Spontaneous Raman scattering in optical fibers with modulated probe light for distributed temperature Raman remote sensing

Long-length fiber-optic remote Raman sensors are used for distributed temperature measurements. Toward this aim, we apply optical-fiber frequency-domain reflectometry. The Raman intensity generated in single- and multimode optical fibers is theoretically investigated for sinusoidally intensity-modulated probe light. Thus, a proper sensor element and wavelength for fiber-optic Raman sensing is determined. Further, the temperature error for long sensor fibers is theoretically analyzed.