A new mechanism for strong Anderson localization of photons in carefully prepared disordered dielectric superlattices with an everywhere real positive constant is described. In three dimensions, two photon mobility edges separate high- and low-frequency extended states from intermediate-frequency pseudogap localized arising remnant geometric Bragg resonances. Experimentally observable consequences are discussed.

A frequency regime in which electromagnetic waves a strongly disordered medium undergo Anderson localization $d=3$ dimensions is suggested. In the presence of weak dissipation $d=2+\ensuremath{\epsilon}$ it shown that renormalized energy absorption coefficient increases as photon $\ensuremath{\omega}$ approaches mobility edge ${\ensuremath{\omega}}^{*}$ from conducting side...

We present a detailed study of photonic band structure in certain self-organizing systems that self-assemble into large-scale crystals with gaps (PBGs) or pseudogaps the near-visible frequency regime. These include colloidal suspensions, inverted opals, and macroporous silicon. show complete three-dimensional PBGs spanning roughly 10% 15% gap center are attainable by incomplete infiltration an opal silicon germanium, respectively. The both face cubic hexagonal close packed evaluated....

We demonstrate that when an optically birefringent nematic liquid crystal is infiltrated into the void regions of inverse opal, photonic-band-gap (PBG) material, resulting composite material exhibits a completely tunable PBG. In particular, three-dimensional PBG can be opened or closed by applying electric field which rotates axis molecules relative to opal backbone. Tunable light localization effects may realized controlling orientational disorder in nematic.

It is shown that in dielectrics exhibiting a complete photonic band gap, quantum electrodynamics predicts the occurrence of bound states photons to hydrogenic atoms. When atomic transition frequency lies near edge, excited level experiences an anomalous Lamb shift and splits into doublet. One member this doublet exhibits resonance fluorescence whereas other dressed by emission reabsorption near-resonant whose amplitude decays exponentially from vicinity atom.

We study spontaneous emission near the edge of a photonic band gap. Instead simple exponential decay in vacuum, displays an oscillatory behavior. A single photon-atom bound dressed state exhibits fractional steady-state atomic population on excited state. For three-level atom we evaluate spectral splitting and subnatural linewidth emission. In presence N-1 unexcited atoms show that collective time scale factor is equal to ${\mathit{N}}^{\mathrm{\ensuremath{\varphi}}}$, where...

Since the beginning of scientific inquiry nature light has played a vital role in our understanding physical world. Physicists have marveled at dual as both corpuscle and wave; we harnessed remarkable coherent properties through use lasers; quantum mechanics interaction photons with matter continue to provide fascinating avenues basic research. In essence, any alteration electromagnetism, fundamental overning atomic, molecular condensed physics, will lead fundamentally new phenomena all these areas.

We describe the quantum electrodynamics of photons interacting with hydrogenic atoms and molecules in a class strongly scattering dielectric materials. These dielectrics consist an ordered or nearly array spherical scatterers real positive refractive index exhibit complete photonic band gap pseudogap for all directions electromagnetic propagation. For transition frequency forbidden optical gap, we demonstrate both existence stability photon-atom bound state. to center ratio...

Abstract We demonstrate through precise numerical simulations the possibility of flexible, thin-film solar cells, consisting crystalline silicon, to achieve power conversion efficiency 31%. Our optimized photonic crystal architecture consists a 15 μm thick cell patterned with inverted micro-pyramids lattice spacing comparable wavelength near-infrared light, enabling strong wave-interference based light trapping and absorption. Unlike previous designs, photogenerated charge carrier flow is...

The photonic band gap of a two-dimensional crystal is continuously tuned using the temperature dependent refractive index liquid crystal. Liquid $E7$ was infiltrated into air pores macroporous silicon with triangular lattice pitch 1.58 $\ensuremath{\mu}$m and wavelength range 3.3--5.7 \ensuremath{\mu}m. After infiltration, for H polarized field shifted dramatically to 4.4--6.0 \ensuremath{\mu}m while that E-polarized collapsed. As sample heated nematic-isotropic phase transition...

The density of states $\ensuremath{\rho}(E)$ in the tail for an electron a correlated Gaussian random potential three dimensions is constructed from first principles by means simple physical argument. This yields linear exponential dependence $\ensuremath{\rho}$ on $E$ which, reasonable values rms fluctuation and correlation length, spans many decades, occupies most experimentally observable energy range. suggested as origin fundamental Urbach optical-absorption edge.

We describe collective spontaneous emission of $N$ two-level atoms placed within a photonic band-gap material. When the atomic resonance frequency lies at band edge, superradiant remains localized in vicinity atoms. This leads to steady state with spontaneously broken symmetry which system acquires macroscopic polarization. The decay rate is proportional ${N}^{2/3}$ and ${N}^{2}$ for isotropic anisotropic 3D gaps, respectively. corresponding peak intensity superradiance ${N}^{5/3}$ ${N}^{3}$,

We describe the transition from extended to localized modes in a disordered elastic medium $2+\ensuremath{\epsilon}$ dimensions as phase an appropriate nonlinear $\ensuremath{\sigma}$ model. The latter is derived by considering fluctuations about mean-field approximation replica field Lagrangian for system. Within this framework, we calculate averaged one- and two-particle phonon Green's functions obtaining density of states frequency-dependent, zero-temperature thermal diffusivity,...

High-refractive-index, 3D photonic crystals (see Figure) are produced by silicon double inversion of a polymer woodpile template fabricated multiphoton direct laser writing. The method incorporates silica chemical vapor deposition fine-tuning the filling fraction an intermediate inverted woodpile, and thus ability to tailor width complete band gap woodpile.

We present a blueprint for three-dimensional photonic band gap (PBG) material that is amenable to large-scale microfabrication on the optical scale using glancing angle deposition methods. The proposed chiral crystal consists of square spiral posts tetragonal lattice. In case silicon in air (direct structure), full PBG can be as large 15% center frequency, whereas background (inverted structure) maximum 24% frequency. This occurs between fourth and fifth bands photon dispersion relation very...

Direct laser writing in chalcogenide glasses of three-dimensional (3D) photonic crystals (see Figure) with a complete bandgap is reported. This novel approach allows for the direct fabrication arbitrarily shaped 3D microstructures high refractive index materials. Woodpile structures are fabricated less than two hours, whose optical properties compatible gap 3.5%.

We present a simple, versatile technique for the fabrication of large, three-dimensional gap photonic crystals using glancing angle deposition (GLAD). A tetragonal lattice suitable large band (PBG) can be synthesized by regular array square spiral structures grown from prepatterned substrate physical vapor and advanced motion. Tetragonal with predicted PBG up to 15% silicon structure produced in visible, NIR, IR spectrum. These PBG's exhibit good stability areas parameter space that readily...

We discuss the diffusing-wave spectroscopy technique for multiple scattering of light as introduced in recent experiments. This has proven to be useful probing self-diffusion particles suspension by measuring light-intensity autocorrelation function. show how function depends upon dynamic structure factor medium presence correlations between particles. There is a simple generalization result obtained uncorrelated media include factor. Previous theoretical work employed white-noise model,...

We demonstrate coherent control of spontaneous emission from a three-level atom with one resonant frequency near the edge photonic band gap. As result quantum interference and photon localization, can be totally suppressed or strongly enhanced depending on relative phase between pump laser fields. The fractionalized steady state inversion depends sensitively initial conditions, suggesting possibility phase-sensitive, optical memory device atomic scale.

We present a formalism for the description of fluorescence from optically active materials embedded in photonic crystal structure possessing band gap or pseudogap. An electromagnetic field expansion terms Bloch modes is used to develop equations local density photon available emitting atoms either high low dielectric regions crystal. then obtain expressions spectra and emission dynamics luminescent crystals. The validity our demonstrated through calculation relevant quantities model...

In several recent experiments, isotropic lasing action was observed in paints that contain rhodamine 640 dye molecules methanol solution as gain media and titania particles optical scatterers. These so-called paint-on laser systems are extraordinary because they highly disordered systems. The microscopic mechanism for activity the coherence properties of light emission this multiple-light-scattering medium have not yet been elucidated. paper we derive intensity a model system with excited...

We describe theoretically how the shape of coherent backscattering peak photons in a disordered dielectric medium is altered by Faraday rotation and natural optical activity. These effects break time-reversal parity symmetries, respectively. The calculated line shapes are qualitatively similar to those presence confined geometry or an absorptive medium: suppression long scattering paths reduces observed intensity. For incident light given circular polarization, however, suppresses only...

We demonstrate two orders of magnitude enhancement light absorption in certain thin-film photonic crystal (PC) architectures due to strong resonances arising from parallel interface refraction (PIR). This anomalous type is acutely negative and usually out the plane incidence. Over a wide range frequencies, impinging on idealized two-dimensional (2D) crystals, over cone at least 20\ifmmode^\circ\else\textdegree\fi{} off-normal directions, couples Bloch modes propagating nearly...

Topological insulators have unconventional gapless edge states where disorder-induced back-scattering is suppressed. In photonics, such lead to unidirectional waveguides which are useful for integrated photonic circuitry. Cavity modes, another type of fundamental component in chips, however, not protected by band topology because their lower dimensions. Here we demonstrate that concurrent wavevector space and real-space topology, dubbed as dual-topology, can light-trapping The resultant...