Abstract: The basic principles of formation of three-dimensional （3D） periodic microstructures by interference of four noncoplanar bearns are explained in both the normal space and the reciprocal space. It is shown that all fourteen Bravais lattices can be formed by this technique. The specific beam designs for making some typical lattices are given,and some related problems such as the selection of amplitude ratio and determination of polarization of each beam are also discussed.

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