Simulations on the influences of polarization combinations on holographic fabrication of complicated photonic crystals

Photonic crystals (PCs) are artificial micro-nano structures consisting of different materials periodically arranged. They can be divided into two categories: simple and compound PCs. They have broad application prospects in many fields such as micro-nano photonics and optoelectronic integration. Laser holography method is an important method for fabricating PCs. In this work, a theoretical study on the production of compound PCs by multi-beam holographic interferometry is carried out, and a four-beam configuration with a certain symmetry is designed to produce two-dimensional compound PCs. Simulations based on MATLAB program are in good agreement with the theoretical analysis. The evolution of the unitcell and contrast of the compound PC under different polarization combinations of a single beam and double beams are further studied. The results indicate that the polarization affects the unitcell of the PC sensitively. Under different polarization combinations, a variety of rich unitcell shapes of compound PCs such as elliptical-like rods and wave-like stripes are obtained. When all interfering beams are linearly polarized within the xoy plane, the compound PC has the best contrast. These above results hold promise for the design and fabrication of compound PCs with various unitcell shapes.