1School of Physics and Key Laboratory of Weak-Light Nonlinear Photonics, Nankai University, Tianjin 300071 2School of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 3Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093
Abstract：In recent years, orbital angular momentum (OAM), as a new usable degree of freedom of photons, has been widely applied in both classical optics and quantum optics. For example, digital spiral imaging uses the OAM spectrum of the output beam from the object to restore the symmetry information of the object. However, the related experiments have been carried out in free space so far. Due to the poor anti-noise performance, limited transmission distance and other reasons, the practicability is seriously restricted. Here, we have carried out a digital spiral imaging experiment through a few-mode fiber, to achieve the identification of the symmetry of object by measuring the OAM spectrum of the output beam. In experiment, we have demonstrated the identification of the symmetry of amplitude-only and phase-only objects with the two-, three- and four-fold rotational symmetries. We also give the understanding of the physics. We believe that our work has greatly improved the practical application of digital spiral imaging in remote sensing.
2019, Vol. 36 
