An effective method to broad band gaps using complex-diamond lattice

A holographic method is proposed to fabricate complex-diamond lattice using the materials with low refractive index. Through this method, very wide band gaps have been experimentally obtained. The width of the band gaps reached 260 nm, the ratio between the width and the central wavelength of the gaps reached 50%. Also, a common gap was observed in a range of 150° of incident angle in [1 1 1] plane at all orientations. This kind of complex-diamond lattice is greatly beneficial for obtaining complete band gaps.