Intracavity Phase Interferometry (IPI) is a detection technique that exploits the inherent sensitivity of a laser’s frequency to the parameters of its cavity. Intracavity interferometry is orders of magnitude more sensitive than its extracavity alternatives. This dissertation improves on previous free-space proof-of-concept designs. By implementing the technique in fiber optics, using optical parametric oscillation, and investigating non-Hermitian quantum mechanics and dispersion tailoring enhancement techniques, IPI has become more applicable and sensitive. 

Ring and linear IPI configurations were realized in this work, both operating as bidirectional fiber optical parametric oscillators. The benefit of using externally pumped synchronous optical parametric oscillation is the removal of the sensor dead band region and simplification of the sensing cavity. These two lasers, along with the theoretical work found in this Dissertation, galvanize future fundamental studies of sensor noise and sensitivity enhancement.