Jun 13 – 19, 2015
University of Alberta
America/Edmonton timezone
Welcome to the 2015 CAP Congress! / Bienvenue au congrès de l'ACP 2015!

Silicon Nitride microdisk resonators as refractometric sensors in water

Jun 17, 2015, 9:45 AM
CCIS L1-047 (University of Alberta)

CCIS L1-047

University of Alberta

Oral (Student, In Competition) / Orale (Étudiant(e), inscrit à la compétition) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) W1-6 Devices (DCMMP) / Dispositifs (DPMCM)


Callum Doolin (University of Alberta)


Optical microdisks are intriguing devices due to their small size, compatibility with standard planar micro/nano-fabrication techniques, and ability to support high-Q whispering gallery modes. We fabricate and explore the use of thin (130 nm) Si$_3$N$_4$ disks with diameters of 15 - 30 μm as refractive index sensors, using a dimpled-tapered fiber to couple with the optical modes under water. The thin disks cause evanescent fields to extend far into the surrounding medium, providing large shifts of > 200 nm/refractive index units (RIU) of the optical modes in response to Lithium salts added to the environment. Loaded quality factors of ~$10^4$ let the resonant frequencies to be determined with great accuracy, providing a limit of detection near $10^{-6}$ RIU, comparable with state-of-the-art RI sensors.

Primary author

Callum Doolin (University of Alberta)


Ms B Lewis (University of Alberta) Mr John Davis (University of Alberta) Mr P Doolin (University of Alberta)

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