One-dimensional Resonant Photonic Crystals Research Articles

Resonant photonic crystals based on van der Waals heterostructures for effective light pulse retardation

We propose to use 2D monolayers possessing optical gaps and high exciton oscillator strength as an element of one-dimensional resonant photonic crystals. We demonstrate that such systems are promising for the creation of effective and compact delay units. In transition-metal-dichalcogenide-based structures where the frequencies of Bragg and exciton resonances are close, a propagating short pulse can be slowed down by few picoseconds while pulse intensity decreases only 2–5 times. This is realized at the frequency of the “slow” mode situated within the stopband. The pulse retardation and attenuation can be controlled by detuning the Bragg frequency from the exciton resonance frequency.

Slow light in resonant photonic crystals with a complex unit cell

Features of the propagation and slowing down of short light pulses (duration of ~0.1–2 ps) in one-dimensional resonant photonic crystals with various types of unit cells containing several quantum wells are discussed. It is established that the use of structures with a complex unit cell makes it possible to reduce the group velocity of exciton-polaritons along with the conservation of the width of the transparency window. The calculations show the possibility of the slowing down of a light pulse by a factor of 50 as compared to a pulse propagating in vacuum. The predicted delay time of the pulse is 2 ps at a damping of only 3–5 times.

Radiative Topological States in Resonant Photonic Crystals

We present a theory of topological edge states in one-dimensional resonant photonic crystals with a compound unit cell. Contrary to the conventional electronic topological states, the modes under consideration are radiative; i.e., they decay in time due to the light escape through the structure boundaries. We demonstrate that the edge states survive despite their radiative decay and can be detected both in time- and frequency-dependent light reflection.

Control of absorption spectrum of a one-dimensional resonant photonic crystal

The crystal under consideration is a layered structure consisting of alternating layers of two materials, one of which is a resonantly absorbing gas. It is shown that the combination of the dispersion of an atomic gas with the dispersion of a photonic-bandgap structures allows one to efficiently control the transmission spectra of s- and p-polarized modes in these combined systems. It is found that the spectrum is highly sensitive to the position of the gas resonance frequency with respect to the bandgap edge and to a change in the gas pressure. The transmission, reflection, and absorption spectra of the resonant photonic crystal are studied at an angle of incidence equal to the Brewster angle of a seed photonic crystal. Possible applications of the found particular features of the dispersion of resonant photonic crystals are discussed.

Ultrafast polarization optical switch constructed from one-dimensional photonic crystal and its performance analysis

All-optical switch with the ultrafast optical switching rate is a key device in the next generation optical network. In this article, we propose a polarization switch with ps switching time, which is constructed from one-dimensional resonant photonic crystal (1D RPC). The model of switch operating at 1.5 µm is established based on the optical stark effect (OSE). We calculate the performance indices of the switch and the influences of errors of periods and refractive index on the performance characteristics.

Spectral properties of a one-dimensional resonant photonic crystal

The eigenexcitation and transmission spectra of a one-dimensional resonant photonic crystal are studied for TM and TE polarized electromagnetic waves. The crystal considered is a layered structure consisting of alternating isotropic layers and layers of a resonantly absorbing gas. The performed calculations show that the band structure of the spectra of the resonant photonic crystal significantly changes as the angle of incidence and the density of the resonant gas are varied. The structure of the spectra of additional transmission in the bandgap of the resonant photonic crystal is studied taking into account the decay of electromagnetic modes. The possibilities of controlling the spectrum of electromagnetic modes are indicated.

Specific features in reflectance and absorbance spectra of one-dimensional resonant photonic crystals

The optical spectra of resonant Bragg and quasi-Bragg quantum-well structures are studied theoretically. The existence of special frequencies in the reflectance and absorbance spectra at which the reflectance or absorbance does not depend on the number of quantum wells in a structure is explained analytically. It is shown that the reflectance and absorbance spectra of structures in which the quantum-well width substantially exceeds the exciton Bohr radius also contain special frequencies and that the smooth spectral component is determined primarily by the interaction of the light wave with the quantum-well ground-state exciton.

Exciton luminescence in one-dimensional resonant photonic crystals: A phenomenological approach

A phenomenological theory of luminescence properties of one-dimensional resonant photonic crystals is developed within the framework of classical Maxwell's equations with fluctuating polarization terms representing noncoherent sources of emission. The theory is based on an effective general approach in determining linear response of these structures and takes into account formation of polariton modes due to coherent radiative coupling between their constituting elements. The general results are applied to Bragg multiple-quantum-well structures, and theoretical luminescence spectra of these systems are compared with experimental results. The relation between absorption and luminescence spectra is also discussed.

Spectral properties of exciton polaritons in one-dimensional resonant photonic crystals

The dispersion properties of exciton polaritons in multiple-quantum-well based resonant photonic crystals are studied. In the case of structures with an elementary cell possessing a mirror symmetry with respect to its center, a powerful analytical method for deriving and analyzing dispersion laws of the respective normal modes is developed. The method is used to analyze band structure and dispersion properties of several types of resonant photonic crystals, which would not submit to analytical treatment by other approaches. These systems include multiple quantum well structures with an arbitrary periodic modulation of the dielectric function and structures with a complex elementary cell. Special attention was paid to determining conditions for superradiance (Bragg resonance) in these structures, and to the properties of the polariton stop band in the case when this condition is fulfilled (Bragg structures). The dependence of the band structure on the angle of propagation, the polarization of the wave, and the effects due to exciton homogeneous and inhomogeneous broadenings are considered, as well as dispersion properties of excitations in near-Bragg structures.

Controlling light by light in a one-dimensional resonant photonic crystal.

We consider the interaction and stability of gap solitons in a one-dimensional, resonant, photonic crystal with a defect state produced by a linear localized mode, or by an incoherent pump. Soliton propagation is investigated using both an analytical treatment and the direct numerical integration of the two-wave Maxwell-Bloch equations. Our results demonstrate that the soliton can be trapped, reflected from, or tunnel through the defect state.