In an application, I need a laser beam that is safe for indirect exposure and has visible beam in lit areas. I understand that 5mW is the maximum power commonly used without the need of safety glasses but 5mW lasers don't seem to have strong visible beams. Is there any work around /suggestions?

My application only requires laser beams to be visible from 5cm-200cm.

  • 2
    \$\begingroup\$ A laser beam is only visible if there is something in the air (dust or smoke, for example) to scatter the light into viewer's eyes. \$\endgroup\$
    – The Photon
    Nov 28, 2015 at 18:37
  • 1
    \$\begingroup\$ Use dry ice machines? \$\endgroup\$
    – Andy aka
    Nov 28, 2015 at 18:49
  • \$\begingroup\$ Very creative! although I can't use it in this application \$\endgroup\$
    – Arash
    Nov 28, 2015 at 19:00
  • \$\begingroup\$ As ThePhoton wrote, you can't see light unless it is scattered. What you're asking for is not going to happen otherwise. When you look up at the moon at night, can you see the enormous amount of sunlight travelling through space before it hits the moon? No. So what are you actually trying to do? \$\endgroup\$
    – gbulmer
    Nov 28, 2015 at 19:36
  • \$\begingroup\$ @ArashRowshan, we need to know what you're actually trying to do here. \$\endgroup\$
    – Tustique
    Nov 28, 2015 at 23:22

1 Answer 1


Higher powered lasers can be used if the average energy hitting the eye is kept below the danger level. This is commonly achieved by pulsing the laser. This is also the strategy for laser shows. Pulsing time depends on laser CW output, wavelength and beam diameter. I would suggest to ask a laser safety expert for help.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.