Enhanced UV/blue fluorescent sensing using metal-dielectric-metal aperture nanoantenna arrays

Abstract

Subwavelength aperture antenna arrays are designed and fabricated for potential applications in fluorescence sensing in the near UV/blue range. They are designed using finite-difference time-domain (FDTD) simulation, fabricated using focused ion beam etching and characterised using angular Fourier spectroscopy. The aperture arrays are formed in the top layer of an aluminum-silica-aluminum trilayer and produce a maximum simulated field intensity enhancement of 5.8 times at 406nm and highly directive emission with a beamwidth of 8.3 deg. The normal incidence reflection response has been measured and shows reasonable agreement with modelled results. In addition, to investigate higher field intensity enhancements, bowtie aperture arrays are simulated and the influence of parameters such as dielectric gap, position of dipole source, and aperture shape and size are discussed and show enhancements up to 67 times are possible.

Review: New sensors and data-driven approaches—A path to next generation phenomics

“…Despite the potential of hyperspectral cameras for estimating biochemical composition of plants, its applicability to sensing elements and micro-elements is very limited given that they do not have specific spectral absorption features. UV fluorescence emission from a material could lead to the development of next generation sensitive and inexpensive fluorescence scanners [36] for phenotyping concentration of elements in plants. Through correct design, integrated sensors with capacity of strong fluorescence capture are on their way, which may be very useful for high-throughput field screening of nutritional components and micro-elements.…”

“…The retrieval of meaningful data from imaging sensors usually involves some degree of pre-processing. Among them we can find: calibrations, geo-referencing, orthorectification, pattern recognition, 3D reconstruction and machine learning [[36], [37], [38], [39]]. Images collected from aerial platforms require geometric and radiometric correction.…”