Thin film thickness variation measurement using dual LEDs and reflectometric interference spectroscopy model in biosensor

Yunfeng Ling; Nan Wu; Wenhui Wang; Leslie Farris; Byungki Kim; Xingwei Wang; Melisenda J. McDonald

doi:10.1117/12.842612

24 February 2010 Thin film thickness variation measurement using dual LEDs and reflectometric interference spectroscopy model in biosensor

Yunfeng Ling, Nan Wu, Wenhui Wang, Leslie Farris, Byungki Kim, Xingwei Wang, Melisenda J. McDonald

Author Affiliations +

Proceedings Volume 7559, Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications X; 75590K (2010) https://doi.org/10.1117/12.842612
Event: SPIE BiOS, 2010, San Francisco, California, United States

Abstract

The potential of thin film thickness variation measurement method, reflectometric interference spectroscopy (RIfS), for a compact label-free biosensor is investigated. A model to estimate thickness variation is built based on RIfS. A set-up of the sensor having dual Light Emitting Diodes (LEDs) and one photo detector are introduced. To verify the model, sample chips with different thicknesses of silica film layers ranging from 2 to 20nm are used in the experiment. The estimated values are compared with their reference values which are measured by an Atomic Force Microscopy (AFM). Since the chosen LEDs' wavelength is not an ideal one, the comparison shows that the model underestimates the thickness variation. By using dual LEDs and a photo detector with the reliable model, the handheld device for transparent thin film measurement will become practical.

Citation Download Citation

Yunfeng Ling, Nan Wu, Wenhui Wang, Leslie Farris, Byungki Kim, Xingwei Wang, and Melisenda J. McDonald "Thin film thickness variation measurement using dual LEDs and reflectometric interference spectroscopy model in biosensor", Proc. SPIE 7559, Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications X, 75590K (24 February 2010); https://doi.org/10.1117/12.842612

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