Efficient and intuitive method for the analysis of light scattering by a resonant nanostructure

Calculation, normalization, and perturbation of quasinormal modes in coupled cavity-waveguide systems

We show how one can use a nonlocal boundary condition, which is compatible with standard frequency domain methods, for numerical calculation of quasinormal modes in optical cavities coupled to waveguides. In addition, we extend the definition of the quasinormal mode norm by use of the theory of divergent series to provide a framework for modeling of optical phenomena in such coupled cavity-waveguide systems. As example applications, we calculate the Purcell factor and study perturbative changes in the complex resonance frequency of a photonic crystal cavity coupled to a defect waveguide.

Roundtrip matrix method for calculating the leaky resonant modes of open nanophotonic structures

We present a numerical method for calculating quasi-normal modes of open nanophotonic structures. The method is based on scattering matrices and a unity eigenvalue of the roundtrip matrix of an internal cavity, and we develop it in detail with electromagnetic fields expanded on Bloch modes of periodic structures. This procedure is simpler to implement numerically and more intuitive than previous scattering matrix methods, and any routine based on scattering matrices can benefit from the method. We demonstrate the calculation of quasi-normal modes for two-dimensional photonic crystals where cavities are side-coupled and in-line-coupled to an infinite W1 waveguide, and we show that the scattering spectrum of these types of cavities can be reconstructed from the complex quasi-normal mode frequency.

Design of an efficient single photon source from a metallic nanorod dimer: a quasi-normal mode finite-difference time-domain approach

We describe how the finite-difference time-domain (FDTD) technique can be used to compute the quasi-normal mode (QNM) for metallic nano-resonators, which is important for describing and understanding light-matter interactions in nanoplasmonics. We use the QNM to model the enhanced spontaneous emission rate for dipole emitters near a gold nanorod dimer structure using a newly developed QNM expansion technique. Enhanced single photon emission factors of around 1500 and output β-factors of around 60% are found near the localized plasmon resonance.

Aperiodic-Fourier modal method for analysis of body-of-revolution photonic structures

Modeling the field produced by a point-like dipole with an arbitrary location in the presence of a rotationally invariant nanostructure is an important issue in the context of designing nanoantennas. This is a challenging problem, as rotational symmetry is broken when introducing a noncentered dipole. Antennas larger than the wavelength are required for directivity, whereas the dipole-antenna distance is highly subwavelength, so there are two different length scales in the problem. In this paper, we introduce an original S-matrix approach based on an aperiodic-Fourier modal method. The potential of the technique is illustrated by considering three examples. We compare our results with a finite element technique.

Focus issue on surface plasmon photonics introduction

The 6th International Conference on Surface Plasmon Photonics (SPP6) was held in Ottawa, Canada from May 26th to 31st, 2013. This independent series of biennial conferences is widely regarded as the premier series in the field, and the 6th edition maintained the tradition of excellence. This Focus Issue collects several papers related to research presented at SPP6, and although the number of papers it comprises is small compared to the total number of papers presented at the conference, the issue is representative and provides a good snapshot of the field at this point in time.