Optical feedback interferometry with 40 km transmission distance based on a distributed feedback fiber laser

This Letter proposes an all-fiber self-mixing interferometric method based on laser feedback technology with long transmission distance, which has advantages of high sensitivity and compact structure. We theoretically and experimentally verify that the measurement distance of the self-mixing sensor is not limited to the coherence length of the solitary laser used. In the experiment, the velocity of a non-cooperative target was successfully measured with 40 km transmission distance. Therefore, the all-fiber self-mixing Doppler velocimeter has a great application prospect in the field of remote sensing measurement. Its unique flexibility can be applied to a variety of complex environments of noncooperative target measurement. (C) 2021 Optical Society of America

Automated summary

This paper introduces an all-fiber self-mixing interferometric method based on laser feedback technology, which enables high-sensitivity measurements over long transmission distances. The experiment demonstrates that the measurement distance of the sensor is not limited by the coherence length of the laser used. This technology has been successfully applied to measuring the velocity of non-cooperative targets, showing great potential for practical applications.