Study On Dual-core Photonic Crystal Fiber Temperature Sensor

Temperature is a basic environmental parameter. Agricultural production can not be separated with temperature measurements, the growth of various crops is directly related to the relationship the temperature, the controlling of temperature changes can bring the growth of crops under control. Industrial production also often requires real-time measurement of temperature, but by human effort which also has a certain risk would be a waste of time, material and human resources, and the measured data is not always accurate, so the research of temperature sensing method and apparatus are of great significance.Fiber is a transmission medium with corrosion-resistant and electrical insulation, anti-electromagnetic interference, safety and reliability. In a variety of large-scale electrical and mechanical, petrochemical, metallurgy high pressure, strong electromagnetic interference, flammable, explosive and strong corrosive environment, fibers can easily and efficiently transfers Sense. Photonic crystal fiber, which was developed in the 20th century, is a new type of the fiber introduces periodic structure in the fiber so that characteristics of endless single mode, controllable nonlinear effects, controllable dispersion and low loss. Photonic crystal fibers which can have flexible structures, are widely used in various fields, therefore, photonic crystal fiber sensor caused extensive research.A dual-core photonic crystal fiber temperature sensor with hybrid optical system was presented, the temperature sensor was achieved with the appropriate air holes selected in the dual-core photonic crystal fiber and filled with liquid crystal material.The liquid crystal material injected into the air holes had thermo-optic effect so when the temperature wes changed, the coupling characteristics of dual-core photonic crystal was changed, thereby a dual-core photonic crystal fiber temperature sensor was constituted for range of room temperature. First of all, the coupling characteristics of the dual-core were analyzed from the basic structure of the dual-core photonic crystal fiber. After the relationship among the incident light wavelength, the coupling length and the photonic crystal lattice constant was obtained, the basis for the structure design of the dual-core photonic crystal fiber was provided. Then the performances of dual-core photonic crystal temperature sensor with the symmetry and asymmetric structure were calculated by Rsoft. At last, the transmission power of the dual-core photonic crystal fiber filled with different types of liquid crystal was calculated by the beam propagation method (BPM Beam propagation method).By this way, the relationship between the temperature and the outgoing power was obtained and the sensor characteristics were analyzed. The temperature range of the dual-core photonic crystal fiber temperature sensor was 273K-373K, and the accuracy was 0.5K. If the optical detection accuracy was enhanced, the accuracy of the dual-core photonic crystal fiber temperature sensor could be further improved. The dual-core photonic crystal fiber temperature sensor with simple structure, improved sensing range and sensing accuracy was conducive to the realization.