Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

WTB: NUBM44 Build

Alaskan

Alaskan

0
Joined
Jan 29, 2014
Messages
12,031
Points
113
Some DPSS lasers give good specs, Laserglow pointers are excellent and stable, there are other pointers which are a great deal for the money such as JetLasers 532nm DPSS pointers, but they do not have nearly as stable output power compared to Laserglow pointers. However, all DPSS lasers suffer from temperature variations and don't work well in the cold, if at all, depending how how cold it is. In Alaska the winter is so cold a DPSS laser doesn't run very long when going outside, the pointer cools off too fast but diode laser pointers don't suffer from this, they like the cold. If you want the best beam specs, laser diodes are crap compared to gas lasers, but as you know, they aren't compact and normally run off of AC power.
 





diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Alaskan said:
Some DPSS lasers give good specs, Laserglow pointers are excellent and stable, there are other pointers which are a great deal for the money such as JetLasers 532nm DPSS pointers, but they do not have nearly as stable output power compared to Laserglow pointers. However, all DPSS lasers suffer from temperature variations and don't work well in the cold, if at all, depending how how cold it is. In Alaska the winter is so cold a DPSS laser doesn't run very long when going outside, the pointer cools off too fast but diode laser pointers don't suffer from this, they like the cold. If you want the best beam specs, laser diodes are crap compared to gas lasers, but as you know, they aren't compact and normally run off of AC power.
Click to expand...


Yeah - DPSS is the way to go for beam specs, unless you live somewhere like here or Alaska. Could always wrap a small electric blanket around the host... :D

Also ... just to be picky - that's pretty compact!:

henelp1.jpg


:p
 
Last edited:
  • Like
Reactions: GSS
Lolvo

Lolvo

0
Joined
Dec 8, 2012
Messages
171
Points
0
So what are my limitations of using DPSS? Could you not in theory take the build that's proposed here and just replace the NUBM44 with a DPSS?

Is there a significant difference in beam quality between the two, or is it just about knowing one is better than the other?

It doesn't get terribly cold here, but winter with snow is some of the best times to break out the lasers :) Is temp that significant of a factor?
 
Last edited:
diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Lolvo said:
So what are my limitations of using DPSS? Could you not in theory take the build that's proposed here and just replace the NUBM44 with a DPSS?

Is there a significant difference in beam quality between the two, or is it just about knowing one is better than the other?

It doesn't get terribly cold here, but winter with snow is some of the best times to break out the lasers :) Is temp that significant of a factor?
Click to expand...

You could replace the entire module (Diode, diode holder [aixiz module usually], lens etc) with a DPSS module, yes. Although you won't get anywhere near as much power as a NUBM44. If you want high power DPSS and portable you're better buying something commercially made. You're still not going to get close to 7W though. At least not in a handheld.

There is a massive difference in beam quality - you'll usually get a round spot, small beam diameter and good divergence with a DPSS laser. With a diode laser like the NUBM44 or similar you get a large rectangular stripe, larger beam diameter and worse divergence.

Diode - unsure on distance here - Anyone have one with a measurement/something for scale handy? This at least gives you an idea of the shape...

2b0j.jpg


Gas - probably from 20ft or so if I had to guess (Close enough to what you'd expect from DPSS - couldn't find a good example for DPSS). Lots of mess around the beam - probably from dirty optics:

5477979898_18a45c21a0_z.jpg


DPSS is really quite temperature sensitive - it'll work outside it's normal operating range but at lower powers/different transverse modes. Get too hot or too cold and it'll stop functioning entirely. DPSS pointers will work just fine as long as you don't stray too much from normal room temperature.
 
Last edited:
Alaskan

Alaskan

0
Joined
Jan 29, 2014
Messages
12,031
Points
113
Of course, there will always be an exception to any monism or statement, I was thinking of lab units which are more powerful.
 
brendon7358

brendon7358

0
Joined
Jul 2, 2011
Messages
1,011
Points
63
Alaskan said:
Edit: Diachi, I deleted my last post and put it after yours, we were writing at the same time, but I was slower:

The NUBM44 has its divergence reduced enough with a 40mm/1.575 diameter output lens to be satisfactory for many, so you don't have to go to 3 inches to get reasonable divergence, about 1.5 inches is enough expansion and with so much power, even with the beam expanded that far it looks good in the night sky, if you are into that kind of thing and are not near an airport.

When using a G2 or 6mm diameter collimation lens the divergence from a NUBM44 is about 12 mRad (reported, I have not verified), if so, then doubling the beam diameter to 8mm the divergence would be reduced to about 6 mRad, at 16mm wide about 3 mRad, at 32mm wide about 1.5 mRad which is acceptable, but I think it is better to use a 2 inch/50mm diameter lens to reduce the divergence to closer to 1.2 mRad which is excellent. This last figure is basing on using 90% of the aperture of a two inch diameter collimation lens and is a ball park figure.

The difference between 1.5 and 1.2 mRad might not seem significant, but for the same beam diameter (in this comparison it won't be, but close enough for this example) and output power, the light intensity or irradiance (Output power / area of beam spot) is up to 56% greater with a divergence of 1.2mrad vs 1.5mrad.

laser-divergence-graph.gif


When it comes to brilliance to the human eye, 1 watt of 520nm green is brighter than 7 watts of 450nm blue.

Comparison.jpg
Click to expand...


I'm confused, are these hypothetical numbers, or are there other types of beam expanders than the super expensive 5x and 10x ones last I looked into them?
 
diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Alaskan said:
Of course, there will always be an exception to any monism or statement, I was thinking of lab units which are more powerful.
Click to expand...

I know, just being picky for the sake of being picky. ;) :p
 
Lifetime17

Lifetime17

0
Joined
Dec 15, 2014
Messages
6,782
Points
113
hi ,
ill take the 520nm over the 455 or 450nm anyway of the week they are brilliant ..

Rich:)
 
Alaskan

Alaskan

0
Joined
Jan 29, 2014
Messages
12,031
Points
113
Diachi, I've seen small gas lasers, but never one that small which runs off of batteries before.

Brandon, these numbers are just general ball park figures when referencing divergence for the NUBM44, but I don't think I'm too far off.

Regarding beam expanders, what do you consider expensive, which models have you looked at? I buy 10X beam expanders on ebay, although even on ebay usually not cheap for the ones built for lab lasers. I think Dragon Laser made a 10X which wasn't too expensive, JetLasers makes one which is relatively inexpensive but for use with the NUBM44 but you have to focus the output of the G2 lens (or what ever 6mm lens) into a smaller focus than infinity to get it to pass through the small diameter input lens, otherwise the beam is too wide to get through without clipping, then you can adjust the focus range of the BE to bring it back to infinity focus. I learned about this trick from RedCowboy.

edit: I don't know, I'm starting to have second thoughts regarding which diode RCB was talking about with the JL BE.
 
Last edited:
diachi

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
Alaskan said:
Diachi, I've seen small gas lasers, but never one that small which runs off of batteries before.
Click to expand...

Yeah! I had one years ago - those little handheld HeNe lasers pop up on eBay every now and then - though they are hard to come by. I think I bought mine from Daguin.

Anyway - this is wayyyy off topic. I'll let you guys get back to it! :D
 
Alaskan

Alaskan

0
Joined
Jan 29, 2014
Messages
12,031
Points
113
I think we scared him off the NUNM44 diode, but it has its strong points, blue is beautiful and it is one he'll of a burner either close up or focused to a fine spot. Although I much prefer 465 blue over 450. Also, when expanded to 2 inches the NUBM44 has great divergence.
 
Lolvo

Lolvo

0
Joined
Dec 8, 2012
Messages
171
Points
0
Alaskan said:
I think we scared him off the NUNM44 diode, but it has its strong points, blue is beautiful and it is one he'll of a burner either close up or focused to a fine spot. Although I much prefer 465 blue over 450. Also, when expanded to 2 inches the NUBM44 has great divergence.
Click to expand...

Not quite, just seeing what's out there. Although, I saw ArcticDude's NUBM07E, and it was love at first sight. I've got to get me one of those.

Anyway I'm moving all this to my own thread just so this can die in peace since brendon is no longer doing this build.
 
You must log in or register to reply here.





Top