Red Light Panel Glossary: 14 Terms Explained in Plain Language

The specification of a red light panel is full of short terms. This glossary explains fourteen of them in plain language, with MARS 400 as the example. For how to use the numbers when you compare panels, see the guide to reading the specifications.

Light and wavelengths

Wavelength

The length of one wave of light. For visible light it decides the colour.

Nanometre (nm)

The unit wavelengths are measured in: one billionth of a metre. MARS 400 uses 660 nm and 850 nm.

Visible light

The range the eye can see, from about 400 nm (violet) to about 700 nm (deep red), with sensitivity fading towards the ends.

Red light

Visible light at the red end of the range. In a MARS 400 it comes from the 30 LEDs at 660 nm.

Near-infrared (NIR)

Light just beyond the red end of what the eye sees. In a MARS 400 it comes from the 30 LEDs at 850 nm and looks dim or invisible.

Numbers on the specification

LED

A light-emitting diode, the small light source a panel is built from. MARS 400 has 60.

Power (W)

Watt is a unit of power. Check whether a listing means a nominal electrical rating, measured wall draw or light output. MARS 400’s 82 W is a listed nominal specification, so this guide does not call it measured consumption.

Irradiance

The power of the light arriving at a surface, for each unit of area. It weakens with distance from the panel.

mW/cm²

Milliwatts per square centimetre: the usual unit for irradiance. The MARS 400 specification gives 130 mW/cm² or more at 15 cm.

Using the panel

Cycle

A timed run of the light. MARS 400’s standard cycle is 10 minutes; stop sooner if needed and do not restart it to extend the session.

Mode

The selected light channels: Red, NIR or both on MARS 400. The separate pulse setting makes repeated light bursts; the same timer and eye precautions still apply.

Auto-off timer

A timer that switches the panel off by itself when the cycle ends.

Two phrases you will meet

Red light therapy

A common name for using red and near-infrared light as part of a wellness routine, and the phrase most people search for.

Photobiomodulation

The term researchers use when they study how light of specific wavelengths interacts with living tissue.

See MARS 400 for the full specification, and 660 nm and 850 nm light explained for the two wavelengths.