2016/06/01 by Paweł Woźniak, Peter Banzer, Frédéric Bouchard +3 · 24 citations
Engineering · Physics and Astronomy · #Angular momentum #Aperture (computer memory) #Beam (structure) #Classical mechanics #Digital Holography and Microscopy #Gaussian beam #Light beam #Near-Field Optical Microscopy #Near-field optics #Numerical aperture #Optical microscope #Optical tweezers #Optics #Orbital Angular Momentum in Optics #Physical optics #Physics #Polarization (electrochemistry) #Scalar (mathematics) #Wavelength #physics.optics
paper · pdf · doi:10.1103/physreva.94.021803
published in Physical Review A 94(2) (American Physical Society) · 6 pages, 3 figures
arxiv created 2016/06/01 · openalex publication_date 2016/08/23 · arxiv updated 2016/08/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The possibility of focusing light to an ever tighter spot has important implications for many applications and fields of optics research, such as nano-optics and plasmonics, laser-scanning microscopy, optical data storage, and many more. The size of lateral features of the field at the focus depends on several parameters, including the numerical aperture of the focusing system, but also the wavelength and polarization, phase and intensity distribution of the input beam. Here, we study the smallest achievable focal feature sizes of coherent superpositions of two copropagating beams carrying opposite orbital angular momentum. We investigate the feature sizes for this class of beams not only in the scalar limit, but also use a fully vectorial treatment to discuss the case of tight focusing. Both our numerical simulations and our experimental results confirm that lateral feature sizes considerably smaller than those of a tightly focused Gaussian light beam can be observed. These findings may pave the way for improving the resolution of imaging systems or may find applications in nano-optics experiments.