Theoretical and experimental research on laser-induced damage of cylindrical subwavelength grating

We designed and fabricated two-dimensional cylindrical subwavelength gratings (SWGs) on fused silica for use in 1064 nm laser system. The transmittance and laser-induced damage threshold (LIDT) under the irradiation of 1064 nm pulses were performed, and a lower LIDT compared to blank fused silica was obtained. To understand damage mechanism quantitatively, macro-temperature on the SWGs integrated fused silica and micro-Electric field, micro-thermal-stress distribution on SWGs during the laser irradiation process were investigated by Finite Element Analysis, and the comparison between theoretical and experimental research indicated the presence of absorption centers and the non-uniform thermal mechanical distribution of SWGs contributed to the LIDT reduction on SWGs integrated fused silica.