Translator Disclaimer
18 April 2006 Optical effects in artificial opals infiltrated with gold nanoparticles
Author Affiliations +
Polystyrene artificial opals are directly grown with embedded gold nanoparticles (NpAu) in their interstices. Reflectance spectra of samples having different sphere diameters and nanoparticles load clearly show a red shift of the photonic band gap as well as a reduction of its width without showing direct evidence of NpAu absorption. The case of transmission spectra is instead more complicated: here, overlapped to a broad NpAu absorption, a structure having unusual lineshape is detected. The infiltration of opal with NpAu removes the polarization dependence of the photonic band structure observed in bare opals. The lineshape of the absorption spectra suggest a spatial localization of the electromagnetic field in the volume where NpAu are confined thus enhancing its local intensity. This effect seems to be effective to stimulate optical nonlinearities of NpAu. Nanosecond transient absorption measurements on NpAu infiltrated opals indicate that a variation of transmission of about 10% is observed. Since this effect takes place within the pump pulse and since NpAu photoluminescence has been subtracted to the signal, we attribute it to an optical switching process.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Davide Comoretto, Valentina Morandi, Franco Marabelli, Vincenzo Amendola, and Moreno Meneghetti "Optical effects in artificial opals infiltrated with gold nanoparticles", Proc. SPIE 6182, Photonic Crystal Materials and Devices III (i.e. V), 61820D (18 April 2006);

Back to Top