Mechanism And Key Technologies Of Distributed Optical Fiber Quantum Sensing

The various scattering effects should be produced by the interaction between the optical quantum and the microscopic particles in the optical fiber core.And these scattering states can be changed under the influence of external stress,which is a foundation of optical fiber quantum sensing.Optical fiber quantum sensing technology can be used as a powerful tool for distributed monitoring with the advantages of high sensitivity,high positioning accuracy,simple installation,anti-electromagnetic interference etc.This thesis is application-oriented and is promoted by perspective research projects of Jiangsu province and our country.It is devoted to the mechanisms and key technologies in distributed fiber quantum sensing,which lays a solid foundation for future research and development.Chapter 1 is a simple introduction of fiber sensing technology and development.Research progress of long distance distributed fiber photon sensing technology and system based on various scattering effect is reviewed and quantum sensing technology and its development status are discussed.On these bases,various influence factors for transmission of quantum information in optical fiber is analyzed.Main research contents of this thesis are also given in this chapter.In Chapter 2,the generation,annihilation operator of quantum oscillators and the matrix element of related operators are deduced from the classic linear quantum oscillator model in quantum mechanics.On this basis,electromagnetic energy is quantized and quantum model of phonon and photon is obtained respectively.The scattering phenomenon in fiber core is then studied and quantum model of spontaneous Raman scattering is deduced by separating material system and electromagnetic wave and taking their interaction as perturbation.The mechanisms of distributed fiber quantum sensing based on scattering effect are then discussed,and a distributed fiber Raman temperature sensor is simulated.The simulation results show that the sensor can effectively measure the temperature along the fiber and a good linear relationship between the measured data and the temperature.In chapter 3,based on the quantum electronic theory,the quantization of the modes in a single mode fiber is studied and a quantum transmission equation is deduced from the classical optical transmission equation through quantization of the amplitude of electromagnetic field.By giving a trail solution and introducing a perturbation term,the transmission equation is solved for the complicated case when dispersion,loss and nonlineareffect are all involved.A dispersion equation that should be satisfied for nontrivial solution is then obtained.From this dispersion equation,the relation between photon power and perturbation frequency is calculated and analyzed,which lays the foundation for experiments.In Chapter 4,Optical properties of multilayer dielectric thin film are analyzed using characteristic matrix of film system.Operation principle of Fabry-Perot interferometer is then studied and the optical properties and performance parameters of Fabry-Perot cavity are deduced and analyzed.On these bases,optical properties of single-cavity filter and double-cavity filter are analyzed respectively.Design method of single-stage and multiple-stage filter is also studied and the results are analyzed and improved.Three types of thin film filter are designed according to the requirements of the experiment system.Chapter 5 devotes to a distributed fiber quantum sensing experimental system that is putted up in our lab.The structure,performance and parameters of the optical source module and photoelectric detection module used in the experiment are investigated,and the performances of the distributed fiber quantum sensing system are experimentally verified.The results show that the distributed fiber quantum perturbation sensing system can reach50 km detection distance with positioning accuracy better than ±50m;while the distributed fiber quantum temperature sensing system can reach 10 km detection distance with positioning accuracy better than ±10m.Conclusion and further research content and outlook are given at the end of this thesis.