Sergey A. Darmanyan

High-gain Brillouin amplification : an analytical approach

We derive a closed-form approximate analytical formula for the gain of a Brillouin fiber amplifier operating in the depleted pump regime. We take into account the material loss of the medium, which is a strong effect in optical fibers. We validate obtained results numerically and experimentally. The presented analysis can be used to accurately predict the performance of high-gain Brillouin fiber amplifiers.

Giant optical resonances due to gain-assisted Bloch surface plasmons

We theoretically study Bloch surface plasmon (BSP) resonances in a thin subwavelength-structured metallic film adjacent to a submicron dielectric layer with gain. We show that for a planar gold-silver bimetallic grating resonant excitation of a BSP with the optimum value of gain may result in giant amplification of both transmitted and reflected waves. We explain the effect and illustrate how the electromagnetic near-field structure determines the type of interference (constructive or destructive) between the eigenmodes of the system, which results in either strong enhancement or suppression of the scattered waves.

Semi-analytical method for light interaction with 1D-periodic nanoplasmonic structures

We present a detailed description of a computationally efficient, semi-analytical method (SAM) to calculate the electomagnetic field distribution in a 1D-periodic, subwavelength-structured metal film placed between dielectric substrates. The method is roughly three orders of magnitude faster than the finite-element method (FEM). SAM is used to study the resonant transmission of light through nanoplasmonic structures, and to analyze the role of fundamental and higher-order Bloch surface plasmons in transmission enhancement. The method is also suitable for solving the eigenvalue problem and finding modes of the structure. Results obtained with SAM, FEM, and the finite-difference time-domain method show very good agreement for various parameters of the structure.

Enhanced Radiation Forces in the Near-Field of a Structured Thin Metallic Film

We compute optical forces exerted on dielectric nano-spheres in the near-field of a structured metallic film. Large field enhancement induced by the fundamental Bloch surface plasmon mode is shown to result in efficient trapping.

Brillouin fiber amplifier in the depleted-pump regime

We have derived an explicit analytical expression for the gain of a Brillouin fiber amplifier operating in the depleted pump regime. The accuracy of the obtained formula is validated both numerically and experimentally.

New families of discrete solitons in quadratic waveguide arrays

More than ten years ago it was realized that an array of nearest-neighbor coupled guides can support localized structures [1]. Nonlinear waveguide arrays on AlGaAs basis have been recently fabricated and localized modes, or discrete solitons (DSs), have been experimentally observed [2].