7 research outputs found
Modal interferometric refractive index sensing in microstructured exposed core fibres
Optical fibre-based sensors measuring refractive index shift in bodily fluids and tissues are versatile and accurate probes of physiological processes. Here, we suggest a refractive index sensor based on a microstructured exposed-core fibre (ECF). By considering a high refractive index coating of the exposed core, our modelling demonstrates the splitting of the guided mode into a surface sensing mode and a mode that is isolated from the surface. With the isolated mode acting as a reference arm, this two-mode one-fibre solution provides for robust interferometric sensing with a sensitivity of up to 60, 000 rad/RIU-cm, which is suitable for sensing subtle physiological processes within hard-to-reach places inside living organisms, such as the spinal cord, ovarian tract and blood vessels.Ivan S. Maksymov, Heike Ebendorff-Heidepriem, and Andrew D. Greentre
Plasmon-assisted high reflectivity and strong magneto-optical Kerr effect in permalloy gratings
10.1063/1.4798657Applied Physics Letters10212-APPL
Sensing magnetic nanoparticles using nano-confined ferromagnetic resonances in a magnonic crystal
We demonstrate the use of the magnetic-field-dependence of highly spatially
confined, GHz-frequency ferromagnetic resonances in a ferromagnetic
nanostructure for the detection of adsorbed magnetic nanoparticles. This is
achieved in a large area magnonic crystal consisting of a thin ferromagnetic
film containing a periodic array of closely spaced, nano-scale anti-dots. Stray
fields from nanoparticles within the anti-dots modify resonant dynamic
magnetisation modes in the surrounding magnonic crystal, generating easily
measurable resonance peak shifts. The shifts are comparable to the resonance
linewidths for high anti-dot filling fractions with their signs and magnitudes
dependent upon the modes' localisations (in agreement with micromagnetic
simulation results). This is a highly encouraging result for the development of
frequency-based nanoparticle detectors for high speed nano-scale biosensing.Comment: 7 pages, 5 figure