Quasiperiodic Photonic Crystals Research Articles

Microwave transmission through one-dimensional hybrid quasi-regular (fibonacci and Thue-Morse)/periodic structures

The transmission properties of hybrid quasi-periodic photonic systems (HQPS) made by the combination of one-dimensional periodic photonic crystals (PPCs) and quasi-periodic photonic crystals (QPCs) were theoretically studied. The hybrid quasi-periodic photonic lattice based on the hetero-structures was built from the Fibonacci and Thue-Morse sequences. We addressed the microwave properties of waves through the one-dimensional symmetric Fibonacci, and Thue-Morse system i.e., a quasi-periodic structure was made up of two different dielectric materials (Rogers and air), in the quarter wavelength condition. It shows that controlling the Fibonacci parameters permits to obtain selective optical filters with the narrow passband and polychromatic stop band filters with varied properties which can be controlled as desired. From the results, we presented the self-similar features of the spectra, and we also presented the fractal process through a return map of the transmission coefficients. We extracted powerfully the band gaps of hybrid quasi-periodic multilayered structures, called pseudo band gaps, often containing resonant states, which could be considered as a manifestation of numerous defects distributed along the structure. The results of transmittance spectra showed that the cutoff frequency could be manipulated through the thicknesses of the defects and the type of dielectric layers of the system. Taken together, the above two properties provide favorable conditions for the design of an all-microwave intermediate reflector.

Light harvesting enhancement in solar cells with quasicrystalline plasmonic structures

Solar cells are important in the area of renewable energies. Since it is expensive to produce solar-grade silicon [Electrochem. Soc. Interface 17, 30 (2008)], especially thin-film solar cells are interesting. However, the efficiency of such solar cells is low. Therefore, it is important to increase the efficiency. The group of Polman has shown that a periodic arrangement of metal particles is able to enhance the absorbance of light [Nano Lett. 11, 1760 (2011)]. However, a quasicrystalline arrangement of the metal particles is expected to enhance the light absorbance independent of the incident polar and azimuthal angles due to the more isotropic photonic bandstructure. In this paper, we compare the absorption enhancement of a quasiperiodic photonic crystal to that of a periodic photonic crystal. We indeed find that the absorption enhancement for the quasicrystalline arrangement shows such an isotropic behavior. This implies that the absorption efficiency of the solar cell is relatively constant during the course of the day as well as the year. This is particularly important with respect to power distribution, power storage requirements, and the stability of the electric grid upon massive use of renewable energy.

Omnidirectional photonic band gaps enhanced by Fibonacci quasiperiodic one-dimensional ternary plasma photonic crystals

An omnidirectional photonic band gap realized by one-dimensional Fibonacci quasiperiodic structure which is composed of plasma and two kinds of isotropic dielectric is theoretically studied. It has been shown that such an omnidirectional photonic band gap is insensitive to the incident angle and the polarization of electromagnetic wave (EM wave). The frequency range and central frequency of omnidirectional photonic band gap cease to change with increasing Fibonacci order, but vary with the thickness and density of the plasma. The bandwidth of omnidirectional photonic band gap can be notably enlarged. The omnidirectional photonic band gap originates from a Bragg gap in contrast to zero-n˜ gap or single negative (negative permittivity or negative permeability) gap. From the numerical results performed by the transfer matrix method (TMM), it has been proved that Fibonacci quasiperiodic one-dimensional ternary plasma photonic crystals have a superior feature in the enhancement of omnidirectional photonic band gap frequency range compared with the conventional ternary plasma photonic crystals. This omnidirectional photonic band gap has potential applications in filters, microcavities, and fibers, etc.

All-Optical Diode Action in Quasiperiodic Fibonacci Nanostructures

We theoretically investigate the feasibility of nonreciprocal light propagation by using the unique features of quasiperiodic one-dimensional photonic crystals. The intrinsic spatial asymmetry of the Fibonacci sequence leads to strong non-reciprocal electric eld distribution, so the nonlinear transmission becomes sensitive to the propagation direction. In this work we emphasise on bistability and all optical switching where the switching threshold for one propagation direction is lower than that for the other. In addition we demonstrate that this structure exhibits high transmission due to the existence of high transmission resonances in its linear transmission spectrum, and these features allow creating an all-optical diode.

Omnidirectional photonic band gap enlarged by one-dimensional ternary unmagnetized plasma photonic crystals based on a new Fibonacci quasiperiodic structure

In this paper, an omnidirectional photonic band gap realized by one-dimensional ternary unmagnetized plasma photonic crystals based on a new Fibonacci quasiperiodic structure, which is composed of homogeneous unmagnetized plasma and two kinds of isotropic dielectric, is theoretically studied by the transfer matrix method. It has been shown that such an omnidirectional photonic band gap originates from Bragg gap in contrast to zero-n¯ gap or single negative (negative permittivity or negative permeability) gap, and it is insensitive to the incidence angle and the polarization of electromagnetic wave. From the numerical results, the frequency range and central frequency of omnidirectional photonic band gap can be tuned by the thickness and density of the plasma but cease to change with increasing Fibonacci order. The bandwidth of omnidirectional photonic band gap can be notably enlarged. Moreover, the plasma collision frequency has no effect on the bandwidth of omnidirectional photonic band gap. It is shown that such new structure Fibonacci quasiperiodic one-dimensional ternary plasma photonic crystals have a superior feature in the enhancement of frequency range of omnidirectional photonic band gap compared with the conventional ternary and conventional Fibonacci quasiperiodic ternary plasma photonic crystals.

Comparative study of optical properties of the one-dimensional multilayer Period-Doubling and Thue-Morse quasi-periodic photonic crystals

The last decades have witnessed the growing interest in the use of photonic crystal as a new material that can be used to control electromagnetic wave. Actually, not only the periodic structures but also the quasi-periodic systems have become significant structures of photonic crystals. This work deals with optical properties of dielectric Thue-Morse multilayer and Period-Doubling multilayer. We use the so-called Transfer Matrix Method (TMM) to determine the transmission spectra of the structures. Based on the representation of the transmittance spectra in the visible range a comparative analysis depending on the iteration number, number of layers and incidence angle is presented.

Omnidirectional photonic band gaps enlarged by Fibonacci quasi-periodic one-dimensional ternary superconductor photonic crystals

First two omnidirectional photonic band gaps (OBGs) realized by one-dimensional (1D) Fibonacci quasi-periodic structure which is composed of superconductor and two kinds of isotropic dielectric are theoretically studied by the transfer matrix method (TMM). From the numerical results, it has been shown that such OBGs are insensitive to the incident angle and the polarization of electromagnetic wave (EM wave), and the frequency ranges and central frequencies of OBGs cease to change with increasing Fibonacci order, but vary with the ambient temperature of system and the thickness of the superconductor, respectively. The bandwidths of OBGs can be notably enlarged. The damping coefficient of superconductor layers has no effect on the frequency ranges of OBGs. Those OBGs originate from a Bragg gap in contrast to zero-n˜ gap or single negative (negative permittivity or negative permeability) gap. It has been proved that Fibonacci quasi-periodic 1D ternary superconductor dielectric photonic crystals (SDPCs) have a superior feature in the enhancement of OBGs frequency ranges compared with the conventional binary dielectric photonic crystals (DPCs).

Omnidirectional band gaps in quasiperiodic photonic crystals in the THz region

In this work we calculate the emittance spectra of the electromagnetic radiation normally and obliquely incident (s- and p-polarized modes) on a one-dimensional multilayer quasiperiodic photonic structure made up by layered system of positive (SiO2) and negative (LiTaO3) refractive index materials organized in a quasiperiodic (Fibonacci-like) fashion. We model the negative refractive index material by an effective medium, whose electric permittivity ϵ(ω) is characterized by a phonon-polariton frequency dependent dielectric function, while for the magnetic permeability μ(ω) we have a Drude-like frequency-dependent function. The emittance spectra are determined by means of a well known theoretical model based on Kirchoff’s second law, together with a transfer matrix formalism. Our results shows that the omnidirectional band gaps appear in the THz regime, in well defined frequency intervals independently of the electromagnetic radiation’s polarized modes.

Matter-wave solitons with the minimum number of particles in two-dimensional quasiperiodic potentials

We report results of systematic numerical studies of two-dimensional matter-wave soliton families supported by an external potential, in a vicinity of the junction between stable and unstable branches of the families, where the norm of the solution attains a minimum, facilitating the creation of the soliton. The model is based on the Gross-Pitaevskii equation for the self-attractive condensate loaded into a quasiperiodic (QP) optical lattice (OL). The same model applies to spatial optical solitons in QP photonic crystals. Dynamical properties and stability of the solitons are analyzed with respect to variations of the depth and wave number of the OL. In particular, it is found that the single-peak solitons are stable or not in exact accordance with the Vakhitov-Kolokolov (VK) criterion, while double-peak solitons, which are found if the OL wave number is small enough, are always unstable against splitting.

Comparative study of photonic band gaps of germanium-based two-dimensional triangular-lattice and square-lattice and decagonal quasi-periodic photonic crystals

Photonic band gaps (PBGs) of germanium-based two-dimensional (2D) triangular-lattice and square-lattice and decagonal quasi-periodic photonic crystals (PCs) with the scatterer radius in the range of [0,0.3a] and within two cases of the construction (germanium cylinders being placed in air, air cylinders being placed in germanium) have been calculated by using the plane wave expansion (PWE) method. Germanium-based 2D triangular-lattice PC and 2D decagonal quasi-periodic PC are more easily to generate PBG than 2D square-lattice PC. 2D decagonal quasi-periodic PC is more easily to generate complete band gap than the other two kinds of PCs. The PBG properties of the three PCs are similar to the properties of silicon-based system as the radius of the scatterer cylinder increases. Nevertheless, the germanium-based system is more likely to generate PBG than silicon-based system. These findings will guide the design of PBG-type microstructure devices.

PROPERTIES OF OMNIDIRECTIONAL PHOTONIC BAND GAPS IN FIBONACCI QUASI-PERIODIC ONE-DIMENSIONAL SUPERCONDUCTOR PHOTONIC CRYSTALS

In this paper, the properties of the omnidirectional photonic band gap (OBG) realized by one-dimensional (1D) Fibonacci quasi-periodic structure which is composed of superconductor and isotropic dielectric have been theoretically investigated by the transfer matrix method (TMM). From the numerical results, it has been shown that this OBG is insensitive to the incident angle and the polarization of electromagnetic wave (EM wave), and the frequency range and central frequency of OBG cease to change with increasing Fibonacci order, but vary with the ambient temperature of system, the thickness of the superconductor, and dielectric layer, respectively. The bandwidth of OBG can be notably enlarged with increasing the superconductor thickness. Moreover, the frequency range of OBG can be narrowed with increasing the thickness of dielectric layer and ambient temperature. The damping coe-cient of superconductor layers has no efiect on the frequency range of OBG under low- temperature conditions. It is shown that Fibonacci quasi-periodic 1D superconductor dielectric photonic crystals (SDPCs) have a superior feature in the enhancement frequency range of OBG. This kind of OBG has potential applications in fllters, microcavities, and flbers, etc.

Transmission properties of Fibonacci quasi-periodic one-dimensional superconducting photonic crystals

The transmission properties of Fibonacci quasi-periodic one-dimensional photonic crystals (1DPCs) containing superconducting material are theoretically investigated based on the transfer matrix method. It is shown that the 1DPCs can possess a same photonic band gap property as the periodic structure superconducting PC. The results of transmittance spectra show that the cutoff frequency can be manipulated through the thicknesses of the superconductor and dielectric layers as well as the ambient temperature of the system. It is observed that the shift of cutoff frequency becomes more noticeable by adjusting the thickness of the superconductor layer than that of the dielectric one. Furthermore, the cutoff frequency becomes very sensitive when the system temperature is tuned to close vicinity of the critical temperature of the superconductor.

Transmission Properties of Thue-Morse Quasi-Periodic 1D Superconducting Photonic Crystals

The transmission properties of Thue-Morse quasi-periodic one-dimensional photonic crystals (1DPCs) containing superconducting material are theoretically investigated based on the transfer matrix method. It is shown that the 1DPCs can possess a same photonic band gap property as the periodic structure superconducting PC. The results of transmittance spectra show that the cutoff frequency can be manipulated through the thicknesses of the superconductor and dielectric layers as well as the ambient temperature of the system. It is observed that the shift of cutoff frequency becomes more noticeable by adjusting the thickness of the superconductor layer than that of the dielectric one. Furthermore, the cutoff frequency becomes very sensitive when the system temperature is tuned to close vicinity of the critical temperature of the superconductor.

Multiple responses of TPP-assisted near-perfect absorption in metal/Fibonacci quasiperiodic photonic crystal

Absorption properties in one-dimensional quasiperiodic photonic crystal composed of a thin metallic layer and dielectric Fibonacci multilayers are investigated. It is found that a large number of photonic stopbands can occur at the dielectric Fibonacci multilayers. Tamm plasmon polaritons (TPPs) with the frequencies locating at each photonic stopband are excited at the interface between the metallic layer and the dielectric layer, leading to almost perfect absorption for the energy of incident wave. By adjusting the length of dielectric layer with higher refractive-index or the Fibonacci order, the number of absorption peaks can be tuned effectively and enlarged significantly.

Transmission properties of Fibonacci quasi-periodic one-dimensional photonic crystals containing indefinite metamaterials

The transmission properties of Fibonacci quasi-periodic one-dimensional photonic crystals (1DPCs) containing indefinite metamaterials are theoretically studied. It is found that 1DPCs can possess an omnidirectional zero average index (zero- n̅) gap which exists in all Fibonacci sequences. In contrast to Bragg gaps, such zero- n̅ gap is less sensitive to the incidence angle, the scale length and the polarizations of electromagnetic waves. When an impurity is introduced, a defect mode appears inside the zero- n̅ gap with a very weak dependence on the incidence angle and scaling.

Omnidirectional phase matching of arbitrary processes by radial quasi-periodic nonlinear photonic crystal

We investigate second-harmonic generation in a nonlinear photonic crystal having radial quasi-periodic order and continuous rotational symmetry. This device enables us to simultaneously phase match different nonlinear interactions in any arbitrary direction of propagation. We have fabricated such a crystal by electric field poling of a magnesium-doped stoichiometric LiTaO(3) and demonstrated frequency doubling of two different pump wavelengths at three different angles. Fourier coefficients were 10 times higher than that of a lattice-based multidirectional frequency doubler.

Bistability and stationary gap solitons in quasiperiodic photonic crystals based on Thue–Morse sequence

The nonlinear properties of quasiperiodic photonic crystals based on the Thue–Morse sequence are investigated. The intrinsic asymmetry of these one-dimensional structures for odd generation numbers results in bistability thresholds which are sensitive to propagation direction. Along with resonances of perfect transmission, this feature allows to obtain strongly nonreciprocal propagation and to create an all-optical diode. The efficiency of two schemes is compared: passive and active when an additional short pump signal is applied to the system. The existence of stationary gap solitons in quasiperiodic photonic crystals is shown numerically, and their difference from the Bragg case is emphasized.

Bistability, multistability and non-reciprocal light propagation in Thue–Morse multilayered structures

The nonlinear properties of quasi-periodic photonic crystals based on the Thue–Morse sequence are investigated. The intrinsic spatial asymmetry of these one-dimensional structures for odd generation numbers results in bistability thresholds, which are sensitive to the propagation direction. Along with resonances of perfect transmission, this feature allows us to achieve strongly non-reciprocal propagation and to create an all-optical diode. The salient qualitative features of such optical diode action are readily explained through a simple coupled resonator model. The efficiency of a passive scheme that does not necessitate an additional short pump signal is compared to an active scheme where such a signal is required.

10.1007/s11455-008-1007-9

The optical properties of one-dimensional quasiperiodic photonic crystals with linear profiles of modulation parameters are considered. It is shown that such systems possess a wider photonic band gap as compared to the ideal periodic system and can be used as omnidirectional reflectors. The asymmetric profiles of parameters in these systems results in the appearance of nonreciprocity of a new type that makes possible their use as the ideal, purely optical diodes.

Omnidirectional reflection from deformed quasiperiodic one-dimensional photonic crystals in high frequency

Transmission spectra in quasiperiodic multilayered band gap structures in high frequency are calculated by using a theoretical model based on Abeles method at any incidence angle and both polarisations S and P. It has been found that the propagation of electromagnetic waves is forbidden in some frequency bands. The forbidden gap included microwave region has been observed for the twelve orders of Fibonacci sequence.This result is compared by periodic sequence. Forbidden gap can be generated in this frequency band by stacking together layers of different dielectric materials A and B according to simple rules. For simplicity, the thicknesses dA,B of the two materials, Roger (layer A) and air (layer B), have been chosen to satisfy the Bragg condition. We noted unusual physical properties like the formation of large photonic band gaps for the tow polarizations S and P in high frequency band width. The study of the deformed Fibonacci stack so that the coordinates y of the deformed object were determined through the coordinates x of the Fibonacci stack in accordance with the following rule y=xk+1 leads to an omnidirectional high reflector band in the desired wavelength spectral range.