Skaaningsloan2415

Among the various methods for computing the T-matrix in electromagnetic and acoustic scattering problems is an iterative approach that has been shown to be particularly suited for particles with small-scale surface roughness. This method is based on an implicit T-matrix equation. However, the convergence properties of this method are not well understood. Here, a sufficient condition for the convergence of the iterative T-matrix algorithm is derived by applying the Banach fixed point theorem. The usefulness of the criterion is illustrated by applying it to predicting, as well as to systematically improving the convergence of the iterative method.This paper focuses on polarized radiative transfer in dispersed layers composed of densely packed optically soft particles while considering the effects of dependent scattering and particle agglomeration. The radiative properties of the particles for different agglomeration degrees are calculated using the Lorenz-Mie theory combined with the Percus-Yevick sticky hard sphere model, and the vector radiative transfer equation is solved by using the spectral method. AF-353 price The normalized Stokes reflection matrix elements of the layers for different particle sizes, particle volume fractions and layer thicknesses are discussed. The results show that the effects of multiple scattering, dependent scattering and particle agglomeration have different degrees of influence on the polarized reflection characteristics of the layers. Due to the inhibition effect of far-field interference interaction on particle scattering, the dependent scattering weakens the depolarization caused by multiple scattering. However, as the particles form agglomerations, the scattering coefficients of the particles obviously increase with the agglomeration degree, which will lead to the significant enhancement of the multiple scattering and depolarization.We propose a light transparency effect induced by coherent feedback. By studying a system comprising a linear optical cavity controlled by a linear coherent feedback loop, we show that the optical signal field passing through the system cavity exhibits novel transparency behaviors. Unidirectional coupling between the system and its feedback control loop enables the group velocity and transmission rate to be tuned separately, thus maintaining the unity transmission rate when the group velocity is significantly suppressed. Furthermore, we demonstrate that simply applying a certain phase shift to the output of the system cavity and feeding it back into the system can induce perfect transmission. Our proposal offers a simple and effective way to control light transmission and group velocity using only linear optics elements.We present, for the first time, an experimental demonstration of RIN noise transfer dampening at low frequencies in random distributed feedback ultralong Raman fibre lasers based on conventional telecommunication fibres. Furthermore, we present a thorough theoretical description of the phenomenon and demonstrate how our model can be used to predict the observed behaviour, identifying the general requirements for system improvement through RIN transfer reduction.Refractometry is a ubiquitous technique for process control and substance identification in the chemical and biomedical fields. Herein, we present an all-dielectric, wafer-scalable, and compact Fabry-Pérot microcavity (FPMC) device for refractive index (RI) sensing. The FPMC consists of a highly porous SiO2 microcavity capped with a thin, quasi-periodically patterned TiO2 hole array partial reflector that enables rapid, nanoliter-scale analyte transport to and from the sensor. Liquid (alcohols) or condensed-vapor (water from human breath) infiltration resulted in spectral redshifts up to 100 nm, highly apparent visible color change, rapid recovery ( less then 20 s), and RI sensitivity of up to 680 nm/RIU. The sensor can also be used in spectral or single-wavelength detection modes. Effective-medium and finite-difference time-domain optical simulations identified that Fano-resonant scattering modes induced by the quasi-periodic TiO2 outcoupling layer effectively filter higher-order Fabry-Pérot cavity modes and thereby confer an easily identifiable red-to-green color transition during analyte infiltration.High color rendering index (CRI) and wide correlated color temperatures (CCTs) white LEDs (WLEDs) employing CaAlSiN3 Eu2+ and Lu3Al5O12 Ce3+ co-doped phosphor-in-glass (PiG) are demonstrated. Through fabrication using a low sintering temperature of 620°C to minimize inter-diffusion between the red phosphor and glass, and adjusting thickness of 0.5-0.7 mm to obtain the chromaticity tailorable co-doped PiG, the WLEDs exhibit high CRI of 94 and wide CCTs of 3900 K to 5300 K. This CRI is the highest yet reported for the co-doped PiG. The proposed of the co-doped PiG with good thermal stability fabricated by using a low sintering temperature may provide a novel technique to achieve high-performance WLEDs with high CRI for use in many high-quality of indoor lighting applications, especially in color inspection, clinical inspection, and gallery lighting.Bidirectional ultrafast fiber lasers capable of generating counter-propagating (CP) coherent solitons are promising to be served as a dual-comb light source for the applications in spectroscopy and gyroscope. In the absence of efficient numerical model, the understanding of the operation of bidirectional fiber lasers is very limited. In this paper, we experimentally explore the pulsating dynamics of CP solitons in a bidirectional mode locked fiber laser and present a set of rich complex dynamics of CP solitons, revealing for the first time, to the best of our knowledge, the periodic breathing and acyclic pulsating dynamics of CP solitons. With a bi-directional pumping configuration, the impacts of gain distribution along the fiber on the dynamics of CP solitons have been investigated and discussed. These results provide further evidence of the universality of breathing dynamics of solitons. More importantly, the abundant dynamical behavior of CP solitons demonstrated in this paper, collaborating with a handful of previous reports on the buildup dynamics of CP solitons in bidirectional fiber lasers, underline further the independent evolving dynamics of CP solitons.