The light source is the core component of any solar simulator. It determines the spectral distribution, irradiance level, and overall performance of the system.
Several types of light sources have been used in solar simulators. Among them, xenon arc lamps and LEDs are currently the most widely adopted technologies.
Xenon arc lamps produce a continuous spectrum that resembles natural sunlight over a wide wavelength range. Because of this property, xenon lamps have long been used in solar simulator systems for photovoltaic testing and solar materials research.
LEDs generate light at specific wavelengths. By combining multiple LEDs with carefully selected wavelengths, it is possible to construct a light source that approximates the solar spectrum. This approach allows flexible control of spectral composition.
Although other types of lamps have been used historically, modern solar simulator design mainly focuses on xenon and LED technologies because of their performance and controllability.