Precision Measurement Of Fiber Optic Diamond NV Color Center Based On FPGA Architecture

The NV color center is a point defect formed by replacing one carbon atom with one nitrogen atom(Nitrogen)in diamond and capturing its adjacent carbon atom vacancy.Diamond NV color center has excellent optical characteristics,is an excellent single photon source,widely used in quantum optics,quantum computing,quantum imaging and biomedical fields.The diamond nitrogen vacancy color center has the advantages of artificial preparation,long electron spin coherence time,bright and stable light emission,etc.It initializes and reads its quantum states in the form of optical methods,and realizes the precise measurement of these physical quantities based on the effects of external electromagnetic fields,temperature,and stress on its quantum states,namely diamond NV color center quantum precision measurement.This paper presents a fiber-optic diamond NV color center quantum precision measurement system based on Field Programmable Gate Array(FPGA)architecture.The system is used for imaging non-destructive,high-resolution microwave fields of microwave integrated circuits,microwave antennas and other microwave devices.In this paper,a microwave probe based on tapered fiber diamond NV color center is proposed.The probe uses micron-sized diamond crystals,which can be close to the sample surface of microwave equipment,and will not cause interference to the microwave field of microwave equipment.This paper explores a photoelectric pulse control system based on amplitude modulation(AM)pulse modulation method.The system sets and generates microwave pulses according to the quantum state evolution law of the ground state spin of the NV color center in the resonant microwave field,and modulate the amplitude of the microwave pulse signal to optimize the signal-to-noise ratio of the fluorescent signal emitted by the detected NV color center.In order to improve the integration of the quantum precision measurement system,this paper studies a data acquisition system based on FPGA architecture to collect and process weak fluorescence signals.The main function is to digitally sample the fluorescent signal detected by the avalanche photodiode,extract it and convert it into a digital signal,and then use Fast Fourier Transform(Fast Fourier Transform,FFT)for signal filtering and processing.In order to verify the feasibility and accuracy of the system,this paper measures and HFSS software simulations of small helical antennas and ultra-wideband antennas,and compares the simulation results with the experimental results.