Optical properties of single droplet of photonic crystal assembled byink-jet printing

An array of droplets of photonic crystal with polystyrene colloidal particles was assembled on silicon using ink-jet printing. A microreflectance spectrum from a single droplet was collected using an optical microscope and a spectrometer. It was observed that the photonic band gap of these droplets shifts as a function of the size of the colloidal particle. The reflectance peak position predicted from the model based on Bruggeman and Maxwell-Garnett effective medium approximations agrees well with those of the experimentally observed peak.