Incandescence Measurement During $CO2$ Laser Texturing of Silicate Glass

Laser zone texture is a new approach to improve tribology performance of high aerial density disks made with glass substrates. In this process, nanotexture is introduced to the surface by discrete laser pulses. The topography change is due to the elevation of fictive temperature in the short time and high temperature scales that occur through the laser energy coupling with glass. To exercise better control over this thermal process, knowing the temperature field induced by the laser pulse and the timescale of the thermal cycle are very important. In this paper, emission measurements are made from a laser-heated surface of approximately 300 μm² and temporally resolved to 100 ns. Several emission bands are collected in the visible. From emission data, the extensive heat capacity of the heat affected zone is derived, allowing peak surface temperatures to be determined from the pulse energy. Experimental results are compared with a numerical model to determine the validity of earlier calculations and conclusions.