The coherence length is a quantitative measure of the path difference between two arms of an interferometer over which the light wave is still able to generate some interference pattern.

The coherence length of a light source is inversely proportional to the width of its emission spectrum. Due to its large bandwidth, an SLED has a much shorter coherence length than a laser. Typically, values for the coherence length of SLED may vary between 5mm and 40mm.

Please download our Applications Notes for more detail on the coherence properties of our SLEDs.