Preparation Of Hollow Core Fiber Side-Wall Resonance Structures And Their Dual Parameters Sensing Properties

Optical fiber sensors have developed rapidly in recent years.The hollow core fiber sensing structure possesses advantages such as low cost,easy preparation,fast response and easy realization multi-parameter sensing.The hollow core fiber has air core and quartz sidewall,and the wavelength matching condition based on the quartz sidewall resonance is particularly sensitive to environmental changes,which can achieve highly sensitive and synchronous detection of different environmental parameters.In this paper,the principle of side-wall resonance with the principle of interference,and transmission and reflection fiber sensing structures based on the side-wall resonance mechanism of hollow core fiber have been proposed,realizing the application of dual-parameter sensing for temperature and strain,temperature and pressure respectively.The main work is as follows:The hollow core fiber side-wall resonance sensing structure is fabricated and its temperature sensing characteristics are studied theoretically and experimentally.The transmission spectrum of light intensity of side wall resonance was simulated.The light field distribution in hollow core fiber was simulated by using the finite element analysis method,and the temperature sensitivity of the transmission sensing structure based on side wall resonance was calculated theoretically.Then we tested the temperature response performance of the structure,and analyzed the sensitivity and linearity of the sensor.A novel temperature and strain synchronization sensing structure based on the sidewall resonance in hollow core fiber was proposed.The intensity distributions under the different offset of hollow core fiber has been simulated by using the finite element analysis method.The transmission spectra of two kinds of principle was calculated,and the sensitivity of temperature and strain was simulated.The hollow core fiber sensing structures with different lengths were prepared,and the influence of the hollow fiber sensing structures on the transmission spectrum was analyzed.The sensor could realize the synchronous sensing detection of temperature and strain.A synchronous sensing structure for temperature and pressure based on hollow core fiber side-wall resonance and Michelson interference was proposed.The spectrum of the of the fiber optic sensing structure was simulated,and the temperature and pressure sensitivity of the fiber optic sensing structure are calculated theoretically.We studied the effects of the length of hollow core fiber and the misalignment of the incident end on the reflectance spectrum experimentally,and tested the temperature and pressure sensitivity,sensing linearity and response time of the structure.The structure can realize the synchronous sensing detection of pressure and temperature under high temperature and high pressure environment with high sensitivity and fast response.