Selectivity of glycerol droplet microresonator humidity sensor

Lase Milgrave; Pauls R. Kristaps; Inga Brice; Janis Alnis; Aigars Atvars

doi:10.1117/12.2621124

17 May 2022 Selectivity of glycerol droplet microresonator humidity sensor

Lase Milgrave, Pauls R. Kristaps, Inga Brice, Janis Alnis, Aigars Atvars

Proceedings Volume 12139, Optical Sensing and Detection VII; 121390F (2022) https://doi.org/10.1117/12.2621124
Event: SPIE Photonics Europe, 2022, Strasbourg, France

Abstract

We have created a highly sensitive humidity sensor that is based on glycerol droplet. Glycerol is hygroscopic and has a specific glycerol-water ratio for every relative humidity (RH) %. It is cheap and environmentally friendly. We use the droplet as a whispering gallery mode (WGM) microresonator. WGMs are known for their high Q factors, which lead to high sensitivity and precision. As RH changes, the resonant wavelength shifts due to a change in the droplet’s radius and refractive index. We have successfully created an experimental set-up and original data analysis method that allow us to follow the resonant wavelength shift in real-time. Results show that the sensor has an average sensitivity of 2.85 nm/% RH in the 50–70 % RH range, it is stable and has a long lifetime. To further investigate the properties of the glycerol droplet sensor, we tested its selectivity and tried two coupling methods (free-space and tapered fiber). We decided to test the sensor’s response to two different gases – ethanol and acetone. Results show that glycerol is highly selective and does not absorb ethanol/acetone molecules, meaning that it can be used for trustworthy humidity measurements.

Conference Presentation

Citation Download Citation

Lase Milgrave, Pauls R. Kristaps, Inga Brice, Janis Alnis, and Aigars Atvars "Selectivity of glycerol droplet microresonator humidity sensor", Proc. SPIE 12139, Optical Sensing and Detection VII, 121390F (17 May 2022); https://doi.org/10.1117/12.2621124

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available