Relationship between Peak Wavelength and Dominant Wavelength of Light Sources Based on Vector-Based Dominant Wavelength Calculation Method

ABSTRACT

Curve fitting and lookup table methods based on vector relationships are proposed to compute dominant wavelength (DW), which is used to characterize hue. A curve-fitting method using a DW–angle relationship is simple but not very accurate, with an error of about 1 to 2 nm. A lookup table method is proposed for higher precision. The methods have been applied to study the relationships between peak wavelength and DW for Gaussian models of light sources’ spectra. For Gaussian models, DW varies as full-width at half maximum (FWHM) increases from 5 to 500 nm, and the trends differ at different peak wavelengths. For purity, as peak wavelength changes from 430 to 530 nm, the purity’s decreasing rate monotonically increases with FWHM, whereas as peak wavelength changes from 530 to 680 nm, the purity’s decreasing rate monotonically decreases with FWHM. Peak wavelength contours and FWHM contours are drawn for determination of DW and purity. The results should be useful for estimating DW (hue) of the Gaussian models of light sources’ spectra, which can guide the spectral design of light sources.

• curve fitting
• dominant wavelength
• FWHM
• peak wavelength
• vector calculation

ACKNOWLEDGMENT

The work is supported by the Science Fund of Shenzhen University and by a key project of the National Natural Science Foundation of China under project no. 51278309.