Related Experiment Video
Updated: Jun 5, 2026
08:01
Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
Analysis of multilevel spiral phase plates using a Dammann vortex sensing grating.
N Zhang1, Jeffrey A Davis, Ignacio Moreno
1School of Electrical & Electronic Engineering, Nanyang Technological University, 639798 Singapore.
Optics Express
|December 18, 2010
Summary
Generating optical vortices with multilevel spiral phase plates (SPPs) is common, but beam quality depends on phase segments. This study validates a theoretical Fourier expansion for SPPs using a Dammann vortex diffraction grating, confirming experimental results.
Area of Science:
- Optics and Photonics
- Diffraction Optics
Background:
- Multilevel spiral phase plates (SPPs) are used to generate optical vortices.
- The quality of vortex beams from SPPs is influenced by the number of phase segments.
Purpose of the Study:
- To review the theory of multilevel SPPs using Fourier expansion for integer topological charge vortices.
- To experimentally validate the theoretical expansion using a Dammann vortex diffraction grating spectrum analyzer.
Main Methods:
- Theoretical review of multilevel SPPs with Fourier expansion.
- Fabrication of a Dammann vortex diffraction grating using SU-8 photoresist on glass.
- Experimental analysis of diffracted orders and angular harmonics.
Main Results:
- The Dammann vortex diffraction grating exhibited uniform diffraction efficiency across desired orders.
- Experimental results revealed extra angular harmonics generated by the multilevel SPP.
- Observed harmonics align with the theoretical Fourier expansion predictions.
Conclusions:
- The Fourier expansion theory accurately describes the behavior of multilevel SPPs.
- Experimental validation confirms the theoretical model for generating optical vortices.
