A microring resonator sensor device for sensitive detection of the explosive 1,3,5-trinitrotoluene (TNT) is presented. It is based on the combination of a silicon microring resonator and tailored receptor molecules.
We investigate a highly sensitive optical sensor based on two cascaded microring resonators exploiting the Vernier effect. The architecture consists of two microrings with a slight difference in their free spectral ranges. This allows the generation of the Vernier effect for achieving ultra-high sensitivities. The sensor chip was fabricated using a silicon nitride platform and characterized with isopropanol/ethanol mixtures. A sensitivity of 0.95 nm/% was found for isopropanol concentrations in ethanol ranging from 0% to 10%. Furthermore, a collection of measurements was carried out using aqueous sodium chloride (NaCl) in solutions of different concentrations, confirming a high sensitivity of 10.3 nm/% and a bulk refractive index sensitivity of 6,317 nm/RIU. A limit of detection of 3.16 × 10−6 RIU was determined. These preliminary results show the potential features of cascaded silicon nitride microring resonators for real-time and free-label monitoring of biomolecules for a broad range of applications.
An optical device operating at wavelengths around 1.3 µm and 1.5 µm is demonstrated experimentally. It is based on cascaded microring resonators (CMRRs) and the Vernier effect (VE). The architecture consists of two microring resonators (MRRs) connected via a common waveguide; two waveguides were added for the interrogation of CMRRs. The free spectral ranges of both MRRs are slightly different in order to activate the VE, which is known to enhance the sensitivity in optical sensors. CMRRs were fabricated on a silicon nitride (SiN) platform. Two types of buffer layers-benzocyclobutene (BCB) polymer and thermal silicon oxide (SiOx)-were tested. A study of CMRRs was carried out with three structures of different structural parameters. The experimental results show good agreement with the theoretical analysis. This approach is promising for the fabrication of highly sensitive optical sensors in wide operating wavelength range.
There is growing demand for robust, reliable, low cost, and easy to use sensor systems that feature multiparameter analysis in many application areas ranging from safety and security to point of care and medical diagnostics. Here, we highlight the theory and show first experimental results on a novel approach targeting the realization of massively multiplexed sensor arrays. The presented sensor platform is based on arrays of frequency-modulated integrated optical microring resonators (MRR) fed by a single bus waveguide combined with lock-in detection to filter out in a reliable and simple manner their individual response to external stimuli. The working principle is exemplified on an array of four thermo-optically modulated MRR. It is shown that with this technique tracking of individual resonances is possible even in case of strong spectral overlap.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.