LARGE-AREA, NEAR-INFRARED (IR) PHOTONIC CRYSTALS WITH COLLOIDAL GOLD NANOPARTICLES EMBEDDING
Shobha Shukla, Alexander Baev, Hongsub Jee, Rui Hu, Ryszard Burzynski, Yong-Kyu Yoon and Paras Prasad
A polymeric composite material composed of colloidal gold nanoparticles (<10 nm) and SU8 has been utilized for the fabrication of large-area, high-definition photonic crystal. We have successfully fabricated near-infrared photonic crystal slabs from composite materials using a combination of multiple beam interference lithography and reactive ion etching processes. Doping of colloidal gold nanoparticles into the SU8 photopolymer results in a better definition of structural features and hence in the enhancement of the optical properties of the fabricated photonic crystals. A 2D air hole array of triangular symmetry with a hole-to-hole pitch of 500 nm has been successfully fabricated in a large circular area of 1 cm diameter. Resonant features observed in reflectance spectra of our slabs are found to depend on the exposure time, and can be tuned over a range of near-infrared frequencies.
Keywords: photonic composite materials, gold nanoparticles, lithography, photonic crystal and structural/optical properties