Laser Color Visibility
The human eye can see light in the visible spectrum ranging from Red to Violet, i.e. the colours of the rainbow. The eye's sensitivity is non linear, so different colours are perceived at different intensities to the eye. So for the same given power, a 100mW Red laser will appear much dimmer than a 100mw Green laser.The colour the human eye is most sensitive to is a shade of Green which has a wavelength of 555nm.
Wavelength Response Color Typical Source/Application 350 nm 0.00001 UV 380 nm 0.0002 Near UV 400 nm 0.0028 Border UV Nichia violet GaN laser diode 410 nm 0.0074 Border UV Nichia violet GaN laser diode 420 nm 0.0175 Violet 442 nm 0.0398 Violet-blue Violet-blue line of HeCd laser 450 nm 0.0468 Blue 457.5 nm 0.0556 Blue Blue frequency doubled Nd:YVO 457.9 nm 0.0562 Blue Blue line of argon ion lase 473 nm 0.104 Blue Blue frequency doubled Nd:YAG 488 nm 0.191 Green-blue Green-blue line of argon ion laser 500 nm 0.323 Blue-green 510 nm 0.503 Green Emerald green line of copper vapor laser 514.5 nm 0.588 Green Green line of argon ion laser 532 nm 0.885 Green Green frequency doubled Nd:YAG or Nd:YVO 543.5 nm 0.974 Green Green HeNe lase 550 nm 0.995 Yellow-green 555 nm 1.000 Yellow-green Reference (peak) wavelength 567 nm 0.969 Yellow-green Green line of Helium-Mercury laser 568 nm 0.964 Yellow-green Y-G line of some krypton ion lasers 578 nm 0.889 Yellow Gold line of copper vapor laser 580 nm 0.870 Yellow 594.1 nm 0.706 Orange-yellow Yellow HeNe laser 600 nm 0.631 Orange 611.9 nm 0.479 Red-orange Orange HeNe laser 615 nm 0.441 Red-orange Orange line of Helium-Mercury laser 627 nm 0.298 Red-orange Orange line of Gold Vapor Laser 632.8 nm 0.237 Orange-red Red HeNe laser 635 nm 0.217 Orange-red Laser diode (DVD, newer laser pointers) 640 nm 0.175 Orange-red Laser diode (DVD, newer laser pointers) 645 nm 0.138 Orange-red Laser diode (DVD, newer laser pointers) 647.1 nm 0.125 Red Red line of krypton or Ar/Kr ion laser 650 nm 0.107 Red Laser diode (DVD, newer laser pointers) 655 nm 0.082 Red Laser diode 660 nm 0.061 Red Laser diode 670 nm 0.032 Red Laser diode (UPC scanners, old pointers) 680 nm 0.017 Red 685 nm 0.0119 Deep red 690 nm 0.0082 Deep red 694.3 nm 0.006 Deep red Ruby laser 700 nm 0.0041 Border IR 750 nm 0.00012 Near IR 780 nm 0.000015 Near IR CD player/CDROM/LaserDisc laser diode 800 nm 3.7*(10)-6 Near IR Laser diodes for pumping Nd:YAG, Nd:YVO 850 nm 1.1*(10)-7 Near IR Laser diodes for pumping Nd:YAG, Nd:YVO 900 nm 3.2*(10)-9 Near IR Laser diodes for pumping Nd:YAG, Nd:YVO 1,064 nm 3*(10)-14 Near IR Nd lasers (including YAG) 1,523 nm 0.0000 Near IR IR HeNe laser 3,390 nm 0.0000 Mid-IR IR HeNe laser 10,600 nm 0.0000 Far-IR CO2 laserThe DPSS Lasers of 532nm is very close to the peak of the eye's sensitivity. The human eye is most sensitive to the color green. Therefore, green laser pointers actually stand out in brightness compared to all other visible lasers including red, blue,violet and yellow laser pointers. The greens and blues produced by a typical argon are further away from the peak response of the eye, so they appear to be dimmer in comparison. This is why DPSS laser are said to be 3 to 4 times brighter than a typical argon laser. So a 100mW DPSS laser will look the equivalent to a 300mw argon laser in terms of apparent brightness. Taking this to an extreme, if you were to compare a 100mw 532nm Diode laser with a 2W Infrared Laser e.g. emitting 1064nm, the 100mW laser will look much brighter because the human eye can't see infrared wavelengths!