Abstract: Interference of multiple noncoplanar beams can be used to fabricate 2D and 3D photonic crystals. The basic physical principles of this method are systematically discussed, including the types of structures it may yield, the beam design and polarization optimization. As the first article of this series, the general analysis of multiple noncoplanar beam interference is provided, and the noncoptanar three - beam interference for making 2D periodic microstructures and microfiber bundle is specifically studied.

Key words: interference of multiple noncoplanar beams, photonic crystals, periodic microstructure fabrication, beam design, polarization