 Near-infrared window in biological tissue

The near-infrared (NIR) window in biological tissue refers to a specific range of wavelengths in the near-infrared spectrum where biological tissues are relatively transparent to light. This window typically ranges from about 700 nanometers (nm) to 1100 nm. In this range, the absorption and scattering of light by water, hemoglobin, and other biological chromophores are minimized, allowing for deeper penetration of light into tissues.