Wavelengths ,colors,lasers

Wavelengths ,colors and laser pointers

Different lasers have different colors, as they have the different wavelength. The green laser pointer has 532nm light wavelength, that's why it's green. There are many other colors such as red, violet, blue, yellow.  The following table show the wavelengths and colors.

Spectral colors

violet 668–789 THz 380–450 nm

blue 631–668 THz 450–475 nm

cyan 606–630 THz 476–495 nm

green 526–606 THz 495–570 nm

yellow 508–526 THz 570–590 nm

orange 484–508 THz 590–620 nm

red 400–484 THz 620–750 nm

That means if a laser is 620nm–750 nm, it’s red.  495nm-570nm, it’s green, 380nm-450nm, it’s violet. However the modern laser technology is mainly focus on 405nm laser, 530nm laser, 473nm laser, 650nm laser. A green laser pointer is green , as its wavelength is 532nm. The red laser pointer is 650nm laser, and the violet laser pointer has 405nm laser beam.  There are some invisible laser , they don’t have colors, but they also have wavelength. The wavelength is < 390nm or > 750nm.  If you understand the relationships between wavelengths ,colors and laser pointers, you will know the wavelength, even the Hz, while you’re playing some colors laser pointers.