• Chinese Optics Letters
  • Vol. 20, Issue 11, 110501 (2022)
Jingyin Zhao1、2、3, Yunxia Jin1、3、4、*, Fanyu Kong1、3, Dongbing He1、3, Hongchao Cao1、3, Wang Hao1、2、3, Yubo Wu1、2、3, and Jianda Shao1、3、4、5
Author Affiliations
  • 1Thin Film Optics Laboratory, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
  • 2Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • 3Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
  • 4CAS Center for Excellence in Ultra-Intense Laser Science, Chinese Academy of Sciences, Shanghai 201800, China
  • 5Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
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    DOI: 10.3788/COL202220.110501 Cite this Article Set citation alerts
    Jingyin Zhao, Yunxia Jin, Fanyu Kong, Dongbing He, Hongchao Cao, Wang Hao, Yubo Wu, Jianda Shao. Measuring the topological charge of optical vortices with a single plate[J]. Chinese Optics Letters, 2022, 20(11): 110501 Copy Citation Text show less
    Scheme of TC measurement of a vortex beam (l = 3 exampled) with a screen plate S located at the x0−y0 plane (z = 0). The cross section of the plate is shown at the bottom left. The diffraction patterns aligned along the z axis illustrate the evolution of the OV edge diffraction.
    Fig. 1. Scheme of TC measurement of a vortex beam (l = 3 exampled) with a screen plate S located at the x0y0 plane (z = 0). The cross section of the plate is shown at the bottom left. The diffraction patterns aligned along the z axis illustrate the evolution of the OV edge diffraction.
    Simulated intensity profiles of OV beams edge-diffracted by an opaque screen for (a) l = −2 to 2 in steps of 1, (b) r¯=0–2 in steps of 0.5, (c) θs = 0°–180° in steps of 45°, and (d) z¯=0.05, 0.1, 0.2, 0.4, 1, respectively. The general case is l = 3, r¯=1, θs = 0°, and z¯=0.1. Auxiliary red dashed lines indicate the dark fringes. Hatched area shows the position of the plate, and the yellow arrow points in the direction of the fork-shaped fringe. The intensity distribution is normalized.
    Fig. 2. Simulated intensity profiles of OV beams edge-diffracted by an opaque screen for (a) l = −2 to 2 in steps of 1, (b) r¯=02 in steps of 0.5, (c) θs = 0°–180° in steps of 45°, and (d) z¯=0.05, 0.1, 0.2, 0.4, 1, respectively. The general case is l = 3, r¯=1, θs = 0°, and z¯=0.1. Auxiliary red dashed lines indicate the dark fringes. Hatched area shows the position of the plate, and the yellow arrow points in the direction of the fork-shaped fringe. The intensity distribution is normalized.
    Simulated intensity profiles at l = 3, r¯=1, z¯=0.1 after edge diffraction by a translucent plate with (a) the transparency α = 0–1 in steps of 0.25, (b) the normalized thickness d¯=0–4 in steps of 1, and (c) the angle between two surfaces of the plate β = −6° to 6° in steps of 3°. The general case is α = 1, d¯=4, and β = 0°.
    Fig. 3. Simulated intensity profiles at l = 3, r¯=1, z¯=0.1 after edge diffraction by a translucent plate with (a) the transparency α = 0–1 in steps of 0.25, (b) the normalized thickness d¯=04 in steps of 1, and (c) the angle between two surfaces of the plate β = −6° to 6° in steps of 3°. The general case is α = 1, d¯=4, and β = 0°.
    (a) Experimental setup for generating the OV beam using SLM1 loaded with (b) fork-shaped blazed gratings and measuring the TC using SLM2 loaded with (c) a phase step. λ/2, half-wave plate; SLM, spatial light modulator; S, an opaque screen in Fig. 1 in the case of α = 0; CCD, charge coupled device.
    Fig. 4. (a) Experimental setup for generating the OV beam using SLM1 loaded with (b) fork-shaped blazed gratings and measuring the TC using SLM2 loaded with (c) a phase step. λ/2, half-wave plate; SLM, spatial light modulator; S, an opaque screen in Fig. 1 in the case of α = 0; CCD, charge coupled device.
    Experimental intensity profiles of the OV beam (l = 3) at z¯ of (a) 0.05, (b), (d) 0.1, and (c) 0.2 after edge diffraction by (a)–(c) an opaque or (d) a transparent plate (d¯=4) at r¯=0–1.5 in steps of 0.5 for column 1–4, respectively.
    Fig. 5. Experimental intensity profiles of the OV beam (l = 3) at z¯ of (a) 0.05, (b), (d) 0.1, and (c) 0.2 after edge diffraction by (a)–(c) an opaque or (d) a transparent plate (d¯=4) at r¯=01.5 in steps of 0.5 for column 1–4, respectively.
    Experimental intensity profiles for (a) unperturbed and (b) opaque screen (r¯=1, z¯=0.1) edge-diffracted vortex beams with topological charge −40 and +40 for columns 1 and 2, respectively. Corresponding enhanced patterns are shown in (c), where the inset with the yellow box shows the partially scaled image, and the cambered red and blue cross sections of the intensity indicate (d) the number of upside and downside fringes, respectively.
    Fig. 6. Experimental intensity profiles for (a) unperturbed and (b) opaque screen (r¯=1, z¯=0.1) edge-diffracted vortex beams with topological charge −40 and +40 for columns 1 and 2, respectively. Corresponding enhanced patterns are shown in (c), where the inset with the yellow box shows the partially scaled image, and the cambered red and blue cross sections of the intensity indicate (d) the number of upside and downside fringes, respectively.
    Jingyin Zhao, Yunxia Jin, Fanyu Kong, Dongbing He, Hongchao Cao, Wang Hao, Yubo Wu, Jianda Shao. Measuring the topological charge of optical vortices with a single plate[J]. Chinese Optics Letters, 2022, 20(11): 110501
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