Microresonators for Compact Optical Sensors

Project Overview

As the demand for continuous, in-situ surveillance of health of systems and environments rapidly increases, miniaturized sensors with fast responses are sought. Optical dielectric resonators supporting whispering gallery modes (WGMs) have exceptional properties, like very high-power density, very narrow spectral linewidth, and extremely small mode volume. As the footprint of these sensors is drastically reduced, measurements of microvolume samples with dramatic reduction in analysis time are possible, enabling large numbers of parallel analyses using microarrays. The high sensitivity and speed of WGM resonators combined with the ability to detect molecules in their native state have great future potential for basic and applied research such as reliable single molecule, trace-gas detection, environmental monitoring, chemical threat sensing, and biodefense. Such appealing peculiarities motivated us developing WGM resonators (WGMRs) for cavity enhanced absorption spectroscopy (CEAS) for chem-bio detection. Specifically, we designed and batch-fabricated microspheres and fiber tapers for resonances excitation. We successfully detected gases (nitrogen and carbon dioxide) in customized environmental chambers, and microorganisms (Inf. A and E. Coli) with integrated microfluidic systems. Background calibration and environmental isolation were always accounted for in proving the performances.

Mission Impact

The technology can lead to the development of a miniature and fieldable platform for real-time gas phase detection. A persistent surveillance capability is relevant to NNSA's stockpile stewardship mission and Lawrence Livermore National Laboratory's Weapons and Complex Integration principal associate directorate for assessing the conditions within the stockpile. With an embedded chemical sensor, high-fidelity systems could be characterized and monitored without disassembly, and aging experiments conducted efficiently without disruption or perturbation due to sample collection. Microresonators for complex optical systems (μRCOS) can also play a key role for Livermore's earth and atmospheric science core competency for monitoring air quality in the evapotranspiration cycles. Finally, it can be impactful in Livermore's bioscience and bioengineering core competency for food safety and clean-up.

Publications, Presentations, and Patents

L. Echeveria et al., "Microsphere Resonators for Biodetection." TechConnect 2021.

B. Demory et al., "Progress on optical microspheres for CO2 sensors." SPIE LASE Proceedings (11672), 2021.

Echeveria L., et al., "Versatile Bio-Organism Detection using Microspheres for Future Biodegradation and Bioremediation Studies." SPIE LASE Proceedings (11266F), 2020.

Singh P., et al., "Microresonators for compact optical sensors (μRCOS) for gas detection." SPIE LASE Proceedings (11266E), 2020.

IL-134890, "Method for fast and efficient fiber tapering," T.C. Bond et al., submitted as patent 08/31/21.