Micro-Machining of Diamond, Sapphire and Fused Silica Glass Using a Pulsed Nano-Second Nd:YVO4 Laser

David G Waugh,Chris D Walton

doi:10.3390/opt2030016

Abstract

Optically transparent materials are being found in an ever-increasing array of technological applications within industries, such as automotive and communications. These industries are beginning to realize the importance of implementing surface engineering techniques to enhance the surface properties of materials. On account of the importance of surface engineering, this paper details the use of a relatively inexpensive diode-pumped solid state (DPSS) Nd:YVO4 laser to modify the surfaces of fused silica glass, diamond, and sapphire on a micrometre scale. Using threshold fluence analysis, it was identified that, for this particular laser system, the threshold fluence for diamond and sapphire ranged between 10 Jcm−2 and 35 Jcm−2 for a laser wavelength of 355 nm, dependent on the cumulative effects arising from the number of incident pulses. Through optical microscopy and scanning electron microscopy, it was found that the quality of processing resulting from the Nd:YVO4 laser varied with each of the materials. For fused silica glass, considerable cracking and deformation occurred. For sapphire, good quality features were produced, albeit with the formation of debris, indicating the requirement for post-processing to remove the observed debris. The diamond material gave rise to the best quality results, with extremely well defined micrometre features and minimal debris formation, comparative to alternative techniques such as femtosecond laser surface engineering.

Highlights

Surface engineering holds the key to enhance surface properties
The materials used within the experimentations were fused silica glass, sapphire, and diamond (Goodfellow Cambridge Ltd., Cambridgeshire, UK, and Diamond Materials Ltd., Freiburg, Germany)
11 Jcm−2 and 74 Jcm−2 and the incident pulse number between 10 and 50,000 pulses on the optically transparent materials, it was found that surface modifications of a differing quality arose

Summary

Introduction

Surface engineering holds the key to enhance surface properties. On account of this, research into surface engineering techniques [1,2,3], such as plasma surface treatment [4,5,6,7], micro/nano printing [8,9,10], and ion/electron beam processing [11,12,13,14], is becoming increasingly significant. On the other hand, is a non-contact method that allows one to process the surfaces of many materials [3,15,16,17,18]. This enables the modification of topography and surface chemistry simultaneously, often requiring minimal post-processing. This is important for the automotive, biomedical, electronic, and communications industries, which require new technologies to lower costs and increase profit margins

Methods

Discussion

Conclusion