Research On Optical Focusing Through Scattering Media Technology Based On Transmission Matrix

The uneven refractive index distribution of the medium will cause multiple scattering during light transmission,making the outgoing light field distribution appear speckle-like.The destruction of the coherence of incident light by scattering media has led scientists to think that scattered light does not contain useful information for a long time.Only by eliminating the effect of scattered light can the quality of optical imaging be improved.However,recent research shows that the scattered light also contains the structural information of the medium.If the transmission matrix of the scattering medium has be calculated,useful information can be extracted from the scattered light to achieve focusing and imaging through the scattering medium.Based on the transmission matrix method in wavefront shaping technology,this paper proposes two calculation methods for the transmission matrix of the scattering medium.The complex transmission matrix and the binary transmission matrix of the scattering medium can be calculated respectively.The simulation of angular spectrum theory confirms these two algorithms scanning and focusing of light through a scattering medium can be achieved.By analyzing the advantages and disadvantages of different algorithms,this paper.finally selects the binary amplitude modulation to achieve the scanning focus of light passing through the multimode fiber,and builds an optical system based on digital micromirror device for experimental verification.The transmission matrix algorithm based on binary amplitude modulation proposed in this paper is of great significance to achieve scanning and focusing of a large field of view through a scattering medium,and has broad application prospects in the field of biomedical imaging.