Lithograph 

The optical interference of multiple laser beams with a single light exposure is the basis of holographic lithography. It is a simple technique with two significant advantages over others. Its advantages are that it is mask-free, low-cost, and compatible with large-scale photonic-crystal manufacturing. Second, because there are enough optical parameters to tweak, such as beam intensity, polarization, and incident angles, photonic crystals with nearly any lattice symmetry can be created. The best producers of lithographs are Kiran Holographics.