Experimental study on the ablation of MgAl2O4 transparent ceramic by a femtosecond laser

The damage threshold and ablation area for MgAl2O4 transparent ceramic (MATC) by a femtosecond laser pulse at a wavelength of 800mn were studied. The ablated spots were examined by means of a charge coupled device (CCD) camera and a scanning electron microscope (SEM). The IR transmission properties of MATC machined by femtosecond laser pulses were measured by a micro-IR spectrum device. The result shows that the damaged area exhibits a linear dependence with the increase of pulse energies under the condition of a single pulse, and the area is Boltzmann distribution with the increase of the pulse number under the condition of multipule pulses. The ablated spot under optimized energy pulses (near the damage threshold energy) can improve the IR transmission from 82% to 86% in the band of 2500-7000cm(-1) for MATC. When the pulse energy exceeds the threshold energy, the transmission of MATC decreases rapidly by 20%.