# Ultrathin Microlens Arrays for Dynamic Beam Shaping Based on 3D Lithography

## TL;DR

This paper introduces a new type of microlens array that can dynamically adjust beam shapes in real time, using advanced fabrication techniques to create ultra-thin lenses.

## Contribution

The novel contribution is the development of ultra-thin microlens arrays with tunable beam shaping capabilities through optimized 3D lithography and ion beam etching.

## Key findings

- Ultra-thin MLAs with a 1:187.5 aspect ratio and 3 nm surface roughness were successfully fabricated.
- The system enables real-time spot-size modulation and reconfigurable working distances for laser applications.
- The design bridges static and dynamic beam shaping, offering a robust solution for laser material processing.

## Abstract

Conventional microlens arrays (MLAs) are often constrained by their static focal properties, which limit post-fabrication adaptability in dynamic optical systems. To address this, we demonstrate a tunable beam shaper capable of real-time spot-size modulation by introducing an adjustable axial displacement between a primary lens and an MLA. A critical advancement of this work is the fabrication of ultra-thin MLAs featuring an exceptionally low aspect ratio (1:187.5) and continuous surface profiles. Through optimizing 3D lithography and ion beam etching (IBE) workflows, we achieved an optical-grade surface finish with a roughness (Sa) of 3 nm. This high-fidelity, low-profile component enables efficient beam homogenization with reconfigurable working distances and spot dimensions. The proposed architecture provides a versatile and robust solution for advanced laser material processing, bridging the gap between static beam shaping and dynamic laser delivery.