A Revisit to Complex Optical Nano- and Micro-Structured Mediums

Wave propagation in optical nano- and/or micro-structured mediums greatly depends on the geometry and materials which the guides are comprised of. This triggers the conceptualization of engineered mediums, which would be realized in varieties of fanciful forms with distinct characteristics. These mediums may also fall into the class of metamaterials under certain geometrical and operational features. Metasurface-based structures are well-established in various optical applications. With this view point in mind, the text emphasizes on the usefulness of some of the newly designed engineered mediums in optical bio-sensing and/or absorber kinds of applications. Apart from this, some micro-structured mediums made of chiral and/or chiro-ferrite mediums are also touched upon, which would be of prudent use in optical communications.