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Ndg4216

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logsquared

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The spec sheet raw divergence numbers have very little to do with the divergence of the beam after collimation. Its the size of the emitting area(for some dumb reason its not listed on most spec sheets).
 
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Atomicrox

Atomicrox

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Not sure about the acrylics, but at this power they should be fine.

TBH I don't like G lenses at all because of the splash/divergence, but I'm pretty curious about the G7!

Having the emitter area would be better, but AFAIK the ratio of the raw divergence of the two axes (sp?) determines how much "faster" the fast axis is in relation to the slow axis. If the ratio is closer to one the dot will be more circular and the final divergence will be usually better.
 
RedCowboy

RedCowboy

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logsquared said:
The spec sheet raw divergence numbers have very little to do with the divergence of the beam after collimation. Its the size of the emitting area(for some dumb reason its not listed on most spec sheets).
Click to expand...

Yes that's true after collimation, but by choosing the power of the lens and the focal length as the raw output diverges you can set the beam width, but the shape will be a reflection of the parallel and perpendicular ratio, in this case it should be a rectangle that is 2.5 to 1
 
Pi R Squared

Pi R Squared

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RedCowboy said:
Yea it will probably make a pretty decent looking beam with out common lenses, I wonder is the acrylic lens will be the best choice?
I am still waiting for my G7's from podo, been about a week and a half now.
Click to expand...

If I were you I would try all 3 types of lens and see what works best. With my PL520 I got terrible results with a 3 element, and excellent results with an acrylic.

Atomicrox said:
Not sure about the acrylics, but at this power they should be fine.

TBH I don't like G lenses at all because of the splash/divergence, but I'm pretty curious about the G7!
Click to expand...

I have seen others say this and I can't understand it, yes the divergence is bad with a G2 but I am unable to get any splash from one on any laser. I always get splash from a 3 element, and with an acrylic you may get 3 lines on either side like this: ((( O ))) but they go out at such a sharp angle that my SL extended focus ring blocks those lines and I get a nice dot with no splash.

Alan
 
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logsquared

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Yes that's true after collimation, but by choosing the power of the lens and the focal length as the raw output diverges you can set the beam width, but the shape will be a reflection of the parallel and perpendicular ratio, in this case it should be a rectangle that is 2.5 to 1
Click to expand...

My bad! I just assumed when the word "beam" and "divergence" was used it was referencing the the typical spread of the beam in a device. Like the beam emitted from a laser pointer. But you are correct the raw "data sheet" divergence is what (plus the lens) determines the size and aspect ratio of the beam right after it leaves the lens. Sorry, I'm here to learn. I mostly build projectors so the pointer lingo is new to me. So its typical for pointers divergence to be characterized by the size and shape of the beam as it leaves the pointer? Not the spread of the beam through free space?

I will get it right eventually.

In any case I am ordering one of these. The color really intrigues me. I have a spectrometer up and running so I can post the wavelength (and beam size shape too)
 
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crazyspaz

crazyspaz

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More expensive (and not a new) alternative to an existing diode? Why...?
 
joeybab3

joeybab3

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Hmm may have to test this with my pl515 if i end up buying one of these...
 
RedCowboy

RedCowboy

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joeybab3 said:
Hmm may have to test this with my pl515 if i end up buying one of these...
Click to expand...

I would like to know what nm the output is at 200mw or where ever we will be running them.
I know I have been dreaming of a 500nm laser, that will be gorgeous.
If these are a lot different than 520 then I will have to get one, I just have so many 532's and so many "want to" projects.
If I could just find and shake the hell out of that elusive money tree I would get 3 of everything I saw. lol
Maybe someone with a really good camera can get a side by side that shows the difference, or if everyone is saying WOW then that will work too.
 
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Atomicrox

Atomicrox

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Pi R Squared said:
I have seen others say this and I can't understand it, yes the divergence is bad with a G2 but I am unable to get any splash from one on any laser. I always get splash from a 3 element, and with an acrylic you may get 3 lines on either side like this: ((( O ))) but they go out at such a sharp angle that my SL extended focus ring blocks those lines and I get a nice dot with no splash.
Click to expand...

That's weird. I get a lot of splash on all blue multimode diodes with all single element lenses I've tried so far. There are lots of pictures of that sort of splash on DTR's site:
z3v0.jpg

1lwb.jpg


I also like to run my buck-driven lasers with a single battery for low power and the splash gets even worse.

That sort of splash disappears almost completely with 3 element lenses. It usually leaves two small "wings", but as you said a proper focus ring fixes that.

logsquared said:
My bad! I just assumed when the word "beam" and "divergence" was used it was referencing the the typical spread of the beam in a device. Like the beam emitted from a laser pointer. But you are correct the raw "data sheet" divergence is what (plus the lens) determines the size and aspect ratio of the beam right after it leaves the lens. Sorry, I'm here to learn. I mostly build projectors so the pointer lingo is new to me. So its typical for pointers divergence to be characterized by the size and shape of the beam as it leaves the pointer? Not the spread of the beam through free space?

I will get it right eventually.

In any case I am ordering one of these. The color really intrigues me. I have a spectrometer up and running so I can post the wavelength (and beam size shape too)
Click to expand...

When we say divergence we mean the spread angle that a beam focused to infinty has in relation to a perfectly parallel beam.

With the lenses we use the divergence tends to be worse when the dot is more rectangular because the lens will not be able to correct both axes at the same time.

IMHO the raw datasheet divergence serves as an indicator, not as an actual usable value.
 
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Pman

Pman

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I wouldn't be so sure that it can't be set for 5mW. Also expect it to act like the 515nm in the GB. It's going to be a cr**-shoot as to what nm anyone gets unless he bins them but I doubt he would do that as it complicates the sale.
I realize most are looking for a low bin but I wouldn't count on it. Prepare to live with whatever it ends up being otherwise be ready for disappointment. You may not even see the difference between a 520nm and the one you get but as they are labeled I would expect the average to be 515nm.
That being said, I am very interested in seeing the plot on these. Don't know why I was able to get such high output on my 2 GB ones and one definitely has a nice blue shift even at that output. You can see it in the pics I took in the GB easily.
 
jander6442

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Seems under heavy fog I see a strong blue line running parallel to the green beam in my 515nm GB diode. Blended of course. sorry no camera still:yabbem:
 
Glutton

Glutton

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Damn just finished my Osram 515 build and now this comes out lol. Looks like the Osram is gonna get the boot and have this replace it. Can't wait to see some reviews of what kind of results this new diode gives.
 
Mattronium

Mattronium

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Just searched for a data sheet and found this: NDG4216 datasheet | Nichia | Electronics Datasheets.

Just noticed that the diode has four pins, two for the laser diode and two for the photo diode.

EDIT: This data sheet might not be for DTR's diode. DTR's diode is 3.8mm and this is 5.6mm.
Not sure how it could be a different diode with the same part number though?
 
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