Figure 1.
Near-infrared light passes through skin and skull readily and is absorbed by certain biological molecules in the brain. A "biological spectroscopic window" exists at the wavelength range 660 - 940 nm.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.