Transformation optics has received considerable attention since the proposal offered for invisibility cloak. The recipe of transformation optics provides a perfect tool to achieve the constitutive parameters for metamaterials. Equipped with the toolbox of transformation optics, many fascinating optical devices have been identified, especially invisibility cloaks and illusion optics. The aim of this thesis is the contribution of transformation optics towards multi-folded transformation optics, and to use it to design novel remote devices for various applications.Many research groups including ours are investigating about remote devices. In this thesis, we rely on numerical simulations and theoretical model to describe that the conventional transformation optics devices can be further transformed into remote devices by applying the compression and the folding techniques. The basic theory of multi-folded transformation optics and designing strategy of remote devices are discussed, which is followed by our published/submitted works.An invisibility cloak that can hide an arbitrary object external to the cloak itself has not been devised before. In this thesis, we introduce a novel way to design a remote cloaking device that makes any object located at a certain distance invisible. This is accomplished by using multi-folded transformation optics to remotely generate a hidden region around the object in which no field can penetrate and this region does not disturb the far-field scattering electromagnetic field. As a result, any object in the hidden region can stay in position or move freely within that region and remain invisible. Our idea is further extended to design a remote illusion optics that can transform any arbitrary object (passive scatterer) into another one. Unlike other cloaking methods, this method would require no knowledge of the details of the object itself. Moreover, the material parameters of the proposed remote device are complex, so we have also discussed the realization method of object-independent remote device. The proposed multi-folded transformation optics will be crucial in the design of remote devices in a variety of contexts.Apart from invisibility cloak, the multi-folded transformation optics method is also used to design a non-contact device for radio frequency shielding. In this case, the proposed “open-shielded” device can shield any object at a distance from the electromagnetic waves at the operating frequency, while the object is still physically open to the outer space. Based on this, an open-carpet cloak is proposed and the functionality of the open-carpet cloak is demonstrated. Furthermore, we investigate a scheme of non-contact wave guiding to remotely control the propagation of surface waves over any obstacles. The flexibilities of such multi-folded transformation optics method demonstrate the powerfulness of this method in the design of novel remote devices with impressive new functionalities.Furthermore, we introduce a novel way to design a remote manipulation device that creates illusion of antennas located at a certain distance. This work is based on the multi-folded transformation optics method and such remotely manipulation is enabled by the use of mapped electromagnetic medium coated with the transformed medium. The proposed concept is applied in the design of three different types of antennas to achieve the desired radiations with devices placed within a certain distance while the antennas are not bounded with any electromagnetic medium. The proposed concept will be very helpful for future antenna design.The major area of my PhD study was related to the design of object-independent remote devices for invisibility cloaking, illusion optics, radio frequency shielding, and surface wave guiding. The works presented in this thesis are published in well-reputed journals like “Light-Science & Applications” and “Scientific reports”. In addition, I continued the same concept and applied to the active sources, e.g. antennas, in order to achieve the freely and remotely manipulation of the antennas, and this work is ready to be submitted.
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