Long path industrial OCT: High-precision measurement and refractive index estimation

Long-path optical coherence tomography was developed for industrial use. The system is compact and easy variable to change the measurement speed and range. In this study, its precision and long-path were designed as 1μm and 100mm, respectively. Refractive index of water was analysed by changing the temperature. The results well coincided with the theoretical curve of group index of refraction.