Temperature Sensor Based On Photonic Crystal Fiber Filled With Quantum Dots

Optical fiber sensor technology is growing gradually with the development of optical fiber and optical fiber communication technology. Compared with the ordinary sensor, optical fiber sensors have many advantages, such as high sensitivity, easy to install embedment, electrical insulation, stability, good insulativity to electromagnetic interference and long service life. Optical fiber sensors have some important applications in the industrial production, environmental protection, biomedicine engineering, microwave processing and the field of dangerous chemical etc.This paper proposes a temperature sensor based on quantum dots solution filled in photonic crystal fiber and tests the temperature characteristic of it, making a new type of optic fiber luminescence temperature sensor based on the the luminescence peak, intensity and a half width of QDs to the temperature. The work in this topic as follows:1. The QDs solution was filled in the air hole of three PCFs, the photonic band gap, total reflection and microstructure photonic crystal fiber. A light source was choosen to excitate the QDs solutions in three kinds PCFs for exploring the influence of PCF’s structure to the luminescence intensity. The purpose is choosing a PCF that was suitable for fabricating optic temperature sensors.2. Two types luminescence temperature sensors, the transmission type and reflection, was designed and the relationships of the luminescence peak, intensity, and full-width at half-maximum(FWHM) of the luminescent emission band with the temperature are investigated. It was proved that the sensitivity of the luminescence peak wavelength of transmission type and reflection type temperature sensor along with the temperature are 135 pm/℃ and 126.9 pm/℃ respectively. The luminescence intensity of QDS with temperature cannot present a good regularity due to the factors of light source fluctuation, quantum dots’ characteristic. A self-referenced method is used to optimize the relationship between intensity and temperature and the sensitivity are-0.008 / ℃ and-0.007/ ℃ respectively in the temperature. With favorable repeatability for the luminescent peak and the self-referenced intensity in the temperature range from-10 °C to 120 °C.3. Two Cd Se/Zn S QDs of different dimension and the luminescence peak wavelength of them are 605 nm and 655 nm respectively was used to fabricate multiparameter optical fiber luminescence temperature sensor combining with microstructure optical fiber and studied the temperature response of it. The sensitivity of the 605 nm QDs luminescence peak wavelength with the temperature is 129.3pm/ ℃, the optimized luminescence intensity with the temperature is 0.0056/℃. The sensitivity of 655 nm QDs luminescence peak wavelength with the temperature is 127.3pm/℃, the optimized luminescence intensity with the temperature is 0.0055/℃. The sensor can be used in measuring the temperature on different position simultaneously. The QDs of different luminescence peak wavelength can be made by controlling the shape, the structure, the size and the material of the QDs. It provides a foundation research for the multiparameter optical fiber luminescence temperature sensor.