Sculpting glass with light

Selective laser etching (SLE) is a manufacturing technique which uses focused ultrashort laser pulses to permanently modify the etching rate of glass locally within the laser focus. In combination with chemical etching, the technique enables the fabrication of complex three-dimensional components with micron-scale feature resolution.

In this talk, I will give a brief overview of SLE, discuss some of its limitations in terms of processing speed and working range, and present our attempts to overcome them. I will then discuss three quite different applications where we have applied SLE in the area of fibre optics. Firstly, for the fabrication of micro-optics for fibre-optic sensors, namely a miniaturised confocal Raman probe with applications in cancer diagnosis. Secondly, a method of modifying glass capillary fibre for diffuse side emission of deep-ultraviolet light, with prospective applications in the safe inactivation of bacteria. Finally, Axi-Stack, a new method, currently under development, for manufacturing complex fibre optic preforms with “freeform” core-cladding structure.