The optical bistability and multistability in one-dimensional photonic crystal with the periodic metal-dielectric structure is investigated theoretically. In linear transmission, a structure with N periods will support N−1 resonant modes which correspond to the transmission peaks. Strong localized effect in these resonant modes is obtained. Optical bistability and multistability can be achieved when the incident wavelength is close to a resonance, which can be seen as an effect of the dynamic shifting of the wavelength of the resonant modes. It is found that the threshold for optical bistability in the periodic resonant structure is lower than the nonresonant metal-dielectric structure.
A nonreciprocal ring optical resonator with the simplest type of nonuniformity in the form of two interacting scatterers is considered. A boundary problem of a periodic type allowing one to write the characteristic equation for determining eigenfrequencies is formulated. Analytic expressions for eigenfrequencies and the distribution coefficient of travelling waves in the mode are derived under the assumption of relative smallness of the reflection coefficient and the nonreciprocity parameter. The peculiarities of splitting these frequencies and the structure of the eigenfrequencies (resonator modes) corresponding to them are discussed.
We consider wave transport phenomena in a
PT-symmetric extension of the periodically kicked quantum rotator model and reveal that dynamical localization assists the unbroken
PT phase. In the delocalized (quantum resonance) regime,
PT symmetry is always in the broken phase and ratchet acceleration arises as a signature of unidirectional non-Hermitian transport. An optical implementation of the periodically kicked
PT-symmetric Hamiltonian, based on transverse beam propagation in a passive optical resonator with combined phase and loss gratings, is suggested to visualize acceleration modes in fractional Talbot cavities.