Patent ID: 8508747

Claim:
An apparatus for triggering uniform wavenumber sampling in an optical frequency domain reflectometry system, the apparatus comprising: an optical coupler configured to receive a reference optical signal from a reference interferometer 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; and 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, wherein the 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 reference optical detector comprises first and second reference 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.