In this work, a drop-and-measure optofluidic platform that exploits capillary microfluidic concepts to infiltrate high-aspect-ratio (HAR) one-dimensional (1D) silicon/air photonic crystals (PhCs), this latter being used as sensing ele-ments, is reported. The platform, which is fabricated by electrochemical micromachining (ECM) technology, is op-tically characterized by measuring PhC reflectivity spectra upon capillary infiltration of liquids with different refrac-tive indices into the PhC air-gaps. Fiber grooves integrated in the platform allow the measurements to be carried out using optical fibers positioned in front of the PhC. Good reliability, sensitivity, and limit of detection are obtained, with best sensitivity value of 310 nm/RIU and worst-case limit of detection of 10-3 RIU, which are comparable to pressure-driven state-of-the-art integrated refractometers.
HIGH-ASPECT-RATIO PHOTONIC CRYSTALS FOR CAPILLARY OPTOFLUIDICS: TOWARDS DROP-AND-MEASURE PLATFORMS
BARILLARO, GIUSEPPE
2014-01-01
Abstract
In this work, a drop-and-measure optofluidic platform that exploits capillary microfluidic concepts to infiltrate high-aspect-ratio (HAR) one-dimensional (1D) silicon/air photonic crystals (PhCs), this latter being used as sensing ele-ments, is reported. The platform, which is fabricated by electrochemical micromachining (ECM) technology, is op-tically characterized by measuring PhC reflectivity spectra upon capillary infiltration of liquids with different refrac-tive indices into the PhC air-gaps. Fiber grooves integrated in the platform allow the measurements to be carried out using optical fibers positioned in front of the PhC. Good reliability, sensitivity, and limit of detection are obtained, with best sensitivity value of 310 nm/RIU and worst-case limit of detection of 10-3 RIU, which are comparable to pressure-driven state-of-the-art integrated refractometers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
