First post, second build. (Osram PLPT9 450LB_E)

[mhostilis]

Looking to understand this concept of divergence better.

I see it expressed in different ways. Could somebody explain how I can understand how to read the divergence in the data sheets.

These are clearly different units right? Also why does negative divergence seem to be declared for the NUBM0E what does this mean?

I haven't been able to find a thread explaining divergence to dilettantes and how to read it unfortunately so pardon by questions...

Also would you knew if there is a database of Nichia diode datasheets so once I understand these concepts I can read through them to understand which LD is best for me without having to continuously badger you guys?

 

[RedCowboy]

I don't use the G7 anymore as the G8 works better. ( aberations and beam width )

I told you in post #2 that the 7A75 would have divergence between the M-140 and NUBM44 and would do 5W+

M-140 and NDB7875 both have the same divergence...... lets call it Level ( 1 ) ........ NDB7A75 lets call it Level ( 2 ) .......... NUBM44 lets call it Level ( 3 )

Level ( 1 ) = about a 15mm long bar @ 5 meters with a G2 ....... with a 3E I got a 9mm long bar @ 5 meters
Level ( 2 ) = about a 30mm long bar @ 5 meters with a G2 ...... with a 3E I got a 16mm long bar @ 5 meters
Level ( 3 ) = about a 50mm long bar @ 5 meters with a G2 ..... with a 3E I got a 23mm long bar @ 5 meters

NOTE: With a G8 or 3E the bar length is not simply half or any linear amount because of clipping, so we need to compare with a G2 as it sits close enough to the facet to catch all or most all of the output in each case.

EDIT:
Data sheet divergence numbers are only part of the picture, there is also the width of the P/N junction, single mode vs.multi mode, ect...

Look at a Sharp data sheet, they give you a little pic of the beam shape and some other info...... how does it all equate to the beam you will get with a specific lens ? Well you need to know all the lens data..... I use a try it and see method and use the data sheet data as a rough guide.

 

[mhostilis]

@RedCowboy

Ah, I see. So it's not as simple as I had initially hoped. Pardon me, I had forgotten you'd mentioned the NDB7a75.

This is seeming like the best choice for me but I see it rated at 3.5 w...how much would pushing it to 5 take off it's life?

I see there's an NDB7y75 rated for 5w but i'm not sure of the divergence for that and I can only find it for quite a bit more money unfortunately...

Where do the 465nm NUBM07 and NUBM0G stand on your 1-3 divergence scale? I feel the NUBM0G runs me into the same price issue as the NDBy75, but if the NUMB07 is not worse than the 7a75, and about as powerful, I would likely go for it......

Side-note: Why are we not considering the G-3 lens?

 

[RedCowboy]

The opening for the G3 is very small as it's a smaller lens and not suited for the level ( 3 ) divergence diodes without substantial clipping.

Overdriving will shorten the MTTF but if you don't overheat the hell out of them, these diodes seem to take a beating for a long time... I don't know how much less than the typically rated 20,000 hours MTTF you will get, but mine are still working well years later, but they are not all used on the daily either.

07 is very similar to 7A75 as far as divergence level ( 2 ), 0G I expect is level ( 3 )ish ??

Remember these direct diodes have an X and Y axis ( rectangle beam ) and each will diverge/propagate differently unlike a dpss operating in TEM00 or a gas laser that makes a round beam. So with these multi mode diodes what starts out as " I " turns into " _______ " and only grows proportionally longer as it goes, the worse the divergence of the fast axis, the faster the long bar gets longer. There are ways to correct this, I like to use c-lenses ( see pic below ), but not on your 2nd build.

Another way is to use a laser diode with an added FAC lens, then you can focus it with a wider and longer focal length lens..... I'm really suprised more people don't build them, but it also depends on your use, for up close/desktop all you need is a G2 lens.

Actually for desktop use the FAC enhanced diodes can make a better beam, again it depends on your purpose.

I was told 7k75 was the same as 7A75 but I haven't bought any that I can remember, 7Y75 is also likely the same and the data sheet is a little different 10.5 and 46 on divergence, but we can't trust Chinese posted data sheets anyway...... that said it's supposed to be a 455nm.

The price difference should be because it has virgin pins ( no solder )

1pcs Nichia NDB7Y75 455nm 5W Blue Laser Diode | eBay

Protect your yourself from the laser when you operate on it.

www.ebay.com

Nichia NDB7K75T Blue 445nm 3.5W Laser Diode | eBay

Find many great new & used options and get the best deals for Nichia NDB7K75T Blue 445nm 3.5W Laser Diode at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Nichia NDB7A75 TO5-9mm Blue 445nm 3.5W Laser Diode | eBay

Find many great new & used options and get the best deals for Nichia NDB7A75 TO5-9mm Blue 445nm 3.5W Laser Diode at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[mhostilis]

@RedCowboy

Gotcha.

Any downsides to the 07 over the 7A75? Otherwise I will very likely go with it as the 465nm is just so pretty to me.

Thanks for all the help thus far. I really appreciate it.

 

[RedCowboy]

The re-canned ( flat lens/window ) NUBM07 should be good.

--------------------------------------

Looking at NDB7Y75 again it looks pretty good, it's likely the same one they are using with a FAC that's doing 6W ( I know it says 5W @ 3.5A ) but you always can get a bit more than advertised and the divergence numbers are slightly better than 7A75 and 7K75 and it's 455nm, it has virgin pins so it's new not used.

That said it will still have about level ( 2 ) divergence.... maybe level ( 1.9 ) ( my speculation ) but you will almost certainly get 6W out of it @ 4A ( overdriven ).... a bit more than the 2.9W rated 07, now there's also a NUBM0C but it's divergence is close to level (3) however it is 465nm.

My NUBM0C below is doing 6W @ 4.1A and divergence is almost the same as NUBM44 with a G2 at 5 meters, ( about 48mm long bar/line ). But it is a nice 465nm bright blue.

 

[Darktron]

use the data sheet data as a rough guide.

Paper is just paper like my old friend said. Real world specs/perf/efficiency will be different sometimes out of the paper specs thats why we have the lucky diodes that can do massive ammounts of optical power at low current.

 

[aaronnoraa]

@RedCowboy

Ah, I see. So it's not as simple as I had initially hoped. Pardon me, I had forgotten you'd mentioned the NDB7a75.

This is seeming like the best choice for me but I see it rated at 3.5 w...how much would pushing it to 5 take off it's life?

I see there's an NDB7y75 rated for 5w but i'm not sure of the divergence for that and I can only find it for quite a bit more money unfortunately...

Where do the 465nm NUBM07 and NUBM0G stand on your 1-3 divergence scale? I feel the NUBM0G runs me into the same price issue as the NDBy75, but if the NUMB07 is not worse than the 7a75, and about as powerful, I would likely go for it......

Side-note: Why are we not considering the G-3 lens?

I'd forget the NUBM07 and I'd suggest going with an NUBM0C instead. It's the same 465nm+ but rated at 4.1W instead of 2.9W of the 07 and has divergence between the 07 and 44. The divergence of the 0C is better than the 0G, 0F, 44, 08 etc. Use it with a G8 lens, run it at 4A and be happy with your 5.5+W of 465nm (probably more like 470nm at that power) with decent divergence.

Here's the cheapest NEW NUBM0C on Ebay, LaserTree renamed it so it does not appear on a regular search. Use this one if you want to just use the ball lens- https://www.ebay.com/itm/225544116972

Here's the cheapest NEW NUBM0C with a flat cap to use with a G8 lens (the best route to choose, by far) - https://www.ebay.com/itm/175663961003

The "Soldered" (used) options from OpticsLD are sketchy AF and their new units are more expensive than lasertree's.

If you want something special, you can get a FAC'd version of the NUBM0C that will have far better divergence than anything you have discussed in this thread. You'll just have to save your lunch money for a few extra days, but the extra $55 is worth it. Use with a G8 lens.

https://www.ebay.com/itm/225644533013

Note- If you decide to buy a "lens removed" (naked, no cap) blue laser of any kind, or decide to remove the ball lens yourself, you may as well throw your project in to the trash because your diode will in fact be trash after just several 10's of hours of use.

 

[RedCowboy]

I had hoped the NUBM0C would have better divergence than a NUBM 44,47,08,0A,0E,0F but it doesn't, well mine doesn't anyway.
With a G2 lens it makes a bar 48mm wide @ 5 meters which is what I also get from my nubm44's.

I got 6W @ 4.1A and pushing to 5A only saw an increase in output to 6.3W with a clean G2 lens, so there's not much point in driving it past 4A

That said this is 1 of 1 NUBM0C re-canned, another 0C diode might test a little better or worse.

Pic is with a G8 lens. ( 1st pic )

Also to use the FAC enhanced 9mm MM diodes in the far field you need to use a wider and longer focal length lens than any of the M9x0.5 threaded barreled lenses, yes you can get a very tight beam waist in the near field, but at any distance our standard lenses won't focus nearly as tight as with a non FAC similar diode, not with the FAC enhanced diodes I have purchased which are set up for home CNC no doubt and I have both the square and line type. The ( 2nd pic ) is a FAC enhanced diode 5W and you can use a 3E lens without any clipping thanks to the added FAC fber, but at any distance the spot is not able to be well focused with G8, 3E, G2..... However you can get a good tight spot with a wider longer FL lens like in my ( 4th pic ) of the line output FAC 5W diode, 3rd and 5th pics show the line and square output FAC enhanced diodes.

 

[mhostilis]

I'd forget the NUBM07 and I'd suggest going with an NUBM0C instead. It's the same 465nm+ but rated at 4.1W instead of 2.9W of the 07 and has divergence between the 07 and 44. The divergence of the 0C is better than the 0G, 0F, 44, 08 etc. Use it with a G8 lens, run it at 4A and be happy with your 5.5+W of 465nm (probably more like 470nm at that power) with decent divergence.

Here's the cheapest NEW NUBM0C on Ebay, LaserTree renamed it so it does not appear on a regular search. Use this one if you want to just use the ball lens-

Here's the cheapest NEW NUBM0C with a flat cap to use with a G8 lens (the best route to choose, by far)

The "Soldered" (used) options from OpticsLD are sketchy AF and their new units are more expensive than lasertree's.

If you want something special, you can get a FAC'd version of the NUBM0C that will have far better divergence than anything you have discussed in this thread. You'll just have to save your lunch money for a few extra days, but the extra $55 is worth it. Use with a G8 lens.



Note- If you decide to buy a "lens removed" (naked, no cap) blue laser of any kind, or decide to remove the ball lens yourself, you may as well throw your project in to the trash because your diode will in fact be trash after just several 10's of hours of use.

Very info-rich response. Thank you sir.

Few questions:

1. How does the NUBM0C compare to the NUBM0G?

2. How does the NUBM44-V2 compare to the NUBM0F? (These are less expensive and that may have to take priority for me over the bluer wavelength ones above)....and while we're at it to the NUBM4F (also too expensive for me but still curious)

3. What is FAC? Is it a recanning of sorts with a different lens? What is the upside can can this not be replicated with something like a G8 or a 3E lens? Does mod allow as much power out of the diode as the standard can lens (all these last questions presume my conclusion about what the FAC is are correct - please correct me if they are not.




At the moment I am inclined toward the NUBM44-V2 or the NUMB0F due to the lower price and slightly higher output. I would prefer the NDB7Y75 since power is almost the same but divergence lower, but pockets don't permit at the moment. I do like the decreased divergence of the NDB7A75 as with the NDB7Y75 at the NUBM44 and 0F price, but I noticed that even within the decreased beam area of the NDB7A75, the NUMBs still deliver more output - not only in extra beam area (if that makes sense), so I would prioritize output over divergence at this power disparity (I would rather not overdrive them since I don't want to have to worry about overheating too much honestly...


All this to say that I will likely go with the NUBM44-V2 or NUBM0F with a g* lens unless you have a source for the NDB7Y75 under 50 bucks or so....Is this a bad choice in your opinion?

 

[mhostilis]

The re-canned ( flat lens/window ) NUBM07 should be good.

--------------------------------------

Looking at NDB7Y75 again it looks pretty good, it's likely the same one they are using with a FAC that's doing 6W ( I know it says 5W @ 3.5A ) but you always can get a bit more than advertised and the divergence numbers are slightly better than 7A75 and 7K75 and it's 455nm, it has virgin pins so it's new not used.

That said it will still have about level ( 2 ) divergence.... maybe level ( 1.9 ) ( my speculation ) but you will almost certainly get 6W out of it @ 4A ( overdriven ).... a bit more than the 2.9W rated 07, now there's also a NUBM0C but it's divergence is close to level (3) however it is 465nm.

My NUBM0C below is doing 6W @ 4.1A and divergence is almost the same as NUBM44 with a G2 at 5 meters, ( about 48mm long bar/line ). But it is a nice 465nm bright blue.

View attachment 76853

The NDB7Y75 is sounding REALLY nice but the price is quite high sadly, as with the NUBM0C and 0G, compared to the NUBM44-V2 and NUBM0F......why do I see no builds made with it? It seems like the perfect diode unless i'm missing something.....

 

[Borislav@87]

Look, these things are expensive in general and very easily damaged. I don't think the prices are that high. Buy what you think you will like. I personally recommend NUBM0F to you. Making a laser can be quite a bit cheaper if you make some things yourself, like a heatsink and use a cheap flashlight body.

 

[RedCowboy]

The 44(V2) and 0F both have the same divergence only the 0F can do 9W+ where the 44(V2) can do 7W+( overdriven ) both are in the 450-455nm range ..... the 44(V1) is 445nm and not quite as strong.

0G is stronger than 0C, both have very aggressive fast axis divergence similar to 44,0F and as you know the 0G, 0C are in the 465nm range.

 

[Darktron]

The NDB7Y75 is sounding REALLY nice but the price is quite high sadly, as with the NUBM0C and 0G, compared to the NUBM44-V2 and NUBM0F......why do I see no builds made with it? It seems like the perfect diode unless i'm missing something.....

Nubm0g build i did a bit back as me and @loreadarkshade had these diodes fresh out the oven.

Note: main reason you don't see much build with 0G is because is a new diode just released this year couple months back. Takes time for price to drop not everyone is willing to spend a lot of money in a mysterious bank of diode.

 

[Darktron]

The 44(V2) and 0F both have the same divergence only the 0F can do 9W+ where the 44(V2) can do 7W+( overdriven ) both are in the 450-455nm range

Id have to disagree the wavelength on 0F is higher (in number) than the 44 or 47 have a center wavelength of 445nm while the center wavelength of the 0F is 455nm and the 4F is also 455nm. This info is gathered from datasheets. (I do not have a spectrometer yet).

 

[RedCowboy]

There are no official data sheets at the Nichia web site for the NUBM44's that I have ever seen, if you have a link to a real data sheet at a Nichia site I would love to see it.

I don't have a spectro, however I can see a difference between a 44-V1 and a 44-V2 as the V1 looks a little more purpleish ( 445nm ) than the V2..... that said these are overdriven units and the eye often is less than accurate, maybe the V2 is centered at 445nm, but I have never found a real data sheet on the 44's.