High-resolution long-range swept-source OCT for volumetric imaging and metrology up to 200  m

We demonstrate a long-range swept-source optical coherence tomography (SS-OCT) capable of high-resolution volumetric imaging up to 200 m ranging distance. By utilizing an advanced akinetic all-semiconductor swept laser operating at 1550 nm with a 50 kHz sweep rate and an ultra-narrow instantaneous linewidth (<0.6MHz), the system achieves a theoretical coherence length exceeding 200 m. By optimizing spectral bandwidth (∼0.09nm) and digitizer sampling (800 MS/s), we experimentally realize imaging ranges up to 53 m with an axial resolution of approximately 1.2 cm. A robust data acquisition and processing pipeline, featuring point cloud compression, geometric correction, and noise suppression, enables compact and portable operation. The versatility of the system is showcased across diverse scenarios, including remote imaging of human subjects, dynamic events, vehicles, and architectural structures. These capabilities position long-range OCT as a compelling alternative to conventional ranging technologies, providing high-resolution volumetric imaging with micron-level precision and immunity to ambient lighting for applications in metrology, robotics, human–machine interfaces, and environmental sensing.