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

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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.

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