NUBM44 6W+ 450nm Laser Diode

[paul1598419]

This has been very entertaining. op:

 

[barthchris]

Man, that driver by X-woosee (weird name!) looks awesome!
That would be perfect for this diode.
I love that it can accept up to 12.6V (fully charged 3s lipo)! I don't recall a small driver being able to do that.

 

[Alaskan]

I have a 70mm beam expander on my NUBM44 and can focus it both within a few feet to burn things, or to infinity with low divergence using this setup:

The host is a modified flashlight with heat sink by Mr. Crouse, the lens a modified 500mm zoom camera telescope setup.

 

[Isaac Clarke]

do you use that thing for baseball as well???

 

[barthchris]

Ha! I used to do DIY beam expanders with pieces from telescope eyepieces and a Barlow lens holder to focus. I discovered it by accident while trying to replace a odd lens from 532.

Yours looks awesome, though, mine was rigged with crudely tapped centering screws, reminded me of Frankenstein's head bolts!

Has the power of this diode caused any lens coating damage?

 

[Lifetime17]

Hi Alaskan,
I have the same Ed Crouse host sitting around for a while now and i also have the same telephoto lens you have but never did anything with it. Do i have to modify the lens internaly?

Rich

 

[Alaskan]

I bought more than one of these 500mm telephoto lens assemblies, one model had that internal lens, the other not. If yours has a internal lens there probably isn't room to slide the heat sink into the tube, right?

I have a second Mace of Doom host Ed made, one of these days I need to try to make it work with that 2nd tube but if the internal lens is removed, then the lens on the end of the tube probably won't focus. If I do that, I have other lenses I can choose from the replace it with to find one with the right focal length, I've done that with this tube too, using a cone on the end for a larger diameter lens:

One of these days I might put the thing together with machined parts, for now everything is only taped together.

I've had no problem with the lens coating, the beam from the G2 lens is defocused to expand to close to the diameter of the output collimating lens, because of this the energy density on the lens is low.

 

[Lifetime17]

Hi,
Thank you Alaskan now for some modding i'll check it out and see what it produces.

Rich

 

[RedCowboy]

I have burned up some cheap monoculars, but they had the tent prism, I am curious what kind of edge clipping you have, I am willing to go with what ever works, but with the rapidly diverging axis how can you get a long range focus without edge clipping.

A good question is weather your far field spot is round or a rectangle, if its round then a lot is being clipped off or if it's a short wide rectangle then the edges are all wasted. If you beam shaped first then telescoped you would get more of the power down range and a more square spot with all the energy in it.

Again I am not looking for faults, I am looking for what works.

I know you used that Linos that we both bought from Sam to expand your slower diverging axis and that could work, but round lenses only would be range limited without clipping, unless you had one 10 feet wide, but then your far field spot should still be a long thin rectangle, really a line, otherwise it's just the center of the line with the ends clipped off.

I get extended range with wider longer fl lens but magnification has to match so the spot is a long line only greatly reduced in size.

Alaskan, have you ever gotten a power reading at long distance?

To get all the diodes power at long range with round optics and no beam correction it should look like a long thin line just shrunken down small.

 

[Alaskan]

There isn't any clipping with this setup, either using the lens which came with the tube originally, or with the larger lens and cone, but the G2 lens inside can be defocused so much clipping can occur, at the output aperture as well as at the iris, if closed all the way, but not when the iris is completely open.

Right now I have the G2 defocused so that the output beam is about half of the diameter of the big lens shown in the 2nd photo, above. When adjusted this way there are no wings on the beam, just a small rectangle spot a great distance away and it doesn't spread much. Due to the expansion and the resulting reduced divergence, to see the shape of the spot 300 feet away I must use binoculars. If I open the focus of the G2 lens up so the beam matches the diameter of the big 5 inch diameter PCX collimating lens (actually larger, but the cone has a 5 inch OD), then I get wings I can't get rid of, unless I close the iris enough to clip them out.

If replacing the lens as I have done with a larger one using a cone of a fixed length, finding the right lens on ebay isn't easy, most sellers have no idea what the focal length is for these larger lenses, but I have a lot of lenses I have been buying on ebay to choose from and got lucky. If looking for these on ebay, search under the term "condenser lens", they are used for photo enlargers.

Edit: To answer your question, the beam at long distance is a small rectangle, there is no beam clipping, if I had some, I'd see it as I was adjusting the rough position of the tube forward or back on the large heat sink so everything would adjust correctly, within the range of the focus mechanism. Also, I've measured the output of the expanded beam into a LPM with a three inch diameter sensor input, only the expected loss from the collimating lens.

There isn't any clipping when I defocus the G2 lens so much the spot fills the entire width of the output lens either, if the iris is completely open, but if partially closed, clipping can occur which I find favorable, since I can then clip out the wings which show up on the beam when opened up that far. Whether I open the focus of the G2 lens up so far the beam fills the entire diameter of the lens, or reduced to half size, it is still a rectangle bar. I could add corrective optics to change the bar shaped beam into more of a square, but they must be used with a collimated beam at or very close to infinity focus, but because I defocus the output of the G2 lens to match the diameter of the output lens on the end of the tube, I can't use a cylinder pair to square the beam.

Although, I could put an additional expander or concave lens in the tube to expand the output of a cylinder lens pair, I've chosen not to do so because then I'd need to find another PCX collimating lens due to tube being too short from the space used up inside the tube for the corrective optics, or lengthen the tube. It's just so simple without adding all of that and the beam remains such a small rectangle at a great distance due to the low divergence, I see no need to do that.

When you ask if I have done a power reading at a long distance, how far? If it is too far, the beam will expand beyond the 3 inch diameter of my power meters sensor which runs off of AC power. I could set the meter up inside the house and shoot into the house with the beam but then I can't see what the meter is reading without leaving the laser unattended. I don't have a backyard of my own in the apartment I am living in.

 

[RedCowboy]

A nubm44 in a 12mm copper module with the lens removed will clip on the edges of the module, into the threads, even a 7875 will. You can see it on the wall with the sides flat and rippled from thread reflection.

Now a G2 can pick up all or most of the output at 2.39mm FL but a 3 element at 5.3mm FL will clip and lose 30%

When you de focus you are unscrewing the lens counter clockwise, Correct?

I have to think you could obtain more power by correcting first, also your spot would have a higher energy density and a tighter focus.

I will have to do some testing, I would love to be able to use Gball diodes with just round lenses, but I think they will need shaping first for best results.

We need to do some real power testing to know.

Have you done any burning with the round lenses?

Maybe at 15, 20 or even 10 feet?

If it's even close then good enough, but I have seen burning with 50% clipping, like my 07E with this 25mm lens, it's losing 1/2 the ends of the bar, some in the module threads and some on the walls of the lens holder, it's black anodized aluminum, no burning inside, but focusing the center it still gets results, but an estimated 40% of the power is being lost and moisture I think could be bad for the gain medium with the Gball removed.

I want to find a way to either use cylindrical pairs or an expander with the Gball intact.

NUBM44 with only 6X infinity correction, no zoom lens, same cat food box same 8 feet, not stable but unsteady handed.



The 07E or a NUBM44 will lose the ends of the line in the threads without a screw in lens and some on the way to this 25mm lens, about 40% estimated, I know cylindrical correction is the better way to get more power, but minimoto kobayashi got good results with his linos expander and nubm44 without any beam shaping, I think he lost like 33%?

Here it is, he got 4.5 watts out of a 7 watt setup, so he lost close to 40% mostly in clipping I bet as the linos is very efficient.
http://laserpointerforums.com/f42/6...-adapted-355nm-linos-beam-expander-95471.html

I just can't see how cylindrical correction and then a beam expander won't be so much better for making useable power.
But I would love to get some LPM numbers to go by, if we can find a better way great, but I bet if minimoto used correction and then his BE his power would be 6.5W , but that's just my estimate. That's not to say his build isn't awesome because it is, it has motivated me to reach for more.

 

[Alaskan]

When I focus to a point just a few feet away I can burn using the large 5 inch diameter lens I have on the 500mm FL telescope, the beam is a rectangle, even with the round lens, of course.

The G2 is unscrewed, I think that is CCW, but only a little, due to the long FL of the collimating lens the output doesn't need to be very far out of focus to produce a large beamwidth for collimation. I will take some measurements for you and yes, I've seen how without a lens the 12mm axiz module clips the beam, a lens is needed to capture the power without clipping.

 

[RedCowboy]

Cool, I'm wanting to figure out how to get the most bang for our bucks and also as we don't know the future holds, but I kinda expect Gball diodes will become the standard.
I want to figure out how to get the best beam/power without removing them, if nothing else just to keep dust and moisture out as heating and cooling can push air out past the threads as it heats and expands and draw cool air in after use and air has moisture in it. This may not be a problem, but I like the added layer of protection, I think I can go right out of the Gball into cylindrical pairs then an expander, make it compact but sturdy and that will be trick.

Together we can help each other find the best way.

Personally I love the higher power diodes, it's hard to put it down and go back to the 7875 or a m-140, it's just not the same once you've tasted some real sizzle.

As always my friend thanks for your help. :beer:

 

[Light superglue]

Hi Red Cowboy,

I know about divergence, I see it very well with this diode, why else would I need 6x cylindricals...

What I see after PBSing 2 of these and coming to the limit of my LPM - maybe it is time to start to change the paradigm.
Before the aim was to push to the limit.
With these multimode LDs going down in price (and later I plan to knife edge 4 or maybe the whole bank if possible) it could be possible to build a super burner keeping at amperage LDs are rated for. And this must be the point of maximum efficiency (ratio between light output and energy consumed), what is about 30% or so. Someone posted in this or NUBM07E thread that at the limit it drops to 20%.

In this way we could save on size, heatsinking (and this would be TEC or watercooling at 80+W of heat!)

Burning at 20 feet can also pose another issue - shaky hands. I looked up and did not find any thread about "Steady lasers" (shake compensating mechanics) or using steady camera sets (professional ones are very heavy!) with lasers. But this could improve high range burning capabilities sooner than more power, could not it?

Alaskan, you wrote you buy LPMs in ebay. How much would you consider reasonable price for 100W capable one? I see one VLP200 on aliexpress, but 1000USD does not seem very cheap. Of course I bought my old one 8 years ago and only today the Nichia technolgy development came to its limits. Can anyone affirm that we will not be able to build 100W before in 8 years from now?

 

[Alaskan]

I know what you mean about not wanting to go back to the M140 after these, when the beam can be corrected. I measured the power out of the laser though my G2 lens at 7 watts, after going through the big PCX lens I loose 1 watt so then down to 6 watts out. Here's a photo of the beam on a trash can 30 feet away. The beam is exiting the lens abot 2 inches wide on one axis, .25" wide on the other but focused down to a point on the trash can, accidentally melted a hole in it, oops.. So, you can see that a pointer can be made which both expands the beam to a diameter of a few inches for low divergence, yet can be focused down to a small spot less than 1/10 of an inch wide too. With this setup I can focus to a point less than 2mm wide at about six feet, 6-8mm at 30 feet and double that at 60 feet. Try that with a small G2 lens, not!

I guess you could build a light weight stabilizer with mirrors, I'm sure it could be done fairly small but at what expense?

I have seen some deals on ebay for a meter which could measure that high for 400-500 dollars, but that doesn't mean better deals might not be possible from time to time. I paid 800 for mine used to read up to 300W.

About 6mm or .25 inch wide at 30 feet.

 

[RedCowboy]

This is my burn mark at 24 feet, my beam is not that much different from aperture to 24feet, just imagine what I could do with a beam expander and how far I could reach with a tight useful spot. I burned a hole in a leaf in my backyard at 40 feet that was not much bigger, a little longer, I think 7X or 8X would be closer to perfect, the point is with a BE from here the range would be better than without it by far.
p.s. I taped a sheet of black cardstock up but it burned through and started to catch making the print useless. Since I had already burned the door I used the print, I have some wood colored putty to fix it.