Research Projects

Early detection and localization of fire sources is a key challenge for extinguishing the fire in a fast and timely manner. Conventional point sensors such as gas detectors/temperature gauges are limited by spatial resolution. Moreover, the complexity of installation, signal monitoring and high installation/maintenance costs prohibit scaling of this methodology. Distributed Anti-Stokes Raman Thermometry (DART) is an attractive approach for the above application because of its ability to make distributed measurements using a single optical fiber. Sensing is carried out using spontaneous Raman scattering in optical fiber, specifically since the anti-Stokes scattering intensity is strongly dependent on temperature. Hence, by observing the anti-Stokes intensity and using optical time-domain reflectometry (OTDR) principles one can accurately measure the temperature across the length of the sensing fiber with high spatial resolution. A DART based sensor can be used for fire detection by setting alarm levels based on reaching a fixed threshold and/or on a rate of rising of temperature. The proposed work is expected to yield a Distributed Anti-Stokes Raman Thermometry (DART) system based on mode demultiplexing in graded-index few-mode fibers (GI-FMF), which will be thoroughly tested in a controlled testbed for fire detection in tunnels. The key deliverable of the project will be a distributed temperature sensing system based on Distributed Anti-Stokes Raman Thermometry (DART) with a 10 km range and with meter-scale spatial resolution developed for sustainable manufacturing. The specifications of the proposed system are as follows: Sensing range: 10 km Spatial resolution: 1 m Temperature uncertainty: 1 deg C Number of sensing channels: 2 Sensing fiber: Graded Index Few Mode Fiber (GI-FMF) Operating temperature: 0 deg C to 120 deg C