A novel miniaturized mid-IR sensor for glucose detection using on-chip plasmonics and quantum cascade detectors

Abstract

Mid-infrared optical sensors integrating plasmonic waveguides and quantum cascade optoelectronics are an emerging field of research leading to promising results in chemical sensing, environmental monitoring, and biomedical diagnosis. In this work, we investigate TiO2 as waveguiding material for mid-infrared surface plasmon polariton waveguides and show its potential for integrated sensors. Simulations reveal suitable TiO2 dimensions and diffraction grating couplers for ~4.3 µm light. Following these theoretical considerations, we fabricated such devices monolithically integrated with quantum cascade detectors (QCDs) and present their characterization. We further discuss their application in innovative biosensing experiments including glucose detection.