplication

A method for triggering uniform wavenumber sampling in an optical frequency domain reflectometry system, the method comprising:

• providing a reference optical signal having a period that varies with a wavenumber of a laser light beam that interrogates a sensor array;
• converting the reference optical signal into at least one electrical signal having the same period as the reference optical signal;
• and
• generating a trigger signal based on the at least one electrical signal, wherein the trigger signal contains more than one trigger per period of the at least one electrical signal, and wherein the triggers have uniform wavenumber spacing,
• wherein converting the reference optical signal into the at least one electrical signal comprises splitting the reference optical signal into first and second output optical signals, wherein the second output optical signal is 90 degrees out of phase from the first output optical signal, and converting the first and second output optical signals into first and second electrical signals, wherein the second electrical signal is 90 degrees out of phase from the first electrical signal.

An optical frequency domain reflectometry system comprising:

• a laser configured to produce a laser light beam;
• a first optical coupler configured to receive the laser light beam from the laser;
• a reference interferometer configured to receive the laser light beam from the first optical coupler and to produce a reference optical signal, wherein the reference interferometer is configured to provide the reference optical signal to the first optical coupler;
• wherein the first optical coupler is configured to receive the reference optical signal and to provide at least one output optical signal having the same period as the reference optical signal;
• at least one reference optical detector configured to receive the at least one output optical signal and to convert the output optical signal into at least one electrical signal having the same period as the output optical signal;
• a trigger unit configured to receive the at least one electrical signal and to generate a trigger signal that contains more than one trigger per period of the at least one electrical signal, wherein the triggers have uniform wavenumber spacing;
• a sensor array coupled to the laser and configured to receive the laser light beam, wherein the sensor array is configured to produce an optical sensor signal;
• and
• a sensor array optical detector configured to receive the optical sensor signal, wherein the sensor array optical detector is configured to receive the trigger signal and to sample the optical sensor signal in response to occurrences of the triggers in the trigger signal,
• wherein the first optical coupler is configured to split the reference optical signal into first and second output optical signals, wherein the second output optical signal is 90 degrees out of phase from the first output optical signal, and wherein the at least one optical detector comprises first and second optical detectors that are configured to convert the first and second output optical signals into first and second electrical signals, wherein the second electrical signal is 90 degrees out of phase from the first electrical signal.