Laser holographic lithography for the fabrication of 3-dimensional periodic photonic structures

Laser holographic lithography method of fabricating three-dimensional periodic photonic templates in SU-8 photoresist has been demonstrated with diffractive optical elements. The laser-lithography has been achieved using one-or two dimensional phase masks or multi-layer phase mask. Various photonic structures have been fabricated by adjusting the distance between phase masks, rotating the phase mask, or controlled the number of exposures. Scanning electron microscope (SEM) of the fabricated 3-dimensional photonic structure has been compared with simulations to verify the laser lithography method. These photonic periodic templates can be inverted into materials with a high refractive index to be used as photonic crystals (or photonic band gap materials) for applications in photonic circuit. Theoretic descriptions of the laser holographic lithography and predictions of photonic band gaps in photonic crystals will be presented. The laser holographic lithography can lead to a mass manufacturing of photonic band gap materials.