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CurtisOliver

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Welcome to the forum FastLaser.
You've already had some good advice on here.
I definitely don't recommend starting out with a 7W laser.
Although it is a valid point that any Class 4 can cause irreversible eye damage, when you start creeping past 3W the laser becomes quite a serious fire hazard with barely anything lying around making a suitable beam stop.
You will be surprised how many small little things we now take into account without thinking about it very much due to having experience. Starting out, you have none. Simple as. A basic reflection can make the difference with these lasers so care must be taken. Start out with a lower Class 3B is my advice. Still have to be careful, but not as dangerous as the Class 4's.

Alaskan, scary but important thread you shared.
 

BobMc

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Hey Bob, the link that Alaskan gave is already a sticky "http://laserpointerforums.com/f53/hit-eye-1000mw-445nm-blue-laser-69469.html"

Edit: Nevermind, after re-reading your post, you are probably thinking of this thread, and not the linked thread.
You were correct I was thinking of the thread http://laserpointerforums.com/f53/hit-eye-1000mw-445nm-blue-laser-69469.html would make a good sticky. Didn't realize it was already. Think it's a great stinky, glad it's there. :thanks: for the heads up :)
 
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lasersbee

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:wave: Welcome to the Forum..
As has been pointed out above...
a 2-3mW cat toy Laser is far different
and a lot less dangerous than a powerful
7 Watt (7000 mW) Blue Laser.

Enjoy your stay and be Laser Safe.


Jerry
 

paul1598419

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I had almost forgotten about that thread when Alaskan brought it back to the fore. This was done with a 1 watt for just an instant.. I'm sure the victim's blink reflex kept the exposure to less than a quarter of a second, but there you have it. The damage is done and a far less powerful one could have done this damage as well. People always seem to forget just how dangerous these laser can be..... and it is the first time users who also seem to be the victims of these terrible injuries that are life changing. That guy was under 30 and will have to deal with vision in one eye for the rest of his life. It should give you pause. Always think about what you are about to do. :cryyy:
 

FastLaser

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Thanks for the many welcome replies.

Duty cycle is something I haven't considered yet and the same applies to divergence.

My first goal is to attach the laserpointer to the tripod of my telescope. It's not very high-class but I want to check if I can burn a line or something similar in approx. 20 m (65 feet).

For the moment a 405nm laser could be my choice. Visibility doesn't matter so much. Could be even better if it's harder so see as my neighbours might call the police if they see something they don't know :crackup:
 

paul1598419

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That distance might make the 405nm diode difficult to burn as the beam will have diverged a lot by the time it gets to your target. The 405nm singlemode diodes have great divergence specs and good power ratings, but 65 feet is going to expand the beam more than a typical 15 feet that these burn great at.
 

FastLaser

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Thanks for these explanations paul1598419. So I've learned something new about single- and multimode diodes.

Asking google about that gives me a link to a pdf "Laser Diode Beam Basics". I'm looking forward learning a lot of new things in the next weeks. This could really become a new hobby :thanks:
 

Alaskan

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Using a big lens on the end of your pointer instead of the standard 6 mm diameter we use on most of them and you can focus the beam down to a burning spot 65 feet away, then divergence isn't a problem. Only thing is, you need to find a large diameter lens at the right focal length so the spot from the laser diode doesn't over shoot the diameter of your big lens, or be far under it. Try for about 80 percent fill for the lens diameter and it should be just right.

Edit: I forgot, I'd recommend a lens at least 1 inch diameter for this trick, 2 to 3 inches even better. For a high power single mode laser diode at 405 nm, 1 inch is probably big enough, but I don't know, maybe use a 1.5 inch diameter lens to be sure. If you were doing this using a multimode diode at 450 nm I'd recommend a 2 to 3 inch diameter lens for sure, but being single mode at 405 nm you should be able to use something smaller.

How to determine the focal length for the diameter of the lens you want to use? Take the collimation lens off of the front of the pointer/diode and see how big a spot it makes on the wall at different distances, match the diameter of the spot on the wall to the diameter of the lens you want to use, measure the distance from the wall to the diode and now you know both the diameter and approximate focal length of the lens to use. Search ebay for a PCX or plano-convex lens to match close to the diameter and focal length you want to use.

Put it all together and burn baby, burn.
 
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paul1598419

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That's a good idea, Alaskan. But, it brings more complex problems in... such as, does the diode's uncollimated beam clear the module without being clipped and you need a way to fix the lens in a way that can be able to be focused.... as these assemblies are not of the shelf available.
 

Radim

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Welcome to LPF.

As others said, take care of laser safety and go with something of low power. I would recommend something from class 3B as the strongest power. Like 100 mW 532 nm green. With this unit you get the best relatively safe laser to learn with it. Once you get practical experience go further. Power is not only what's matter. I've recently got "just" 1.4+ W 532 nm laser and it is much greater beast than my 3.5 W blue laser with much worse divergence and beam diameter. With 100 mW and better beam specs of DPSS compared to diode lasers you might even burn stuff better than with same power of diode. My Evo is able to light up cigarette quite easily.
Also when considering your first serious laser think about purposes you want to use it. There are many lasers and hosts to meet your different needs. Use search bar here and if you do not find an answer, do not hesitate to ask.

Enjoy and stay safe.
 

Alaskan

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That's a good idea, Alaskan. But, it brings more complex problems in... such as, does the diode's uncollimated beam clear the module without being clipped and you need a way to fix the lens in a way that can be able to be focused.... as these assemblies are not of the shelf available.

Oops, I accidentally must have edit that out, I initially included mention of it. However, a single mode 405 nm laser diode won't be clipped, I guarantee, not with an Aixiz module.
 

paul1598419

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Good to know. Some modules i use are deeper than others and that was my concern.
 

Alaskan

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Many do though, NUBM44 for sure! Multimodes usually do. Focus adjustment is a good thing, I've built collimators to the exact focal length without adjustment, but then you must experiment and get your hardware just right, easier to build in FL adjustment.
 




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