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Old Mar 14th 2018, 04:56 PM   #1
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Laser Safety Glasses question

Hello all. I am buying a laser engraver for my business. The company I'm getting it from and the "industry" in general doesn't think I need safety glasses when operating it (most say cause the light isn't visible to the eye) . I don't personally feel safe with that assumption for my eyes or my wife's. Anyway on to my question....

Is any "light" the same that has equal wavelengths no matter the source? In my case 1064nm (fiber laser). Would 1064nm YAG laser light or CO2 laser light be equal to the fiber laser light (not accounting for power input and assuming they could actually produce the same wavelength).

Also how does frequency come into this? I though frequency was the wavelength but obviously not since the unit has a frequency output of 20khz-300khz. Would this be on/off pulses?

I know I'm not a student but I need some knowledge so I can make an educated decision to protect our eyes and I bet you guys and gals can probably answer my questions.

Specs on the unit (in case some needs to know)
Power(W): 30w
Wavelength: 1064nm
Laser frequency range : 20khz-300khz

Thank you in advance.

Neal W
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Old Mar 14th 2018, 07:52 PM   #2
Pmb
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Originally Posted by DipItIn View Post
Is any "light" the same that has equal wavelengths no matter the source?
Absolutely not. Place your hand out palms facing skyward on a nice warm summer day. Do you feel pain? No. Of course not. However, if you were to take a magnifying glass and focused the suns rays onto a small spot on your hand you'd soon scream out in agony. That's because focusing concentrates the energy so that the intensity of the light increases to the point where it will burn your skin.

Who told you otherwise? They're nuts!

And just because a wavelength of a beam of light cannot be detected by the human eye it doesn't mean that an intense beam of the same wavelength can't damage it. I happen to have experience in this area as a patient. I had a cataract in my right eye that had to be fixed. The surgery has a 0.2% chance causing a detached retina and of course, with my poor luck, I had a detached retina from the surgery (sigh!). That required more surgery (a vitrectomy - a nasty procedure - blech!). This resulted in glaucoma. They had to correct the glaucoma by drilling holes in my iris with a laser and you guessed it -
They used a Yag laser.

See https://www.glaucoma.org/treatment/laser-surgery.php

Originally Posted by DipItIn View Post
Also how does frequency come into this? I though frequency was the wavelength ...
No. Frequency and wavelength are related. The frequency of light is inversely proportional to the wavelength of light. For details please see: Frequency to Wavelength Calculator - Wavelength to Frequency Calculator

Originally Posted by DipItIn View Post
I know I'm not a student but I need some knowledge so I can make an educated decision to protect our eyes and I bet you guys and gals can probably answer my questions.
Smart. But use caution. If you use goggles or some other kind of eye protection make sure that the material in the lens/eye protection is opaque to the light you want protection from.

It would be helpful to know the details of what you'll be using the laser for.

If I were you I'd study this website very carefully
How to Choose Laser Eyeware at:
https://www.lasersafety.com/resources/how-to-select/

Last edited by Pmb; Mar 14th 2018 at 07:56 PM.
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Old Mar 16th 2018, 05:08 PM   #3
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Pmb,

That link is EXACTLY what I needed. Thank you so very much.

The unit will be used for polymer frame engraving and stippling, as well as engraving on aluminum machined parts, steel and stainless steel slides. From that you can probably figure out what we will be using it for exactly. Don't want to get super specific because of the potential "arguments" it could cause on here with the current state of affairs in the country.

Then how can the unit have a variable frequency if its a fixed wavelength?
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Old Mar 17th 2018, 04:37 AM   #4
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For light wavelength and frequency are synonyms for the "colour" of the light.
As PMB says "The frequency of light is inversely proportional to the wavelength of light"

However in your case, I am guessing, that possibly your laser gives its output as pulses of light.
then the frequency might be referring to the rate at which these pulses are emitted
Not to the other interpretation of frequency which is connected to the wavelength or "colour" of the light.
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Last edited by Woody; Mar 17th 2018 at 04:42 AM.
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Old Mar 19th 2018, 08:36 AM   #5
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Just had a quick look at the numbers for wavelength vs frequency for light:
<Wikipedia:Colours>

1064nm is in the infrared (below red) region
which will have a frequency of about 350Thz.

i.e. not your quoted "Laser frequency range : 20khz-300khz"
so this frequency cannot be referring to the "colour" of the laser.

Note I have put colour in quotes since infrared is not strictly speaking a colour (which we can see).
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