Research On Polarization Parameter Imaging Method Based On Quadrature Modulation

Orthogonal polarization imaging method can effectively eliminate the influence of the surface reflected light with the same polarization direction as the incident light,improve the contrast of imaging,and is sensitive to the polarization characteristics of samples.In recent years,it has been widely used in biomedicine and optical detection,and has made a lot of achievements,and developed a new method called the orthogonal polarization difference imaging method which can characterize the dichroism of samples.However,there are still two problems to be solved,one is that the imaging results have no intuitive physical meaning,and the characterization dimension of the polarization characteristics of the sample is very limited;the other is that the image results generated under the initial incident polarized light in different polarization directions are very different.In this paper,based on modulated orthogonal polarization and polarization parameter imaging method,the model of modulated orthogonal polarization parameter imaging system is established,the expressions of linear birefringence,dichroism and depolarization intensity parameters of samples are derived,the modulated orthogonal polarization parameter imaging system controlled by software and hardware automatically is built,the system calibration is carried out,and the derivation of polarization parameter image is realized by MATLAB,cervical cells and the surface defects of quartz glass were measured.The experimental results show that the multi-dimensional polarization parameter images used in this paper are sensitive to polarization characteristics,in which the images of Idp parameter,cos ? parameter and D parameter are not affected by the polarization directi on of the initial incident light.The difference between ? parameter and ?D parameter images under different initial polarization direction of incident light is only a constant related to modulation angle interval,which has little influence.This method is superior to the traditional methods,and has a certain application prospect in the field of tissue and cell imaging and optical detection of surface defects.