Fiber-Optic Distributed Sensor Based on Hybrid Raman and Brillouin Scattering Employing Multiwavelength Fabry–PÉrot Lasers

We propose the use of standard multiwavelength Fabry–PÉrot (FP) lasers for distributed strain and temperature measurement in hybrid Raman- and Brillouin-based fiber-optic sensors. The multiple longitudinal modes of FP lasers allow for accurate spontaneous Raman scattering measurement and for simultaneous high-sensitivity coherent detection of the Brillouin frequency shift parameter for all longitudinal modes. Experimental results confirm great performance improvement in simultaneous strain and temperature measurement using a single optical fiber.