Research On The Key Technology Of Polarization Imaging Of Liquid Crystal Lens

Compared with traditional imaging methods,the polarization imaging can not only obtain light intensity information of objects,but also obtain polarization information.The polarization imaging is a beneficial complement to traditional imaging methods.It is used in remote sensing telemetry,security monitoring,rescue and disaster relief,and military target recognition.Liquid crystal lens is a new type of liquid crystal device that is electronic control.It can focus,zoom and measure of depth without mechanical movement.This paper mainly uses the birefringence characteristics of liquid crystal lenses to conduct research on polarization imaging.Firstly,this article introduced the basic principles,device structure,and characteristics of liquid crystal devices used in this subject: liquid crystal lenses and 90°twisted nematic liquid crystal cell.The above devices were fabricated and tested.The basic principle of polarization imaging was simply deduced.Then,for the problem of incomplete acquisition of information in the liquid crystal lens imaging,a new liquid crystal lens imaging system was built using the liquid crystal lens and the liquid crystal polarization rotator.Using this system can also realize the detection of polarized light in the scene.Then using the polarizer-free imaging algorithm of the liquid crystal lens,the detection of polarized light in the scene is also achieved without using a polarizer.In view of the lack of some information in the imaging of the liquid crystal lens,this paper proposes a liquid crystal lens imaging method using a 90 ° twisted nematic liquid crystal cell instead of a polarizer.After the liquid crystal lens is focused,a 90 ° twisted nematic liquid crystal cell is used to obtain two images of incident light orthogonal to the polarization direction.And the defocused image is obtained when the liquid crystal lens is not operated.A well focused image is obtained by image programing of thous three images.This method removes low-frequency components introduced by unmodulated light and enhances image contrast.This method reduced the noise generated by the original polarizer-free imaging process.Experiments verify the effectiveness of this method,and clear images can be obtained without any polarizer.In this paper,the characteristics of electronically controlled birefringence of a liquid crystal lens are used.The birefringent lens,which is a combination of a liquid crystal lens and an ordinary glass lens,is used for optical imaging subtraction.The edges of the object are extracted.For birefringent lenses,the image of the target object actually has two images,o-light image and e-light image.By adjusting the voltage of the liquid crystal lens,a slight magnification difference is generated between the two images.To achieve the effect of real-time extraction of object edges.