Corrected knife-edge-based reconstruction of tightly focused higher order beams

TL;DR

This paper improves the knife-edge beam profiling method for tightly focused higher order beams by introducing correction techniques to mitigate artifacts caused by material and geometric interactions.

Contribution

It presents a corrected knife-edge reconstruction method specifically designed for tightly focused radially and azimuthally polarized beams, addressing previous limitations.

Findings

Successful reconstruction of beam profiles with the adapted method

Demonstrated consistency with linearly polarized Gaussian beams

Proof-of-concept tests validate the correction approach

Abstract

The knife-edge method is an established technique for profiling of even tightly focused light beams. However the straightforward implementation of this method fails if the materials and geometry of the knife-edges are not chosen carefully or in particular if knife-edges are used that are made of pure materials. In these cases artifacts are introduced in the shape and position of the reconstructed beam profile due to the interaction of the light beam under study with the knife. Hence, corrections to the standard knife-edge evaluation method are required. Here we investigate the knife-edge method for highly focused radially and azimuthally polarized beams and their linearly polarized constituents. We introduce relative shifts for those constituents and report on the consistency with the case of a linearly polarized Gaussian beam. An adapted knife-edge reconstruction technique is presented and proof-of-concept tests demonstrating the reconstruction of beam profiles are shown.