Plasmonic tomography of optical vortices

Area of Science:

• Optics and Photonics
• Plasmonics
• Beam Characterization

Background:

• Optical vortices possess unique wavefront properties crucial for applications.
• Traditional wavefront analysis methods like interferometry can be complex.
• Surface plasmon polaritons (SPPs) offer a potential alternative for optical measurements.

Purpose of the Study:

• To develop a non-interferometric method for analyzing optical vortex wavefronts.
• To utilize surface plasmon polaritons (SPPs) for wavefront characterization.
• To enable rapid determination of optical vortex charge.

Main Methods:

• Employing a subwavelength slit in a gold film to generate SPPs from an optical vortex.
• Measuring the diffraction of SPPs scattered by a second slit.
• Scanning slits across the optical vortex to create a tomographic reconstruction.

Main Results:

• Demonstrated a tomographic method for wavefront analysis.
• Successfully determined the vortex charge of optical vortices.
• Achieved analysis for both integer- and half-integer-vortex charges.

Conclusions:

• The SPP-based method provides an effective alternative to interferometry for optical vortex analysis.
• This technique allows for straightforward determination of vortex charge.
• The method is applicable to various types of optical vortices.