Photonic superlattices for photonic crystal lasers

Abstract

Colloidal photonic crystals, even with low refractive index contrast have a significant effect on the spontaneous emission of internal emitters. This is observed as a modification of the emitters' fluorescence spectrum and as a narrowing and shortening of the decay rate distribution. The decay rates are observed to be nonexponential. This modification was then put to use by fabricating a photonic superlattice, consisting of several photonic crystal slabs deposited on top of each other. Because of the two different photonic bandgaps and effective passband is created between the two and leads to enhancement of emission in this spectral region. These experiments indicate that the threshold for lasing can possibly be lowered by spectrally narrowing the emission of fluorophores infiltrated in suitably engineered self-assembled photonic crystal superlattices, and are therefore important towards the realization of efficient all-optical integrated circuits from functionalized photonic superlattices and heterostructures.