| In recent years,the performance of lidar has been greatly improved.In addition to providing basic information such as distance and speed,the common multi-beam lidar imaging system can accurately capture a variety of characteristic parameters such as the size and shape of the target object,thereby establishing more Accurate 3D dynamic model.A significant advantage of lidar based on the single photon detection system is its high detection sensitivity,which can detect echo signals of the single-photon magnitude.The multi-quantum state method used in quantum secure communication can be used to distinguish whether the target has been camouflaged,so as to realize the security detection and material discrimination of the target object.The combination of the two can obtain more dimensional target surface related information on the basis of the original lidar's three-dimensional imaging of the target,which can bring new detection concepts in the field of active photoelectric detection.The main research is based on the quantum characteristic lidar technology based on the wavelength-time-quantum state random interleaved pulse sequence.It combines the detection methods of multiple wavelengths and multiple polarization states.The scattering characteristics of different target surfaces can be identified through the weak response of a high-sensitivity single-photon detector.Starting from the establishment of a reflection model of photons and atoms,the analysis of the photon scattering characteristics reaching the target surface to the typical photon's quantum state in the lossless and lossy medium surface is related to the transmission characteristics of the theoretical basis to distinguish between different material surfaces;a set of system simulation model of multi-wavelength and multi-quantum state was established,and then demonstrate the key characteristics and verify the theoretical results by establishing a desktop device.The multi-channel photon echo data is successfully used to distinguish metal materials from non-metal materials.Furthermore,the antiinterference characteristics of the target detection method are verified by the antiinterference experiment design of the active light source.The main content and innovation of the dissertation are summarized as follows:1)The free space quantum entanglement HBT correlation measurement technology is studied,the lidar equation containing quantum characteristics is deduced,and the free space HBT ranging system model is established.The relationship between photon logarithms provides a design basis for the multi-quantum state lidar system.2)A target detection technology based on random interleaved pulse train of wavetime-quantum polarization state is designed,the overall design of the whole system is carried out,and the key technologies of each architecture are analyzed.A set of twowavelength four-quantum state system simulation physical model is established to verify the feasibility of the quantum correlation measurement of multi-wave and multiquantum state.By comparing the detection results of typical targets at wavelengths of 532 nm and 1064 nm,as well as the different imaging effects in four quantum states of |H|,|V|,|D| and |A|,the feasibility of multi-wavelength multi-quantum state detection was demonstrated.3)A set of multi-polarization laser measurement desktop verification device was established.The error jitter is less than 20 mm when multiple measurements are made on the target at a distance of about 7 m.In the experiment,the surface of metal and nonmetal was distinguished by the statistics of the depolarization echo photons on the horizontal and vertical channels.The number of depolarized photons on metal surface at different incident angles(0 °,30 °,45 °)is discussed.Through the experimental design of interference with existing active light source,the true distance of metal surface material(6.750m)and non-metal surface material(7.050m)can be obtained from various interference information of 5.700 m,6.325 m,6.750 m,7.050 m and 8.300 m,respectively. |
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