LAUSR

In this paper, a method based on the inherent event-based sampling capability of the laser optical feedback interferometry (OFI) is proposed to recover sub- $\lambda $ /2 displacement with a nanometric precision. The proposed method operates in open-loop configuration and relies on OFI’s fringe detection, thereby improving its robustness and ease of use. The measured white noise power spectral density is less than 100pm/ $\sqrt {\text {Hz}}$ with a corner noise frequency of approximately 80Hz for a laser diode emitting wavelength $\lambda _{{0}}$ of 785nm placed at 30cm of the target.