New Computational Methodologies Enable SSL to Measure and Self-Adjust Based on Conditions

May 6, 2019

An article published in the SPIE journal Optical Engineering, “Arbitrary spectral matching using multi-LED lighting systems,” marks a substantial advance in lighting science and technology. In their paper, the researchers announce a two-pronged approach to both measure and self-adjust the spectral power distributions (SPDs) of LED lighting systems. Their methodology demonstrates the system’s ability to maintain consistency and stability over an extended period of time.

Solid state lighting (SSL) can be used to enhance our vision, sleep patterns, and wellbeing. SSL benefits are evident across their wide use in residences and offices as well as across industrial and commercial sectors, including the ongoing development of applications in medicine, imaging, agriculture, communication, transportation, and museum lighting. Some of these applications require highly precise light spectra that don’t produce optical power variations or shifts in colour over time.

The four graphs show the best fit (blue solid line) to daylight D65 (a), an incandescent spectrum (b), the Melanopic (c) and a white LED spectrum (d) (Ph-LED YAG) (dashed black lines) made by optimizing the weights of the 10 different channels of the LED light engine (coloured dash-dot lines). In all cases the spectra were normalized and are shown in arbitrary units.

The open-access paper addresses two challenges: how to keep temperature changes and age-based deterioration from impacting a light emission’s strength, consistency, and colour, as well as providing a reliable, internal, self-monitoring method.

The authors use a fast-computation, high spectral fidelity algorithm to determine channel weights of a targeted SPD; in conjunction with that method, an internal microprocessor provides a closed-loop control system that monitors and corrects the spectral output, compensating for shifts due to temperature changes or LED wear and tear. The authors’ use of a general framework for multi-channel SSL systems ensures the universal applicability of their findings across different lighting technologies.

According to Optical Engineering Associate Editor, SPIE Senior Member, and U.S. Air Force Research Laboratory Technical Advisor Daniel A. LeMaster, the research showcases significant advances in terms of lighting technologies, “This method to monitor and quickly compensate for the colorimetric issues that arise from junction heating and LED aging will be of great utility in the global LED lighting market.”

The article authors are Aleix Llenas, of the Catalonia Institute for Energy Research (IREC) and Ledmotive Technologies, Spain, and Josep Carreras, of Ledmotive Technologies.

Michael T. Eismann, an SPIE Fellow and senior scientist at the U.S. Air Force Research Lab, is the editor-in-chief of Optical Engineering. The journal is published in print and digitally by SPIE in the SPIE Digital Library, which contains more than 500,000 publications from SPIE journals, proceedings, and books, with approximately 18,000 new research papers added each year.

About SPIE

SPIE is the international society for optics and photonics, an educational not-for-profit organization founded in 1955 to advance light-based science, engineering, and technology. The society serves 257,000 constituents from 173 countries, offering conferences and their published proceedings, continuing education, books, journals, and the SPIE Digital Library. In 2018, SPIE provided more than US$4 million in community support including scholarships and awards, outreach and advocacy programs, travel grants, public policy, and educational resources; www.spie.org.

This article was first published online by SPIE, the International Society for Optics and Photonics;spie.org/about-spie/press-room/press-releases/solid-state-lighting-self-adjusts-based-on-conditions.

Related Articles


Changing Scene

  • Contact Delage & Solvic Announce New Representation Partnership

    New Collaboration – A New Solar Lighting Manufacturer Joins Contact Delage’s Offerings

    Contact Delage is excited to announce the addition of a new trusted partner to their lineup: Solvic, an innovative manufacturer specializing in solar lighting. This new partnership reflects Contact Delage’s ongoing commitment to offering sustainable, high-performance solutions tailored to real-world applications. With Solvic, they are expanding their range of autonomous solar products—perfect for lighting streets, parks,… Read More…

  • July 10, 2025 - Mac’s II Agencies Announce Addition to Project & Specification Sales Team

    Mac’s II Agencies Announces Addition to Project & Specification Sales Team

    Mac’s II Agencies is pleased to announce that Drazen Jerkovic will be joining their Project & Specification Sales team in the Lighting Division later this fall. With over 25 years of experience in the lighting and electrical industry, Drazen is a highly respected consultant known for his technical knowledge and deep understanding of project delivery. His recent role… Read More…


Design


New Products

  • Prolux: Lumithree PT-1016 Glass Diffuser Pendant

    Prolux: Lumithree PT-1016 Glass Diffuser Pendant

    The PT-1016 is a glass diffuser that can be mounted in any room to provide an elegant touch. The diffuser comes in several translucent finishes to match any decor, and the hardware is available in a variety of powder-coated colours. Lumithree’s quality decorative lighting solutions offer their customers a diverse range of unique and flexible… Read More…

  • Magic Lite: Tri-Proof Lights

    Magic Lite: Tri-Proof Lights

    Tri-Proof Lights are a durable lighting solution that can replace traditional linear fluorescent luminaires. Tri-Proof Lights are designed for a variety of applications requiring, dust-, moisture- and impact-resistance. Suitable environments such as corridors, stairwells, warehouses, parking garages and car washes allows this versatile fixture in a variety of applications. Read More…