LED-based Vis-NIR spectrally tunable light source - the optimization algorithm

Abstract

Background: A novel numerical method for calculating the contributions of individual diodes in a set of light emitting diodes (LEDs), aimed at simulating a blackbody radiation source, is examined. The intended purpose of the light source is to enable calibration of various types of optical sensors, particularly optical radiation pyrometers in the spectral range from 700 nm to 1070 nm. Results: This numerical method is used to determine and optimize the intensity coefficients of individual LEDs that contribute to the overall spectral distribution. The method was proven for known spectral distributions: "flat" spectrum, International Commission on Illumination (CIE) standard daylight illuminant D65 spectrum, Hydrargyrum Medium-arc Iodide (HMI) High Intensity Discharge (HID) lamp, and finally blackbody radiation spectra at various temperatures. Conclusions: The method enables achieving a broad range of continuous spectral distributions and compares favorably with other methods proposed in the literature.

Divalent europium-doped near-infrared-emitting phosphor for light-emitting diodes

“…However, the low efficiency, poor stability or complex fabrication technique restrict their development. As a contrast, the high luminous efficiency, long operating life, and compact sizes make NIR LEDs useful, however, a narrow full-width at half maximum (FWHM) below 50 nm seriously limit their applications in 3D sensing, food analyzing, and other specific fields 8 . Therefore, discovery of broadband-emitting NIR light sources is a necessary and urgent requirement.…”

Cr3+‐Doped Broadband NIR Garnet Phosphor with Enhanced Luminescence and its Application in NIR Spectroscopy

“…Therefore, a broadband NIR light source was demanded . The NIR light emitting diode (LED) was an ideal alternative for fast response and small volume, but it suffered from narrow emission band (<50 nm) . To solve the problem, broadband NIR phosphor‐converted LED (pc‐LED), inspired by commercial white LED (WLED), was developed.…”

Optimization of a spectrally tunable daylight simulator using four quantum dot light‐emitting diodes for visual appraisal of color

“…These advantages lead to the fact that LEDs could be used for the correlated color temperature (CCT) tunable white LEDs, as well as the spectral tunable daylight simulators, which manifest their great potential to replace daylight simulators that use traditional sources. Some LED‐based spectrally tunable daylight simulators made using multichannel LEDs have been reported . However, their control and adjustment systems were extremely complex and expensive as a result of using a large number of LEDs.…”

“…Some LED-based spectrally tunable daylight simulators made using multichannel LEDs have been reported. [9][10][11][12][13][14][15] However, their control and adjustment systems were extremely complex and expensive as a result of using a large number of LEDs. In addition, there were significant differences between the colorimetric performances (such as chromaticity, color rendition, and CIE metamerism) of the daylight simulator and that of the standard daylight illuminant.…”