Study Of Acceleration Sensing Technology Based On Spin Magnetic Resonant Effect Of Diamond NV Centers

Developing efficient sensors for accleration with high sensibility and reliability is of uttermost important,especially in civilian and military applications.Micro-accelerometers,as inertia devices,are promising candidate for their small size and low cost.However,the effects caused by the fabrication materials and techniques greatly restrict the improvement of the sensitivity and detection accuracy for MEMS acceleremeter.Therefore,some researchers have turned attention to employing new method for developing the performance of accelerameter.Recently,the development of quantum technologies are highly attractive for their ultra-sensitivity and ultra-precision.Nitrogen-vacancy(NV)centers,as one of the typical quantum systems,is a special lattice defect structure in diamond.In particular,the quantum information of NV centers can be manipulated to realize the measurement of the physical parameters with ultra-sensitivity.This unique property can offer remarkable flexbility in the design of the physical sensors.In order to develop an acceleration sensor with high sensitivity and precision,this thesis proposed a NV center-based sensor for sensing acceleration.With attempts to optimize the design and the measurement system,a quantum technology with high sensitivity for acceleration detection was developed and demonstrated.At the beginning,the concept of the NV center was introduced,and the states of art of NV centers and their applications were presented as well as high sensitivie accelerameter.Afterwards,an acceleration sensing model based on NV centers was established by utilizing the theory of the permanent magnet as a constant magnetic field source,followed by the studies of the spatial magnetic field distribution,equivalent magnetic charge model and equivalent current model of permanent magnet.After the establishment of the mathematical model for cylindrical permanent magnet,a detection method based on NV centers was proposed for sensing acceleration.To develop the sensitivity of the detection system,a series of attempts were investigated in this work,including a simulated analysis of the cylindrical permanent magnet model for obtaining the linear distribution area of magnetic field,the optimization of the fabrication process of NV centers,and the readout method to acquire the photoluminescence spectra of NV centers.After that,the luminescent intensity of NV centers was characterized,and the experimental results showed that the intensities of the fluorescence and Raman spectra of NV centers were significantly enhanced compared with those of unprocessed diamond.These indicated that the concentration of NV centers increased and had sufficient capacity to improve the detection sensitivity.The spectra signal efficiency of NV centers was investigated experimentally by employing optically detected magnetic resonance(ODMR)system.The experiment results demenstrated that the optimal microwave and laser power for excitating ODMR signal were 60 mW and 10mW,respectively.A potential limit sensitivity for magnetic detection was estimated to be 2.818nT/Hz~?,simultaneously.At last,a sensing system based on NV centers was established and employed for the measurement of acceleration.A sensitivity of 88.89 V/g and a resolution of22.5?g were obtained,respectively.The measured results indicated that the proposed method based on NV centers is capable of detecting acceleration with high sensitivity and high-accuracy.