Lagging propagation phase of spatially structured beams

Wan, Z., Tang, Z. and Wang, J. (2023) Lagging propagation phase of spatially structured beams. Optics Express, 31(25), pp. 42667-42676. (doi: 10.1364/oe.510341)

Abstract

The structured beams especially with spatially varying phase distribution have attracted tremendous attention in both physics and engineering. Recently, studies have shown that the transverse spatial confinement of optical fields or photons leads to a modification of the group velocity but the phase velocity of propagating structured beams is revealed insufficiently in the experiments. In this work, we provide the theoretical model and experimental observation of propagation phase of structured beams. The analysis suggests that the spatially structured beams with a definite axial component of wavevector kr carry a so called “lagging propagation phase”, which can be considered as a generalized Gouy phase that originally appears within a focal region. Taking the higher-order Bessel beam as an example, the propagation phase difference is demonstrated by mapping to the rotating angle of intensity patterns superposed with different radial and angular phase gradients. Physically, the lagging propagation phase may provide an interpretation for the dynamic evolution of complex structured beams or interfering fringes upon propagation such as the vortex knots or braids. From the application aspect, the lagging propagation phase would facilitate a promising way for structured beams in optical sensing and metrology.

• Item Type: Articles
• Additional Information: Funding. National Natural Science Foundation of China (62125503, 62261160388); Natural Science Foundation of Hubei Province (2023AFA028); Shenzhen Science and Technology Program (JCYJ20200109114018750); Innovation Project of Optics Valley Laboratory (OVL2021BG004).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wan, Zhenyu
• Authors: Wan, Z., Tang, Z., and Wang, J.
• College/School: College of Science and Engineering
• Journal Name: Optics Express
• Publisher: Optica Publishing Group
• ISSN: 1094-4087
• ISSN (Online): 1094-4087
• Copyright Holders: Copyright © 2023 Optica Publishing Group
• First Published: First published in Optics Express Vol. 31(25):42667-42676
• Publisher Policy: Reproduced under a Creative Commons licence