looking for highest output 510-520nm single mode

[nkgamer1990]

Been out of the scene for a while

Title says it all

 

[Gryphon]

I'm fairly certain the best you can get in 510nm are ~35mW diodes (all single mode) but if you go 520nm there has been a bit more development. The Sharp GH0523AD2G claims 300mW with divergence specs that look like single mode. I haven't tried this diode so that's just going off the spec sheet.

 

[RedCowboy]

Wow that's not bad and they have apparently come down in price, I'm in for a couple.

Sharp 520nm 300mW Green 5.6mm GH0523AD2G Single Mode Laser Diode LD 524205019532 | eBay

Find many great new & used options and get the best deals for Sharp 520nm 300mW Green 5.6mm GH0523AD2G Single Mode Laser Diode LD at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[dubious speculation]

Bear in mind the 300mw Sharp diode's may be rated for the same divergence as their single mode diodes (θ// 7° , θ⊥ 23°), but it is still a multimode diode. The field patterns clearly show how much difference there really is as far as the beam characteristics.

GH05280E2KC_Green-LaserDiode 80mw Single Mode

GH0523AD2G_Green-LaserDiode 300mw Multi mode

It seems the most powerful single mode diode I could find is the Sharp GH0521DE2G 130mw diode. Some have over-driven it to 220mw at 500ma. Probably at drastically reduced lifespan.

GH0521DE2G

 

[RedCowboy]

Yea I ordered a couple of these " 300mw 5.6mm GH0523AD2G " from two different sellers on ebay and one listed it as single mode in the title and the other didn't say either way in the title, but when I looked at the divergence I saw they were not the same as known single mode diodes I already have. They should arrive soon and I will compare them. Should be better divergence than the 1w gh05c01a9g and the newer 1b9g as well as having a smaller emitter footprint, I'm hoping they can be overdriven quite a bit.

 

[RedCowboy]

GH0523AD2G is certainly not a single mode, it's far field spot/bar looks the same as my NDG7475 ( both with G8 lens )

It's advertised spec sheet said 500ma TYP and 850ma MAX
@ 850ma I get 600mw with a G2 and 540mw with a G8.
@ 1.4A I get 720mw with a G2 and 650mw with a G8.

I don't know how much more it might take, but I don't think it's worth pushing it anymore for the amount gained.

 

[dubious speculation]

GH0521DE2G is certainly not a single mode.

The datasheet and part number you linked is for the 130mw single mode Sharp, 270ma operating current.

It's the GH0523AD2G that is rated at 500ma typical and is falsley advertised as single mode by a few sellers.

Is the divergence at least better than the 7475? A comparison shot would be great!

 

[RedCowboy]

I already took the module out of my test bed and filed it with my other " never again " purchases.

For all practical purposes it ( GH0523AD2G ) looks like a weaker NDG7475 when held side by side with the wide to narrow and/or narrow to wide sides facing up and compared side by side from near to far. ( compared by eye )

Without measuring I would put the far field spot/bar width between a NDB7875 and a NDB7A75, closer to the NDB7875, but again I have no use for these diodes...... now someone who was selling pointers could make use of them as they cost less, but I only build for myself so I will pay more for a superior diode, these are in my judgment inferior to NDG700, NDG7475, NUGM01,02,03,04,06 and likley the Sharp 9mm size 520nm offerings so I won't be buying them ever again..... Actually the Sharp GH05C01A9G had a better looking beam dimension from what I remember ( blew mine up ).

 

[RedCowboy]

Ok..... I was a bit annoyed the other night by the poor divergence of these 5.6mm GH0523AD2G, but I did stick it back in a test bed today and snap a side by side pic of a GH0523AD2G with a G2 lens next to a NUGM03 with a G2 lens both at 15 feet ( 5 meters ) and they are both the same width bar shape, hell the NUGM03 might be slightly better.

Both are about 17-18mm wide @ 5 meters with a G2
NUGM03 is the bottom spot/bar and GH0523AD2G is on top.

These could be used for pointers, I just wanted either higher output or better divergence, but not this time.

 

[dubious speculation]

For all practical purposes it ( GH0523AD2G ) looks like a weaker NDG7475

Wow ok that's a shame, was hoping the divergence would at least be maybe half that of the bigger diodes but no matter. Thank you for the tests and comparison photos!

 

[ZRaffleticket]

I see all the talk about the lenses, what about the 2E green lenses DTR sells? That significantly tamed the fast axis on my NDG7475

 

[RedCowboy]

It's a matter of focal length, with the G8 being 8mmFL and the 2EG adds up to somewhere around 4.5 - 5mm FL, however you also get more spherical aberrations from internal edge clipping with a multi element lens as well as it being a longer FL than the G2.

The G2 is 2.39mm FL and that's why we test with the G2, because it doesn't clip any of the diodes output as it sits closest to the facet where the beam has spread out less and the opening is wide enough to catch all of the diodes output.

You can't get a fair assessment of a diodes divergence for comparison if you use a lens that clips part of the output.

When testing the GH0523AD2G @ 850ma I got ( 600mw with a G2 ) and ( 540mw with a G8 ) and ( 420mw with the 2EG ) which reflects the clipping I was talking about, that said the 2EG did produce a slightly smaller bar than the G8 but with many spherical aberrations and reduced output.

 

[RedCowboy]

I received my 2nd GH0523AD2G from a different seller and it's the same divergence, however it won't do any more than 550mw output around 1A and starts to dim down around 1.2A.
At 850ma it's doing 500mw with a G2.

I don't know if it's a different/earlier batch or what, but that's what I received..... also these don't have the anti static protection that the 9mm diodes do.