Why are LEDs not considered true laser therapy devices?

The reason LEDs are not considered true laser therapy devices lies in their lack of coherence. Coherence in this context refers to the property of laser light that allows it to remain focused over distances with very little divergence. Laser beams are highly directional and maintain a consistent phase relationship, which is crucial for therapeutic effectiveness.

In contrast, LEDs emit light that is incoherent, meaning the light waves are not synchronized in phase and do not travel in the same direction. This incoherence results in a broader spectrum of light being emitted and causes the light to spread out more quickly than laser light. Consequently, while LED light can still have some therapeutic effects, they lack the precision and focused energy delivery that characterizes laser therapy.

Understanding this fundamental difference helps clarify why lasers are chosen for specific therapeutic applications over LEDs, particularly in contexts where targeted energy delivery is essential for effective treatment results.