Cascaded four-wave mixing in tapered plasmonic nanoantenna

We study theoretically the cascaded four-wave mixing (FWM) in broadband tapered plasmonic nanoantennas and demonstrate a 300-fold increase in nonlinear frequency conversion detected in the main lobe of the nanoantenna far-field pattern. This is achieved by tuning the elements of the nanoantenna to resonate frequencies involved into the FWM interaction. Our findings have a potentially broad application in ultrafast nonlinear spectroscopy, sensing, on-chip optical frequency conversion, nonlinear optical metamaterials and photon sources

The analytical basis for the resonances and anti-resonances of loop antennas and meta-material ring resonators

Interest in the electromagnetic properties of loop structures has surged with the recent appearance of split-ring resonator meta-materials (SRRs) and nano-antennas. Understanding the resonances, anti-resonances, and harmonics of these loops is key to understanding their response to a wide range of excitation wavelengths. We present the classical analytical solution for the input impedance of a loop structure with circumference on the order of the wavelength, and we show how to identify these resonances from the function. We transform the classical solution into a new RLC formulation and show that each natural mode of the loop can be represented as a series resonant circuit, such that the full response function can be resolved by placing all of these circuits in parallel. We show how this formulation applies to SRRs.This work has been partially supported by the Australian Research Council and the Australian Solar Institute

Study of strong photon-magnon coupling in a YIG-film split-ring resonant system

By using the stripline Microwave Vector Network Analyzer Ferromagnetic Resonance and Pulsed Inductive Microwave Magnetometry spectroscopy techniques, we study a strong coupling regime of magnons to microwave photons in the planar geometry of a lithographically formed split-ring resonator (SRR) loaded by a single-crystal epitaxial yttrium-iron garnet (YIG) film. Strong anti-crossing of the photon modes of SRR and of the magnon modes of the YIG film is observed in the applied-magnetic-field resolved measurements. The coupling strength extracted from the experimental data reaches 9 percent at 3 GHz. Theoretically, we propose an equivalent circuit model of an SRR loaded by a magnetic film. This model follows from the results of our numerical simulations of the microwave field structure of the SRR and of the magnetization dynamics in the YIG film driven by the microwave currents in the SRR. The equivalent circuit model is in good agreement with the experiment. It provides a simple physical explanation of the process of mode anti-crossing. Our findings are important for future applications in microwave quantum photonic devices as well as in magnetically tunable metamaterials exploiting the strong coupling of magnons to microwave photons

Menadione sodium bisulfite effect on growth performance and fatty acid profiles of geese muscle tissues

The specific effect of menadione sodium bisulfite (MSB, vicasol) on the content of specific fatty acids in skeletal muscle and muscular stomach of geese was established. MSB can stimulate the biosynthesis processes and catabolism of fatty acids depending on the period of the geese ontogenesis. Experimental use of MSB in skeletal muscle helps to increase the total content of unsaturated fatty acids (FA) primarily due to n-3 FAs. MSB increases the content of PUFA and SFA on the 35th day of ontogenesis, so the nutritional value of meat improves, and the resistance of myocyte membranes increases to oxidative damage. In the smooth muscle tissue of the goose stomach, the action of MSB revealed a higher content of UFA only on the 21st day of ontogenesis, due to PUFA, in particular, n-6 and MUFA. On the 28th day of ontogenesis, the content of PUFA increases due to n-3, with a decrease in the total content of UFA. At the end of the experiment, the UFA content decreases with increasing SFA. Reducton of the content of essential n-3, n-6, and UFA negatively affects the nutritional value of the product but increases the resistance of tissues to the active forms of oxygen. The use of MSB contributes to the overall increase of the average daily weight gain of geese from the 21st to the 28th day. The average body weight from the 21st to the 35th ontogenesis relative to the control group. We recommend using MSB at a dose of 0.7 mg/kg body weight for gosling feeding to increase the essential FA content in skeletal muscle tissue

Enhanced Single Photon Emission from a Diamond-Silver Aperture

We have developed a scalable method for coupling single color centers in diamond to plasmonic resonators and demonstrated Purcell enhancement of the single photon emission rate of nitrogen-vacancy (NV) centers. Our structures consist of single nitrogen-vacancy (NV) center-containing diamond nanoposts embedded in a thin silver film. We have utilized the strong plasmon resonances in the diamond-silver apertures to enhance the spontaneous emission of the enclosed dipole. The devices were realized by a combination of ion implantation and top-down nanofabrication techniques, which have enabled deterministic coupling between single NV centers and the plasmonic modes for multiple devices in parallel. The plasmon-enhanced NV centers exhibited over six-fold improvements in spontaneous emission rate in comparison to bare nanoposts and up to a factor of 3.6 in radiative lifetime reduction over bulk samples, with comparable increases in photon counts. The hybrid diamond-plasmon system presented here could provide a stable platform for the implementation of diamond-based quantum information processing and magnetometry schemes.Comment: 16 pages, 4 figure