NUBM44 6W+ 450nm Laser Diode

I said I never operated it without a lens (for the very purpose of not getting dust/particles inside). You don't mean the mark on the can, do you?

Edit: I think I see something on the window, but could you maybe crop your pic more and use higher res?

Alaskan said:

If you use it without a lens there is some risk that particulates can get on the diode and burn the window, or if you hold it close to something and burn with it, the smoke can get on the diode window and burn dark marks into it. If I had initially thought this was an honest mistake I wouldn't have opened a dispute, my apologies for thinking so. If we come to terms there is no harm done to your PayPal account.

I took a photo showing the burned mark on the window. I tested the diode with a lens on it first and then saw the distortion to the output, later testing it again without a lens myself to see the raw output power at 5 amps of current draw was low and not a problem with my lens.

From your last response this appears to have been an honest mistake, if you will allow me to try to clean the window and the problem is solved, I will consider everything good.

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Please forgive me if I sounded defensive (I have never been in a dispute on Paypal before, and was quite surprised).

I truly hope it is just the window being dirty.

I can see the mark on the window much better by eye than can be seen in the photograph, that's what it is, no doubt in my mind now. I have a zoom-scope at work I can use to take a clear photograph with tomorrow, but if you will allow me to try to clean it and the problem is solved, I will be a happy camper.

Edit: I looked at the problem much closer and the damage to the window appears to be etched into it, I have little hope cleaning it with 99% Isopropanol will help to any appreciable degree. What lens did you use with it, the one you sent it with? That dark mark on the can is a small indentation to the metal. I don't have any alcohol to try to clean the window with, I don't want to use even 99 percent IPA, fiber optics require 99.9 percent IPA, nearly zero water, that's what I need to get, but it looks hopeless to me.

I think it's also worth noting that the guy in the video shared above was only able to get around 4 watts out of his with a highly controlled setup. I'm interested to see how yours turns out after cleaning the window. I'm really hoping the guy in the video is either doing something wrong(unlikely), has a (bad) freak diode, or somehow has the wrong diode. Maybe he accidentally damaged it slightly upon removal. I hope. Lol.

Jstr said:

The reason I sold this to you was so I could buy the remaining parts I needed for about 4 different lasers I had parts for, which I want to sell. I sold it for $125 because that's how much I needed and I thought it was more than fair. I also sort of impulse-bought the diode, thought it wasn't all that special due to its terrible divergence, reasoned I could make back the $40 to buy another if I sold my other projects, so I went ahead. Is that wrong? Evil?

And also, as I told you before this, I want to save that host for another build. I would also like to save this diode for when corrective optics is something I want to mess with.

I am an honest person, 18 years old, attending Dartmouth College.

I have no problem admitting fault if it is mine. But I reiterate, I truly believe neither of us could have damaged the diode under these conditions.

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Your location says Texas, Dartmouth is in Hanover, New Hampshire, and anyone who can attend Dartmouth can afford to buy laser parts. Dartmouth College is a Ivy League school and ranks among the world's greatest academic institutions, only 1 in 10 who apply are even accepted. Was the diode shipped from New Hampshire? Or from Texas?

Alan

Peter, your LinkedIn profile shows you started college at Dartmouth in 2015, this year, so I believe your age. Young, just out of high school. I didn't go to college until I was 25 years old.

Yeah, I'm planning on going mechanical engineering.
I'm going out on a limb, but are you an engineer?

I built my first laser when I was 16. I really hope you do not think I'm some dishonest and dirty kid. I have never had any problem buying or selling stuff on LPF, and I value the forum and members highly. I do not want to see you have to deal with a damaged diode. See my above post, I think that could be a viable solution. Hopefully DTR can fix it. If he does not want to, I might be able to offer a refund when I sell some other stuff. It's still a 4W+ diode.

Hi, I can possibly de-can it and still use it, I found a thread here on LPF showing how to do so using a battery operated drill to spin the diode while cutting the base of the can with a serrated knife.

I work as a telecom engineer, reality is, I am just a very experience RF technician who now holds that position.

Alaskan, don't use a serrated knife, just take a razor blade (like a box cutter) and put the diode in the drill, and gently push against the base while sturdying your hand against something. You'll eventually cut through the metal, and since you've got your hand resting on something you won't risk hitting the delicate inner bits.

Alternatively, there are a few people on the forum who own dedicated decanners from ThorLabs. I don't know if Daguin still frequents here or not, but I'm leaning towards not since I haven't seen him post in a while.



Honestly, as an out of party guy this all just sounds like an honest to goodness mistake. A random act of god or something somehow made it so that a particle got stuck to the window, and when you turned it on it melted and etched the glass.

Hope you guys can manage to work it out.

Wow this went downhill quick. Here shoot it over to me. I have a proper decanning tool to remove the window. Well see what we can work out to make all parties satisfied. Worst case it is an open can diode now. Based on the pictures it was in good health except the diode window.

This could have happened at any time even in transit if something got in the wrong position and when fired after being received but if you powered the diode it would be impossible to miss with the lens in or out. It will not collomate into a nice beam but be scattered light in a halo. this is a risk anytime you have the lens out and these high power diodes will burn something on there in a fraction of a second.

Anyway send it over and lets see what we can do to resolve it without continuing to derail this thread.:beer:

Cyparagon said:

Made by username planters

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Isn't the reason this guy is only getting 4 watts because of all the corrective optics he is using? If you watch the whole video he explains at the end how the optics he is using reduce the divergence by tenfold. So I'm pretty sure that's why he's only getting 4 watts passing thru about 4 different lens

bandlasing said:

Isn't the reason this guy is only getting 4 watts because of all the corrective optics he is using? If you watch the whole video he explains at the end how the optics he is using reduce the divergence by tenfold. So I'm pretty sure that's why he's only getting 4 watts passing thru about 4 different lens

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Yea it is running though a bunch of different optics and ar coated windows. I did ask him to do a test direct to the power meter. He also is using a stock projector lens from a 9mm diode that may or may not be clean.

DTR said:

Yea it is running though a bunch of different optics and ar coated windows. I did ask him to do a test direct to the power meter. He also is using a stock projector lens from a 9mm diode that may or may not be clean.

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That's what I figured with just one lens you will get at least 6watts with these guys

I was following a different thread about these and hadn't realized how involved this one had become. Skipping all the "other" posts I noticed some pages back that just like the other thread people comment about the brightness compared to a 520nm and I don't get it. If the perceived calculator is reasonably accurate this diode will not have as bright a beam as the 520nm regardless of whether it hit 462nm and 7.8W not to mention the "dot". Remember that many of us hit 1.5W+ with the 1W diode
However, the price on this diode is great and that's one heck of a lot of blue that I'm hoping to get my hands on I'll put my trust in what Jordan actually finds to be the honest characteristics of them.

Pman said:

I was following a different thread about these and hadn't realized how involved this one had become. Skipping all the "other" posts I noticed some pages back that just like the other thread people comment about the brightness compared to a 520nm and I don't get it. If the perceived calculator is reasonably accurate this diode will not have as bright a beam as the 520nm regardless of whether it hit 462nm and 7.8W not to mention the "dot". Remember that many of us hit 1.5W+ with the 1W diode
However, the price on this diode is great and that's one heck of a lot of blue that I'm hoping to get my hands on

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I'm not sure about it being accurate or not, to me my 3 watt 445 laser is the same brightness as my 1 watt 520nm PLE PRO.

I understand as different people see things differently plus there so many other factors that I think it's very difficult to compare one color to the next once it gets to a certain point. Personally my 1.5W 520nm is so much brighter to me than my 3.5W blues there's no comparison.
In the other thread the calculator was used over and over again and not what members eyes actually saw so you can see where I'm coming from.
http://laserpointerforums.com/f67/making-new-nubm44-450nm-diode-handheld-94243-2.html#post1368218

There is clearly some inconsistency with the power values I am generating and the power others are seeing. The stock lens is clean (after mounting I inspected it under a video microscope). The can window appeared clean. I did not place this under the microscope or attempt to do anything to it after receiving it from DTR. So, I suppose this could be a source of loss. The "stock" lens that DTR supplies called the G-9 is familiar to me and I have used it with several other blue laser installations. Is there a suggestion that it has significant loss vs the G-2 lens? 50% loss from three Edmund optics Vis-0 coated lenses, one Vis-0 coated optical window and one MgFl lens (the -25mm cylinder) is unlikely, but I can certainly test the diode with only the collimator in place.

Now, my question. Through all this long thread has anyone documented the beam characteristics of this diode? In many of my videos, I take time to analyze and improve the beam dimensions as well as the divergence of these lasers. I am seeing and you can see as well, the output from this laser is not symmetric and has significantly higher divergence than the lower power blue diodes. Of course it is multimode, but even the main stripe is large in both the X and the Y and it cannot be brought to a tight focus. The asymmetry may represent facet damage or a problem with the can window, but the large stripe may be inherent to a larger junction dimension that can accommodate the higher current input. If true, that cannot be improved with optics.