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FrozenGate by Avery

Green 10K Long Distance Pointing

Alaskan said:
Very nice, thank you for sharing. I've long wanted to know how that diode performs at distance with a beam expander on it. I did a divergence calculation using the pseudonomen link in my signature and, if I did everything correctly, the divergence comes out to be somewhere from .09 to .14 mRad using the 3X expander, based on having a 1 and 1.5 meter spot at that distance.

pseudonomen137's JScript mRad Calculator
Click to expand...

Thank you!
PLP520 B1 is one of my favourite diodes.

My 520nm PLP520 B1 divergence results:

Beam at 0 meters (without beam expander) : 3mm
dot at at 4500 meters : 1,5 meters (1500mm) (without beam expander) Youtube video >

Result: 0.3326666543949145 mRad


Now, if we add Sanwu X3 beam expander :
0.3326666543949145 mRad
divided by three
=
0.110888885 mRad


If I got it all right... :thinking:



BTW Alaskan... I assume you have same problem with DPSS lasers: They just don't work in cold weather :D
I have used PLP520 B1 in winter at -15°C many times and: It Just Works
 
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I have a 10x beam expander and some very powerful diodes to use it with. I wonder how far I could get it, given that my 10x can go up to 20x if you truncate the wings. What did you take the pictures with and use to zoom?
 
DPSS does not work very long outside in the winter where I live, right about that, but diodes like it cold :

Without beam expanders I would own far less pointers. My largest BE is 160X for my PL520 laser but it is very heavy, must sit on something. You can see it in my avatar photo's with the the beer bottle next to it and another pointer.
 
Alaskan said:
Without beam expanders I would own far less pointers. My largest BE is 160X for my PL520 laser but it is very heavy, must sit on something. You can see it in my avatar photo's with the the beer bottle next to it and another pointer.
Click to expand...

Post a photo of it would ya.
 
My, my... for divergence...The "B1"....IS "tighter than a......" well....you know !!!

Quite the Farfield geometry....no cylindrical's and no BE....and the LD is a MM !!

It is perfect for a small EDC !!! Thanx for the share ! :p
 
ArcticDude said:
I would love to see that X160 too! :drool:
-Any divergence test / data with PL520+X160? -Or beamshot pics?
Click to expand...

I used it to put a nice beam into the night sky a few times, but never bothered to make divergence measurements. No photo's of that unit in operation, unfortunately. It was so darn heavy I couldn't use it except with both hands and arms to hold it.
 
I suppose you could put a tripod mount on it?

A decent full size photography tripod can carry several kilograms, more if you manage to put the mount somewhere near the center of gravity of the beam expander, similar to how they mount really large and heave telelenses.
 
some advice:1.make sure you wear the goggles 2.keep your laser away from trees!
 
I get the goggles, but are you affraid you'll burn through a tree and it falls on your head or something? :)
 
A PL520 single mode laser diode at less than 100mw output when expanded to close to six inches diameter is so diluted you can't even feel anything putting your hand in front of the output lens for as long as you wish.

At 160X expansion, that means the input beam must be under 1mm wide with a 150mm diameter output lens, anything larger and the beam will be clipped. Even though the beam is weak looking, it sure can put a nice spot on a high cloud :)
 
Probably. It would also be pretty safe to work with - if you expanded 100 mW to a 150mm circular output it would actually be perfectly safe to directly look into that if the brightness distribution is somewhat uniform.

One advantage of beam expanders is that they make lasers less dangerous to use, distributing the power over a large area like that can make a class IV laser completely harmless if set up correctly.
 
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