General Safety Help

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y7deluxe said:

Background: just purchased a couple of the 1W artic lasers. Also purchased a 300mW 532nm that does NOT have an IR filter.

1. I've read in a variety of different places that goggles are NOT required for outdoor use if the beam is pointed into the sky or at a very distant object that doesn't have a reflective surface... IG: trees. The question here is, if I have a laser that does NOT have any IR filter, is there any potential harm that could be done in a perfect scenario, where no accidents can occur, where the laser is pointed into the sky or at a very distant object that will NOT reflect back?

1.1 Is it safe to look at the beam of a laser, WITH IR protection, pointed into the sky without goggles?

1.2 Is it safe to look at the beam of a laser, WITHOUT IR protection, pointed into the sky without goggles?

2. I was looking at these goggles for my 532nm laser... Protection Goggle Glasses for multiple wavelength Laser - eBay (item 220440028992 end time Jul-17-10 08:10:10 PDT). Safety is my priority. Will these goggles provide the safety necessary? If not, which ones will (I'm willing to spend as much as it takes on safety goggles)?

3. What would be a good IR filter for the 532nm laser? I've read that the good IR filters can block 98% of the IR and they cost around $40, but I don't know where to find these.

4. There are "shades" that are included with the artic. Something tells me these aren't high quality. Does anybody have any insight on this? If they are NOT high quality, can somebody recommend a pair that are high quality for the 445nm?

5. Do any goggles exist that would provide safety for the 445nm and the 532nm lasers? A two-in-one setup is what I'm asking about. And if such an item does exist, is it any less safe than wearing different goggles for each laser? Also, if such an item does exist and it meets the same safety requirements, is there any down-side to it? IG: it blocks more light and less can be seen from the goggles?

Thanks in advance for the help

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1-No it should be fine as long as you keep it pointed at distant objects. Just keep your face away from the aperture where stray IR could be coming out.
1.2-Yes
2-I don't know. Preferably get some certified goggles.
3-Check on Novalasers or optotronics they both sell cheap IR filters.
4-Nobody knows yet as we haven't got them.
5-Most goggles that block 532nm also block 405nm 445nm and 473 nm. My nova lasershades do at least.

y7deluxe said:

Background: just purchased a couple of the 1W artic lasers. Also purchased a 300mW 532nm that does NOT have an IR filter.

1. I've read in a variety of different places that goggles are NOT required for outdoor use if the beam is pointed into the sky or at a very distant object that doesn't have a reflective surface... IG: trees. The question here is, if I have a laser that does NOT have any IR filter, is there any potential harm that could be done in a perfect scenario, where no accidents can occur, where the laser is pointed into the sky or at a very distant object that will NOT reflect back?

1.1 Is it safe to look at the beam of a laser, WITH IR protection, pointed into the sky without goggles?

1.2 Is it safe to look at the beam of a laser, WITHOUT IR protection, pointed into the sky without goggles?

2. I was looking at these goggles for my 532nm laser... Protection Goggle Glasses for multiple wavelength Laser - eBay (item 220440028992 end time Jul-17-10 08:10:10 PDT). Safety is my priority. Will these goggles provide the safety necessary? If not, which ones will (I'm willing to spend as much as it takes on safety goggles)?

3. What would be a good IR filter for the 532nm laser? I've read that the good IR filters can block 98% of the IR and they cost around $40, but I don't know where to find these.

4. There are "shades" that are included with the artic. Something tells me these aren't high quality. Does anybody have any insight on this? If they are NOT high quality, can somebody recommend a pair that are high quality for the 445nm?

5. Do any goggles exist that would provide safety for the 445nm and the 532nm lasers? A two-in-one setup is what I'm asking about. And if such an item does exist, is it any less safe than wearing different goggles for each laser? Also, if such an item does exist and it meets the same safety requirements, is there any down-side to it? IG: it blocks more light and less can be seen from the goggles?

Thanks in advance for the help

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1. Correct. Generally speaking for lasers with powers less than multi- watts, diffuse reflections even from relatively close range (a few feet) will not cause acute eye damage, though they may be very dazzling (and blue wavelengths from any light source - lasers or anything else - can also cause chronic photochemical damage).

If you are viewing without goggles, as would be usual for outside use (unless you are burning or measuring divergence), then the IR isn't really relevant. It's only significance is that your 300mw green, may be putting out an additional 100mw of IR thus giving 400mw altogether. But that has no real relevance to the safety analysis because in safety terms 300mw and 400mw are much the same (and anyway, your rated 300mw green might be giving out 400mw of green anyway- the figures are only rough specs).

1.1. Yes.

1.2. Yes

2. These look ok. They cover 442 which is close enough to 445 and they also cover 532. The rating is 4 and 4+ which means a 10,000 + fold reduction. This will reduce your 1 watt blue down to 0.1mw, which is a safe level for brief accidental exposure.

3. The ebay goggles should also be ok for the IR. The IR frequency from the green will be a mixture of 1064 and 808 (I think mostly 1064 though I'm not 100% sure about that). The ebay goggles give you 2+ for the 808 which will reduce it by 100+ and the 1064 is reduced by 4+ (i.e. 10,000+). The 2+ is not a huge reduction but the quantity of 808 is likely tbe fairly limited so it should still be sufficient for accidental beam exposure.

4. I don't know what the "shades" are intended to do. For any close work (burning etc) you should use the goggles.

5. The Ebay goggles will do what you need. In fact generally, the same goggles will protect from blue and green. It is only red lasers that require different goggles. Broadly speaking, blue goggles are used for red lasers and red goggles for blu ray/blue/green lasers.

In terms of visibility. any laser goggles will make the beam invisible. All you will see is the spot. Also the spot will look much smaller than with the naked eye because the surrounding bright areas become invisible. Thus goggles are essential for measuring things like divergence.

You sound very sensible. Enjoy

David

I don't agree with the preoccupation on OD when choosing safety goggles for hobbyist use. We want to see the beam, right? What's the point of playing with laser beams if you need to block away 100% of it to be safe? That's why my safety post says nothing about goggles.

Everyone agrees that if you take 5mW directly into an eye, you'll shut the eye and /or look away and the eye will be OK, right? So if you use OD2 goggles you can take a direct hit of 500mW and be just as safe. That's a direct hit. OD3 goggles provide the same protection up to 5 Watts!

The more important things to consider, in my opinion, are the design for side sealing to the head, comfort, large lenses, and whether you'll really ever wear them or not. C'mon, how many have OD>2 goggles that never get worn?

Eidetic said:

I don't agree with the preoccupation on OD when choosing safety goggles for hobbyist use. We want to see the beam, right? What's the point of playing with laser beams if you need to block away 100% of it to be safe? That's why my safety post says nothing about goggles.

Everyone agrees that if you take 5mW directly into an eye, you'll shut the eye and /or look away and the eye will be OK, right? So if you use OD2 goggles you can take a direct hit of 500mW and be just as safe. That's a direct hit. OD3 goggles provide the same protection up to 5 Watts!

The more important things to consider, in my opinion, are the design for side sealing to the head, comfort, large lenses, and whether you'll really ever wear them or not. C'mon, how many have OD>2 goggles that never get worn?

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1. If you want to view the beam then there is no point wearing any goggles. Even low OD goggles will make the beam of a high power laser invisible. So the OD rating for beam viewing is a non-issue.

2. If you are doing anything else that does not involve beam viewing, such as divergence measurements or burning, then at least for high powered lasers, I wouldn't want to use OD2. Suppose you are using a 500mw. 0D2 takes it down to 5mw. True, that may not produce permanent damage, but it wouldn't be much fun getting a direct hit. Also, the spot will still look uncomfortably bright. Try staring at a 5mw green spot at close range for a minute and you'll see what I mean.

3. Agreed about design.

You're right about seeing a beam. It's a goggles-off activity. That's why good safe beam handling technique is so important.

A point I missed in my list is to avoid looking at the "dot" (where did that term come from?). If you have to look at it, use as much density as is necessary to see what you want to see. Block it all if you just want to see what's happening to whatever's soaking up all that energy. I have a set of two 4" diameter polarizers (from Edmund Scientific I think) that I use as a variable shade to look through. Like a big astronomical moon filter. There's a good product idea! An 8" diameter variable "dot" viewing shade. Kick me 10%.

Looking at the scattering beam in the air should be safe at these power levels - but make sure there is nothing in the path that will give a refelction, such as a window you shine through.

As far as goggles go: if you are working with dpss, its desirable to get some that block near-IR too, both the 808 nm pump light and the 1064 nm light from the solid state laers. Blue (or red) diode lasers dont pose that concernt at all since they have no ir leak at all.

Universal goggles would be difficult to find now, since those would need to block near-IR, red, 532, 471, 445 and 405, leaving a very narrow passband to observe anything.

Eidetic said:

You're right about seeing a beam. It's a goggles-off activity. That's why good safe beam handling technique is so important.

A point I missed in my list is to avoid looking at the "dot" (where did that term come from?). If you have to look at it, use as much density as is necessary to see what you want to see. Block it all if you just want to see what's happening to whatever's soaking up all that energy. I have a set of two 4" diameter polarizers (from Edmund Scientific I think) that I use as a variable shade to look through. Like a big astronomical moon filter. There's a good product idea! An 8" diameter variable "dot" viewing shade. Kick me 10%.

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The dot ("spot"?) from even a low powered green is a bright beast and very dazzling. That's the main reason why I use high power goggles for burning. Otherwise it is hellishly uncomfortable and you end up with an after-image that lasts for many minutes. On the other hand, looking at the dot even at fairly close range is not actually dangerous (except for extremely high powered lasers - way above hobbyist range). So I think it is more a question of comfort than risk. Certainly there is no harm in looking at the dot outside from a distance of a few feet or more and I'm sure everybody in the forum has done so many times!

I would summarise it this way for new laser owners (It took me a while to work this out):

Viewing beam
No risk. No goggles required. Note "viewing beam" means looking at the beam from the side or behind. Looking into the beam towards the laser is extremely dangerous - see below.

Viewing dot on non-reflecting surface (e.g. brick, clothing, carpets, wood)
Generally very low or no risk of eye damage for powers < 1 watt. So no need for goggles if you are just looking at the spot of a handheld on a non-reflecting surface. However, it can become very uncomfortable at close range - you will get after-images etc - so goggles are recommended/compulsory for close range or sustained viewing (e.g. activities such as burning, measuring the spot size etc - all of which involve getting close up and personal with the spot). Also see below for blue and blu ray lasers.

Viewing dot on reflecting surface (e.g. mirror, window, other glass or polished metal surfaces)
High risk to you (or others) because of possibliity of beam being reflected into an eye. Avoid or wear goggles if there is any risk.

Direct viewing of focused beam into eye - i.e. pointing the beam into your eye
Extremely dangerous/Darwin Award level stupid. Risk of permanent damage for powers > 5mw. If any significant risk of accicdental exposure, wear suitable goggles (including infra red filter for 532 green and 473 blue - no infra red filter required for 405, 445 or most reds except rare DPSS types).

Direct viewing of unfocused or very distant beam into eye -i.e. looking into a beam from a long distance away or looking into a beam that has been defocused to a width of many feet
Reduced risk if viewed from very long distances (minimum > 1 mile) or if spot is defocused to a diameter > 6 feet and is viewed at the edge of the spot. But still may pose some risk for very high powered lasers. Take care.

Blue / blu ray lasers
Long term risk of photochemical damage from blue light (not just laser light) - avoid prolonged repeated viewing of blue or blu ray spot without goggles. Basically limit your exposure to minutes rather than hours over the course of a year.

Skin
Risk of skin burns from high powers (300mw+) though this is not really a serious problem with handheld powers unless you are very drunk

I don't agree with the preoccupation on OD when choosing safety goggles for hobbyist use. We want to see the beam, right? What's the point of playing with laser beams if you need to block away 100% of it to be safe?

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And I don't agree with your statement. I'm a hobbyist, yet I do care about the optical density of safety goggles. I'm not into lasers because I "want to see the beam", I'm into lasers because I like using coherent light to burn stuff. And my retinas are NOT included in the stuff I want to burn.
I don't care about seeing the beam when I use a laser, I care about my eyes not being damaged. And if I wanted to see the beam, I could just set up a camera, record the burning operation and see the beam in my video.

Devil_Master said:

And I don't agree with your statement. I'm a hobbyist, yet I do care about the optical density of safety goggles. I'm not into lasers because I "want to see the beam", I'm into lasers because I like using coherent light to burn stuff. And my retinas are NOT included in the stuff I want to burn.
I don't care about seeing the beam when I use a laser, I care about my eyes not being damaged. And if I wanted to see the beam, I could just set up a camera, record the burning operation and see the beam in my video.

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Did you miss my post #6? I use lower OD goggles to work with beams when I need to do so with the laser at full power, so I can see enough of the spot to know what I'm doing with it. But that assumes actually doing something with laser light beyond simply adjusting an attached lens to focus it onto a piece of tape.:tired::thinking: