Formation of plano-convex micro-lens array in fused silica glass using CO2 laser assisted reshaping technique

TL;DR

This paper presents a rapid and straightforward method to fabricate high-density plano-convex micro-lens arrays on fused silica using femtosecond laser encoding and CO2 laser reshaping, with demonstrated optical properties and simulation of focal length.

Contribution

It introduces a novel combination of femtosecond laser encoding and CO2 laser reshaping for efficient micro-lens array fabrication on fused silica.

Findings

Micro-lens arrays with 50 um and 100 um sizes were successfully fabricated.

The focal length of the spherical micro-lens array was simulated to be 35 um.

The technique is simple, fast, and promising for various transparent materials.

Abstract

We report on fabricating high-fill-factor plano-convex spherical and square micro-lens arrays on fused silica glass surface using CO2 laser assisted reshaping technique. Initially, periodic micro-pillars have been encoded on the glass surface by means of a femtosecond laser beam. Afterwards, the micro-pillars are polished several times by irradiating a CO2 laser beam on top of the micro-pillars. Consequently, spherical micro-lens array with micro-lens size of 50 um x 50 um and square micro-lens array with micro-lens size of 100 um x 100 um are formed on fused silica glass surface. We also study the intensity distribution of light passed through the spherical micro-lens array engraved glass sample. The simulation result shows that, the focal length of the spherical micro-lens array is 35 um. Furthermore, we investigate the optical properties of the micro-lens array engraved glass samples. The proposed CO2 laser based reshaping technique is simple and fast that shows promises in fabrication arrays of smooth micro-lenses in various transparent materials.