Free-Space–Coupled Frequency-Locked Microtoroid Resonators for Ultrasensitive Gas-Phase Detection
Happy to share our latest paper in Laser & Photonics Reviews.
We demonstrate free-space–coupled, frequency-locked microtoroid resonators for gas sensing—overcoming the long-standing limitation of fragile fiber tapers and moving WGM sensors closer to real-world use.
We accomplished:
• 25 ppt detection limit at room temperature
• >10⁷ Q factors preserved after polymer coating
• 3 orders of magnitude improvement over prior work
• Compact, robust, and capable of long-duration, unattended sensing
Using a mustard gas simulant (2-CEES), we show that ultrahigh sensitivity and real-world robustness can coexist.
This is the first demonstration of free-space–coupled WGM microtoroids for chemical sensing, opening new opportunities in defense, security, and environmental monitoring.
Thanks to our excellent collaborators and generous sponsors.