Serrodyne‐Enabled Dual Electro‐Optic Comb Interferometry for High‐Precision Absolute Ranging and Integration‐Ready Metrology

Abstract Optical frequency combs (OFCs) have revolutionized precision metrology, enabling highly precise frequency and distance measurements. Dual electro‐optic frequency comb ranging systems traditionally rely on acousto‐optic modulators (AOMs) to shift the local oscillator frequency, mitigating frequency degeneracy but restricting tuning flexibility, response speed, and power efficiency. Here, an AOM‐free dual electro‐optic frequency comb ranging system is introduced, employing a serrodyne‐modulated electro‐optic modulator (EOM) for frequency shifting, achieving superior phase coherence and high‐precision distance measurement. Experimental validation confirms nanometric ranging precision, with Allan deviation below 0.1 nm at 1 ms integration. The system effectively tracks high‐frequency vibrations (up to 100 kHz) from a piezoelectric transducer and enables dynamic 3D surface imaging. Moreover, it detects nanoscale water surface vibrations through precise laser‐ranging analysis. Notably, the system maintains high measurement precision across a wide spatial scale—from meter‐level free‐space ranging to nanometer‐scale vibration sensing—demonstrating exceptional versatility. Compared to conventional AOM‐based approaches, the method provides enhanced flexibility, reduced RF power consumption, and improved photonic integration compatibility, thus offering substantial benefits for precision metrology and high‐resolution sensing applications.