Mechanisms to improve measurement accuracy through differential signaling in homodyne interferometers

Homodyne interferometers (HIs) utilize differential signaling to reduce common-mode noise and enhance measurement stability. However, their potential to improve measurement accuracy has not been thoroughly investigated. To address this gap, we reveal two unrecognized mechanisms enabled by differential-output signal (DS): self-compensation for odd-order periodic nonlinear error (PNE) and mitigation of PNE caused by ghost reflections. Leveraging these mechanisms, we propose a method for quantitatively extracting PNE using redundant phase information.