Share Email Print
cover

Proceedings Paper

Thin film thickness variation measurement using dual LEDs and reflectometric interference spectroscopy model in biosensor
Author(s): Yunfeng Ling; Nan Wu; Wenhui Wang; Leslie Farris; Byungki Kim; Xingwei Wang; Melisenda J. McDonald
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper 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.

Paper Details

Date Published: 24 February 2010
PDF: 7 pages
Proc. SPIE 7559, Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications X, 75590K (24 February 2010); doi: 10.1117/12.842612
Show Author Affiliations
Yunfeng Ling, Univ. of Massachusetts Lowell (United States)
Nan Wu, Univ. of Massachusetts Lowell (United States)
Wenhui Wang, Univ. of Massachusetts Lowell (United States)
Leslie Farris, Univ. of Massachusetts Lowell (United States)
Byungki Kim, Univ. of Massachusetts Lowell (United States)
Xingwei Wang, Univ. of Massachusetts Lowell (United States)
Melisenda J. McDonald, Univ. of Massachusetts Lowell (United States)


Published in SPIE Proceedings Vol. 7559:
Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications X
Israel Gannot, Editor(s)

© SPIE. Terms of Use
Back to Top