808nm - $600

[Cuddly Ninja]

Hello, I have recently brought a 450mw - green laser and it is prity good, don't get me wrong but I wan't somthing that can burn better, I hear that this is a job for 808nm as its could be the cheapest burner. I have $600 to spend and the larger one I can find on the market is 4W by laser lands, can any one give me some advice and let me know if anyone sells them on the forum or builds them?

 

[anselm]

$600 to spend

for that much you could get a CO2 setup doing tens of Watts of 10XXXnm!

 

[Cuddly Ninja]

Im sure that I would fail at that, kinda new, someone would have to teach me.

Is there any website or resource where I could learn?

 

[AUTO XX]

You can get a kit from someone on the forums (there are a few around here) that will be relatively easy to build and you should be able to get a working, burning ~1.5W 445nm (blue) laser along with laser safety goggles, batteries, charger, etc. for ~$200-$250.
I'd avoid infrared as a new laser enthusiast, you can't see the beam, you can barely see the dot a very close distances, and they can be HUGELY damaging without you even knowing it is on.
445 has the "wow factor" most new members are looking for as well and I was actually just out in the bush for the last few days. I lit quite a few fires with my 445 and even managed one with the 405 (600mW) so they can easily burn/etch most combustible materials.
I would recommend building your own also because you can say you built it and you will respect it more.
There is a temptation to misuse some of these things and building it yourself is usually enough to keep your head right when you do use it.

 

[TheTeslaWarrior]

if you are willing to treat ir with the respect it deserves, then you have three options co2, solid state, or diode. Co2 can achieve the highest power continuous wave laser you can get, however the bare tubes require a high voltage PSU and water cooling. I would not recommended co2 to anyone new to lasers or hv (i wouldn't recommended any of these to someone who doesn't have the sense to while using a 450mW green laser). Solid state lasers have enormous power for a very short amount of time. some solid state systems will deliver 200mJ which my not sound like mush but in 4ns, that is 50KW. Even if the solid state laser is visible, it will blind you many times over before you can blink. The 808nm laser you mentioned is a diode based laser, diodes can be incredibly compact and powerful with diode bars reaching above 100W of continuous wave laser radiation. Diode bars need cooling, usually by TEC or water cooling, they need lots of power (I've seen diodes that run in excess of 100amps), and due to their horrible beam properties they require a large amount of optics to get anything reasonable. these lasers can and will blind you if misused. Safety glasses are a MUST i cannot stress this enough. Even diffuse reflections will cause permanent blindness. Please, if you are going to buy one of the aforementioned lasers, treat it with the utmost respect.

 

[Don't Laze Me Bro]

if you are willing to treat ir with the respect it deserves, then you have three options co2, solid state, or diode. Co2 can achieve the highest power continuous wave laser you can get, however the bare tubes require a high voltage PSU and water cooling. I would not recommended co2 to anyone new to lasers or hv (i wouldn't recommended any of these to someone who doesn't have the sense to while using a 450mW green laser). Solid state lasers have enormous power for a very short amount of time. some solid state systems will deliver 200mJ which my not sound like mush but in 4ns, that is 50KW. Even if the solid state laser is visible, it will blind you many times over before you can blink. The 808nm laser you mentioned is a diode based laser, diodes can be incredibly compact and powerful with diode bars reaching above 100W of continuous wave laser radiation. Diode bars need cooling, usually by TEC or water cooling, they need lots of power (I've seen diodes that run in excess of 100amps), and due to their horrible beam properties they require a large amount of optics to get anything reasonable. these lasers can and will blind you if misused. Safety glasses are a MUST i cannot stress this enough. Even diffuse reflections will cause permanent blindness. Please, if you are going to buy one of the aforementioned lasers, treat it with the utmost respect.

This man knows his sh*t. I second this, and don't really have anything more to add. Thank you tesla for putting this out here, :thanks::gj::topic:

 

[rhd]

This is slightly off topic, but I didn't want to create a whole new thread for it.

Regarding laser diode bars -
I've never seen one in person. What is the width of the point of emission? It looks like it could be as wide as half an inch? But I've never seen any photos with anything in them for scale, nor any spec sheets.

Is my understanding correct, that the axis that diverges fastest is the vertical? IE, the beam gets TALL (floor-to-ceiling) quite fast, but doesn't get wide as quickly?

If that's the case, then couldn't you put something like these:
PRECISION PCX CYLINDRICAL LENS 25MMX6MM, 6.4MM FL - Surplus Shed
PRECISION 60MM X 22MM PCX CYLINDRICAL LENS 24.4MM FL - Surplus Shed
PRECISION 35MM X 16MM PCX CYLINDRICAL LENS 95MM FL, CTD - Surplus Shed
In front of the point of emission to tame the fast axis, and then a regular convex lens to get a tight beam?

I'm not looking to jump on this - just a curiosity.

 

[TheTeslaWarrior]

you would want to set up some kind of corrective optic setup like anamorphic prisms, or anamorphic lenses. billg519 made a video with a diode bar using an anamorphic lens setup
here: YouTube - 60 Watt IR Laser Diode Does Some Burning

 

[Prototype]

With the CCP package bars (the most common you probably see on eBay) are about the size of a quarter, the emitter package is quite small. Well less than half an inch, maybe a cm or so wide at most, even for the stronger ones.

 

[rhd]

That's a neat video. I wish I could see more of his optics setup in that video. I see the one cylindrical lens, but can't tell what else he is using. Although I'm glad there's not too much spoon feeding going on in that youtube clip. I can just imagine a kipkay "here's how to burn through your school's brick walls from a hundred yards" video...

Do either of you know of a graphic off hand that helps visualize what the bare "beam" looks like coming out of a diode bar? I have trouble decoding written explanations into an understanding of something three-dimensional, without seeing it. I'm still not clear on what the bare emission looks like three dimensionally.

 

[Prototype]

He's using a lensed bar, in that the metal package houses an internal thermistor, TEC, and lens, so the output isn't true, other than the two lenses shown that's all he's using. Here's the 'raw' output of the same type of bar, albeit it at lower power:

 

[rhd]

Interesting - it looks like one of the axes isn't diverging at all - the vertical (?) axis stays razor thin ?
That's raw, no optics at all ?

EDIT: Nevermind, I watched closer, and it is diverging.

 

[TheTeslaWarrior]

EDIT: the video proto posted has optics built into the housing.

 

[rhd]

EDIT: the video proto posted has optics built into the housing.

In the bottom right of that photo, I can't tell what the red beam is doing vertically. I can see it expand horizontally, but is is expanding vertically also?

 

[anselm]

but is is expanding vertically also?

Physics tells us it HAS to.

 

[rhd]

Physics tells us it HAS to.

Physics prevents a perfectly parallel beam of light?