Surface-relieved gratings film with high laser damage thresholds

A kind of surface-relieved gratings ZrO2 film with high laser damage thresholds is prepared. The ZrO2 sol is achieved by hydro-thermal method, the thin ZrO2 film with the thickness of 1-2 μm, the refractive index of 1.57-1.70, the roughness of 2.3 nm and the laser damage thresholds of 25-30 J/cm2 (1 ns, 1.06 μm) is coated on plastic foil substrate by the speed of 20 m/min at 80-100 degree C. The master structure of the gratings is produced by the holographic optical process of two coherent beams from an argon ion laser source interference. The period of gratings is 1-2 μm and the depth is 70-100 nm. The patterns on the photoresist are transferred to nickel replicas by electroplating process. Finally, the surface-relieved gratings are embossed onto the ZrO2 coated plastic foils using the nickel replicas as stamps. The influences of the period and the depth of the grating, the incident angle and the refractive index of nano-coating to diffraction efficiency are researched. Therefore, this structure provides a feasible approach to detect high-power laser