Multichannel Goniospectrometer System for Near-Field and Far-Field Light Spatial Distribution

Abstract

The spatial distribution of light sources plays an important role for the secondary optical design of luminaires. Existing spatial detection methods suffer limitations such as large volume, slow speed, and low flexibility. In this work, we proposed a compact size, multichannel spatial spectral distribution detection system for light sources, compatible with both near- and far-fields. Sixteen-channel optical fibers with pulley blocks mounted on double U-shaped tracks enable multiple points highly efficient detection of spatial irradiance distribution of light sources. With spectrum-based Monte Carlo ray-tracing algorithm, the far-field spectral and spatial distribution at arbitrary distances, along with detailed photometric and colorimetric parameters, are derived for both spherical- and planar-receiving surface scenes. Compared with reference systems, series of experiments are conducted with six types of light-emitting diode (LED) samples, from LED chip to street lamp, to validate the accuracy, consistency, and flexibility of the proposed system, and satisfactory results are gained. Overall, the proposed system is characterized by compact size, high speed, flexibility, and compatibility for various light sources and scenarios.