Science Illustrated

TOP 5 · What colour of laser is the most powerful?

-

Purple: 380-450 nanometres

Energy per photon: 3.3 MeV. The energy of a light particle (photon) intensifie­s with its wavelength. The shortest wavelength­s that the human eye can identify is about 390 nanometres (nm), correspond­ing to a purple colour. BLUE 450-495 nm 2.8 MeV Although blue laser includes less energy per photon than purple, it is more hazardous to eyes. The eyes absorb more light with increasing wavelength­s. GREEN 495-570 nm 2.5 MeV Green laser is the most harmful. Our vision is better at perceiving green hues than other colours, as the eyes absorb more light at such wavelength­s. YELLOW-ORANGE 570-620 nm 2.2 MeV RED 620-750 nm 2 MeV Eye surgeons use yellow lasers to stop bleeding in the retina at the back of the eye. 577 nm light is absorbed by the blood, boosting coagulatio­n. The safest laser colour is red. At 700+ nm, the eyes cannot detect the light, which is known as infrared and can only be seen with a thermal camera.

 ??  ??

Newspapers in English

Newspapers from Australia