We report on a new random laser phenomenon that gives rise to narrow emission modes without requiring optical cavities. Sharp peaks are observed experimentally over broad range of scattering strengths and analyzed in numerical calculations. find the introduction exponential gain multiple light process strongly increases importance very long paths. Such paths rare often neglected passive disordered materials but we show they can dominate spectrum from an amplifying system.

We report on surface plasmon (SP)-enhanced random laser emission from a suspension of silver nanoparticles in dye operating at diffusive and subdiffusive scattering strengths. SP resonance enhances the cross section, while geometrical section remains small, thus providing large gain volume. The localized electromagnetic field near particle leads to enhanced absorption excitation light larger amplification fluorescence. metal-nanoparticle-based yields linewidth narrowing lower pump fluence...

We report on an experimental and numerical study of chaotic behavior in random lasers. The complex emission spectra from a disordered amplifying material with static disorder are investigated configuration controlled, stable conditions. It is found that, upon repeated identical excitation, the distinct uncorrelated. This can be understood terms strongly coupled modes that triggered by spontaneous emission, expected to play important role most pulsed

We measure intensity statistics and identify statistical regimes crossovers in random lasers based on nonresonant feedback. A single parameter extracted from an α-stable Levy fit is used to characterize the distributions all regimes. Measurements made over a range of scattering strengths, excitation energies, sample sizes enable us demarcate three corresponding crossovers. An initial subthreshold Gaussian regime abruptly transits into at lasing threshold, which followed by continuous gradual...

Critical excitation in random lasers under picosecond and nanosecond pumping was experimentally studied. The resulting emission intensity statistics were analyzed using fits to $\ensuremath{\alpha}$-stable distributions. We find that the transition value of $\ensuremath{\alpha}$, tail exponent stable distribution, is a clear indicator threshold lasing. discuss this as an identifier threshold. This definition compared with conventional definitions for threshold, namely, probability lasing...

We have observed angular anisotropy in weak localization of light from highly scattering, orientationally ordered, nematic liquid crystals. This demonstration a multiple-scattering interference phenomenon was facilitated by scattering instrument with extraordinary resolution. The measured anisotropies were consistent simple model coherent backscattering generalized for propagation-direction dependent mean free paths.

We report the experimental implementation and theoretical analysis of a random laser system that constitutes an amplifying periodic-on-average superlattice (PARS). The stringent conditions on monodispersity required for are fulfilled using linear array spherical microresonators whose separation size distribution can be controlled. Statistical studies lasing frequency reveal frequency-controlled behavior. perform transfer matrix calculations with gain to analyze origin modes, their...

High-dimensional quantum entanglement in photons offers notable technological advancements over traditional qubit-based systems, including increased information density and enhanced security. However, such high-dimensional states are vulnerable to disruption by complex disordered media, presenting significant challenges practical applications. Spatially entangled conventionally generated using a nonlinear crystal via spontaneous parametric downconversion. While the effect of disorder on...

We report experimental demonstration of photonic band-edge lasing in three-dimensionally ordered self-assembled crystals consisting rhodamine-B dye doped nanospheres diameter 295 nm. Our all-solid crystal shows a well-resolved stop gap the visible region. Laser-induced emission experiments reveal more than 51$%$ inhibition spontaneous intensity molecules within and an enhancement near blue side gap. With increase incident pump energy, we achieve photonic-band-edge-induced at room temperature...

We examine the dependence of Gaussian-L\'evy transition in random lasers on disorder strength, through experimental and theoretical studies. Experiments are performed samples whose strength varied over almost an order magnitude. It is found that L\'evy regime easily accessed under low excitation when weak, compared to energetically expensive strong disorder. Besides, conditions weak disorder, energy mildly dependent strength. The also progresses rapidly weakly scattering samples. In...

Lévy fluctuations have associated infinities due to diverging moments, a problem that is circumvented by putting restrictions on the magnitude of fluctuations, realizing process called truncated flight. We show perfect manifestation this exotic occurs in coherent random lasers, and it turns out be single underlying explanation for complete statistical behavior nonresonant lasers. A rigorous parameter estimation number summand variables, truncation parameter, power-law exponent carried over...

We discuss experimental studies of the interaction between a nanoscopic object and photonic crystal membrane resonator quality factor Q=55000.By controlled actuation glass fiber tip in near field crystal, we constructed complete spatio-spectral map mode its coupling with tip.On one hand, our findings demonstrate that scanning probes can profoundly influence optical characteristics near-field images devices.On other show introduction provides low loss method for on-command tuning...

We report on intensity fluctuations of a coherent random laser based incoherent feedback via nonresonant multiple scattering. quantify the spectral line shape in terms correlations an individual spectrum with ensemble-averaged spectrum, which infers signature gain profile medium. These are studied relation to highest modes. evaluate distribution ratio and fractions emission, after independently assessing their statistics. Finally, these graphically represented single scatter plot, centroid...

We present the first experimental observation of Anderson localization in terahertz frequency range using plasmonic structures. To accomplish this goal, we designed THz waveguides consisting a one-dimensional array rectangular apertures that were fabricated freestanding metal foil. Disorder is introduced into waveguide by offsetting position each aperture random distance within prescribed range. For example, for with spaced 250 μm periodic waveguide, 10% disorder would correspond to being...

Photonic crystals are essentially a periodic ("crystalline") arrangement of dielectric nanoparticles that respond in unison to incident light. They can be used harvest light various applications such as photocatalysis, solar cells, and lasing. In this work, we prepared the photonic dendritic fibrous nanosilica (DFNS) by their self-assembly. Because narrow particle size distribution as-synthesized DFNS, they readily formed colored crystals. The band gap was found tunable using DFNS sizes...

Non-Hermiticity is known to manifest interesting modifications in the transport properties of complex systems. We report an intriguing regime hybrid quasiparticles a non-Hermitian setting. calculate probability transport, quantified by Thouless conductance, plasmons under varying degrees disorder. With increasing disorder, we initially observe expected decrease average transmission, followed anomalous rise at localizing The behavior originates from confluence hybridization and...

Electron multiplying charge-coupled devices (EMCCDs), owing to their high quantum efficiency and spatial resolution, are widely used study typical optical phenomena related applications. Researchers have already developed a procedure that enables one statistically determine whether pixel detects single photon, based on its output is higher or lower than the estimated noise level. However, these techniques feasible at extremely low photon numbers (≈0.15 mean number of photons per exposure),...

High-dimensional entangled states have now been identified as excellent candidates towards the enhancement of bandwidth quantum systems. A variety methods exist that aim to certify and set bounds entanglement. However, rapid accurate approaches for precise quantification dimensions remain a challenge. Here, we report facile, robust approach quantifies wide range spatial high-dimensional using an interferometric technique only two images. Our process works class pure two-photon states,...

We report numerical studies on temperature-tunable, multiple-scattering media with gain. describe Monte Carlo simulations that model the behavior of such a system through three-dimensional random walk light in temperature-dependent disordered medium amplification. compare results our previous experimental dielectric for which scattering strength could be tuned by changing external temperature. The agreement between and enables us to predict spectral features emission from tunable laser under...

Anderson localization is associated with a definite spectral behavior whereby the widths and spacings of eigenvalues characterize transport via subunity Thouless conductance. Towards experimental measurements, formidable challenge to identify sufficient number in statistically consistent manner. Here, authors extract peaks multitude localizing configurations over an ultrabroad band, directly determine optical The log-normal distribution conductance localization, while spacing statistics...

We demonstrate coherent random lasing from an aerosol of dye-doped microdroplets in air. The is the form a linear array polydisperse, arbitrarily shaped, and randomly spaced with average dimensions about 30 μm. Upon optical excitation, ultranarrow modes were observed emission along axis array, while transverse exhibited intrascatterer resonance peaks. Direct spatiospectral imaging threshold studies confirmed origin peaks to be spatial that extended over polydisperse microdroplets.