Rapid On-Site Formation of a Free-Standing Flexible Optical Link for Sensing Applications

• Published in: Sensors (Basel, Switzerland) Vol. 16; no. 10; p. 1643
• Main Author: Barrios, Carlos Angulo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05.10.2016; MDPI
• Subjects: Aluminum; Detection; Devices; diffraction gratings; Formations; Geometry; Gratings (spectra); guided waves; Light emitting diodes; Links; liquid detection; micro-optical devices; optical links; optical sensors; Optoelectronic devices; plastic waveguides; Process controls; Sensors; Waveguides; Madrid Spain; Spain; optical links; guided waves; liquid detection; optical sensors; diffraction gratings; micro-optical devices; plastic waveguides
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s16101643

An optical link, based on a conventional Scotch tape waveguide, for sensing applications requiring rapid on-site assembly is proposed and demonstrated. The flexible waveguide contains an integrated aluminum one-dimensional grating coupler that, when stuck on the radiative surface of a light emitting device, allows light to be coupled in and transmitted through the tape, whose tip end is, in turn, adhered onto the photosensitive surface of a photodetector. The (de)coupling approaches exhibit high alignment tolerances that permit the formation of a free-standing flexible optical connection between surface-normal optoelectronic devices without the need of specialized equipment. As the first demonstration of a sensing application, the proposed optical link is easily configured as a cost-effective intensity-based refractometric sensor for liquid detection, which can be applicable to on-site quality and process control of, for example, beverages.