We demonstrate phase-drift suppression (PDS) to enhance stabilization of the computed signal intensity (CSI) in heterodyne detection without optical and/or electronic feedback systems. CSI is defined as the square root of the sum of the squares of each harmonic intensity in the heterodyne beat signal. The PDS theoretically and experimentally demonstrates stabilizing conditions for modulation indexes and stability enhancements; for example, the CSI stability was enhanced 49 times through simulations and by 6.3 times through experiments for a modulation index of 2.62 rad. Optical coherence tomography images using a fiber Mach–Zehnder interferometer and a superluminescent diode verify the validity of PDS as an application.
