2020/03/24 by Giuseppe Antonacci, Antonacci, Giuseppe, Jeroen Goyvaerts +9 · 2 citations
Engineering · Physics and Astronomy · #Advanced Fiber Optic Sensors #Applied Physics (physics.app-ph) #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Mechanical and Optical Resonators #Optics (physics.optics) #Photonic and Optical Devices
paper · pdf · doi:10.48550/arxiv.2004.04260
openalex publication_date 2020/03/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Portable and cost-effective gas sensors are gaining demand for a number of\nenvironmental, biomedical and industrial applications, yet current devices are\nconfined into specialized labs and cannot be extended to general use. Here, we\ndemonstrate a part-per-billion-sensitive refractive index gas sensor on a\nphotonic chip based on silicon nitride waveguides functionalized with a\nmesoporous silica top-cladding layer. Low-concentration chemical vapors are\ndetected by monitoring the output spectral pattern of an integrated\nMach-Zehnder interferometer having one coated arm exposed to the gas vapors. We\nretrieved a limit of detection of 65 ppb, 247 ppb and 1.6 ppb for acetone,\nisopropyl alcohol and ethanol, respectively. Our on-chip refractive index\nsensor provides, to the best of our knowledge, an unprecedented sensitivity for\nlow gas concentrations based on photonic integrated circuits. As such, our\nresults herald the implementation of compact, portable and inexpensive devices\nfor on-site and real-time environmental monitoring and medical diagnostics.\n