OSA: Measurement of Chromaticity Coordinates and Dominant Wavelength of Visible Light

Visible light evaluation may require evaluation based on not only the physical characteristics of light but also the sensitivity characteristics of the human eye. That is because the color of light is determined by the product of the spectral radiance of the light source and the spectral luminosity of the eye of the viewer. The International Commission on Illumination (CIE) defines three color matching functions (x‾(λ), y‾(λ), z‾(λ)) corresponding to the spectral response of the human eye. When measuring a light source, the respective outputs through these color matching functions are represented by X, Y, and Z. This is called the tristimulus value.

The applicable models measure the optical spectrum using a monochromator, calculate the tristimulus values X, Y, Z according to JIS Z 8701 (Color matching function based on the 2-degree visual field), and obtain the chromaticity coordinates x, y, z based on CIE 1931 (Color display method). The CIE chromaticity diagram and the dominant wavelength can be obtained using the COLOR analysis function in [Analysis 2]. The CIE chromaticity diagram and the dominant wavelength can be obtained using the COLOR analysis function in [Analysis 2].