A drawback of optical modes in microdisk cavities is their isotropic light emission. Here we report a novel, robust, and general mechanism that results highly directional emission from high-quality modes. This surprising finding explained by combination wave phenomena (wave localization along unstable periodic ray trajectories) chaotic dynamics open systems (escape manifolds) applies even to microlasers operating the common multimode regime. We demonstrate our novel for limaçon cavity find...

We introduce a new scheme to design optical microcavities supporting high-Q modes with unidirectional light emission. This is achieved by coupling low-Q mode emission mode. The due enhanced dynamical tunneling near an avoided resonance crossing. Numerical results for microdisk suitably positioned air hole demonstrate the feasibility and potential of this concept.

Anderson's orthogonality catastrophe [Phys. Rev. Lett. 18, 1049 (1967)] in graphene, at energies close to the Dirac point, is analyzed. It shown that, clean systems, suppressed due vanishing density of states point. In presence preexisting localized energy, shows features similar those found normal metals with a finite Fermi level. The implications for Kondo effect induced by magnetic impurities, and edge singularities tunneling processes, are also discussed.

Quasibound states in an open system do not general form orthogonal and complete basis. It is, however, expected that the nonorthogonality is weak case of well-confined states, except close to a so-called exceptional point parameter space. We present numerical evidence showing for passive optical microspiral cavities regime where significant rather broad. Here we observe almost-degenerate pairs modes which are highly nonorthogonal. Using non-Hermitian model Hamiltonian demonstrate this...

We study the effect of dynamical tunneling on emission from ray-chaotic microcavities by introducing a suitably designed deformed disk cavity. focus its high quality factor modes strongly localized along stable periodic ray orbit confined total internal reflection. It is shown that dominant originates to chaotic ones; latter eventually escape cavity refractively, resulting in directional unexpected geometry orbit, but fully explained unstable manifolds dynamics. Experimentally performing...

We study spin-dependent magnetoconductance in mesoscopic rings subject to an inhomogeneous in-plane magnetic field. show that the polarization direction of transmitted spin-polarized electrons can be controlled via additional flux such spin flips are induced at half a quantum. This quantum interference effect is independent strength nonuniform field applied. give analytical explanation for one-dimensional and numerical results corresponding ballistic microstructures.

We report experimental demonstration of directional light emission from limaçon-shaped microcavity semiconductor lasers. Quantum cascade lasers (QCLs) emitting at λ≈10 μm are used as a model system. Both ray optics and wave simulations show that for deformations in the range 0.37<ε<0.43, these microcavities support high quality-factor whispering gallerylike modes while having far-field profile with beam divergence θ∥≈30° plane cavity. The measured profiles good agreement...

Recently, it has been shown that spiral-shaped microdisk cavities support highly nonorthogonal pairs of copropagating modes with a preferred sense rotation (spatial chirality) [J. Wiersig et al., Phys. Rev. A 78, 053809 (2008)]. Here, we provide numerical evidence which indicates such are common feature deformed lack mirror symmetries. In particular, demonstrate discontinuities the cavity boundary as notch in spiral not needed. We find quantitative relation between nonorthogonality and...

Abstract When spinning particles, such as electrons and photons, undergo spin–orbit coupling, they can acquire an extra phase in addition to the well-known dynamical phase. This is called geometric (also known Berry phase), which plays important role a startling variety of physical contexts photonics, condensed matter, high-energy space physics. The was originally discussed for cyclically evolving system with Abelian evolution, later generalized non-cyclic non-Abelian cases, are most...

We study the dielectric annular billiard as a quantum chaotic model of micro-optical resonator. It differs from conventional billiards with hard-wall boundary conditions in that it is partially open and composed two media different refractive indices. The interplay reflection transmission at interfaces gives rise to rich dynamics classical light rays variety wave phenomena. ray propagation terms Poincaré surfaces section complement full numerical solutions corresponding equations. introduce...

Recently, an interesting phenomenon of spatial localization optical modes along periodic ray trajectories near avoided resonance crossings has been observed [Wiersig, Phys. Rev. Lett. 97, 253901 (2006)]. For the case a microdisk cavity with elliptical cross section, we use Husimi function to analyze this in phase space. Moreover, present semiclassical explanation terms Goos-Hänchen shift, which works very well even deep wave regime. This correction dynamics modifies phase-space structure...

The limacon-shaped semiconductor microcavity is a ray-chaotic cavity sustaining low-loss modes with mostly unidirectional emission patterns. Investigating these systematically, we show that the correspond to ray description collectively, rather than individually. In addition, present experimental data on multimode lasing patterns high unidirectionality and closely agree description. origin of this agreement well explained by collective correspondence mechanism.

Mesoscopic billiard systems for electrons and light, realized as quantum dots or optical microcavities, have enriched the fields of chaos nonlinear dynamics not only by enlarging class model systems, but also providing access to their experimental realization. Here, we add yet another system class, two-dimensional billiards with anisotropies. One example is anisotropic dispersion relation relevant in bilayer graphene known trigonal warping, birefringent closed disk cavity. We demonstrate...

While billiard systems of various shapes have been used as paradigmatic model in the fields nonlinear dynamics and quantum chaos, few studies investigated anisotropic billiards. Motivated by tremendous advances using controlling electronic optical mesoscopic with bilayer graphene (BLG), representing an easily accessible material for electrons when trigonal warping is present, we investigate billiards anisotropies geometries a trajectory-tracing approach founded on concept ray–wave...

We develop an amended ray-optics description for reflection at the curved dielectric interfaces of optical microresonators which improves agreement with wave optics by about one order magnitude. The corrections are separated into two contributions similar magnitude, corresponding to ray displacement in independent quantum-phase-space directions, can be identified Fresnel filtering and Goos-H\"anchen shift, respectively. Hence we unify effects only have been studied separately past.

A striking signature of the non-Hermitian physics in open systems is existence exceptional points (EPs) parameter space. In contrast to a conventional degeneracy, an EP involves not only coalescence eigenvalues but simultaneously that corresponding eigenstates as well. Here, we study EPs optical microdisk cavities with concentrically layered refractive index profile. For double-layered cavity show two coalescing modes. triple-layered verify and discuss emergence involving three modes single cavity.

We introduce generalized Husimi functions at the interfaces of dielectric systems. Four different can be defined, corresponding to incident and departing wave on both sides interface. These allow identify mechanisms confinement escape directions in optical microresonators, give insight into structure resonance functions. Off resonance, where systematic interference neglected, are related by Snell's law Fresnel's coefficients.

The availability of microlasers with highly directional far-field characteristics is crucial for future applications. To this end we study the emission active microcavities a spiral shape using Schrödinger-Bloch model. We find that they can provide under conditions (i) pumping along resonator boundary and (ii) specific geometries. systematically variation pumped area cavity geometry identify directionality optimized regime. Our results consistently explain previously obtained experimental results.

The key characteristic of an optical mode in a microcavity is its quality factor describing the losses. numerical computation this quantity can be very demanding for present-day devices. Here we show certain class whispering-gallery cavities that related to dynamical tunneling, phenomenon studied field quantum chaos. We extend recently developed approach determining tunneling rates open cavities. This allows us derive analytical formula which good agreement with full solutions Maxwell's equations.

The dispersion of any given material is crucial for its charge carriers' dynamics. For all-electronic, gate-defined cavities in gapped bilayer graphene, we developed a trajectory-tracing algorithm aware the material's electronic properties and details confinement. We show how anisotropic graphene induces chaotic regular dynamics depending on gate voltage, despite high symmetry circular cavity. Our results demonstrate emergence nonstandard fermion optics solely due to characteristics.

We discuss curvature corrections to Fresnel's laws for the reflection and transmission of light at a nonplanar refractive-index boundary. The coefficients are obtained from resonances dielectric disk within sequential-reflection model. Goos-Hänchen effect curved fronts planar interface can be adapted provide qualitative quantitative extension ray model which explains observed deviations laws.

We study spin effects in the magnetoconductance of ballistic mesoscopic systems subject to inhomogeneous magnetic fields. present a numerical approach spin-dependent Landauer conductance which generalizes recursive Green-function techniques case with spin. Based on this method we address spin-flip quantum transport spin-polarized and spin-unpolarized electrons through wires various two-dimensional Aharonov-Bohm geometries. In particular, investigate range validity spin-switch mechanism...

We introduce and investigate billiard systems with an adjusted ray dynamics that accounts for modifications of the conventional reflection rays due to universal wave effects. show even small specular law have dramatic consequences on phase space classical billiards. These include creation regions non-Hamiltonian dynamics, breakdown symmetries, changes in stability morphology periodic orbits. Focusing optical microcavities, we our provides missing counterpart previously observed phenomena...

We study the far-field characteristics of oval-resonator laser diodes made an $\mathrm{GaAs}/{\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ quantum well. The resonator shapes are various oval geometries, thereby probing chaotic and mixed classical dynamics. pattern shows a pronounced fine structure that strongly depends on cavity shape. Comparing experimental data with ray-model simulations for Fresnel billiard yields convincing agreement all geometries reveals importance...

We report the experimental realization of deformed microcavity quantum cascade lasers (QCLs) with a Limaçon-shaped chaotic resonator. Directional light emission beam divergence θ∥≈33° from QCLs emitting at λ≈10 μm was obtained in plane cavity for deformations range 0.37<ε<0.43. An excellent agreement between measured and calculated far-field profiles found. Both simulations experiments show that preserves whispering gallery-like modes high Q-factors low (ε<0.50). In addition, while spectra...