What is this laser? Greenie 300 mW with active Temp regulation

[Hiemal]

Hey all.

I traded gren on here a 445 nm build for a 300 mW (supposed) greenie. It's relatively old, and apparently he had paid $500 for it a few years ago when he got it.

This thing is hefty, and looks a lot like a German grenade from WWII!

However, I've had a few small issues with it, and would like to ask a few questions....

Anyway, before I ask those questions, I need to show a few things;

This laser runs off of one 18650, which is pretty nice. Times between charges are pretty low, as the laser draws something like 2-3 amps of current, depending on how fresh the battery is...

There's a beamshot of it.

I've taken the top part of it off and peered inside of it, and found the green module. It has an IR filter built in, and looks to be nice quality. You can see the crystals inside, and they're separate and rather large. I also got a peek at the pump diode; a C-mount!

Unscrewing the top half reveals something rather cool; the laser has [DEL]active TEC cooling[/DEL] not really I guess, and temperature regulation. When the laser gets too hot, the driver will automatically throttle the laser down, so that it does not destroy itself. Pretty awesome!

Shows the thermistor; the little black thing with two wires hanging out in the middle of it all.

And this is a rectangular mode laser.



So, my questions are;

1. What module is it? I think I've seen one before on here but I can't remember where...

2. The lens for focusing it is kind of derpy; it's a C@sio lens JBwelded onto the focusy bit. It's sort of scratched and the dot gets clipped, and is also very splashy. I'm also having issues getting the beam centered. What do?

3. Was this is a good trade on my part?

4. Is the rectangular mode expected of a laser of this power? The dot when unfocused sort of "jiggles" but doesn't seem to really mode hop... it's sort of neat to watch.


Overall, I like the laser module but not the laser itself. I rather wish I could put it in a new host as the current one isn't to my tastes. Any ideas?

Thanks for your help!

 

[Sigurthr]

Re: What is this laser? Greenie 300 mW with active TEC cooling

If it's >200mW it is a good trade in my book, especially since it had active temperature regulation.

The square mode is normal for a high power C mount diode, and it looks to be pretty clean and even output.

Lenses are lenses, especially when you're dealing with green since we don't have an AR coated one available to us. Nothing wrong with the C@$!0 being used if it collimates well.

Nice laser Jared.

 

[Hiemal]

Re: What is this laser? Greenie 300 mW with active TEC cooling

If it's >200mW it is a good trade in my book, especially since it had active temperature regulation.

The square mode is normal for a high power C mount diode, and it looks to be pretty clean and even output.

Lenses are lenses, especially when you're dealing with green since we don't have an AR coated one available to us. Nothing wrong with the C@$!0 being used if it collimates well.

Nice laser Jared.

Actually, I took it apart competely, and couldn't find a TEC... what I thought was the TEC was actually a mosfet. Unless it's hidden where the laser diode is of course, which doesn't make sense as the diode part of it only has one wire going to it.

 

[Sigurthr]

Re: What is this laser? Greenie 300 mW with active TEC cooling

Hmm, 4A draw is pretty damn excessive for no TEC, especially given the Vf for IR diodes.

 

[Hiemal]

Re: What is this laser? Greenie 300 mW with active TEC cooling

Hmm, 4A draw is pretty damn excessive for no TEC, especially given the Vf for IR diodes.

Well, I had gotten the laser for a short amount of time before this and I had measured it...

I think I got something mixed up, because I measured around 2.11 amps of draw tailcap current. But the li-ion I'm using needs to be charged.

 

[RA_pierce]

Those are Chinese lasers. Those modules used to be sold at O-like (not sure if they still are).

The beam profile of the green is not directly influenced by the shape of the pump diode's output.
The diode pumps the medium and the medium emits its own light.

I think it is common for high power portable DPSS lasers to have less than ideal beam characteristics.
Of course, the more money you spend, the better your beam can be (take the Hercules for example).

Here is a link to a laser from O-like:
http://laserpointerforums.com/f52/400mw-532nm-laser-torch-o-like-photos-video-62898.html
Scroll down toward the bottom of the first post for the images of beam profile and video of mode shift.

And here is the profile of the beam from a CNI PGL-III-C 400 (similar to Aries).


Neither of these lasers have a perfect profile but both are still circular.
The CNI PGL I had would peak above 800mW and averaged 650-700mW over a few minutes and actually produced higher power when the mode was "worse."

 

[Hiemal]

Welp, I measured the draw, again, and got 2.5 amps with 4 volts on the battery...


I need fresh 18650's. All of mine are old.

 

[jimdt7]

Nice laser you got there !
My O-like Crown 600mW, also has
a thermistor next to the diode !
Both module designs look pretty similar.

Jim

 

[Wolfman29]

Looks like a CNI build. If that's the case, they are using a linear driver, so it doesn't matter exactly how old your batteries are

 

[Hiemal]

Looks like a CNI build. If that's the case, they are using a linear driver, so it doesn't matter exactly how old your batteries are

Why does it draw more current the more charged the battery is then? It drew 2 amps with a battery at 3.6 volts. with 4 volts it drew 2.5 amps.

:thinking:

Explain that!


It really needs some fixing up though. New lens (splash is absolutely horrendous at the moment), perhaps some centering (the beam is NOT centered at all, comes out at an angle), etc. I would also like it to be LPM'd...

I Pm'd Lazeerer about it but he seems to be ignoring me...

Could you do it Wolfy?

 

[Wolfman29]

I could definitely LPM it, but I wouldn't trust myself to do any realigning on it I love LPMing new lasers though... especially ones I have never seen before!

And it may draw more current on a higher voltage battery because it may not be in regulation with the lower voltage. These typically operate between 3.7 and 4.2V, right? So 3.6V may be out of regulation, and we know exactly how much .1V difference in Vf makes for current.

 

[Hiemal]

Okay what the hell.

So, he lied about the IR filter too, apparently. That or the filter in place is shit, because take a look;

Oh lookie that, IR. :I

I wonder how much power it actually is.

 

[Oceansoul]

That's not a CNI host.

That's similar to the hosts Viasho use, except I suspect this one's been heavily modified (they don't come with a push-button on the back of the thing, and they're anodized black).

He must've removed the anodizing from the host himself.

Anyway, as for the module, they're a special form factor that we just call '26.5mm modules' around here because that's how wide they are.

There's no 'standard' for them as there exists with 12mm modules; it's just become a de facto standard for high-powered green modules as you can only get >200mW handheld modules in them.

You can also get 473nm modules in that size as well.

TEC regulation is standard with those units, as is the C-mount pump. Some of the more expensive models also have active optical feedback.

As for the beam mode -- two factors come into play:

1. A C-mount diode ass-rammed onto a block of Nd:YVO4 hardly makes for ideal pumping.

2. You're trading off a half-decent mode for more power.

When a laser runs in TEM00 only a small area of the gain medium is used. In a higher-order mode, more area of the gain medium can lase, resulting in a higher power output, but also a potentially-terrible beam.

That'd also account for RA_Pierce's observations.

At the very least, the beam profile looks regular. Square isn't nearly as bad as it could be.