| Human beings mainly perceive environmental information through vision.In modern times,as the lenses have been continuously developed in design and manufacture,the functions of imaging devices have become more and more powerful.Nowadays,with the help of advanced imaging devices,people have a deeper understanding of the world.In recent years,Transformation Optics(TO),as an emerging electromagnetic theory,is expected to play an important role in the field of imaging.TO was first proposed by British scientist Pendry et al.in 2006,which is based on the form invariance of Maxwell’s equations.With the help of TO,designed spatial transformation relations can control the propagation of light.Since proposed,novel electromagnetic devices based on TO have received extensive attention.Traditional lenses are mainly based on the refraction and reflection in geometric optics to design.In this paper,a novel method combines TO and wide angle imaging lens is theoretically developed.The coordinate transformation relationship and the electromagnetic parameters required by the imaging device have been proposed.Based on this method,it is possible to converge light from all directions to the observer using the device.Compared with the traditional lenses,the imaging device designed with TO doesn’t need calibration.Compared with other image stitching technologies,which need computers to complete the task,the imaging device designed with TO doesn’t require active devices and can achieve real-time imaging.In this paper,we carried out the numerical simulation of wide angle imaging method based on TO.With the help of commercial finite element software COMSOL,we modeled the imaging device and calculated electromagnetic parameters for simulation.The simulation mainly consists of two parts:Gaussian beams were used to mimick the propagation trajectories of light and the reversibility of light was used to verify the overall performance of the device.In the simulation of Gaussian beams,under the ideal conditions,the device can change the propagation of Gaussian beams and the trajectories in the device matched the coordinate transformation relationship have been verified.Based on the reversibility of light,the source was set inside the device,electromagnetic wave excited by the source can bypass perfect electric conductor and radiated full cylindrical wave outward,which verified that the device has the ability to converge the beams from all directions.The numerical simulation results proved the accuracy of wide angle imaging method based on TO proposed in this paper. |
