Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Mahi R. Singh


In this thesis, we study the quantum optical interaction in polaritonic nanocomposites. These systems are made by the combination of two or more micro- or nano-scale structures with complementary optical properties, such as polaritonic materials, excitonic materials, photonic crystals (PCs), quantum dots (QDs), waveguides, couplers, metal nanorods (MNRs), bionanoparticles. The nanocomposites systems studied included QDs doped within a polaritonic PC, an excitonic waveguide coupler, and a metamaterial waveguide. Also addressed are systems consisting of MNRs paired with biological labelling dye or QDs.

The application of a strain field, known as the acousto-optic effect, was found to control photon transmission in polaritonic PC, and through that, the spontaneous emission of a QD doped within the crystal. Furthermore, a theory of reservoir induced-transparency (RIT) was developed in the QD-exciton-polaritonic coupler and QD-metamaterial waveguide nanocomposites. Transparent states in the absorption spectrum of the QD can be induced via the presence of bound polariton states in the coupler/waveguide. The nature of the states could be controlled by the separation of the couplers or the thickness of the metamaterial.

Energy transfer is found and an explanatory theory is developed for MNRs with QD/biological labelling dye nanocomposites. Decrease in fluorescence lifetime from the dye is shown to be greater for excitation through that two-photon process. Increase of two-photon intensity is shown to significantly increase enhancement of the energy transfer.