Low-cost vertical taper for highly efficient light in-coupling in bimodal nanointerferometric waveguide biosensors
Grajales García, Daniel (Institut Català de Nanociència i Nanotecnologia)
Fernandez-Gavela, Adrian (Institut Català de Nanociència i Nanotecnologia)
Dominguez, Carlos (Institut de Microelectrònica de Barcelona)
Sendra Sendra, José Ramón (Universidad de Las Palmas de Gran Canaria)
Lechuga, Laura M (Institut Català de Nanociència i Nanotecnologia)

Date:	2019
Abstract:	There is still the need for a compact and cost-effective solution for efficient light in-coupling in integrated waveguides employed in photonic biosensors, especially when these waveguides are of submicron dimensions and operate at visible wavelengths. The employment of a vertically stacked taper with a larger input area is proposed to meet this need. The design of the taper is divided into two stages: in the first stage, light is guided downwards by two vertically stacked tapers; in the second stage, an inverted taper directly confines the light inside the waveguide. The design parameters are optimized using commercial software, obtaining a total theoretical light coupling efficiency of 72. 25%. The taper is manufactured using SU-8 polymer as the main material, employing standard photolithography techniques at wafer level. After characterization, the results show the practicality of the taper when coupling light from macrometric sources to nanometric waveguides, obtaining an experimental coupling efficiency of 55%. With this vertical taper, a compact, easy-to-couple and cost-effective solution is achieved for waveguide-based biosensors operating at visible wavelengths, opening the way for a truly portable point-of-care biosensor for low-cost and label-free diagnostics.
Grants:	Ministerio de Economía y Competitividad SEV-2013-0295
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Integrated optics ; Biosensor ; Interferometer ; Light coupling ; Photonic devices
Published in:	JPhys Photonics, Vol. 1, Núm. 2 (February 2019) , art. 25002, ISSN 2515-7647

DOI: 10.1088/2515-7647/aafebb

13 p, 1.4 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles