At what wavelength is the best penetration reached?

The best penetration of laser light into biological tissues is typically achieved at around 800 nm. This wavelength falls within the near-infrared (NIR) range, where water absorption is relatively low compared to shorter wavelengths. At this range, laser light can penetrate deeper into tissues without significant scattering or absorption, which are crucial for effective therapeutic applications.

The 800 nm wavelength allows laser energy to reach deeper layers of the skin and underlying tissues, making it particularly useful for treating conditions such as pain, inflammation, and tissue healing. Those involved in low-level laser therapy (LLLT) and Class IV laser systems often prefer this wavelength due to its optimal balance of penetration depth and therapeutic efficacy.