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Introduction
Published in Kim Hwi, Park Junghyun, Lee Byoungho, Fourier Modal Method and Its Applications in Computational Nanophotonics, 2017
Kim Hwi, Park Junghyun, Lee Byoungho
A photonic metamaterial is one of the newest subfields in nanophotonics. Metamaterials [17–24], especially photonic metamaterials, refer to any artificial materials with optical properties that cannot be observed in natural materials. Metamaterials have fine optical structures at a deep subwave-length scale, which show various resonant responses to electromagnetic waves and result in unprecedented macroscopic optical properties, such as negative refraction, a strong magnetic response, and nonlinear coordinate transformation. Optical waves propagating in a metamaterial create an effective homogeneous medium with special dispersion or resonance properties. The difference between a photonic crystal and a photonic metamaterial can be understood with respect to critical size and a functional analogy to electronic solids. A photonic crystal is analogous to a natural material or a composite material with periodicity. Periodicity is the most critical point in a photonic crystal. However, the use of a photonic metamaterial to control optical wave propagation is a completely different approach. The periodicity of a metamaterial is on a deep subwavelength scale much smaller than the critical feature size of a photonic crystal. Using an analogy to an electron, we are able to understand that photonic crystals with periodic dielectric potential and a photonic band structure correspond to solid crystals with periodic electronic potential and an electronic bandgap structure. The photonic band-gap structure is fundamentally derived from the periodicity of the dielectric potential. The point of comparison is that the periodicity (including topology, size, and permittivity distribution in a unit primitive cell) is the key factor in creating a photonic band structure and managing the optical properties of a photonic crystal, while for a photonic metamaterial, individual scatter, i.e., photonic atoms, needs to be recreated with special resonance characteristics, which is analogous to creating a new atom with a special orbital structure. Plasmonic nanostructures are usually employed to make up individual photonic atoms of a photonic metamaterial due to its strong resonance properties on a deep subwavelength scale. Such collections of newly created atoms result in an artificial photonic metamaterial with unnatural optical properties such as negative refraction, invisibility, superlensing, and deep sub-wavelength nondiffracting ray propagation.
Measurement of Sucrose Concentration Using Optical Metamaterial Structure Via FDTD Technique
Published in IETE Journal of Research, 2022
Susanta Gaan, Subhra Rani Mondal, S. Sivaranjani, C. S. Mishra, S. K. Behera, G. Palai
Now a days, metamaterial plays a vital role in day-to-day life in the field of communication, networking, biotechnology, and sensor technology. Metamaterial is an artificial material, which shows extra ordinary properties. As far as applications relating to the metamaterial is concerned, some papers have been published pertaining to the cloaking, filtering, optical sensor detector, laser communication, miniaturized triangular microstrip antenna, glucose sensor, biomedical application, IR application using metamaterial waveguide, and antireflection coating for solar cell using photonic metamaterial [1–9]. Apart from this, researchers around the globe are also working on metamaterial to realize the practical application. The basic properties of metamaterial depend on the thickness of the material, nature of medium, permeability and permittivity, and incident wave, which controls the output upshot from it. Though various works have been carried out with the help of plane wave expansion (PWE) method, we in this paper compute the sucrose concentration by dissecting different types of losses such as reflection, absorption, propagation, diffraction, and scattering. Here, absorption loss depends on the absorption coefficient, where the reflection loss relies on the photonic band gap of the proposed structure. Similarly, propagation loss relies on crystalline defect and surface irregularities [9,10]. Moreover, the diffraction and scattering loss depends on the effective refractive indices and incident signal, respectively. Sucrose is the most important part of carbohydrates, which is useful in our human beings providing energy for maintaining physical and mental functions.