New approach to the measurement of refractive index

2005 ◽  
Vol 44 (5) ◽  
pp. 058002 ◽  
Author(s):  
L. M. Bali
Author(s):  
Nghia Quang Truong ◽  
Huong Tu Ngoc Nguyen

In this article, we introduce a new approach to receive general solutions which describe all of the properties of the light propagating across optical uniaxial crystals. In our approach we do not use the conception of refractive index ellipsoid as being done in references. The solutions are given in analytical expressions so we can handly calculate or writing a small program to compute these expressions.


1978 ◽  
Vol 19 (2) ◽  
pp. 201-225 ◽  
Author(s):  
M. J. Giles

A new approach to the problem of the radiation emitted from a localized external current source embedded in a magnetoplasma is described. It is argued that the calculation of the fields in the radiation zone can be substantially simplified by adopting at the outset a suitable parametrization of the dispersion surface. We illustrate the approach by calculating the far fields using the full expression for the dielectric tensor of a warm magnetized electron gas. In this case one can take the angle of rotation about the external magnetic field and the square of the refractive index as the curvilinear co-ordinates of the dispersion surface. The form of the surfaces of constant phase and the amplitudes of the emitted waves are described for each topologically different region of parameter space and their structures are related to the shapes of the refractive index surfaces. Attention is also drawn to the existence of locally cylindrical waves that can produce beams which are highly collimated in the direction of the external magnetic field.


Open Physics ◽  
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Milen Nenkov ◽  
Tamara Pencheva

AbstractA new approach for determination of refractive index dispersion n(λ) (the real part of the complex refractive index) and thickness d of thin films of negligible absorption and weak dispersion is proposed. The calculation procedure is based on determination of the phase thickness of the film in the spectral region of measured transmittance data. All points of measured spectra are included in the calculations. Barium titanate thin films are investigated in the spectral region 0.38–0.78 μm and their n(λ) and d are calculated. The approach is validated using Swanepoel’s method and it is found to be applicable for relatively thin films when measured transmittance spectra have one minimum and one maximum only.


2010 ◽  
Vol 1245 ◽  
Author(s):  
Corsin Battaglia ◽  
Jordi Escarre ◽  
Karin Söderström ◽  
Franz-Josef Haug ◽  
Didier Dominé ◽  
...  

AbstractWe investigate the influence of refractive index contrast on the light scattering properties of nanotextured interfaces, which serve as front contact for p-i-n thin-film silicon solar cells. We here focus on ZnO surfaces with randomly oriented pyramidal features, known for their excellent light trapping performance. Transparent replicas, with a different refractive index, but practically identical morphology compared to their ZnO masters, were fabricated via nanoimprinting. Within the theoretical framework we recently proposed, we show how the angular and spectral dependence of light scattered by nanostructures with identical morphology but different refractive index may be related to each other allowing direct comparison of their light trapping potential within the device.


2018 ◽  
Vol 5 (2) ◽  
pp. 144-158 ◽  
Author(s):  
Yuri Kivshar

Abstract Most optical metamaterials fabricated and studied to date employ metallic components resulting in significant losses, heat and overall low efficiencies. A new era of metamaterial physics is associated with all-dielectric meta-optics, which employs electric and magnetic Mie resonances of subwavelength particles with high refractive index for an optically induced magnetic response, thus underpinning a new approach to design and fabricate functional and practical metadevices. Here we review the recent developments in meta-optics and subwavelength dielectric photonics and demonstrate that the Mie resonances can play a crucial role in the realization of the unique functionalities of meta-atoms, also driving novel effects in the fields of metamaterials and nanophotonics. We discuss the recent research frontiers in all-dielectric meta-optics and uncover how Mie resonances can be employed for a flexible control of light with full phase and amplitude engineering, including unidirectional metadevices, highly transparent metasurfaces, non-linear nanophotonics and topological photonics.


Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 154 ◽  
Author(s):  
Christian Tavella ◽  
Paola Lova ◽  
Martina Marsotto ◽  
Giorgio Luciano ◽  
Maddalena Patrini ◽  
...  

Photonic technologies are nowadays dominated by highly performing inorganic structures that are commonly fabricated via lithography or epitaxial growths. Unfortunately, the fabrication of these systems is costly, time consuming, and does not allow for the growth of large photonic structures. All-polymer photonic crystals could overcome this limitation thanks to easy solubility and melt processing. On the other hand, macromolecules often do not offer a dielectric contrast large enough to approach the performances of their inorganic counterparts. In this work, we demonstrate a new approach to achieve high dielectric contrast distributed Bragg reflectors with a photonic band gap that is tunable in a very broad spectral region. A highly transparent medium was developed through a blend of a commercial polymer with a high refractive index inverse vulcanized polymer that is rich in sulfur, where the large polarizability of the S–S bond provides refractive index values that are unconceivable with common non-conjugated polymers. This approach paves the way to the recycling of sulfur byproducts for new high added-value nano-structures.


2005 ◽  
Vol 123 (23) ◽  
pp. 234508 ◽  
Author(s):  
Akira Hitachi ◽  
Vitaly Chepel ◽  
M. Isabel Lopes ◽  
Vladimir N. Solovov

2005 ◽  
Vol 869 ◽  
Author(s):  
Eugen Foca ◽  
Helmut Föll ◽  
Frank Daschner ◽  
Vladimir V. Sergentu ◽  
Jürgen Carstensen ◽  
...  

AbstractThis work focuses on photonic crystals (PC) that can be ascribed an effective index of refraction > 1 or even > 0. We investigate the possibility to design optical elements (in this case a lens) based on this type of PC. A new approach for determining the effective refractive index of PCs with unusual index of refraction is used, which is simpler than earlier methods based on analyzing equi-frequency surfaces in k-space. An ultra-low refractive index PC is given a form approximating a concave lens and is proven theoretically and experimentally that it efficiently focuses the electromagnetic radiation in the microwave range. Strong focusing effects are found for both polarizations (TE and TM mode). Intensity gains as large as 35 for TM polarizations and 29 for TE polarizations are found. Measurements are in a good accordance with simulations.


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