Experimental Study on Sub-Wavelength Security Grating Structures in the Visible Region

The basic principle of multi-interference lithography processes designing and fabricating sub-wavelength grating microstructures is presented.Microstructures with special grating shape can be realized by optimizing and designing the total exposure dose at the substrate surface.One dimension and two dimension security grating microstructures were fabricated,and experimental data and theoretical analysis related to the SEM and AFM of microstructures provided,and the optical variable effect of security grating microstructures in color also validated. Experimental results showed: that complicated security grating microstructures with better quality and deeper grooving can be fabricated by multi interference lithography processes.These security grating microstructures can show chromatic optical variable effects in color to a certain extent.