2017/11/22 by Yiyu Zhou, Mohammad Mirhosseini, Dongzhi Fu +4 · 128 citations
Engineering · Mathematics · Physics and Astronomy · #Advanced Fiber Laser Technologies #Algorithm #Angular momentum #Azimuth #Computer science #Field (mathematics) #Fourier transform #Mathematics #Optical Polarization and Ellipsometry #Optics #Orbital Angular Momentum in Optics #Orbital angular momentum of light #Paraxial approximation #Photon #Physics #Quantum #Quantum entanglement #Quantum mechanics #Sorting #Spontaneous parametric down-conversion #Superposition principle #Total angular momentum quantum number #physics.optics #quant-ph
paper · pdf · doi:10.1103/physrevlett.119.263602
published in Physical Review Letters 119(26), 263602 (American Physical Society)
arxiv created 2017/11/22 · openalex publication_date 2017/12/28 · arxiv updated 2018/01/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Laguerre-Gaussian (LG) modes constitute a complete basis set for representing the transverse structure of a paraxial photon field in free space. Earlier workers have shown how to construct a device for sorting a photon according to its azimuthal LG mode index, which describes the orbital angular momentum (OAM) carried by the field. In this paper we propose and demonstrate a mode sorter based on the fractional Fourier transform to efficiently decompose the optical field according to its radial profile. We experimentally characterize the performance of our implementation by separating individual radial modes as well as superposition states. The reported scheme can, in principle, achieve unit efficiency and thus can be suitable for applications that involve quantum states of light. This approach can be readily combined with existing OAM mode sorters to provide a complete characterization of the transverse profile of the optical field.