Application of an artificial neural network for simultaneous measurement of temperature and strain by using a photonic crystal fiber long-period grating

A general analysis of an inserted long-period grating in an air- clad photonic crystal fiber for temperature and strain measurement is presented. The temperature and strain can be detected simultaneously by using an artificial neural network. A simulation study was carried out with the data set generated by using theoretical strain and temperature sensitivities of the long- period gratings. It indicates that the maximum temperature error is 0.04 degrees C in the temperature range from 35 degrees C to 120 degrees C. At the same time, the maximum strain error is 2.7 mu epsilon in the strain range from 0 to 3000 mu epsilon.