Protective goggles for laser...

Thread Starter

Externet

Joined Nov 29, 2005
1,817
Good day.


1652495070698.png
1.- Are the color of the lenses on laser protective goggles related to the wavelength of the laser beam ?
2.- Or is something else in the lenses doing the protection ?
3.- Or a single lenses color will protect against several wavelengths lasers ?
4.- Or for a laser color different color lenses can be used ?
5.- Or the color of lenses is irrelevant ?
6.- Or the color of lenses must be the same of the laser wavelength ?
7.- Or for every laser wavelength there is only one lenses color to block the laser ?
8.- Or depends if the protection is by reflecting the laser color ?
0.- Or the protection is by blocking the laser color ?
10.- Or the protection is by absorbing the laser color ?
How exactly does it work ?

Example: for violet laser, what color should the lenses of the protection goggles be ?
 

nsaspook

Joined Aug 27, 2009
9,443

MrSalts

Joined Apr 2, 2020
1,532
Plastic Goggles that protect from Near IR wavelengths are surprisingly expensive because the dyes needed to absorb 1060nm (or anything beyond 900nm) that dissolve in clear plastics and withstand the plastic processing temps are unusual and expensive (because they are difficult to make and not needed in any significant volume to justify scale-up to efficient volumes).

some glass lenses are ok in IR with inorganic mineral absorbers but glass lenses are becoming less and less common so prices are rising there too.

best, keep IR lasers in an enclosure and any other non-eye safe laser class if possible. Much better than wearing glasses.

I know several people who had IR laser burns in their neck, arms and hands from a government lab. They finally took safety seriously in the late 1980s when someone had a deep burn on their hand and another with a line across their cheek and nose from bending across the Newport table when they thought the beam was blocked. Complete luck that it wasn't her eye.
 
Last edited:

MrChips

Joined Oct 2, 2009
25,920
As the above posters have said, it depends on the wavelength of the laser.

If we are referring strictly to wavelengths in the visible region, then the colour of the lens indicates the wavelength that is transmitted. A red lens gives you no protection from a red laser.

The transmission spectrum of the lens needs to be examined if you wish to know which wavelengths are attenuated.
 
I purchased this laser, haven’t set it up yet not sure what color the laser is, a friend of mine has one as I remember was green, noticing the shield has Orange cover, the glasses are of the same color that came with the laser.

https://www.amazon.com/dp/B09K5GT47D?ref=ppx_yo2ov_dt_b_product_details&th=1

Burning in the same room not good unless well vented, my plan is to obtain an old vent hood, to capture Particulate putting it together this weekend hopefully, I’ll do a run exhibiting the burn and ask the same question? I want to know even if no one else does, worth talking about, safety first.

kv
 

MrChips

Joined Oct 2, 2009
25,920
The key parameter here is the wavelength of the laser emission. Pay attention to this parameter.

1652535505905.png

Visible spectrum is from 400nm-800nm
Ultra UV, UV or near UV will be in the 400-450nm range (blue and beyond, invisible)
NIR (Near Infra Red), IR and deep IR will be 800-1200nm.

Your laser engraver is in the 400-450nm range. This is why the protection lenses tend to have an orange colour.
 

Thread Starter

Externet

Joined Nov 29, 2005
1,817
Thanks.
OK, for 405nm violet diode laser the protection lenses should be orange. Not red, not yellow but ~650nm orange. I do not see the numerical reason/relation.
 

MrChips

Joined Oct 2, 2009
25,920
On a side note, be aware of too much exposure to light <400nm "blue light", in particular UV radiation which is invisible (beyond the blue spectrum).

UVC 100-280nm
UVB 280-320nm
UVA 320-380nm

The sun emits a lot of "blue" light which increases the risk of cancer, eye diseases such as cataracts.
It would be wise to always wear protective sunglasses when outside in bright sunlight. Make sure that the sunglasses are designed to filter out the damaging "blue" light.
 

MrChips

Joined Oct 2, 2009
25,920
Thanks.
OK, for 405nm violet diode laser the protection lenses should be orange. Not red, not yellow but orange. I do not see the numerical reason/relation.
I do not see how you arrived at this distinction. Orange is between yellow and red in terms of wavelength. If the lens blocks the 405nm then it is appropriate to use.
 

Thread Starter

Externet

Joined Nov 29, 2005
1,817
Last edited:

Thread Starter

Externet

Joined Nov 29, 2005
1,817
The colour does not matter. What matters is that the lens effectively block the laser emissions.
OK, then it is number 5.- at post #1

Is there a way to know if a goggle works by reflecting, blocking or absorbing the intended wavelength ( numbers 8, 9 ,10 at post #1 ) ?
 
Your laser engraver is in the 400-450nm range. This is why the protection lenses tend to have an orange colour.

I did not say the lenses have to be orange.
The colour does not matter. What matters is that the lens effectively block the laser emissions.
Not sure if you meant me but mine is in 450-500nm the laser cover maybe Orangish to Yellow light maybe? I don’t know lol

I’m color blind, in the Purple, Blue, Orange, Red, spectrum. Other colors not to bad

Should see me read resistors, I have to have my multimeter Mag and Light to tell the difference.

kv

 
Last edited:

MrChips

Joined Oct 2, 2009
25,920
The colour of the lens does not matter.
But think about it for a second.

If the lens were opaque to all colours in the optical region it would be BLACK. You would not be able to see through the lens.
If the lens were transparent to all colours in the optical region it would be CLEAR.
If the lens attenuated all colours shorter than 650nm it would appear somewhere in the range ORANGE-RED.

Thus the colour of the lens is a consequence of the wavelengths that are transmitted.
As a protective filter you want a lens that attenuates the eye damaging wavelengths. What is transmitted is the colour of the lens you see which is not your primary concern in this application of filters.

In other words, you are interested in the stop band of the filter, not the pass band. You want to let some wavelength through otherwise it would not be a practical filter for human eye protection while performing your duties.
 
Top