Broken azimuthal degeneracy with whispering gallery modes of microspheres
TL;DR: In this paper, a system of two eccentric spheres, wherein an inclusion sphere is embedded in a larger sphere with a different refractive index, is considered, and the authors demonstrate broken azimuthal degeneracy for non-axisymmetric illumination resulting in splittings in extinction peaks.
Abstract: We consider a system of two eccentric spheres, wherein an inclusion sphere is embedded in a larger sphere with a different refractive index. We demonstrate broken azimuthal degeneracy for non-axisymmetric illumination resulting in splittings in extinction peaks. The mode splitting and mixing effects are shown to be nonresonant, valid for all modes having sufficient quality factors. We demonstrate strong dependence of the splittings on the polarization of the incident light to the extent that one can diagnose the polarization characteristics of the whispering gallery mode. We show how a set of quantum numbers can be assigned to a given peak of the split resonances. We further investigate the field distribution in suitable coordinate planes in order to bring out the close relation between the magnetic quantum number, the polarization of the bisphere modes and that of incident light.
Citations
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TL;DR: This paper presents an update to the comprehensive database of T-matrix publications compiled by us previously and includes the publications that appeared since 2007 and lists several earlier publications not included in the original database.
Abstract: The T-matrix method is among the most versatile, efficient, and widely used theoretical techniques for the numerically exact computation of electromagnetic scattering by homogeneous and composite particles, clusters of particles, discrete random media, and particles in the vicinity of an interface separating two half-spaces with different refractive indices. This paper presents an update to the comprehensive database of T-matrix publications compiled by us previously and includes the publications that appeared since 2007. It also lists several earlier publications not included in the original database.
128 citations
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TL;DR: In this paper, the results of generalized Lorenz-Mie theories in spherical coordinates are modified from scalar results in the framework of the Bromwich method to vectorial expressions using vector spherical wave functions (VSWFs) in order to match the T-matrix formulation, and to express the T
118 citations
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TL;DR: The generalized Lorenz-Mie theory (GLMT) as mentioned in this paper is a generalization of the LMT, which deals with the more general case when the illuminating wave is an arbitrary shaped beam (say: a laser beam) still interacting with a homogeneous sphere defined by its diameter d and its complex refractive index m.
Abstract: During the year 2008, we have been commemorating, in several places, the hundredth anniversary of the famous 1908-paper by Mie describing the interaction between an electromagnetic plane wave and a homogeneous sphere defined by its diameter d and its complex refractive index m . Due to the existence of a prior version by Lorenz, Mie's theory may also be named as Lorenz–Mie theory (LMT). The generalized Lorenz–Mie theory (GLMT) stricto sensu deals with the more general case when the illuminating wave is an arbitrary shaped beam (say: a laser beam) still interacting with a homogeneous sphere defined by its diameter d and its complex refractive index m . The name “GLMTs” is generically used to designate various variants for other particle shapes when the method of separation of variables is used. The present paper provides a review of the work accomplished in this generalized field during the last decade (the third decade). As a convenient selection criterion, only papers citing the work of the group of Rouen have been essentially used, with ISIweb of knowledge providing a database.
104 citations
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TL;DR: In this article, the authors considered the case of a focused fundamental Gaussian beam (TEM(00) mode) illuminating a glass sphere with an eccentrically located spherical water inclusion (having a real refractive index equal to 1.33).
Abstract: Based on the recent results in the generalized Lorenz-Mie theory, solutions for scattering problems of a sphere with an eccentrically located spherical inclusion illuminated by an arbitrary shaped electromagnetic beam in an arbitrary orientation are obtained. Particular attention is paid to the description and application of an arbitrary shaped beam in an arbitrary orientation to the scattering problem under study. The theoretical formalism is implemented in a homemade computer program written in FORTRAN. Numerical results concerning spatial distributions of both internal and external fields are displayed in different formats in order to properly display exemplifying results. More specifically, as an example, we consider the case of a focused fundamental Gaussian beam (TEM(00) mode) illuminating a glass sphere (having a real refractive index equal to 1.50) with an eccentrically located spherical water inclusion (having a real refractive index equal to 1.33). Displayed results are for various parameters of the incident electromagnetic beam (incident orientation, beam waist radius, location of the beam waist center) and of the scatterer system (location of the inclusion inside the host sphere and relative diameter of the inclusion to the host sphere).
40 citations
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TL;DR: In this paper, a theoretical investigation of morphology-dependent resonances (MDRs) excited in a sphere with an eccentrically located spherical inclusion illuminated by a tightly focused Gaussian beam is presented.
Abstract: Following the recent results in generalized Lorenz–Mie theory concerning the description of an arbitrary shaped electromagnetic beam propagating in an arbitrary orientation, a theoretical investigation of morphology-dependent resonances (MDRs) excited in a sphere with an eccentrically located spherical inclusion illuminated by a tightly focused Gaussian beam is presented. Calculations of extinction efficiency spectra and backward-scattering intensity spectra are made for different locations and radii of the inclusion with respect to the host sphere. Exemplifying field distributions inside of the scatterer under both off-resonance and on-resonance conditions are exhibited. The influences of the relative size of the inclusion with respect to the host sphere and of the separation distance between the two sphere centers on the positions and on the amplitudes of the MDRs peaks are studied. As are the cases for spheres and concentrically multilayered spheres, the resonance positions of MDRs in an eccentrically layered sphere are located at the same size parameter for Gaussian beam illumination and for plane-wave illumination. In contrast with the lift of azimuthal modes m degeneracy in MDR peaks for an eccentric sphere illuminated obliquely by a plane wave, we display a kind of lift that cannot be observed in extinction efficiency spectra with an oblique illumination of a tightly focused Gaussian beam. Nevertheless, asymmetric distributions of the internal field inside of the eccentric sphere at resonance conditions are observed both with an oblique illumination of a tightly focused beam and with an oblique illumination of a plane-wave illumination. Interpretation from a perspective of the localization principle is applied to the simulation results.
30 citations
References
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01 Jan 1983
TL;DR: In this paper, a Potpourri of Particles is used to describe surface modes in small Particles and the Angular Dependence of Scattering is shown to be a function of the size of the particles.
Abstract: BASIC THEORY. Electromagnetic Theory. Absorption and Scattering by an Arbitrary Particle. Absorption and Scattering by a Sphere. Particles Small Compared with the Wavelength. Rayleigh--Gans Theory. Geometrical Optics. A Potpourri of Particles. OPTICAL PROPERTIES OF BULK MATTER. Classical Theories of Optical Constants. Measured Optical Properties. OPTICAL PROPERTIES OF PARTICLES. Extinction. Surface Modes in Small Particles. Angular Dependence of Scattering. A Miscellany of Applications. Appendices. References. Index.
16,859 citations
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TL;DR: It is demonstrated that quality factor Q - (0.8 +/- 0.1) x 10(10) of whispering-gallery modes in fused-silica microspheres at 633 nm, close to the ultimate level determined by fundamental material attenuation as measured in optical fibers, is demonstrated.
Abstract: We demonstrate the quality factor Q - (0.8 +/- 0.1) x 10(10) of whispering-gallery modes in fused-silica microspheres at 633 nm, close to the ultimate level determined by fundamental material attenuation as measured in optical fibers. The lifetime of ultimate Q is limited by adsorption of atmospheric water. Monitoring of adsorption kinetics with submonolayer sensitivity by Q factors and frequencies of whispering-gallery modes is demonstrated. The possibility of supermaterial Q's owing to intrinsic suppression of scattering losses in micropheres is discussed.
986 citations
"Broken azimuthal degeneracy with wh..." refers background in this paper
...In fact WGMs have been shown to possess extremely high quality factors (∼1010 in the visible range [12])....
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TL;DR: A review of active and passive ring laser devices is given in this paper, with special emphasis given to the problems associated with the achievement of greater sensitivity and stability with respect to the ring laser gyroscope.
Abstract: This paper presents a review of both active and passive ring laser devices. The operating principles of the ring laser are developed and discussed, with special emphasis given to the problems associated with the achievement of greater sensitivity and stability. First-principle treatments of the nature of quantum noise in the ring laser gyro and various methods designed to avoid low-rotation-rate lock-in are presented. Descriptions of state-of-the-art devices and current and proposed applications (including a proposed test of metric theories of gravity using a passive cavity ring laser) are given.
562 citations
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TL;DR: In this article, the fundamental limit for the quality factor in fused-silica microspheres is revisited, and Q≃1012 is predicted in few-millimeter-size fused silica spheres, if the surface hydration problem is ovecome.
Abstract: The Rayleigh scattering has to be largely suppressed in high-Q whispering-gallery modes in microspheres because of restrictions imposed on scattering angles by cavity confinement. Earlier estimates of the fundamental limit for the quality factor in fused-silica microspheres are revisited, and Q≃1012 is predicted in few-millimeter-size fused-silica spheres, if the surface hydration problem is ovecome. Particular effects of surface scattering losses are analyzed, and the manifestation of scattering in the form of intermode coupling is calculated. The predominant effect of counterpropagating mode coupling (intracavity backscattering) is analyzed in the presence of a mode-matched traveling-wave coupler. As much as 100% resonance reflection regime is shown to be feasible.
445 citations
"Broken azimuthal degeneracy with wh..." refers methods in this paper
...Corresponding theory was developed by the same group using a coupled mode theory [9]....
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TL;DR: High-Q traveling-wave-resonators can enter a regime in which even minute scattering amplitudes associated with either bulk or surface imperfections can drive the system into the so-called strong modal coupling regime, and resonance properties radically altered and can mimic a narrowband reflector.
Abstract: High-Q traveling-wave-resonators can enter a regime in which even minute scattering amplitudes associated with either bulk or surface imperfections can drive the system into the so-called strong modal coupling regime. Resonators that enter this regime have their coupling properties radically altered and can mimic a narrowband reflector. We experimentally confirm recently predicted deviations from criticality in such strongly coupled systems. Observations of resonators that had Q>10^8 and modal coupling parameters as large as 30 were shown to reflect more than 94% of an incoming optical signal within a narrow bandwidth of 40 MHz.
382 citations