Looking for 520-525 1-1.5W Lowest divergence w/o correction

[Nordhavn]

Any 1W Guardian owners here (520nm)? Hows the divergence with a simple collimator? (G2, G7, etc.)
I'm trying to get something that's not as bad as MM 445 diodes.
I'd love to have something like my 100mW 405. Simple GRIN lens and I'm under .5mRad!

 

[Alex2893]

There is no greens over 1w with that low if divergence. Your best bet is the plp520-b1. It's around 200mw and the divergence in my testing is under .5 mrad. The divergence of a 1w 520nm is about the same as a m140 445nm diode. Also your 405 is a single mode so you can't expect great divergence with multimode diodes which all the 1w or higher 520nm are.

 

[trinh hong phuoc]

PM me if you want 100-200mw 520nm 0.5mrad
1w-1w4 520nm is 2mrad-it can reach 0,5mrad when use 2x otp pair lens
I also think 1w 520nm is great beam when you use g7 or 3 element lens,it is so bad beam when you use g2 lens

 

[CurtisOliver]

Unfortunately you will only achieve divergence that low with these multimode diodes if you use beam correction, or if you use a beam expander. The G7 is a good lens. But there has been discussion about a new lens from DTR (Jordan) which he is calling the G3. Tests are still being conducted so I don't know if there is any radical difference with the 520's yet.

 

[paul1598419]

I tested the G3 with my NDG7475 1100 mW laser. It has splash in a circle around the beam's profile about 2 feel in diameter at 15 feet. I like his two element 520nm AR coated lens for this diode as it has no artifacts and gives a nice clean beam profile at a loss of only 15% over a G2.

 

[Alaskan]

If you want that low of a divergence consider having a custom host built for you from one of the members here which uses a longer focal length larger diameter collimation lens and you won't need to use a beam expander and won't need correction with a cylinder pair to achieve that low of a divergence, or lower, for both axis of the diode output.

However, it will still be in the shape of a rectangle, regardless, unless the beam is somehow corrected to turn it into more of a square shape. For .5 mRad divergence of the fast axis, you will need a lens diameter of roughly about 25 mm. That will produce a "fat" beam, but it won't diverge nearly as much. You could also look at some of the 520 nm lasers sold by JetLasers.org or SanwuLasers.com and buy their beam expander, there will be more loss and lower power than a custom host using just one lens, but quick to get.

The Sanwu beam expander is about 3.3 expansion and won't reach .5 mRad with a one watt 520 laser diode unit, but the JetLasers will with their 10X expander, lower than .5 mRad. If the divergence going into a 10X expander is about 2.6 mRad, which is common using a collimation lens of about 6 mm diameter with a laser diode like the 1 watt rated NDG7475, the 10X expander in front of it should give 1/10 that amount of divergence.

 

[Lifetime17]

Hi Alaskan,
Don't you mean a NDG7475 , not NUGM7475??
Rich

 

[Alaskan]

Yes, editing. Thanks.

 

[Lifetime17]

No Problem Buddy
Rich

 

[Alaskan]

I'm still unable to know if the NDG7575 is just a vendor trick trying to sell NDG7475 diodes as an upgraded device.

 

[Lifetime17]

Try to dig up the data sheets for each of the diodes. They should tell something about each diodes efficiency I would think.

The top is for the NDG7575 diode and the bottom is for the NDG7475 diode from what I found
Rich

 

[Alaskan]

Earlier, when searching the net, I was unable to find the diode existed, except on ebay. Although just now I found something:

[Hot Item] Nichia High Power 9mm 1000MW 520nm Green Laser Diode (NDG7575)

Certification: RoHS, CE, ISO, CCC Application: Stage Show, Laser Module Structure: To5-9mm Wavelength: 510nm ~ 525nm Power: 1W/1000MW Color: Green Light

bulaser.en.made-in-china.com

Studying the document now, the current is the same.

 

[Encap]

I'm still unable to know if the NDG7575 is just a vendor trick trying to sell NDG7475 diodes as an upgraded device.

According to DTR' site NGD7575 is a really a 700 mW diode and vendors trick selling it as a 1 W. See https://sites.google.com/site/dtrslasershop/home/diodes/ndg-700mw-520nm-laser-diode

Nichia lists an NDG7K75 an actual 1W green diode and is only one listed on Nichia's site now -- see: https://www.nichia.co.jp/en/product/laser.html

 

[Alaskan]

That's why I was having trouble earlier, I could not find a 7575 on their web site, thank you. I guess I shouldn't even look at the Chinese ebay sellers for individual diodes anymore, even the one China vendor I used to fully trust is pulling tricks like this now. Still true, has always been better to buy from DTR LPF google store, you know what you are getting with him.

 

[Lifetime17]

The 7K75 forward current is 1.8 thats the same as the NDG700 that on DTR site I would assume

 

[DTR]

I'm still unable to know if the NDG7575 is just a vendor trick trying to sell NDG7475 diodes as an upgraded device.

That is the real part number for the diodes I sell as NDG700. I named them that as i did not know what the part number was when I first got them and did not have a fake datasheet for them.

This is the oldest batch I could find in my archive. 6/15 Production

https://imageshack.com/i/pmlC59Gpj


The mfg page does not get a lot of updates and seems to be more of just a showcase. The accession number on that is as old as the 3.5W blue. I have never seen a K number out there and whenever you see K there is not a sheet provided. The current 3.5W ones are still NDB7A75 even though listed on that page is only the NDB7K75.




Anyway no need to go digging for datasheets you won't find ones that match any diodes you can get. Really we should stop posting ones that are not verified.

Some you can just look at the meta data like these and see that at the very least they have been modified. Like these.

This was downloaded from the manufacturer. The other two were from sellers. I don't think they are using 2007 PP or 2010 MS Word to create then MS print to PDF to create them. They might be accurate but edited there is no way to know if they are not just complete fiction.