Patent ID: 6490299
Filing Date: 2002-12-03
Classification: B23K,B44B,H01S

Abstract:
A method for production of high quality laser-induced damage images inside a transparent material, comprising the steps of:providing the transmission in rapid succession of two laser output pulses one of which is a Q-switched pulse, and another is a free-running pulse to the location of a damage; adjusting a summary energy of said output pulses to create laser-induced damages of desired sizes; adjusting the time interval between said output pulses so as it is longer than the existence time of the general shock wave induced by the laser-induced breakdown inside the work material; controlling the said second laser pulse width for creation of the laser-induced damage of the required size; adjusting the ratio of the said Q-switched pulse energy to the said free-running pulse energy so as the first laser pulse of the said pair initiates plasma inside work material and the second laser pulse of the said pair maintains plasma condition for production of the right gray shades of the etch points.