At its core, the module operates on the principles of differential detection and common-mode noise rejection. Optical signals are converted into electrical currents by two highly matched photodiodes, followed by precise signal subtraction. This process effectively suppresses laser intensity noise and other common-mode interference, significantly enhancing system signal-to-noise ratio (SNR).
As a result, weak OCT signals embedded in background noise can be accurately extracted, ensuring high-fidelity imaging and stable system performance.