Time-independent perturbation for leaking electromagnetic modes in open systems with application to resonances in microdroplets.
ABSTRACT Laser cavities are open systems, in that energy can leak to the outside via output coupling. The ‘‘normal modes’’ are therefore quasinormal modes, with eigenvalues that are complex and eigenfunctions that extend outside the cavity, such that any normalization integral is dominated by the region outside; in short, such systems are non-Hermitian. This paper addresses the question: How is the complex eigenvalue (i.e., the mode frequency) changed when the cavity is perturbed by a small change of dielectric constant? The usual time-independent perturbation theory fails because of non-Hermiticity. By generalizing the work of Zeldovich [Sov. Phys.—JETP 12, 542 (1961)] for scalar fields in one dimension, we express the change of frequency in terms of matrix elements involving the unperturbed eigenfunctions, so that the problem is reduced to quadrature. We then apply the formalism to shape perturbations of a dielectric microdroplet, and give analytic formulas for the frequency shifts of the morphology-dependent resonances. These results are, surprisingly, independent of the radial wave function, so that all integrals can be performed and explicit algebraic expressions are given for axially symmetric perturbations.
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ABSTRACT: We discuss three formally different formulas for normalization of quasinormal modes currently in use for modeling optical cavities and plasmonic resonators and show that they are complementary and provide the same result. Regardless of the formula used for normalization, one can use the norm to define an effective mode volume for use in Purcell factor calculations.01/2015;
Conference Paper: Nonlinear optics with liquid hydrogen droplet[Show abstract] [Hide abstract]
ABSTRACT: Nonlinear optics in a liquid hydrogen droplet is discussed. We carry out the stimulated Raman scattering (SRS) experiments using high-Q whispering gallery modes. We show that the liquid hydrogen droplet readily leads to high cavity Q-values exceeding 10^9 from ultraviolet to visible wavelength region. Using the high-Q liquid-hydrogen droplet, we demonstrate that, by pumping with an ultraviolet laser radiation, the SRS generates multiorder SRS sideband series through vibrational and rotational coherences covering whole ultraviolet-visible region from 200 nm to 900 nm, which may turn out as a super wideband optical comb generator. We also show that the SRS in the liquid hydrogen droplet proceeds for continuous operation with multiorder sidebands.Photonics West 2001 - LASE; 04/2001
Conference Paper: Resonant spectra of symmetric microcavity[Show abstract] [Hide abstract]
ABSTRACT: The properties of Morphological Dependant Resonance (MDR)'s for spherical, cylindrical microcavity have been investigated. The behaviour of locations, quality factors of resonances for spherical and cylindrical microcavity has been discussed. The resonance spectrum for symmetric microcavity is rigorously calculated and shows the strong dependence of the resonance spectrum on the physical characteristics of the microcavity. Note that the position of the resonance peaks is extremely sensitive to wavelength or diameter, permitting a very accurate determination of symmetric microcavity size.2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies; 02/2006