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Diode With 4+ Watts With Best Divergence?

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What the title says. What diode has the best divergence that is over 4 watts?
 



Alaskan

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Doesn't matter how terrible the divergence of a multimode laser diode is, if the beam is expanded enough, the divergence goes down to equal or beat the pants off of the lowest divergence single mode diode using a smaller standard ~6 mm diameter lens. Does this apply to all laser diodes? Yep, every one of them. The price for a custom laser using a big lens is generally higher (well, probably always higher), but due to the far lower divergence which is possible with a fat beam, it can be visible as a beam at much greater distances.

There are inexpensive laser beam expanders which can be had which might fit on to your pointer without too much extra work, but that adds at least two more lenses and due to that more loss and less power out, but if you just use a large collimation lens at the output of the laser diode, only one lens is needed to produce a low divergence beam.
 
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reloader45

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Hello,

at the DTR side, the NDB 7875 has a much smaller dot than the NDB 7A75. Doesn`t that mean, that the divergence is better?


best regards

Edgar
 

trinh hong phuoc

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ndb7875 max iss 3w3-3w5
for 4w+ we have some diode with same divergence:nubm05,nubm06.nubm07 and ndb7a75
nubm0x is gball so it is difficult for newbie(if you decand ,diode will die faster at max current suggestion),so i think ndb7a75 is good,price not bad when use a TIN-PIN diode( 40-50$)
 

GSS

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Hello,

at the DTR side, the NDB 7875 has a much smaller dot than the NDB 7A75. Doesn`t that mean, that the divergence is better?


best regards

Edgar
Yes more or less.
The OP though want's 4W+ I believe and the NDB 7875 only does about 3W's max.
To me 3W is plenty and the 7875 is really close to a M140 as far as divergence. He must has his reasons?
 
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Alaskan

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Yep, if you want 4 watts or more, the choices for acceptable divergence are reduced and the choices worse, that is, unless you use a larger lens with a longer focal length, or put a beam expander on it. To have decent divergence at the higher power levels, either have Lifetime or Trinh make a custom pointer, or buy a JetLasers pointer, they have inexpensive beam expanders available.

Screen shot of JL price with beam expander included:


You would need to check on this, but I believe the divergence would be less than .25 mRad with their BE on it.

If you are going to buy a JL, I'd recommend their 465 nm PLE-Pro instead, although 3.5 watts, it is on sale right now and can also have low divergence with a beam expander you can buy with it as an option, below is the sale price right now with the BE:



3.5 watts of 462-465 nm will be brighter to the eye than four watts of 445 nm!

 
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reloader45

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Hello,

yes, the NDB 7875 has approx. 3 W. Thinking about cutting, this Diode should work well.

Where can I buy bigger lenses? I thought 9mm is the standard diameter.


best regards


Edgar
 

Alaskan

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6.33 mm diameter is the standard for the lens itself, there are a lot of higher power diodes which are 9 mm, maybe that is what you are thinking about, or perhaps the diameter of the lens assembly itself, with threads, are a bit more than 9 mm,
 

reloader45

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Hello,

yes, I mean the diameter of the threads. Are there bigger lenses on the market than 6.33 mm?


best regards

Edgar
 

Alaskan

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Not standard that I am aware of which can fit or thread into a DTR type of laser diode mount, but you can get a beam expander with a 38 mm diameter lens from Sanwu cheap which can be interfaced to a custom laser, or buy a pointer from them which uses it.
 
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Thanks everyone. I'm looking to make a compact hobbie laser gun. I was thinking of combining 2 NUBM44 7 watt diodes to make 14 watts using phase combine prism for combining the 2 beams. But i want the gun to have good range too. How is the divergence on the NUBM44? Would its power make up for range compared to slightly weaker diodes with better divergence?

Ps, I've already made 15-20 laser SMG using 3 laser modules with knife edge combining.
 

Alaskan

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If I remember correctly, the divergence of the NUBM44 using a 6 mm collimation lens is close to 11 mRad, member Redcowboy measured it and can confirm or correct. He is working on combining two NUBM44 diodes soon himself. If you want to make the NUBM44 burn better, use a pair of cylinder lenses to adjust the fast and slow axis to be close to the same dimensions, that is key with that diode. You can expand it too, and have the collimation lens adjustable to allow it to either focus to a point, or be collimated to infinity.
 

cistercian

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Yep, if you want 4 watts or more, the choices for acceptable divergence are reduced and the choices worse, that is, unless you use a larger lens with a longer focal length, or put a beam expander on it. To have decent divergence at the higher power levels, either have Lifetime or Trinh make a custom pointer, or buy a JetLasers pointer, they have inexpensive beam expanders available.

Screen shot of JL price with beam expander included:


You would need to check on this, but I believe the divergence would be less than .25 mRad with their BE on it.

If you are going to buy a JL, I'd recommend their 465 nm PLE-Pro instead, although 3.5 watts, it is on sale right now and can also have low divergence with a beam expander you can buy with it as an option, below is the sale price right now with the BE:



3.5 watts of 462-465 nm will be brighter to the eye than four watts of 445 nm!

I have this laser and mine does 3.8 watts+. I bought the beam expander too for use with my 1 watt 520nm PLE-Pros.
Highly recommended!

The beam is beautiful. I still do not own a 445! I don't plan on it either. This laser has much worse divergence than the 1 watt 520
ones do. At long range it projects a line like all the high power blues do. I have not used the expander on the blue, just the greens.
It works great. I use the 462 for burning...which it is excellent for.
 




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