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Spectrum sampling reflectometer
Author(s) -
Henrie Justin,
Parsons Earl,
Hawkins Aaron R.,
Schultz Stephen M.
Publication year - 2005
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2051
Subject(s) - light emitting diode , wavelength , sampling (signal processing) , optics , diode , materials science , optoelectronics , electromagnetic spectrum , detector , physics
In this work we demonstrate that the semi‐continuous wavelength spectrum used by a reflectometer for thin‐film determination can be replaced by a small set of fixed‐wavelength sources. We demonstrate how this spectrum sampling reflectometer (SSR) can be implemented with low‐cost visible light‐emitting diodes (LEDs). A detailed analysis of the system is provided, showing how measurement error and the number of sources affect accuracy. A bench‐top SSR was constructed that consisted of five low‐cost LEDs with central wavelengths that ranged from 450 to 650 nm. Thickness measurements of the SSR were compared with measurements made by other commercially available equipment with <5% variation. Copyright © 2005 John Wiley & Sons, Ltd.