Optical memory based on ultrafast wavelength switching in a bistable microlaser

We propose an optical memory cell based on ultrafast wavelength switching in coupled-cavity microlasers, featuring bistability between modes separated by several nanometers. A numerical implementation is demonstrated by simulating a two-dimensional photonic crystal microlaser. Switching times of less than 10 ps, switching energy around 15--30 fJ and on-off contrast of more than 40 dB are achieved. Theoretical guidelines for optimizing the performance of the memory cell in terms of switching time and energy are drawn.Comment: to appear in Optics Letter

Exponential parameterization of the neutrino mixing matrix - comparative analysis with different data sets and CP violation

The exponential parameterization of Pontecorvo-Maki-Nakagawa-Sakata mixing matrix for neutrino is used for comparative analysis of different neutrino mixing data. The UPMNS matrix is considered as the element of the SU(3) group and the second order matrix polynomial is constructed for it. The inverse problem of constructing the logarithm of the mixing matrix is addressed. In this way the standard parameterization is related to the exponential parameterization exactly. The exponential form allows easy factorization and separate analysis of the rotation and the CP violation. With the most recent experimental data on the neutrino mixing (May 2016), we calculate the values of the exponential parameterization matrix for neutrinos with account for the CP violation. The complementarity hypothesis for quarks and neutrinos is demonstrated to hold, despite significant change in the neutrino mixing data. The values of the entries of the exponential mixing matrix are evaluated with account for the actual degree of the CP violation in neutrino mixing and without it. Various factorizations of the CP violating term are investigated in the framework of the exponential parameterization

Nonreciprocal switching thresholds in coupled nonlinear microcavities

A novel concept for the design of nonlinear optical diodes is proposed which uses the multistability of coupled nonlinear microcavities and the dependence of switching thresholds on the direction of incidence. A typical example of such diode can be created by combining two mirror symmetric microcavities where modes of the opposite parity dominate. It is shown that a strong nonreciprocal behavior can be achieved together with a negligible insertion loss. To describe the dynamical properties of such systems, a model based on the coupled mode theory is developed, and a possible implementation in the form of multilayered structures is considered.Comment: 3 pages, 3 figure

Plasmonic rod dimers as elementary planar chiral meta-atoms

Electromagnetic response of metallic rod dimers is theoretically calculated for arbitrary planar arrangement of rods in the dimer. It is shown that dimers without an in-plane symmetry axis exhibit elliptical dichroism and act as "atoms" in planar chiral metamaterials. Due to a very simple geometry of the rod dimer, such planar metamaterials are much easier in fabrication than conventional split-ring or gammadion-type structures, and lend themselves to a simple analytical treatment based on coupled dipole model. Dependencies of metamaterial's directional asymmetry on the dimer's geometry are established analytically and confirmed in numerical simulations.Comment: 3 page

Dark-field hyperlens: Super-resolution imaging of weakly scattering objects

We propose and numerically demonstrate a technique for subwavelength imaging based on a metal-dielectric multilayer hyperlens designed in such a way that only the large-wavevector waves are transmitted while all propagating waves from the image area are blocked by the hyperlens. As a result, the image plane only contains scattered light from subwavelength features of the objects and is free from background illumination. Similar in spirit to conventional dark-field microscopy, the proposed dark-field hyperlens is promising for optical imaging of weakly scattering subwavelength objects, such as optical nanoscopy of label-free biological objects.Comment: 6 figure