Patterned polymer photonic crystals using soft lithography and holographic lithography

We fabricated patterned polymer photonic crystals by holographic lithography in conjunction with soft lithography. A patterned SU-8 photoresist film was created by preformed pattern of a hard-baked SU-8 photoresist, transferred by a PDMS mold. Then, four-beam holographic exposure carved 3D photonic crystal structures onto the patterned photoresist. Because of refractive index matching of the photoresist and the hard-baked photoresist, scattering, which might have caused a distortion of interference pattern, did not occur. Eventually, an f.c.c. polymer structure with a line pattern was successfully created after development.