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ArcticMyst Security by Avery

Focus and Filter a green laser.

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Feb 11, 2009
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Green lasers, usually, do not have a focusing assembly. they are not mounted in modules like an aixis, and some dont even have an ir filter.

Do you lose many milliwatts off the power when you filter a green laser? i want a 150mw green O-like module, fit some sort of focusing assembly, and filter the Infra Red, to create a real quality handheld.

How should i do this? i like to ask the experts here on the forum before i screw up some good work.

where should i mount the filter? what sort of glue would i use, if i need it? any way i can make a focus assembly or otherwise focus THIS laser:

EDIT: It may be useful for some to know that im trying to get a narrower beam for more burning power, rather than fork out for a huge host for the large green laser modules at higher power ratings.

http://www.laserpointerforums.com/forums/YaBB.pl?num=1232226720/0
 





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That 150mW module should be plenty to burn objects, have you tried it yet? A filter should have you lose 20mW or less of power (according to what Jayrob has seen). Those o-like modules sometimes come in overspec as well so if you buy a 150mW module, you may get lucky and find one that outputs 175mW or more!

You can find IR filters on Novalasers' website.
 
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I made a 400mW handheld from an O-like module. http://www.laserpointerforums.com/forums/YaBB.pl?num=1230788830  The big module is focusable and has an IR filter included IF you buy the $15 collimation upgrade. This laser came out well, peaks at well over 500mW and slowly declines to the low to mid 400's. The host is custom machined to fit the module. I have on order the same module as you, it hasn't arrived yet, should have it next week. I will be machining a custom host for it and am planning to make mine focusable. The thread referred to by chipdouglas

http://www.laserpointerforums.com/forums/YaBB.pl?num=1233420934

is a very creative way of implementing focus on this type of module. I will be doing something quite similar on my build. IR filters can be found on ebay, I think snoctony has some available currently. I will be putting an IR filter into my build.
 
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certainly very interesting considering i had the same idea. i actually got out of bed to write it down last night :) only thing is, theres no guarantees that these modules will fit. but im glad to hear the large green o-likes are focusable on their own, though i'd like to focus it even more... hmmmm
 

murrat

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have you ever think why we need IR filters?
Everybody says IR light is invisible and you can suffer without knowing it.
But we cannot collimate it! So it cannot be dangerous after a feet away.
I think this IR filter is used to cheat more customers by telling non filtered ones are cheap poor quality lasers ::)
 
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murrat said:
have you ever think why we need IR filters?
Everybody says IR light is invisible and you can suffer without knowing it.
But we cannot collimate it! So it cannot be dangerous after a feet away.
I think this IR filter is used to cheat more customers by telling non filtered ones are cheap poor quality lasers ::)

True but once they DO break IDIOTS decide  DUUUR I want to look into now cause its broken and won't blind the **** out me.

But most laser websites dont put up big signs saying OUR LASERS HAVE IR FILTERS!!!!
(not inculding wicked lasers and techlasers)

dragonlasers have IR filter but it took a while to figure that out too  ;D ;D ;D
 

murrat

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WL, DL, even Novalasers mention that their lasers have IR filters not with big signs but with a dedicated page to IR filers ;)
 
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murrat said:
have you ever think why we need IR filters?
Everybody says IR light is invisible and you can suffer without knowing it.
But we cannot collimate it! So it cannot be dangerous after a feet away.
I think this IR filter is used to cheat more customers by telling non filtered ones are cheap poor quality lasers ::)


Not True. IR light is invisible, but it can still easily be collimated and burn your eyes the same as visible light. If you own a green laser with an output over 50mW it is a good idea to have an IR filter. If the green output is less than 50mW then IR filtering is optional.

There are many items in a house or anywhere that the beam from a laser pointer could bounce off of or pass through which could cause the IR beam to become separated from the green. this increases the danger posed by the IR. Collimated IR by itself is VERY dangerous due to the fact that it is invisible. Invisible light does not trigger a blink reflex like visible light does, therefore the beam could be directly focused on your retina and you wouldn't even know it until later, sometimes years later since the brain makes up for the burned areas at first. As time progresses, the brain becomes less able to make up for the missing cells, and dark spots appear in your field of vision.

Common sense would seem to dictate that since we only get one set of eyes, it's not a good idea to take chances with them..
 

murrat

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ElektroFreak said:
Not True. IR light is invisible, but it can still easily be collimated and burn your eyes the same as visible light. If you own a green laser with an output over 50mW it is a good idea to have an IR filter. If the green output is less than 50mW then IR filtering is optional.

Can be easily collimated?
How far?
You can focus but can you collimate?
I don't think so. Show me a video of IR laser that can burn anything from 50cm (~20")!
 
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murrat said:
[quote author=ElektroFreak link=1234914014/0#8 date=1235237573]
Not True. IR light is invisible, but it can still easily be collimated and burn your eyes the same as visible light. If you own a green laser with an output over 50mW it is a good idea to have an IR filter. If the green output is less than 50mW then IR filtering is optional.

Can be easily collimated?
How far?
You can focus but can you collimate?
I don't think so. [highlight]Show me a video of IR laser that can burn anything from 50cm (~20")![/highlight][/quote]


look up CO[sub]2[/sub] lasers on youtube..
 
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last i heard, it cant be collimated well and pisses in all directions like a torch spits light hither and thither, so the chance of collimated ir damaging the eye is slim. im pretty sure many lasers would be made illegeal if it was so dangerous.

thats what i heard from a few people on here anyway, dont flame me me to a crisp.
 
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GAFFNEYYY said:
last i heard, it cant be collimated well and pisses in all directions like a torch spits light hither and thither, so the chance of collimated ir damaging the eye is slim. [highlight]im pretty sure many lasers would be made illegeal if it was so dangerous. [/highlight]

thats what i heard from a few people on here anyway, dont flame me me to a crisp.


Lasers over 5mW ARE illegal to buy, sell or use in public in many 1st world countries (not that this is actually enforced well..). Also, what you've heard is incorrect. 808nm light (for example) is just 148nm higher than 660nm red visible light which can easily be collimated. Not much changes over those 148nm. Light at 808nm can be collimated as well as red. CO[sub]2[/sub] lasers run at 10,600nm. That's a lot bigger jump, but they can still be easily collimated over a fairly great distance.

The thing that defines a laser is the light's ability to be collimated. If it "pisses light in all directions like a torch" after it's been through a collimating lens then it's not a laser.

As I previously said on another thread: This entire point could be rendered moot by buying a cheap IR filter. What's $10 if it could end up saving your eyes some day?

Don't believe anyone on here that can't at least explain the science behind why IR is dangerous.
 
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ElektroFreak said:
[quote author=GAFFNEYYY link=1234914014/0#11 date=1235408453]last i heard, it cant be collimated well and pisses in all directions like a torch spits light hither and thither, so the chance of collimated ir damaging the eye is slim. [highlight]im pretty sure many lasers would be made illegeal if it was so dangerous. [/highlight]

thats what i heard from a few people on here anyway, dont flame me me to a crisp.


Lasers over 5mW ARE illegal to buy, sell or use in public in many 1st world countries (not that this is actually enforced well..). Also, what you've heard is incorrect. 808nm light (for example) is just 148nm higher than 660nm red visible light which can easily be collimated. Not much changes over those 148nm. Light at 808nm can be collimated as well as red. CO[sub]2[/sub] lasers run at 10,600nm. That's a lot bigger jump, but they can still be easily collimated over a fairly great distance.

The thing that defines a laser is the light's ability to be collimated. If it "pisses light in all directions like a torch" after it's been through a collimating lens then it's not a laser.

As I previously said on another thread: This entire point could be rendered moot by buying a cheap IR filter. What's $10 if it could end up saving your eyes some day?

Don't believe anyone on here that can't at least explain the science behind why IR is dangerous.[/quote]

i had my doubts, ive seen a co2 laser burning like pinpoint. if the laser is powerful enough to damage the eye, IR or no, then wouldnt it be ok to just be sensible with it, and NOT get it in your eye? even with an IR filter, enough mW of any colour will be trouble

??
 
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GAFFNEYYY said:
i had my doubts, ive seen a co2 laser burning like pinpoint. if the laser is powerful enough to damage the eye, IR or no, then wouldnt it be ok to [highlight]just be sensible with it, and NOT get it in your eye[/highlight]? even with an IR filter, enough mW of any colour will be trouble

??

That is the single best way to avoid any potential problems.

There are several ways that the IR and green can become separated, and the higher the power, the more it becomes a potential hazard. A prism is one example of an optic that will separate the beams, and the prism effect can also be seen just by shining the beam through a pane of glass or a vase or any number of other places.
All I've been trying to say is that everyone who uses DPSS lasers should have a bit of respect for the potential hazard from IR rather than just dismiss it as being perfectly safe. I'd hate to see anyone accidentally find out the hard way, no matter how remote the chances of it happening.

One of the cardinal rules of working with mid- to high-powered lasers is not to allow the beam to travel anywhere that you do not have complete control over it. This is nearly impossible with a laser pointer to begin with, so I take the stance that those who use them, particularly higher-powered inexpensive Chinese DPSS pointers, should at least make an effort to avoid potential problems. Plus, there's nothing wrong with becoming more educated along the way...
 

murrat

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ElektroFreak said:
[quote author=murrat link=1234914014/0#9 date=1235292608][quote author=ElektroFreak link=1234914014/0#8 date=1235237573]
Not True. IR light is invisible, but it can still easily be collimated and burn your eyes the same as visible light. If you own a green laser with an output over 50mW it is a good idea to have an IR filter. If the green output is less than 50mW then IR filtering is optional.
[highlight]Show me a video of IR laser that can burn anything from 50cm (~20")![/highlight][/quote]
look up CO[sub]2[/sub] lasers on youtube..[/quote]

I watched many of them. SchrenkenLicht has a 20W CO2. Ask her if he can collimate it :)
At 1m it is not effective ;D.
 




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