A.I. Nosich

Radiation and absorption losses of the whispering-gallery-mode dielectric resonators excited by a dielectric waveguide

The scattering of a surface wave of a dielectric layer backed by a ground plane from the whispering-gallery-mode dielectric resonators is considered by use of the surface potential approach and analytical regularization. Efficient numerical algorithms have been developed with applications to the bandstop filter design. Transmitted and reflected power fractions and radiation and absorption losses are calculated and compared for two alternative field polarizations. The effect of excitation of the higher order modes of the waveguide is also studied.

MICRO-OPTICAL RESONATORS FOR MICROLASERS AND INTEGRATED OPTOELECTRONICS

Optical microcavities trap light in compact volumes by the mechanisms of almost total internal reflection or distributed Bragg reflection, enable light amplification, and select out specific (resonant) frequencies of light that can be emitted or coupled into optical guides, and lower the thresholds of lasing. Such resonators have radii from 1 to 100 mkm and can be fabricated in a wide range of materials. Devices based on optical resonators are essential for cavity quantum-electro-dynamic experiments, frequency stabilization, optical filtering and switching, light generation, biosensing, and nonlinear optics.

Q factor and emission pattern control of the WG modes in notched microdisk resonators

Two-dimensional (2-D) boundary integral equation analysis of a notched circular microdisk resonator is presented. Results obtained provide accurate description of optical modes, free from the staircasing and discretization errors of other numerical techniques. Splitting of the double degenerate whispering-gallery (WG) modes and directional light output is demonstrated. The effect of the notch depth and width on the resonance wavelengths, Q factors, and emission patterns is studied. Further improvement of the directionality is demonstrated in an elliptical notched microdisk. Applications of the notched resonators to the design of microdisk lasers, oscillators, and biosensors are discussed.

Small hemielliptic dielectric lens antenna analysis boundary integral equations vs. GO and PO

The purpose of research is to outline the domain of applicability of the geometrical optics (GO) and physical optics (PO) in the small dielectric lens analysis. As a benchmark solution, we use the Mullers boundary integral equations (IE) discretized with trigonometric Galerkin scheme that has guaranteed and fast convergence. The lens cross-section is chosen typical for practical applications, namely an extended hemiellipse whose eccentricity satisfies the GO focusing condition. The lens flat side dimension varies between 2 and 8 wavelengths in free space, and its material is rexolite (s = 2.53). We consider the 2D case with an E-polarized plane wave incidence and extract comparison characteristics from the near field analysis.

Microcavities: an inspiration for advanced modelling techniques

Compact photonic devices are at the forefront of much of the state-of-the-art research for a wide range of integrated optoelectronic applications. Microlasing, optical switching, optical memory and enhanced non-linear properties are demanding the development of efficient, accurate and flexible simulation tools for microcavity design. With this in mind we discuss some recent relevant advances in the development of numerical simulation tools and alternative algorithms based on integral equation (IE) formalisms.

Plasmon resonances in the H-wave scattering by a nanosize thin flat silver strip

Nanosize thin flat silver strip in the air is considered as an optical resonator. The scattering characteristics of the H-polarized electromagnetic wave diffraction are analyzed using the decoupled singular and hyper-singular integral equations (IEs) for the electric and magnetic surface currents on the strip. IEs are discretized with the aid of the interpolation type quadrature formulas. This algorithm, also known as the method of discrete singularities (MDS), is numerically efficient and guarantees fast convergence and controlled accuracy of computations.

Micro-resonators: simulation and application

Compact photonic devices based on micro-resonators are at the forefront of much of the state-of-the-art research for a wide range of optoelectronic applications. Exploiting and optimising practical devices requires careful consideration of the effects of realistic geometries and material properties. In this paper the development of simulation tools for micro-resonator structures that will significantly aid future scientific progress and the design of practical commercial products exploiting the new technologies are described.

Design and optimisation of planar waveguide network components based on optical microcavities

A boundary integral equation method is combined with a genetic algorithm to simulate and optimise dielectric and semiconductor microcavities. Waveguide filters and microlaser resonators are tuned by modifying the microcavity shape, coupling mechanism, gain/loss.

Resonant spectra of the WGM dielectric resonators deformed from the circular geometry

WGM cylindrical dielectric resonators deformed from the circular symmetry are of special interest for the design of new optoelectronic devices. They provide advantages for integration into microwave and optical circuits and obtaining directional emission from WG-type lasers. The effect of increasing the deformation magnitude on the complex resonance frequencies of the WG-modes is studied using an efficient algorithm based on the method of analytical regularization.

Comparison of resonance optical scattering of plane waves by infinite gratings of silver cylinders and strips

Periodic structures possess a specific feature, there is a set of high quality resonances near to the wavelength equal to the grating period and their Q-factors rise higher if the grating becomes sparser. Making a grating from silver elements brings other resonances - surface-plasmon ones appearing in the visible-light band. We investigate interaction between the grating and the plasmon resonances in the scattering and absorption by infinite gratings of silver circular cylinders and silver thin strips, for the E and H-polarization cases.