Laser-Assisted Etching of EagleXG Glass by Irradiation at Low Pulse-Repetition Rate

Roberto Memeo,Francesca Bragheri,Andrea Crespi,Roberto Osellame,Mattia Bertaso

doi:10.3390/app12030948

Abstract

Femtosecond laser micromachining is becoming an established technique for the fabrication of complex three-dimensional structures in glass. The combination of laser writing and chemical etching increases the technique versatility by allowing the fabrication of hollow structures within the bulk material. The possibility to encompass both optical and fluidic components in a single substrate allows us to realize optofluidic devices usable in several application fields. Here, we present new investigations of laser-assisted etching in Eagle XG glass showing good etching conditions at low repetition rates, where thermal effects can be neglected, and low irradiation speeds, which allow for complex microchannel network formation.

Highlights

Femtosecond Laser Micromachining (FLM) is a highly-versatile technique for the rapid prototyping of integrated devices in dielectric substrates [1]
FLM enables a wide portfolio of microstructuring possibilities, which can be accessed by proper tuning of the irradiation parameters and the correct choice of substrate
In a more restricted subset of substrates, including fused silica [3,4,5] and photosensitive glasses [6], the irradiated tracks can yield a higher etching rate than the pristine material, when exposed to chemical agents such as aqueous solutions of hydrofluoric acid (HF) or potassium hydroxide (KOH). The latter feature is exploited to realize buried microchannels and hollow 3D microstructures inside the bulk material, in a method known as laser-assisted etching or FLICE (Femtosecond Laser Irradiation followed by Chemical Etching)

Summary

Introduction

Femtosecond Laser Micromachining (FLM) is a highly-versatile technique for the rapid prototyping of integrated devices in dielectric substrates [1]. In a more restricted subset of substrates, including fused silica [3,4,5] and photosensitive glasses [6], the irradiated tracks can yield a higher etching rate than the pristine material, when exposed to chemical agents such as aqueous solutions of hydrofluoric acid (HF) or potassium hydroxide (KOH). The latter feature is exploited to realize buried microchannels and hollow 3D microstructures inside the bulk material, in a method known as laser-assisted etching or FLICE (Femtosecond Laser Irradiation followed by Chemical Etching)

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