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DTR's Laser Shop - Laser Diodes & More

RedCowboy

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The small rear opening/lens dia. could limit it's usefulness for our higher output higher divergence diodes unless we want to accept the clipping, the single element though should be more efficient and it's the center of the output is the hot spot so a LPM test will show what we want to know and it may be acceptable for some diodes such as m-140, but it's also adding heat by clipping especially for the more highly divergent diodes.

At 8mm RFL I'm afraid the opening is much too small, look at the opening the G7 offers and even that is stretching the M9 lens barrel to it's limits.

The wider lens barrel with a wider longer FL lens I think is the way to go, it's something I would love to see available for our current favorite diodes, future diodes may be stronger more divergent GBall diodes that will need more than 1 lens to manipulate, but that's not what we are talking about here.

NUBM44fix1a3.jpg


---edit---

I received the G3 for testing and I used a NDB7A75 in a small heat sink and got comparable results between the G7 and G3, but because of the small heat sink I won't test with that unit anymore, all my nubm44's have c-lens correction and or beam expanders so I will have to put another one together or swap out and dial in a G3 with 3XBE to test with a 44 later.

Later using a high mileage NUBM06 or what I got from China sold to me as an 06, with a G2 I got 4.4w, with the G3 - 3.7w, with a G7 - 3.8w and 3 element was 3.5w, the power with all but the G2 is not all that much different, what is important is the spot width and the sharpness of the spot/bar or thickness.

The G2 makes a sharp bar but it's almost 2 inches wide at 15 feet, the 3 element prints a bar about 3/4 of an inch wide while the G3 and G7 both print about an inch long bar, but the G3 prints tight, that is it makes a sharp bar like the G2 and that's what will shine when used with the 3.3x beam expander, rather the spot/bar will be much sharper and burn better than the 3 element and it's spherical aberrations which are very noticeable at night as seen through attenuation laser safety glasses especially when used with a 3.3x beam expander and less noticeable but present during the day because the blur is drowned out by the sunlight somewhat during daylight making the hot center easier to see and focus, the G2, G3, and G7 make a better sharper spot/bar that is easier to see through laser safety glasses and focus tight at night especially when paired with a beam expander.

Pretty much a single element replacement for the 3-element but more efficient and cleaner without the spherical aberrations, may be some clipping with highly divergent diodes although it works well with this nubm06 and 3x beam expander.

More testing to be done.


---edit---

OK, I tested the G3 with a gently used NUBM44 @ 4.5a in a heavy host with a 3X beam expander, with the beam expander focused to fit my LPM sensor I got 5.2w that's the same as I get with a 44 @ 4.5a running a 3 element and 3X beam expander, so there is likely some amount of clipping offsetting the higher efficiency single element G3, however the spot/bar at 15 feet is a nice sharp 9mm x 1mm which is a couple mm wider than with the same setup running a 3 element only the bar is sharper without the heavy spherical aberrations.



DTR: Are you going to add the G3 to your lens selection for sale ?
 
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DTR

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Yep will get them up on the lens page in the next day. I was also thinking it would be more of a alternative to the three/two element lenses as they have a very clean output and I assumed a similar power loss from clipping.
 

RedCowboy

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Yep will get them up on the lens page in the next day. I was also thinking it would be more of a alternative to the three/two element lenses as they have a very clean output and I assumed a similar power loss from clipping.
Power will be higher than 3-element for most diodes and beams will look better, also the barrels and lens position works out better than the G7 letting you focus normally, I am ready to order several as soon as you have them listed, Thanks.

----NEW DAYS POST COMBINED----

Hey Jordan I have quite a few 7875's running 3 elements as well as 1w greens running 2 elements that I would like to possibly replace with G3's, also want to try it out on some other diodes and PBS combine some with this lens as primary.

Do you think you might have some posted for sale soon ?

Thanks
 
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paul1598419

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I was never that unhappy with the divergence of the 7875s. I have always used a short focal length aspheric lens with this diode. I haven't tried this new lens out on an NDG7475 yet, though I have tried it with the two element 520nm AR coated ones. Will have to give that a try.
 

RedCowboy

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I was never that unhappy with the divergence of the 7875s. I have always used a short focal length aspheric lens with this diode. I haven't tried this new lens out on an NDG7475 yet, though I have tried it with the two element 520nm AR coated ones. Will have to give that a try.

Yes, the beam looks much better with the longer FL G3 IMHO than the short FL G2 and focuses much tighter far field, also burns better with a beam expander using the longer FL lens. The 2-element and 3-element throw spherical aberrations.

I just grabbed some more G3 from DTR's site and empty lens barrels to try out some ebay glass.
 
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paul1598419

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I did try one on my new NDG7475 build, but was disappointed with the amount of splash around the dot with the G3 lens. I think I will stick to the 2 element 520nm AR coated lenses from DTR. The beam profile looks much cleaner and there is no artifact that you get with the G2.
 

RedCowboy

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It's not the close range artifact but the spot/bar itself and the far field shadow around the beam that's better with a single element.......well for me the removal of the heavy smudge around the spot/bar when using a beam expander with a 3-element at across the backyard distances, so it may not suit your purpose as well or may be diode dependent, that is a diode without much artifact may be cleaner without the spherical aberration if that's the only detractor.

Did you do a power test and if so what did you get ?
 

paul1598419

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I have not done a power test past the initial one I did when I finished this build. The artifact is the same old rectangular one that can be seen with all the newer Sharp diodes and a G2 lens. At 15 feet, the G3 give a large ring around the dot about 2 feet in diameter. Since this diode doesn't have the awful divergence of some of the other diodes, I doubt it is clipping as much as with one of those.
 

paul1598419

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I think I might have one of those stored in my stock somewhere. I will look forward to your tests with the ones you have coming. I also have a 12 mm EFL lens in my stock. I bought it several years ago, but never found a use for it.
 

RedCowboy

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12mm would need to be put in the lens barrel backwards so you could thread it in backwards with the lens sticking out past the module end, but clipping would be a bigger factor, really using c-lens correction close to the diode is the best way to go, still would be fun to find some inexpensive glass to play with.
 

paul1598419

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I knew at the time I purchased it that the 12 mm FL lens wouldn't be something I could use very easily, but the price was not very high at the time, so I just went for it. It may sit in my stock forever, but if I ever find a diode that I think could be improved by using it, at least I've got it.
 
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Hey Jordan,
I know I'm new on the forums, but I've read so many great things about you and your shop. It sounds like things are crazy on your end with all the changes, glad to hear you've found some help to ease the load you've got.
I put in an order for an N465 about a week ago, and I'm really excited to see what it can do. Should be seeing my host from SL in the next couple days! :giggle:

BTW I noticed that the link for the N465 is broken on the shop page now, not sure if that's due to the updates that are going on.
Hope this finds you well!
 

DTR

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Hey Jordan,
I know I'm new on the forums, but I've read so many great things about you and your shop. It sounds like things are crazy on your end with all the changes, glad to hear you've found some help to ease the load you've got.
I put in an order for an N465 about a week ago, and I'm really excited to see what it can do. Should be seeing my host from SL in the next couple days! :giggle:

BTW I noticed that the link for the N465 is broken on the shop page now, not sure if that's due to the updates that are going on.
Hope this finds you well!
Yep been a lot more time consuming to get my new helper up to speed than I thought. Had no idea how much stuff I take for granted knowing even the most simple stuff has a foundation of knowledge that I have to go back to and explain which is based on another foundation and so on. He picked up on me showing him how to build single configurations of one item and has got pretty good at that but only this weekend did we really get some traction as things are starting to come into focus and have some of the more basic orders I can just shoot over to him to do from start to ship. Got a new appreciation for being new to building.

I hope to get back to updating the new site hopefully finished by this weekend if everything goes as planned. Getting caught up and back to a day or two handling time with my ebay and amazon listings back up.

Anyway yep you grabbed one of the last I have in stock. My supplier is waiting for restock so will put it back up when more are available.
 




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