Which laser is considered “eye safe”?

Question

a) Laser bar-code scanners

b) The eximer laser

c) Communications lasers

Answer 1

Bar code scanners are not low frequency (they are red after all, which is typical frequency for a laser) and do not have a very short wavelength (again they are red, which is average frequency... and you can't simultaneously have low frequency and short wavelength, since they are inversely proportional).  That being said, they do have low power since no one wants people to be blinded while waiting in the line at the store.  So bar code scanners are made to be "eye safe".

Eximer lasers are powerful and use UV radiation.  Both of these properties make them very dangerous for your eye.

Communications lasers are IR lasers, I think at 1550 nm. They are usually high power and, because they are high power and not visible (so you don't know that you are being hit by them until it's too late), they too are not safe for your eyes.

Answer is a).

Answer 2

Not sure what you mean by " eye safe"

Bar code scanners are a very low frequency and have a very short wavelength, therefore pose no danger to anyones eyes.

The Eximer of course is used by skilled surgeons for eye surgery, and is quite powerful.

And, I don't know what you mean by communications lasers. They are used in different forms, but never as a beam of light that could harm your eyes.