Turbulence Field Detection Based On The Interference Of Two Gaussian Schell-model Vortex Beams

With the development and utilization of marine resources,monitoring the marine environment to ensure the safety of core interests becomes an important topic in the field of marine safety.Underwater turbulent flow detection is an important part of marine environmental monitoring.The temperature distribution,salinity distribution,and velocity field distribution will form turbulence fields with different intensity distributions.Various types of underwater navigation objects will have turbulent flow fields.The measurement of the distribution of ocean turbulent flow can enable the monitoring of specific targets of the marine environment.Gaussian Schell-model vortex beam used as the measuring beam on the basis of the traditional method of measuring the structure function of the ocean turbulence refractive index by the plane-Polach-Zehnder interferometer,the transmission characteristics of the beam in ocean turbulent flow,the interference characteristics of the two beams,the verification of turbulent flow field detection methods and non-uniform turbulent flow field measurements are carried out to investigate underwater turbulent flow field detection based on double Gaussian Schellmodel vortex beam interferometry will be investigated.In order to obtain a larger turbulent field measurement range,±1 order Gaussian Schell-model vortex beam is selected as the measurement beam.The transmission characteristics of a single beam in a uniform turbulent flow field is discussed using the cross-spectral density method,and the single beam intensity is obtained.The relationship between the distribution and various parameters of the turbulent flow field,and the relationship between the light intensity distribution and the intensity of the turbulent flow field is verified through experiments,and the correctness of the cross-spectral density method is verified.The phase of the Gaussian Schell-model vortex beam is obtained according to the complex degree of coherence.Then,the relationship between the intensity distribution of the two-beam interference and the various parameters of the turbulent flow field under different intensity uniform turbulent flow fields is obtained.Taking into account the offaxis effect of the double beam generated by the random refraction of the beam under strong turbulence,the effect of strong turbulence on the performance of the dual-beam measurement system is simulated.Using the methods to deal with the uniform turbulent flow field,the relationship between the two-beam interference light field and the non-uniform turbulent flow field is obtained.Two-beam interferometric experiment is performed,for underwater inhomogeneous turbulent flow field induced by a single heat source.The correctness of the complex degree of coherence method is discussed,and the feasibility of the dual Gaussian Schell-model vortex beam interferometry to measure non-uniform turbulent flow is verified.Using the obtained dual-beam interference intensity data,a simplified model has been developed to analyze the spatial correlation of temperature-induced non-uniform turbulent field fluctuations induced by a single underwater heat source.And preliminary theoretical and experimental studies of underwater non-uniform turbulent flow are performed.