History of LS

Five decades of light-source science and smart lighting

From the first Light Sources symposium in 1975 to LS21 in Athens, the conference series has followed the evolution of lighting research, technology, and practice.

Origin

The International Symposium on the Science and Technology of Light Sources

The LS series began as a focused forum for the physics and engineering of light sources. Over time it expanded alongside the field itself, moving from incoherent sources to solid-state, sustainable, smart, and human-centric lighting systems.

Phase 1

The Triennial Era

1975-2010

For the first 35 years, the symposium was held every three years, establishing the fundamental physics and engineering of light sources.

Edition	Year	Location
LS1	1975	Loughborough, United Kingdom
LS2	1978	Sheffield, United Kingdom
LS3	1983	Toulouse, France
LS4	1986	Karlsruhe, Germany
LS5	1989	York, United Kingdom
LS6	1992	Budapest, Hungary
LS7	1995	Kyoto, JapanFirst edition outside Europe
LS8	1998	Greifswald, Germany
LS9	2001	Ithaca, New York, USA
LS10	2004	Toulouse, France
LS11	2007	Shanghai, China
LS12	2010	Eindhoven, Netherlands

Phase 2

The Biennial Era

2012-2018

As LEDs and Solid-State Lighting began to move faster, the symposium increased its frequency to every two years.

Edition	Year	Location
LS13	2012	Troy, New York, USA
LS14	2014	Lake Como, Italy
LS15	2016	Kyoto, Japan
LS16	2018	Sheffield, United Kingdom

Phase 3

The Annual and Modern Era

2022-Present

After a brief disruption due to the global pandemic, the series returned with a renewed focus on Sustainable Smart Lighting and moved to an annual cycle.

Edition	Year	Location
LS17	2022	Toulouse, France
LS18	2023	Mumbai, India
LS19	2024	Eindhoven, Netherlands
LS20	2025	Monastir, Tunisia
LS21	2026	Athens, GreeceUpcoming

Name changes

From Light Sources to Sustainable Smart Lighting

1975

Launched as the Symposium on Incoherent Light Sources.

1970s-2022

Known globally as the International Symposium on the Science and Technology of Light Sources, often abbreviated as "Light Sources" or "LS".

2023-Current

Formally rebranded as the IEEE Sustainable Smart Lighting World Conference to reflect the shift from basic light sources to integrated, smart, and human-centric lighting systems.