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FrozenGate by Avery

Single Wavelength vs. Broadband Safety Eyewear

Traveller

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Hi,

I'm looking for a pair of goggles and I currently will only be working with 532nm laser(s) but red lasers are also a possibility in the future. Hence I came across safety goggles that are considered "broadband" or RGB oriented. My question is there any drawback to broadband goggles? The site selling said broadband goggles is Laserwave:

laser-wave.com/eproduct_show.asp?fatherid=31&classid=46&id=46

Thanks for your feedback in advance :)
 





Reflective vs. absorption Safety Eyewear

Hi again,

I will call this "part B" (I didn't want to post a new thread). Those LaserWave glasses I'm looking at use reflective coatings (vs. absorption). The few goggles I've used in the past were all of the absorption type, so I thought I would ask the community if there's any known shortcomings with reflective type safety wear (for the wearer).

Thanks again :)

P.S. I found this thread (after the fact) and so there must be at least a few of you using this model...
laserpointerforums.com/forums/YaBB.pl?num=1219510605
 
Reflective coatings are usually made of a thin film that can be damaged or burnt away quite easily, leaving you with no protection. Absorption-based goggles are superior in that they are not susceptible to scratches and other factors that may reduce their effectiveness.

Certified safety goggles are designed to absorb beams they're rated for, for a minimum of 10 seconds.  That includes the time that would be required to physically destroy the filter due to high energy absorption.  You won't find that kind of protection from a thin reflective layer.

For broadband goggles, the downsides are that they generally cost more, and offer lower protection at specific wavelengths you require. It's like a jack of all trades, ace of none. For example, I have a pair of broadband goggles that are good for 532nm and IR wavelengths. It can also do 635-650nm, but not with an OD rating that is enough for higher powered red laser diodes (> 120mW or so); so I don't use that one with red lasers. The broadband is nice for protecting me against any IR that may leak out of the green pointers though.

If you're interested in getting some certified eye protection, you should check out the goggles on OEM Laser Systems. $50 is well worth the price of saving your eyes.
 
Bionic-Badger said:
Absorption-based goggles are superior in that they are not susceptible to scratches ... Certified safety goggles are designed to absorb beams they're rated for, for a minimum of 10 seconds ... For broadband goggles, the downsides are ... offer lower protection at specific wavelengths you require...
Click to expand...
Thx for the very informative & useful reply (& link!)

Those are the reasons why I like Oakley sunglasses - their UV-A/B/C & HEV* is integral in the lens material and not as coatings. This protection's also available in their clear lenses (I own their M-Frames with replaceable lenses).
*High Energy Visible wavelengths (aka blue light rays)

But that's sunglasses and my knowledge of laser safety glass is limited, as you can see  :P

So thanks again for the recommendation as well as the link  8-)
 
Does that mean that the goggles from laserwave are not (that) good?
Because i want to buy the broad-band ones ...
 
Haha, yeah, that was a great deal we got on those. Just right for everything except red wavelengths.
 
well it turns down a 250 or(can't remember which) 300mw red to 10mw.Do you ware goggles for 10mw.
 
The main drawback of broadband glasses as no one has pointed out is this: If you block red green and blue laser wavelengths, you block all the light you would normally see! Laser goggles do not block "laser" light only, anything within their wavelength range is blocked. This means for example, if you had those on, you would not be able to see this website.     :-/

What Bionic-Badger said about the costings is true, in very cheap goggles. The professional ones that are used in industrial environments have the reflective coating between 2 layers of plastic or on the backside (closest to your eye). Reflective glasses are the preferred choice because they do not absorb the light and such they do not take damage from relatively low power lasers. When you get into the Watt level, the glasses are made of actual glass and have reflective coatings on both sides. These have a very high damage threshold.    ;)

If you are going to get glasses, it's fine to get the plain absorbing glasses so long as you are staying below half a watt or so. Don't get a pair of RGB ones unless you are working on a RGB system. There is really no point to them other then that one application. They would work just like sunglasses and cause your pupils to be dilated. In the case of a specular reflection around the glasses' sides, you would be even more vulnerable.   :o
 
Laser Ben said:
...you block all the light you would normally see!
...Reflective glasses are the preferred choice because they do not absorb the light and such they do not take damage from relatively low power lasers.
Click to expand...

Thx for the added info - very interesting stuff! Can you please give me an approx. idea of  how much damage absorption-based eyewear take on...? Do they have to be replaced regularly and if so, at what intervals. Please base your suggested figures on sub-.5W lasers, thx.

p.s. I did note that certified eyewear is based on a time minimum. For example, OEM Laser System's standard product description:

"Polycarbonate goggles are hardcoated and unbreakable with laser protection and absorptive dyes molded into the plastic. Utilizing non-reflective technology, energy is absorbed for a minimum of 10 seconds before loss of protection and will not photo-bleach or degrade over time. Surface scratches have no effect on laser protection affording outstanding protection"

But they also state that their eyewear "will not photo-bleach or degrade over time"... What's your take on that claim, then?
 
[quote author=Laser Ben link=1230003334/0#9 date=1230450231] The main drawback of broadband glasses as no one has pointed out is this: If you block red green and blue laser wavelengths, you block all the light you would normally see! Laser goggles do not block "laser" light only, anything within their wavelength range is blocked. This means for example, if you had those on, you would not be able to see this website. :-/


I'm not sure thats 100% true. I thought that the broadband goggle would only block the exact wavelengths that they are rated for (I may be wrong and thinking of multi-wavelength goggles so please pm me if you think I'm wrong).

--hydro15
 
Not really, it will block a lot more of the light then just the exact wavelength. There is no coating that has that sharp of a dropoff.
 
Bionic-Badger said:
Certified safety goggles are designed to absorb beams they're rated for, for a minimum of 10 seconds. *That includes the time that would be required to physically destroy the filter due to high energy absorption. *You won't find that kind of protection from a thin reflective layer.
Click to expand...

So anything over 10 seconds could ruin your goggles.

Laser_Ben said:
What Bionic-Badger said about the costings is true, in very cheap goggles. The professional ones that are used in industrial environments have the reflective coating between 2 layers of plastic or on the backside (closest to your eye). Reflective glasses are the preferred choice because they do not absorb the light and such they do not take damage from relatively low power lasers. When you get into the Watt level, the glasses are made of actual glass and have reflective coatings on both sides. These have a very high damage threshold. ;)
Click to expand...

How do you know if your safety goggles have gone bad?

Jon
 
Last edited:
Well seeing as no one responded before I found the answer I figured I should go ahead and post the answer here.


The question:
kikbot said:
A quick question(s) ... How do you know when the goggles are no longer good? Is there some indicator that the goggles are no longer protecting your eyes?

IR5 - Broadband IR Protection IRD5 Laser Protective Eyewear [NOR-IR5-EN207] - $138.48

Polycarbonate goggles are hardcoated and unbreakable with laser protection and absorptive dyes molded into the plastic. Utilizing non-reflective technology, energy is absorbed for a minimum of 10 seconds before loss of protection and will not photo-bleach or degrade over time.
Click to expand...

The Answer:
frothychimp said:
The quote you are providing indicates that the dyes are infused in the polycarbonate. Under normal diffuse viewing they should never wear out even if they get scratched. They should be thrown away and replaced under direct irradiation because it does begin to break down the dyes. If you see spots on the lenses that are slightly to grossly discolored the dyes may be no good in that spot. Be sure the spots are not like water spots or something like that. In many cases the surface will be pitted due to prolonged exposure to a single area (generally what happens when someone wants to see if they stop a beam and shoots one right though the lenses).

The comparison is to dielectric protective eye wear where the protective coating is applied to the surface of the lenses and could be scratched or ablated under direct irradiance and could lose effectiveness over time due to oxidation of the materials.
Click to expand...

Thank you Frothy :)

Jon
 
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