Abstract : Light-matter interaction plays such an important role in our life that we almost take it for granted. The new and emerging paradigms of nanophotonics have been pushing this frontier forever and the envisaged ambitions and dreams can be realized in practice only if ideal and convenient materials that permit the novel forms of interaction with light can be developed. This talk highlights some recent trends of research on light-matter interaction in regular and random media.
Only recently has it become established that most of the beautiful objects of nature, such as the peacock feather, butterfly wings and gem stones owe their brilliant color to various optical phenomena occurring at structures of different length scales, at the micro and the nano levels. Regular extra-thin layered structures with alternating refractive index have been demonstrated to give rise to photonic bandgaps , emission enhancement, lossless fiber communication and even reduction in the speed of light . On the other hand, light propagation through random media can give rise to new modes of laser action , revolutionize biomedical imaging and contribute to the design of economic and nontoxic paints, textiles and displays of brilliant color. Apart from promising wonderful technological advances, research on light-matter interaction also probes into some very deep secrets of Nature at the conceptual level.