Strange (maybe not?) thing when burning with red.

[X FLY]

Chip Weevils - CPFWiki

omg is that a joke or?

 

[BShanahan14rulz]

:shhh:
;-)

 

[RoDnSuE]

omg is that a joke or?

Yep. It's a joke:beer:

As is..
They are Murphy's EVIL grandchildren

As in Murphy's Law

 

[NightRunner417]

HAHAHAHA! Pure awesome.

 

[Toaster]

Is it the burning of the materials?

 

[NightRunner417]

Is it the burning of the materials?

It is definitely associated with it. I've tested my blue ~1 watt on lots of materials and you only ever see this effect with materials that will burn. Try it on bare metal or pencil graphite, ceramics, etc, nothing happens except reflected glare. Try it on organic materials like electrical tape, wood, paper, bugs, etc, and boy yeah, it can get extremely bright, so bright that even though you're wearing proper laser goggles, you still get afterimage spots in your vision.

I'm curious to know the exact mechanism by which the energy becomes released in the form of white light at what observations show is clearly a threshold level of energy.

 

[Toaster]

If it is organic materials it is more colorful in then it much be the proteins. Just a thought.

 

[Benm]

There are two options that can produce the visible effect, and they do not exlude eachother with all materials:

- combusion, which just produces a small flame. This is very well visible when you light a cigarette using 445 or 405. Red lasers also produce this effect, but since the typical color of starting combusion is orange-ish, it may not always be so easy to see.

- thermal emission, where you heat the target to a point where it becomes a black-body emitter. This is what appears white when using red or IR to heat up something producing white-ish light.

The latter doesnt require any combustible material, and could also work on a blackened metal foil, ceramic surface or something similar. The problem is it requires rather high temperatures to display this effect, and few substances will tolerate those temperatures without degrading.

As an experiment you could try putting a piece of (char)coal in a sealed test tube, and remove any oxygen from this tube (by sealing it off and burning part of the coal if you must). In the now oxygen-free atmosphere you should be able to make the coal glow brighly in the focus point, but the lack of oxygen will prevent its combustion allowing for a long lasting demonstration.

To make it more visible using goggles for the laser wavelength will always help, regardless of what laser you are using. Its just a matter of the camera or your vision not getting overwhelmed by the laser light.

 

[oic0]

I was wondering what this was. I couldn't stand to burn my black leather wallet from the super bright little cinders that kept appearing.

 

[IsaacT]

I engraved my brown leather wallet with a giant laser warning sign turned out pretty well too. At first I was not going to burn it but at Best Buy I didn't want to do a demonstration using their counter so I pulled out my wallet and used that....after that I kinda got trigger-happy(or is it clicky-happy?)

 

[leftkidney]

asked some "laser guys" I know at work (I work for IBM) who work with really powerful lasers and some co2 lasers

they said it can be a problem for red lasers because it is a blue or white light that is similar to the ark of a welder and will cause damage to your eyes - they showed me some goggles that are for all sorts of wavelengths of lasers from UV to IR and they are basically welding goggles, I was told that some really dark welding goggles will work for laser eye protection for all colors of light including UV 200nm and IR 2000nm and everything in between except for 532nm +/-50nm

also the "auto darkening" welding goggles will not work unless you use them as they are designed which is to look at the thing about to be bright and then close your eyes for a second while you make it bright and then open them again because the "auto darkening" takes longer to happen then it takes to damage your eyes

 

[NightRunner417]

asked some "laser guys" I know at work (I work for IBM) who work with really powerful lasers and some co2 lasers

they said it can be a problem for red lasers because it is a blue or white light that is similar to the ark of a welder and will cause damage to your eyes - they showed me some goggles that are for all sorts of wavelengths of lasers from UV to IR and they are basically welding goggles, I was told that some really dark welding goggles will work for laser eye protection for all colors of light including UV 200nm and IR 2000nm and everything in between except for 532nm +/-50nm

I have some solar viewer glasses that are meant for observing eclipses and such but are dark enough to allow you to look right at the noon sun in pristine skies indefinitely. They totally kill ALL the light from my 1.3W 445nm. Given the results of THAT, I am still thinking that I could get ahold of some neutral density film and create a kind of addon filter attachment for my blue laser goggles that would water down the rest of the spectrum and make the broad spectrum emissions more tolerable to look at. I just now tested this theory by half-ass wearing some pretty dark sunglasses underneath my blue laser goggles and found quite to my surprise that the broad spectrum emissions from burning are still too bright to really look at, so what I'm thinking is that the "best" scenario would be to work under extremely bright room lighting (or outdoors under full sun) with extra dark eyewear coupled with proper laser protection. I'm actually thinking the BEST solution would be to pair up some linear polarizers, two for each eye, mounted on the front of the laser goggles. It should be really easy to pull this off, because you could just glue some SLR camera adapter rings to some cheap laser goggles, and then when needed, thread your polarizer pairs onto the rings. You can then adjust the total brightness as needed by rotating the polarizers against each other.

Thanks to the power of relativity, I can now tell you that the idea does in fact work. At maximum uh... hmm... cross polarization? At maximum darkness, anyway, with the two linear polarizers at 90 degrees to each other, and the pair held over the front of the laser goggles, the dot at its VERY brightest (burning paint on a Stanley steel carpenter's square, which I've found is viciously bright across the spectrum, brightest I've seen yet), looks merely like a tiny red speck, just there and not bright nor dim. Downside, of course, is that you can't see anything else. This would be perfectly useful, but it would have to be used in VERY bright room lighting or you won't see your target, much less anything else. Very important to note is that I have no way of knowing how much IR or UV is getting past the setup and into the eyes. In theory, the goggles take care of all the UV, so that shouldn't be a problem. In addition, a plain old Tiffen Standard Hot Mirror filter should be perfect in combination with the polarizers to cut any IR that tries to get by. One could work under one of those mad crazy Wicked Lasers 4100 lumens flashlights aimed at the target, minding of course how easily they can cause burns, and have quite the little burning laser paradise setup.

See what happens when I start the morning off with a strong coffee?

 

[IsaacT]

What if we just made a Faceshield with a camera on the front that feeds to a screen located on the face side of the shield. Sure it wouldn't be as satisfying as seeing it with your eyes, but then again you will still be able to get satisfaction from your eyes when you are 80.....you would just need to protect the camera a little....possibly a coating on the lens that reflects that light? Or a Lasergoggle like filter that you could fit in front of the lens....If you did that you could have a wheel with different filters on them and rotate it to match whatever laser you would be using. Like a pencil sharpener when you rotate it for different sizes.

BTW: NightRunner417, I dig the sig d(^_^)b

 

[JaiNobeZ]

What if we just made a Faceshield with a camera on the front that feeds to a screen located on the face side of the shield.

I did basically this when i was trying out a pump diode from a broken green. My first decent laser and the crystal assembly broke off, so i thought it'd be funny to use the pump diode to try to burn. I had it set up so that the button (momentary) was held down by cabletie so that i could push it over the button to turn it on, then i had a match taped to some wood just in front of it. I then had the lid of a cardboard box with a hole in it between me & this set-up and my mobile phone camera pointing at the match celotaped so that the hole in the box was lined up with the screen.
I could see everything that was going on, and there was no risk to my eyes. It didn't work, but it was a fun experiment.

Back on topic, I've noticed the same thing. I, wearing safety goggles, use a peice of plywood to find the focus of my red. Setting the red down somewhere, i move the plywood back and forth until i see white flashes. Then i make a mark on the surface with a drywipe pen & at this mark i am able to burn quickly and efficiently.

My school has a 30W CNC laser cutter (i'm fairly sure is CO2) which i'm pretty much addicted to using because i hate sawing stuff. I'm told (via. the clever people at laserchat) that the wavelength CO2 lasers produce is absorbed by pretty much everything it hits with a few exceptions, and so they assume it's eye-safe because of the clear acrylic lid. But that produces the same effect, bright white flashes. Whatever it's cutting. I find it's most visible when it's cutting acrylic, but that might just be because acrylic is shiny. When it's cutting a sheet of fluorescent acrylic sometimes the whole sheet lights up, presumably due to the shorter wavelengths being produced in the flashes.

But if we're putting in light from the far Infrared end of the spectrum and getting out visible light, what else is coming out? IR & UV? I'm going to assume not further than that at either end, but *shrugs*... i'd be interested if anyone knows.

 

[ILIKELASERS]

Thats cool. My arctic did this while it worked, i think it happens best when your laser is focused to infinity and you get the center of the focus right over what your burning. One of the only things i did while my arctic lived was attack a spider with it. It ran from the beam itself, so I went back with the focus lens on and tried again. The moment the focus point crossed the spider I saw the white flash and...........it exploded.
:lasergun:

 

[IsaacT]

Thats cool. My arctic did this while it worked, i think it happens best when your laser is focused to infinity and you get the center of the focus right over what your burning. One of the only things i did while my arctic lived was attack a spider with it. It ran from the beam itself, so I went back with the focus lens on and tried again. The moment the focus point crossed the spider I saw the white flash and...........it exploded.
:lasergun:

That is f*ing awesome! :drool: