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Divergence

brendon7358

brendon7358

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Which 520nm (or 515nm) diode has the best divergence? I don't care about the power. Are dpss 532nm lasers still better? What's the best divergence diodes available in any wavelength? I read about the lpc-826 is that still the best? I want to build a laser, and I want the divergence to be the best possible. :thanks:
 





As far as I am aware DPSS modules have better divergence over all, than direct diode lasers. :thinking:
Hopefully someone that knows for sure will chime in.

Just so you know, the new n450 and the n465 produce a real nice beam with some nice divergence, if your interested in a higher power unit. :thinking:
 
These are the lowest divergence Diode lasers I have found so far (re-branded Blue Sky Research modules)

Top notch model had 0.02 mrad divergence, IIRC.
Some DPSS could have even lower

Long Distance Targeting Lasers | Global Laser

Blue Sky Research - Home

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EDIT

MiniLase OEM Modules Datasheet (PDF) >>

minilase.jpg


 
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The sharp 505nm diodes basically don't diverge. Seriously.

Spot at aperture:


Spot at 50 feet, with the focus a little less than perfect:




Edit: and video evidence


You're also good with the pl520 and the pl520b, though the plp520b is multimode (albeit barely) and won't have as good divergence.

Sharp's is the best though.
 
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Yup my PL520 is quite good even with a G2..
For higher powers the PLTB450B is really great and cheap on Dtr's sight.

I also thought the 209's and 12x's 405's were just about the best??
 
The sharp diodes slightly outperform the 209's for divergence. Not sure about the 12x's

Edit: cross referenced, at 50 feet I see no winner between the bdr-209, the sharp 505nm, and sharp 480nm
 
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Wow, so those 505’s and 480’s are also have incredible divergence which I wasn’t aware of. Thanks for sharing that.
 
Yep. The WL was more important at the time. Knowing that they are also great with beam quality is now making me want one even more. :p
 
BobMc said:
As far as I am aware DPSS modules have better divergence over all, than direct diode lasers. :thinking:
Hopefully someone that knows for sure will chime in.

Just so you know, the new n450 and the n465 produce a real nice beam with some nice divergence, if your interested in a higher power unit. :thinking:
Click to expand...

DPSS generally offers better divergence, at least assuming the beam quality is good and the laser is producing a nice Gaussian beam, which is easier to achieve with high powered DPSS compared with high powered direct diode lasers. Single mode diodes can be rather good too but the power is generally lower, with a few exceptions.

ZRaffleticket said:
The sharp 505nm diodes basically don't diverge. Seriously.

Spot at aperture:


Spot at 50 feet, with the focus a little less than perfect:




Edit: and video evidence


You're also good with the pl520 and

Sharp's is the best though.
Click to expand...

Impressive! Still need to get my hands on one of those...
 
I am surprised the divergence is that low, also those diodes on that list, huh? That's incredibly low.
 
Not sure what you are meaning by diode divergence. Raw diode or divergence of a diode + lens or lenses.

The raw uncorrected beam from any laser diode has very high divergence due in part to the fact that the cavity is a few mm long (if that).

Divergence of a pointer beam is more a matter of optics employed than raw diode divergence.
 
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Alaskan said:
I am surprised the divergence is that low, also those diodes on that list, huh? That's incredibly low.
Click to expand...

One of their descriptions say they use a long focal length lens. The beam diameter on a red laser is 14mm.
 
brendon7358 said:
I want to build a laser, and I want the divergence to be the best possible. :thanks:
Click to expand...

Take any single mode laser and work on optics to get a desired divergence. Hint: a telescope helps a lot.

If you have some other constrains, then you need to spell them out.
 
I just want to build a simple pen or small laser that looks like it goes on forever. My first laser was a 532nm from ebay and the divergence was fantastic. I didn't realize it until it broke and the laser I replaced it with (also a 532nm) was much worse, could have been because it was more powerful so I could notice it more though. I have had a pl520 before and I remember it being really good, I just didn't remember what diode it was. I took the laser out after not using it for a few months and it didn't work anymore. Anyways, in short I want to build a small simple laser that has good enough divergence that it looks like it goes on forever. Preferably powerful enough to see on the clouds. A 12x that can pop balloons at 100ft would be awesome but unfortunately I wouldn't really be able to see it much at that distance.
 
I'm guessing your PL520 is the *sram unit for $25 on Dtr's sight..
Mine is in a pen size defiant flashlight host and is doing 100mw at .325mA with the G2.
I see your sig shows a 515nm diode, are you not happy with the spec's or is it just under powered?
 
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