405nm
405 nanometers is a wavelength of light in the visible spectrum that falls within the violet portion of that spectrum. It lies just below the ultraviolet region, with wavelengths shorter than 405 nm being classified as ultraviolet-B. In terms of frequency, 405 nm corresponds to about 741 terahertz. The light at this wavelength is perceivable to the human eye as a strongly blue–violet hue and has a relatively high photon energy compared to longer visible wavelengths.
Because of its position just below the ultraviolet range, 405‑nm light can be used in applications that
Health considerations differ from those of ultraviolet lasers. While 405‑nm photons carry less energy than UV,