Abstract

The Pound–Drever–Hall (PDH) technique has been widely adopted in high-resolution fiber-optic sensors, but its performance degenerates as the probe power drops. In this work, we develop a coherent PDH technique for detection of very weak probe light, in which the probe beam is coherent detected with a strong local oscillator. Assisted with an analog frequency doubler and a band-pass filter, the configuration of proposed coherent PDH technique is highly compatible with classical PDH technique. The influence of fiber dispersion is also assessed. In the demonstrational experiments, the signal-to-noise ratio of the extracted PDH signal is dramatically improved compared with classical PDH technique, especially under weak probe power. Using a π-phase shifted fiber Bragg grating as the sensing element, a nϵ-order strain resolution is achieved at a low probe power down to –43 dBm, which is about 15-dB lower compared with classical PDH technique. The proposed technique has great potentials in high-resolution large-scale fiber sensor networks.

© 2017 IEEE

PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription