Distributed fiber temperature and strain sensor using coherent radio-frequency detection of spontaneous Brillouin scattering.
A novel technique that enables coherent detection of spontaneous Brillouin scattering in the radio-frequency (<500 MHz) region with excellent long-term stability has been demonstrated for distributed measurements of temperature and strain in long fiber. An actively stabilized single-frequency Brillouin fiber laser with extremely low phase noise and intensity noise is used as a well-defined, frequency-shifted local oscillator for the heterodyne detection, yielding measurements of spontaneous Brillouin scattering with high frequency stability. Based on this approach, a highly stable real-time fiber sensor for distributed measurements of both temperature and strain over long fiber has been developed utilizing advanced digital signal processing techniques.
Geng
Jihong
J
NP Photonics, Inc., Tucson, Arizona 85747, USA. geng@npphotonics.com
Staines
Sean
S
Blake
Mike
M
Jiang
Shibin
S