Noob question  - Need help building laser.

Hi everyone,

As you can see I am new to these forums. I have some experience with lasers and electronics, so I'm not going to burn my eyes out or shine lasers at airplanes or anything. I am planning on building a red burning laser but I need a little help.

Things I have obtained:
I have a broken flashlight that can hold 2 batteries and has a switch.
I have bought a 650nm 245mW LD from here (still in the mail): I have an Aixiz laser module with driver board and 5mW LD. Link: (Interesting note: it used to eat batteries a little, but then the power wires broke off, so I resoldered them to a different part of the laser, and now it's really bright and efficient, and has not been damaged through normal operation.)
And about $20 in my PayPal account in case I need to buy anything else.

Questions:
Do I need to get anything else?
Does the 5mW driver board work with the 245mw LD? If not how can I get the proper driver board.
Do I need to worry about heat during normal operation?
I was going to get a True 50mW, True 100mW or non-true 200mW green laser from DX. (I know they aren't that great. But I can't afford anything quality.) Which one should I pick, and are there any concerns?

And if you have any other information that would help me a lot.

Thanks.

Re: Noob question  - Need help building laser

I'll leave the lazor-building question to the pros, but what I do know is get the True 50, because it has an IR filter and will be more reliable. If you want to buy something more powerful, fork out for a Nova X-series (X125 with carrying case and membership is $300). The X125 will be above spec guaranteed and will be virtually IR-free. It will pop balloons and light matches. With the DX 200, it might be 80mW of green +100mW of IR :-/ Not good... and that's if you're lucky. Get a low-power laser first... the True 50 has a good visible beam at night and will pop balloons with any luck.

Oh, and get some eye protection especially if you're going to have a 200mW red! People have injured their eyes permanently with 100! OD2 will do, it's better to be hit by 2mW than 200. WickedLasers can set you up with LaserShades with fast shipping for cheap.

Re: Noob question  - Need help building laser

Minousoft said:

Do I need to get anything else?

Click to expand...

You need a driver to power the diode, otherwise you'll kill it by connecting it straight up to the batteries.
You can either build your own, (here's a thread, and here's a video tutorial) or you can buy one, either this one or this one.

Minousoft said:

Does the 5mW driver board work with the 245mw LD? If not how can I get the proper driver board.

Click to expand...

No, that driver will not work with the high powered LD, (btw, that's not a 245mW LD) you need to build one or buy one, check the links above.

Minousoft said:

Do I need to worry about heat during normal operation?

Click to expand...

Of course you need to worry about it, heat kills laser diodes. I recommend you don't go over 250mA when using this LD, you can get away by using the bare aixiz module as a heatsink as long as you don't keep the laser on for more than a minute. If you want to keep it on longer I suggest you get a heatsink for the aixiz module. Just get a chunk of aluminum and drill a hole through it, either big enough for the module to fit in and then use thermal epoxy to glue it to the heatsink, or make the hole big enough so that the module needs to be pressed into the heatsink with a vice, the point is to get the module to fully connect with the aluminum heatsink for heat dissipation.

EDIT: Also, get a pair of safety goggles, remember, you only get one pair of eyes.

Re: Noob question  - Need help building laser

Thanks for the replies - I have got some better ideas for my laser now. However, I've got more questions now.

Does the 5mW driver board work with the 245mw LD? If not how can I get the proper driver board.

No, that driver will not work with the high powered LD, (btw, that's not a 245mW LD) you need to build one or buy one, check the links above.

Click to expand...

Umm, chido... just one thing... what exactly do you mean by "that's not a 245mW LD"?

---

More questions:
So, to clarify, the driver board that comes with the Aixiz laser, with the 5mW laser attached won't work if I solder on my DVD LD instead?
Do the DVD LDs emit IR?
I know IR is dangerous, but why? If it's collimated with the beam, well... you aren't supposed to look at the beam anyway, so precautions could be taken not to hit shiny objects or stare into it. If it leaves the laser aperture as a cone (like a flashlight) then theoretically the IR power would drop as the viewing angle+distance increases. Or something.
Does IR 'burn things' faster than visible light?
Just a side thought: If there is a material that is clear for visible light, but reflective for IR (instead of absorbing), then I think that could boost the 532nm output of unfiltered DPSS lasers by reflecting IR leaks back into the DPSS crystals. Or would that just fry the laser...?
Are eBay laser goggles OK or do I need to get the more expensive WL ones?
How much heat does the DVD diode put out? Is it dangerous to run for more than a minute w/o extra heatsinks?

:exclamation Big scary laser: Do not stare into beam with remaining eye. ;D

Re: Noob question  - Need help building laser

Minousoft said:

Umm, chido... just one thing... what exactly do you mean by "that's not a 245mW LD"?

Click to expand...

The 245mW is just for advertisement, here's the diode's power graph:



I don't recommend you get past 250mA with this diode, otherwise you'll significantly shorten its lifespan and you also risk killing it, the diode should put out around 180mW at that current.

If you want a bit more power then I suggest you get a StoneTek/SenKat diode. Hemlock Mike tested one at 400mA for 14 hours without any issues at all, the diode was putting out around 240mW. But I don't recommend you get past 350mA just to be safe, the diode would still put out around 220mW at that current which is fantastic. Here's its power graph:

Minousoft said:

So, to clarify, the driver board that comes with the Aixiz laser, with the 5mW laser attached won't work if I solder on my DVD LD instead?

Click to expand...

Nope, like I said, it won't work. It's simply because the driver board is designed to provide power to a lousy 5mW LD, if you connect your high powered laser to it it will either put out 5mW only, or put out way less than that.

Minousoft said:

Do the DVD LDs emit IR?
I know IR is dangerous, but why? If it's collimated with the beam, well... you aren't supposed to look at the beam anyway, so precautions could be taken not to hit shiny objects or stare into it. If it leaves the laser aperture as a cone (like a flashlight) then theoretically the IR power would drop as the viewing angle+distance increases. Or something.

Click to expand...

DVD burner red laser diodes do not emit IR, they only emit 650 - 660nm red light. The IR problem is common with unfiltered green DPSS lasers.
IR is dangerous because you can't see it, if it's hitting a reflective surface and it's hitting your eyes you won't notice until it's too late. Plus IR light is reflective to things that normal light wouldn't be so you can't play around with an IR laser without any eye protection and expect to be safe as long as you don't hit any shinny surfaces. For example, coke is opaque to visible light but it's transparent to IR light.
You're right about the cone thing, many DX 30 True green lasers emit a bit of unfocused IR light, but since the mW aren't great, it doesn't really present a problem. Now if it's a high powered IR laser than it's still dangerous, imagine focusing the dot of a red high powered laser to a diameter of 30 cm, sure it's big and thus the mW per cm2 have been lowered but it can still cause some damage to the eyes.

Minousoft said:

Does IR 'burn things' faster than visible light?

Click to expand...

Well, it depends on a lot of things, 100mW is 100mW no matter what the nm is, it can be green, blue, red, violet, pink, whatever but 100mW will always be 100mW. The key is how much of a certain wavelength the material you're trying to burn will absorb, a piece of red plastic will reflect a red light so it would be a little hard to burn it with a red laser, but if you used a green laser you shouldn't have any problems at all smoking it.

Minousoft said:

Just a side thought: If there is a material that is clear for visible light, but reflective for IR (instead of absorbing), then I think that could boost the 532nm output of unfiltered DPSS lasers by reflecting IR leaks back into the DPSS crystals. Or would that just fry the laser...?

Click to expand...

What you're talking about is an IR filter, and IR filter is used in DPSS lasers to let the visible light through but to reflect any left over IR light that might get past the crystals, and no it won't fry the laser.

Minousoft said:

Are eBay laser goggles OK or do I need to get the more expensive WL ones?

Click to expand...

I wouldn't trust ebay laser goggles, most of them are from some companie over at China and they're probably crap. Don't be cheap, they're your eyes so get yourself a pair of proper safety goggles. Get the ones from StoneTek, they're 15 bucks cheaper than the ones sold directly from WL.

Minousoft said:

How much heat does the DVD diode put out? Is it dangerous to run for more than a minute w/o extra heatsinks?

Click to expand...

That depends on the kind of DVD diode and the current it's being driven at, I already told you what the safe current for the HighTeckDealz diode is, you can get away with the bare aixiz module but don't keep it on for a long time.

Hope this helped.

Re: Noob question  - Need help building laser

Thanks... I needed the info. Didn't expect such a quick response though!

Re: Noob question  - Need help building laser

Minousoft said:

Thanks... I needed the info. Didn't expect such a quick response though!

Click to expand...

Yeah, I didn't check up on the forum a lot the other day, sorry it took me a whole day to answer. Wait.....are you serious or are you being sarcastic? :-? ;D

Re: Noob question  - Need help building laser

chido said:

[quote author=Minousoft link=1211349507/0#5 date=1211522791]Thanks... I needed the info. Didn't expect such a quick response though!

Click to expand...

Yeah, I didn't check up on the forum a lot the other day, sorry it took me a whole day to answer. Wait.....are you serious or are you being sarcastic? :-? ;D
[/quote]

LOL YOU are a nut, sir !

Re: Noob question  - Need help building laser

A nut..... excuse me? ;D

Re: Noob question  - Need help building laser

LOL... I was being serious.