Laser Markings on Transparent Materials Using Nanosecond-Pulse Laser

The precise manipulation on the transparent glass substrates using the pulse lasers has attracted much attention because of the advanced developments in the optical components used for the applications in the microelectromechanical system, biomedical devices and modern communications. The nano- or micro-second pulsed lasers are dominant equipment in the industry because they are cost-affordable, technically mature, despite that minimal heat effect induced by the ultrafast pulse laser is reported. Hence, we investigate the effect of process variables on the appearance of the glasses using the laser system with the wavelength of 355 nm and nanosecond pulses. The sheet glass of Schott B270 is applied as the samples and the relations between the burn marks and the laser pulse energy are obtained. The profiles of the burn marks on the surface and inside are examined by a confocal and an optical microscope, respectively. A heat conduction model is established to estimate the possible maximum temperatures accumulated in the glass subjected to the multi pulses if the glass is an ultraviolet energy absorber. The geometric and feature dimensions of the marks in the glass are measured and compared to the input energy to estimate the absorption efficiency of the glass transparent materials.