Simultaneous force and temperature measurementusing long-period grating written on the jointof a microstructured optical fiber anda single mode fiber
APPLIED OPTICS/Vol.49, No.3/20 January 2010，-0001，（）：
A novel approach to simultaneous force and temperature measurement is proposed and demonstrated inthis paper. The sensing element is based on a single long-period grating (LPG) formed by irradiating thejoint of a microstructured optical fiber (MOF) and standard single mode fiber (SMF) with CO2 laserpulses. The grating exhibits two groups of attenuation bands with distinctly different responses to temperatureand force: the resonant notches in the MOF involving couplings between fundamental mode andcore LP11 modes are almost temperature insensitive but highly sensitive to force, while resonant notchesin the SMF coming out of couplings between fundamental mode and cladding modes show high sensitivityto temperature but marginal sensitivity to force. Based on the LPG, a simple and efficient dualparametersensor simultaneously measuring temperature and force with a sensitivity of ∼0:086nm=℃and∼−2:18nm=N, respectively, is achieved. Furthermore, we propose a simple sensing configuration forsimultaneous strain and temperature measurement.