Design and Verification of a Flat-Top Beam Shaper Utilizing Spherical Lenses

TL;DR

This paper introduces a novel flat-top beam shaper using spherical lenses that exploits spherical aberration, offering a simple, wavelength-flexible, and extended depth of focus solution for laser beam shaping.

Contribution

It presents a new coaxial spherical-lens system for flat-top beam shaping, demonstrating advantages over aspherical systems in simplicity, wavelength adaptability, and depth of focus.

Findings

Achieves flat-top beam with spherical lenses using aberration

Demonstrates wavelength and waist radius flexibility

Provides extended depth of focus for the shaped beam

Abstract

We propose a novel coaxial spherical-lens shaping system to achieve a flat-top focus profile by exploiting the spherical aberration of the lens. The well-known aspherical-lens shaping system is compared to ours, and a comparison of etching on silicon is conducted between a Gaussian beam and the one shaped by the proposed system. Analytical and experimental results show that the proposed system is able to achieve flat-top beam shaping using only spherical lenses. Compared with the existing systems, our proposed one is capable of shaping Gaussian beams with different wavelengths and waist radii. Furthermore, the shaped one obtained by ours is the flat-top beam with extended depth of focus. This letter provides an efficient and precise flat-top beam shaping scheme for optics and laser technology, and increases the potential of spherical lenses in the field of laser shaping.