Implementation of Er-doped random fiber laser self-mixing sensor with ultra-limit sensitivity

• Published in: APL photonics 2024-03, Vol.9 (3), p.036113-036113-7
• Main Authors: Hu, Jun, Li, Ruifeng, Hu, Zhijia, Li, Haosen, Yang, Yaozhong, Li, Hongtao, Lv, Jialiang, Yu, Qi, Zhao, Yunkun, Yu, Benli, Lu, Liang
• Format: Article
• Language: English
• ISSN: 2378-0967; 2378-0967
• DOI: 10.1063/5.0192626

This study first demonstrates that the random distributed feedback fiber laser (RDFL) can be implemented for sensing detection by using the self-mixing effect as a sensing mechanism. By constructing a compact self-mixing velocimeter based on Er-doped RDFL with the integration of a laser, sensing element, and transmission platform, we successfully measured the minimum detectable feedback intensity of 38.65 fW for the velocity signal, corresponding to 0.55 photons per Doppler cycle, exhibiting ultra-high sensitivity dynamics characteristics. In addition, the velocity measurement of a non-cooperative target at a single-channel distance of 100 km is accomplished because of the natural feature of long-distance transmission for the random distributed feedback fiber lasers, which greatly improves the ultra-long detection range in the field of self-mixing sensing. The proposed sensing scheme not only unveils a fresh perspective on the exploration of random fiber laser sensing but also showcases its diverse and wide-ranging applications within the realm of remote sensing measurements.