Photonic crystal with diamondlike structure fabricated by holographic lithography

In this letter, we report a diamondlike structure. Our theoretical analysis reveals that a large complete band gap exists between the second and third bands with only a very low refractive index is needed (n⩾2.05) to open the complete band gap for this inverse structure. Large-scale and high-quality three-dimensional structures with this diamondlike symmetry are fabricated by a holographic lithography method using four laser beams incident from the same half-space. The beam geometry is similar to that for the face-centered cubic (fcc) structure except that the central beam is circularly polarized and the polarizations of the three outer beams must be optimized, which is critical to construct this diamondlike interference pattern.