Research Of Optical Fiber Temperature Sensor Based On The Fluorescence Effect Of Quantum Dots

Temperature sensors are widely used in many fields,such as daily life,agricultural production and aviation and spaceflight.The common temperature sensors mainly include thermocouple,thermal resistor and infrared sensor.It is true that these temperature sensors are low in price,simple in structure and mature in technology,but there are some security risks for the main use of current induction,which is not suitable for high risk areas.The quantum dots filled capillary quartz glass tube and hollow core fiber(hollow-core,fiber,HCF),by using quantum dots,the peak wavelength of the photoluminescence spectrum of the peak intensity and FWHM and many other optical parameters of thermal effect,can be characterized on temperature.Therefore,based on the CdSe quantum dot optical fiber fluorescence temperature sensor,it has the advantages of immunity to electro-magnetic interference,high temperature measurement accuracy,high resolution,good dynamic response and wide measurement range.It can be used for temperature measurement under extreme conditions,and has a strong application prospect.This thesis presents a CdSe quantum dot filled capillary quartz glass tube and HCF temperature sensor based on fluorescence,the fluorescence peak wavelength,intensity and FWHM of CdSe quantum dots as the characteristic parameters for temperature measurement,a novel optical fiber fluorescence temperature sensor is studied deeply.The specific work is as follows:(1)Selected guide capillary quartz tube and hollow fiber glass light mechanism is different,respectively,CdSe QDs solution filled capillary quartz glass tube,the wavelength of the excitation of 400nm light as light source excitation filled CdSe quantum dot glass tube and HCF the capillary fluorescence,comparing the fluorescence characteristics.(2)According to the theory of CdSe quantum dot photoluminescence spectra of three kinds of optical parameters is peak wavelength,peak intensity and FWHM,and the change of temperature between the combined advantages of capillary quartz glass tube and HCF,the design of a CdSe quantum dot filled capillary quartz glass tube and HCF fluorescence temperature sensor based on research the filling of CdSe quantum dots in capillary quartz glass tube and HCF in photoluminescence spectra(photoluminescence,PL)variation of peak intensity,peak wavelength and the FWHM of three parameters of temperature.(3)The theoretical results show that with the increase of temperature,the CdSe quantum dots photoluminescence peak intensity with increasing temperature changed at the same time.The peak wavelength of photoluminescence spectra CdSe quantum dot and FWHM and peak wavelength is related to temperature,as the temperature increases toward the long wavelength direction,FWHM with the temperature of quadratic function relation.CdSe quantum dots with size distribution of about 12 nm are selected in this thesis.The experimental results show that at 30-130? temperature range,so the sensor probe in the capillary filling quartz glass tube and the length of HCF is only CdSe quantum dots around 1-2 mm in the emission intensity decreases as temperature rises,while the PL peak wavelength and the FWHM increases with temperature rising.Some HCF capillary filled with CdSe quantum dots and the fluorescent temperature sensor are particularly distinct:sensing probes are fabricated.According to the experimental results with HCF fluorescence temperature sensor with optical fiber transmission and reflection sensitivity of CdSe quantum dots were 0.12nm/? and 0.1 nm/?,filled with a fluorescence temperature sensor with optical fiber transmission and reflection sensitivity of CdSe quantum dots with a quartz glass tube are respectively 0.13 nm/? and 0.12 nm/?.The experimental results show that the sensor can measure the temperature.At the same time,the sensing probe is only 1-2 mm long,which is expected to achieve distributed measurement.