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FrozenGate by Avery

Which is the BEST laser color for BURNING?

Anthony P said:
J-Tech Photonics sells 2 lenses that will fit right in pointers that are specifically designed for burning. They sell CNC engraving type diode lasers. I have dealt with this company before and I have no complaints. Do not confuse them with a different company called Jye Tech. They are junk dealers.
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Do you know more about the lenses, type and FL? AR coated, WL? Probably safe to assume IR?

Edit: This company appears to only use visible wavelength diodes and they appear to use something like a aspheric G2 or three element lens: https://jtechphotonics.com/?product_cat=accessories - bottom of page.
 
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Alaskan said:
Do you know more about the lenses, type and FL? AR coated, WL? Probably safe to assume IR?

Edit: This company appears to only use visible wavelength diodes and they appear to use something like a aspheric G2 or three element lens: https://jtechphotonics.com/?product_cat=accessories - bottom of page.
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WL is 450nm. The one I have has adjustable focus spot from about 1-3". They come in the same threaded lens mounts that you would get with DTR G-2 etc. I have not tried their high resolution lens, but apparently it has some sort of astigmatism correction.
I took my 2.5w CNC type module and put a G-8 lens in it. OMG. It made me wonder what you guys do with that much portable power.
 
My thought on that high resolution lens is it has a longer FL, maybe just a common three element lens? I've never seen a single, or multi-element lens in one of those threaded lens holders have the ability to correct, only collimate. If it could do both, that would be a hot seller for our wide bar high power multimode laser diodes. I did see a design which could correct as well as collimate that way, but not in a small ~9 mm threaded lens holder.

Edit: I am looking forward to trying that G8 lens soon myself, with its longer FL that will make a thicker beam for our pointers and due to that reduced divergence. Although I've yet to see how bad the clipping is using a NUBM44 with the increased FL in that tiny tube. I bet Redcowboy already posted on this, but I've missed it.
 
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No - don't worry - enough people have joined the discussion that the thread's been revived :p Point about necros is generally for if a topic is no longer worth discussing, or nobody wants to :) Not the case here at all
 
I feel I should clarify. The jtech lenses focus to a point at about an inch or so from laser aperture, then rapidly diverge. They are made for short range burning, not distance.
 
Isn't it amazing how little of a change in nanometers causes such a drastic change in behavior?
 
Coonie said:
Isn't it amazing how little of a change in nanometers causes such a drastic change in behavior?
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By my math there's a 62.3% change in wavelength going from 650nm to 405nm. Would hardly call it little. ;)
 
Coonie said:
Isn't it amazing how little of a change in nanometers causes such a drastic change in behavior?
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650nm to 405nm is a leap across most all of our visible range, hardly a little change at all.

adalah said:
Blu-ray obviously burns better somewhat
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obviously better somewhat .......... is that some kind of oxymoron ? something like " Yes you Can't " or " Giant shrimp "
 
Power density is the thing to look for in a burner, if the spot can be focused tight enough up it goes. Typically, the shorter wavelengths can be focused to a tighter spot. Beam correcting optics will help with that for our higher power blue laser diodes with their wide stripe shaped output.

Robert has testified to that reality with his beam corrected NUBM44 laser. I’ve also found using as wide a PCX lens as you can find will focus the beam much tighter at distances of 30 feet, probably applies to several times that distance when adjusting the focus to a tight spot that far out. I used a 8 inch diameter PCX lens for that which worked wonderfully.
 
Raw power is a really big help as well and counter intuitive is what happens when you have a high power beam very tightly focused...........it cuts rather than burning because it obliterates a very small line of material quickly without imparting energy into material adjacent to the cut line, you can even see this with the 44 diode and DTR G2 lens, focused up close very tight it cuts popsicle sticks, but defocus and it imparts enough energy to exceeded the flashpoint without cutting into a wider surface area.
Granted focusing a 50mw laser as tight as you can be will not produce a good burner, so it's actually a balance of power and focus although with enough power the focus is less important.
 
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Agreed, good points, having enough power to cut is just as important. Depending upon the material, there is going to be a needed amount or it just gets absorbed instead of vaporizing the material quickly and cleanly.
 
The amount of power is part of it. The frequency and hence energy in the beam is part of it. But the real point is the ability of the object to absorb the energy. Think of a lens that is transparent. Most of the energy goes right through. Now think of a black object meaning black for the frequency of the laser. Most of the energy is absorbed. If the object can’t get rid of the energy it heats. The answer what is best is based on what you want to heat and what it best absorbs. Putting in more energy helps so it looks like 405nm would be the winner provided you can focus it the same as say 660nm however if the object is reflective of 405nm game over.

One more point I see was made just before I posted. Yes. If the object absorbs the energy and can move the energy away faster than it is heating again nothing will happen or it will be extremely localized which might even be good if you are laser cutting say wood and want to minimize burning of the edge. That’s why high power pulsed lasers can cut so well. Also some materials under extreme energy actually b come transparent temporarily. Look up transparent aluminum. None of us I hope reach these energy levels.
 
so........the 405nm is best for burning kecked for mw v price yes?



ps, can you build a white beamed laser?
 
Since white light is a combination of all wavelengths, you can build a laser with an apparent white beam by combining beams of multiple colours. Search for RGB lasers and you'll find lasers that can produce many colours, including white.
 
cool
and thanks

ps how do you watch a thread and recieive alerts via website only

i did in preferences but its not doing it
 
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