Effective parameters for photonic crystals with large dielectric contrast

2009 ◽  
Vol 80 (7) ◽  
Author(s):  
Ruey-Lin Chern ◽  
Yu-Tang Chen
Keyword(s):  
Photonic Crystals ◽  
Effective Parameters ◽  
Dielectric Contrast

Light emission from thin opaline photonic crystals of low and high dielectric contrast

2001 ◽  
Vol 124 (1) ◽  
pp. 131-135 ◽  
Author(s):  
Sergei G. Romanov ◽  
Torsten Maka ◽  
Clivia M.Sotomayor Torres ◽  
Manfred Müller ◽  
Rudolf Zentel
Keyword(s):  
Photonic Crystals ◽  
Light Emission ◽  
Dielectric Contrast ◽  
High Dielectric

scholarly journals Study on the Photonic Band Gaps of the Face Centered Cubic Crystals

2016 ◽  
Vol 70 ◽  
pp. 63-75
Author(s):  
K.B.S.K.B. Jayawardana ◽  
K.A.I.L. Wijewardena Gamalath
Keyword(s):  
Photonic Crystals ◽  
Band Gap ◽  
Filling Factor ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
Face Centered Cubic ◽  
Gap Ratio ◽  
Dielectric Contrast ◽  
Dielectric Spheres ◽  
Face Centered

Since the dielectric contrast of photonic crystals play an important role in determining the existence of a photonic gap, the photonic energy bands, density of states of face centered cubic structured photonic crystals formed from spheres of several dielectric materials placed in air were calculated using the plane wave expansion method. A complete band gap was obtained between second and third bands with a gap to mid gap frequency ratio in the range for the dielectric contrast in the range 11-16 with dielectric spheres of radius with a filling factor of 0.134 and fordielectric contrast of 200 with . A complete gap was not found for the dielectric contrast of 3.9. A complete band gap can be obtained for filling factors for the dielectric contrast in the range with an optimum band gap for the filling factor 0.134 while GaAs () has almost a constant optimum band gap in this range. The largest gap to mid gap ratio of was obtained for GaP (). For dielectric spheres of and larger gap to mid gap ratio were obtained for the dielectric contrast while the largest were obtained for . The only dielectric material BaSrTiO3 () which gives a band gap for the filling factor of 0.4524 can be used in microwave applications.

scholarly journals High Refractive Index Inverse Vulcanized Polymers for Organic Photonic Crystals

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 154 ◽  
Author(s):  
Christian Tavella ◽  
Paola Lova ◽  
Martina Marsotto ◽  
Giorgio Luciano ◽  
Maddalena Patrini ◽  
...  
Keyword(s):  
Refractive Index ◽  
Photonic Crystals ◽  
Photonic Band Gap ◽  
High Refractive Index ◽  
Melt Processing ◽  
Added Value ◽  
New Approach ◽  
Dielectric Contrast ◽  
High Dielectric ◽  
Photonic Band

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.

scholarly journals Pulse Reshaping in Double-zero-index Photonic Crystals with Dirac-like-cone Dispersion

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tao Xu ◽  
Dejun Zhu ◽  
Zhi Hong Hang
Keyword(s):  
Photonic Crystals ◽  
Numerical Simulations ◽  
Group Velocity ◽  
Brillouin Zone ◽  
Flat Band ◽  
Effective Parameters ◽  
Double Zero ◽  
Linear Dispersion ◽  
Frequency Components ◽  
Zero Index

Abstract Triply-degenerate Dirac-like cone at the Brillouin zone center attracts much research interest in recent years. Whether the linear dispersion in such a Dirac-like cone reflects the same physics to Dirac cones at the Brillouin zone boundaries is still under investigation. In this manuscript, through microwave experiments and numerical simulations, we observe intriguing pulse reshaping phenomena in double-zero-index photonic crystals, which cannot be fully understood from their close-to-zero effective parameters. A reshaped pulse, with frequency components close to the Dirac frequency filtered, is propagating at a constant group velocity while part of these filtered frequencies appears at a much later time. In time domain measurements, we find a way to separate the effect between the linear dispersion and the extra flat band in Dirac-like cone to have a better understanding of the underneath physics. We succeed in obtaining the group velocity inside a double-zero-index photonic crystal and good consistence can be found between experiments, numerical simulations and band diagram calculations.

Characteristic band gap structures of high dielectric contrast photonic crystals

2011 ◽  
Vol 1343 ◽  
Author(s):  
Sheng D. Chao ◽  
Hsin Y. Peng
Keyword(s):  
Photonic Crystals ◽  
Band Gap ◽  
Hexagonal Lattice ◽  
Dispersion Curves ◽  
Band Gaps ◽  
Circular Cylinders ◽  
Change Characteristics ◽  
Dielectric Contrast ◽  
Full Band ◽  
High Dielectric

ABSTRACTConventional photonic crystals exhibit low-lying full band gaps for the dielectric contrast smaller than 15. As the dielectric contrast increases, the band gap patterns change characteristics and exhibit interesting properties. In particular, the dispersion curves near the band gap region become concentrated to the middle band frequencies and exhibit an overall red shift in frequency. For a dielectric column photonic crystal made of a hexagonal lattice of circular cylinders, the maximum full band gap was found at the dielectric contrast as high as 27.5, which is attainable by using ceramics materials. The gap opens at high-lying bands, has simultaneous TM and TE band edges, and exhibit flattened dispersion curves near the band edges.

scholarly journals Effective Parameters for 1D Photonic Crystals with Isotropic and Anisotropic Magnetic Inclusions: Coherent Wave Homogenization Theory

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1475 ◽  
Author(s):  
J. Flores Méndez ◽  
A. C. Piñón Reyes ◽  
M. Moreno Moreno ◽  
A. Morales-Sánchez ◽  
Gustavo M. Minquiz ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Displacement Vector ◽  
Effective Permittivity ◽  
Homogenization Theory ◽  
Effective Parameters ◽  
Good Correspondence ◽  
Filling Fraction ◽  
Coherent Wave ◽  
Electric And Magnetic Fields ◽  
Magnetic Inclusions

A homogenization theory that can go beyond the regime of long wavelengths is proposed, namely, a theory that is still valid for vectors of waves near the edge of the first zone of Brillouin. In this paper, we consider that the displacement vector and the magnetic induction fields have averages in the volume of the cell associated with the values of the electric and magnetic fields in the edges of the cell, so they satisfy Maxwell’s equations. Applying Fourier formalism, explicit expressions were obtained for the case of a photonic crystal with arbitrary periodicity. In the case of one-dimensional (1D) photonic crystals, the expressions for the tensor of the effective bianisotropic response (effective permittivity, permeability and crossed magneto-electric tensors) are remarkably simplified. Specifically, the effective permittivity and permeability tensors are calculated for the case of 1D photonic crystals with isotropic and anisotropic magnetic inclusions. Through a numerical calculation, the dependence of these effective tensors upon the filling fraction of the magnetic inclusion is shown and analyzed. Our results show good correspondence with the approach solution of Rytov’s effective medium. The derived formulas can be very useful for the design of anisotropic systems with specific optical properties that exhibit metamaterial behavior.

scholarly journals Erratum: Flores, J., et al. Effective Parameters for 1D Photonic Crystals with Isotropic and Anisotropic Magnetic Inclusions: Coherent Wave Homogenization Theory. Materials 2020, 13, 1475

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3053
Author(s):  
J. Flores Méndez ◽  
A. C. Piñón Reyes ◽  
M. Moreno Moreno ◽  
A. Morales-Sánchez ◽  
Gustavo M. Minquiz ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Homogenization Theory ◽  
Effective Parameters ◽  
Coherent Wave ◽  
Magnetic Inclusions

The authors wish to make the following corrections to this paper [1]: replace: (37) 1 ε z = f ε m = 1 − f ε d and (39) 1 μ z = f μ m = 1 − f μ d with the correct expressions: (37) 1 ε z = f ε m + 1 − f ε d and (39) 1 μ z = f μ m + 1 − f μ d [...]

Optical spectroscopy of high dielectric contrast 3D photonic crystals

2001 ◽  
Vol 56 (2) ◽  
pp. 207-213 ◽  
Author(s):  
P. V Braun ◽  
R. W Zehner ◽  
C. A White ◽  
M. K Weldon ◽  
C Kloc ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Optical Spectroscopy ◽  
Dielectric Contrast ◽  
High Dielectric
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