With the rapid development of artificial electromagnetic materials, people focus onthe design of various kinds of fascinating electromagnetic devices, wheretransformation optics, as a powerful theoretical tool, provides an effective guidance forthis work. Cloak is the most famous device, which is capable of guiding the incidentwave to propagate around the cloaked object as if it travels in free space. Unfortunately,the fascinating performance is accompanied by complicated materials. Therefore, it hasbeen a challenging task in realm of transformation optics to propose novel cloakingdevices and simplify its constitutive parameters.Based on transformation optics, this dissertation proposed some novel cloakingdevices and some innovative electromagnetic transformation devices including adaptivewaveguide bender and optical elevator. Besides, some useful conclusions and results areobtained, where primary research and innovation are as follows:1. Two kinds of novel open cloaking devices are proposed, namely, distributedexternal cloaking device and open-closed cloaking device. Distributed external cloakingdevice is designed based on compressing transformation, and consists of severalindependent subsystems. Besides, the constitutive parameters of subsystems do not relyon the cloaked object, and a communication window appears between each twosubsystems. Open-closed cloaking device is designed with discontinuous boundary,which can be manipulated to create fully open, partially open, and fully closed cloakingdevices. More importantly, the communication window of fully open cloaking device isgreatly tunable. The blinded problem of traditional cloaking devices can be solved withproposed open cloaking devices.2. Several simplified cloaking devices with simple constitutive parameters areproposed. Firstly, based on the latest embedded linear transformation theory, the flatcarpet, which is capable of hiding object placed on ground, is designed. This flat carpetis composed of homogeneous material, and can be realized with uniaxial crystal.Secondly, twofold transformation method is proposed to design two-dimensionalpolygonal cloaking devices with homogeneous and nonsingular parameters. Finally, with the help of linear transformation, diamond and triangular complementary cloakingdevices with advantage of homogeneous parameters are designed.3. Gain-assisted cloak is proposed. Based on complex transformation theory, thepermittivity and permeability of material are assumed to be complex, which means theloss and gain is considered, and finally the specific complex parameters are obtained byusing implicit transformation theory. Accordingly, the relationship between loss andgain can be found in complex parameters, which provides guidance on how to overcomethe intrinsic loss with gain compensation to keep perfect performance. This providestheoretical principle for practical engineers.4. New electromagnetic device, adaptive waveguide bender, is proposed. Basedon linear transformation theory, we rigorously analyze the adaptive waveguide bender,which connects two waveguides with different cross sections and can ideally tunnel thewave along any directions. According to effective media theory, this proposed benderwith homogeneous and anisotropic parameters can be realized with only two alternatinglayered dielectric media, which greatly simplifies the design scheme and lay importanttheoretical foundations for engineering applications.5. New electromagnetic device, optical elevator, is proposed and experimentallydemonstrated. This elevator can lift up an entire plane virtually without distortion inlight path or phase, and the lifted height keeps invariant with different angles of incidentwave. This optical elevator is fabricated using uniaxial crystal, namely calcite, andexperimental results match well with theoretical design. |