Experimental measurement of the temperature-birefringence characteristics of birefringent photonic crystal fiber filled with ethanol

摘要

The birefringence value of the birefringent photonic crystal fiber (PCF) is not sensitive to the change of temperature, while the refractive index of ethanol will be changed with the varied temperature. So if the air-holes of PCF are filled with ethanol, the birefringence value will surely change along with the varied temperature, which can be used as a sensing principle to measure temperature. In this paper, a method called End Face Reflection of the optical fiber was used to measure the refractive index against the change of temperature. The experimental results indicated that, on the condition of the incident wavelength of 1550 nm, the refractive index of ethanol changed from 1.3691 to 1.3602 within the temperature ranging from 24.5℃ to 44.5℃. The birefringence value of the filled PCF changed from 1.8900e-04 to 2.1500e-04. That is to say, the temperature sensitivity coefficient could reach 10e-6 order of magnitude.