Frequency-swept feedback interferometry ranging method based on resonant-cavity enhancement

Addressing the issue of low measurement accuracy of conventional Frequency Sweep Interferometry (FSI) ranging methods for long-distance non cooperative targets. This work proposed a Frequency-Swept Feedback Interferometry (FSFI) ranging method based on resonant cavity enhancement for long-distance non-cooperative targets measurement and weak signal detection. The FSFI ranging method has simpler and contact system setup, which also has high precision and sensitivity. After experimental verification, it was found that with a target of oxidized black aluminum plate at a distance of 16m, the Standard Deviation (STD) was better than 70μm, the measurement accuracy was better than 27μm, and the system ranging resolution was better than 0.13mm when the target feedback light was very weak.