Development of a Compact-Size Standard Led for Sphere-Spectroradiometer in 2pi Geometry

Abstract

For total luminous flux calibration by sphere-spectroradiometer with small-size integrating sphere in 2 geometry, compact-size LED-based standard source (standard LED) had been developed. The body diameter of the compact-size standard LED is 25 mm that is useful size to be mounted on the 1-inch port equipped in many commercial integrating spheres. The developed compact-size standard LED has sufficient spectral power over the full visible wavelength range using 365 nm UV-LED dies and four types of phosphors. Properties of the compact-size standard LED such as intensity distribution, stability, and reproducibility were also evaluated. The results indicate that the developed compact-size standard LED has good properties as a standard light source for the 2 total spectral radiant flux scale.