Soliton mode-locked fiber laser for distance measurements

Absolute distance measurement is crucial for many applications including metrology, large-scale manufacturing, range finding, and surveying. In this paper, a novel, to the best of our knowledge, technique is introduced for precise distance measurement by including the distance under measurement in a soliton mode-locked fiber ring laser (SMFRL). Consequently, the measured distance can be calculated from the change in the repetition rate of the emitted pulses due to the laser cavity length change. The SMFRL technique is implemented here to measure distances up to 57.4 m with precision of less than 9 µm. Therefore, we believe that the SMRFL technique provides a relatively simple and precise technique to measure relatively long distances.