Harnessing spectral property of dual wavelength white LED to improve vertical scanning interferometry

Unlike a conventional white light source that emits a continuous and broad spectrum of light, the dual wavelength white light emitting diode (LED) generates white light by mixing blue and yellow lights, so there are two distinct peaks in its intensity spectrum. Prior works had shown that the spectra...

Full description

Bibliographic Details
Main Authors: Chong, Wee Keat, Soh, Yeng Chai, Li, Xiang
Other Authors: School of Electrical and Electronic Engineering
Format: Journal Article
Language:English
Published: 2013
Subjects:
Online Access:https://hdl.handle.net/10356/98025
http://hdl.handle.net/10220/12231
Description
Summary:Unlike a conventional white light source that emits a continuous and broad spectrum of light, the dual wavelength white light emitting diode (LED) generates white light by mixing blue and yellow lights, so there are two distinct peaks in its intensity spectrum. Prior works had shown that the spectral property of the dual wavelength white LED can affect the vertical scanning interferometry negatively if the spectral effects are not compensated. In this paper, we shall examine this issue by modeling the spectral property and variation of the dual wavelength white LED, followed by investigating its effects on the interference signal of vertical scanning interferometry. Instead of compensating the spectral effects of the dual wavelength white LED, we harness its spectral property to improve the performance of a phase-based height reconstruction algorithm in vertical scanning interferometry.