574nm 36 mW Yellow Laser

[Alaskan]

Agreed. I know our vision is most sensitive to 555 nm during daylight hours, at night scotopic sensitivity centers down around 507 nm, so yellow would actually be further away in wavelength than 520 or 532 nm green, regardless what wavelength I am very concerned about lasers being abused that way too.

By the way, I received three more 575 modules today, bought some from China :wave::wave::wave:

Edit: One of the three modules is EDIT; 565 nm, it's marked 575, but not. All three pull .5 or less than 1/2 amp at 12 VDC, these run differently than the Aussie unit I bought which draws closer to an amp at 12 VDC.

I will try to directly drive the diode in one of these China seller 575 nm lasers later and report. Also, turning the current adjustment pot the most current the driver will pull at 12.5 VDC is .80 amps but then after awhile, the driver is getting too hot like the other one from the Aussie seller did, and the output begins to cycle off and on again. It's the same exact driver. If I reduce the voltage from 12.5 VDC to 5.6, the current goes up to 1.0 amps and the beam is brighter, but not as bright as the Aussie unit at that current, I think the difference is brightness is just due to manufacturer variations, nothing more and the output from these China seller units is very round, unlike the oval shape I got from the unit I bought from our Aussie seller, but that too is probably just a manufacturer variation, as these do appear to be the same units.

Another edit: OK, directly driving the diode I get the same bright output at 1.75 amps as I did from the Aussie unit, and it appears to have the same maximum brilliance at 2.0 amps which is probably far too much for that diode. Also, the same as the Aussie unit, if you keep pushing the current up above 2 amps I couldn't see any extra brilliance and at about 2.25 amps the output dims. Right now I believe they are identical units (but current draw variations between them) at far less cost when ordered from the China source directly, but I haven't torn it down to confirm.

Another nother edit:

They are identical, both the Aussie units and the China sellers units are the same, I feel a bit ripped off because the Aussie source was reported to be made by a different company and higher quality, if they are made by different people, they source the same parts:



Left 130 dollar Aussie unit, right 30 dollar China unit. They both had heat sink compound on them when first removed.

 

[CurtisOliver]

Glad your units arrived, wierd you received a wrong unit. Are you sure it’s 561 not 565?

Are the beam characteristics identical too?

 

[Alaskan]

Oh, I guess it's 565, I said 561 out of habit.

 

[CurtisOliver]

How is the beam quality of the cheap 575 compared to the Aussie 575?

 

[paul1598419]

I hate to say I told you so, but I did. I had a feeling there was no difference in these units except that the current to the head had been increased and that seems to be correct. If you want a module like those from Australia, just turn the current up on your pump diode.

 

[CurtisOliver]

Well that's good to know. Just wish their shipping was reasonable. The laser head costs less for me.
Also how do you go about getting a 575 from the chinese supplier?

 

[paul1598419]

I paid more for shipping than I did for my laser from OPT Laser. But, in all fairness, I got my laser in less than four days from the Chinese mainland. If these lasers were selling for $200, the shipping wouldn't seem that high. It is the fact that the laser is so inexpensive that we complain about the shipping cost. I did too.

If you want the 575nm laser, email Freeman at fb@optlaser.com. Last I heard they were building new ones as they were out of their current stock of them.

 

[CurtisOliver]

The thing is, i'd rather them offer a cheaper (slower) option for shipping. Not everyone wants to pay ~£50 for shipping regardless of the item cost.
I don't mind waiting a few extra days if it means I can bring the cost down. It might be because i'm tight atm so I'm giving things like that more thought than usual. :undecided:

 

[paul1598419]

Email Freeman and ask him if there is a less expensive shipping option. I know that he gave me a cheaper option recently, but I had to ask for it.

 

[CurtisOliver]

Thank you Paul. It's good that he will offer it if asked.

 

[Encap]

Another nother edit:

They are identical, both the Aussie units and the China sellers units are the same, I feel a bit ripped off because the Aussie source was reported to be made by a different company and higher quality, if they are made by different people, they source the same parts:

Left 130 dollar Aussie unit, right 30 dollar China unit. They both had heat sink compound on them when first removed.

Typical reselleritis---the Australian guy touches it and solders a couple of wires, put on a few nylon wires ties, adjusts a pot and thinks it is magically worth 3X to 4X the price + silly shipping cost. Is all smoke and mirrors.

OPT is the manufacturer---the Australian guy is just a reseller in a hut in Australia

I hate to say I told you so, but I did. I had a feeling there was no difference in these units except that the current to the head had been increased and that seems to be correct. If you want a module like those from Australia, just turn the current up on your pump diode.

Exactly

Thank you Paul. It's good that he will offer it if asked.

The shipping from OPT in China was not so bad---was $35 for DHL + $30 for the unit. That's 48GBP total not just for the shipping which was 26GBP of it

 

[CurtisOliver]

When the time is right I will place my order directly to the supplier and do my own adjustments. No need to pay more for the same item.

 

[Atomicrox]

Yes that thermal tape you found looks thin, but if you end up having a host made the 2 pieces heat sink would make assembly easier. :beer:

BTW I bought some 1W NUGM diodes at auction and they are not 520nm like my NDG7475, they look like possibly 525nm, they are noticeably more of a yellow green next to the 7475, it's still very much green just obviously not 520nm.

Sorry to derail but I'm interested in this 525nm diode.
Do you have a link?
Did you compare it's power and brightness to the 7475?

 

[RedCowboy]

Sorry to derail but I'm interested in this 525nm diode.
Do you have a link?
Did you compare it's power and brightness to the 7475?

Yea, Sorry about the derail, was just mentioning that the 1w Green Gball I just got looks like a 525 next to my 520, both are very bright.


They both look very bright, I am running them with 1.8a drivers from DTR even though my 7475's came with clean pins.

The 525nm ( looking ) I have no spectro, are noticeably more green yellow than the 520nm green, I assume power is around 900mw - 1000mw @ 1.8a with 2 element 520 lenses, I still have not bought a LPM, I want a LPM that can handle higher power and I am not all that concerned about 3/4 or 1 watt for my pretty to look at lasers, either looks great, now for burning I want to know how my optical train is working so I will need a big thermopile, I can make a meter ( haven't done one yet so don't ask for plans ).

Here's the ad for 525nm although I won an auction for a Green GBall and received what looks to be 525, I'm not upset, it cost me 42 dollars and looks great, being only 1w and not getting worked hard like a blue burner I hope it will last de-canned, I will be able to compare to my 7475's over time and see, I will get a thermopile when I find just what I want, it may not be any good for fraction of a watt stuff but IDC about measuring those.


---EDIT--- I would love to see a 1w yellow direct diode.

https://www.ebay.com/itm/TO9-Tin-Pi...91115473?epid=24010197641&hash=item3d65371bd1

https://www.ebay.com/itm/NICHIA-520...e=STRK:MEBIDX:IT&_trksid=p2055359.m1431.l2649

 

[paul1598419]

Did you decan the diode, or are you using a two element lens on top of the ball lens?

 

[RedCowboy]

In the pics above ( post 302 ) the 520 has a 3 ele and the 525 has it's factory GBall, not a bad beam really but not good enough so I did de-can it.

At night out in my backyard they both look great, but the color difference is noticeable, I took a side by side but did not get a beam pic, I need to mix a little smoke into the air and take the pic from a different angle, the pics above were initial bench test pics I had when I tested the diodes after pressing into modules.

---EDIT---

Here's a couple of better pics, my camera is not really picking up the difference when they are side by side, but my eye see's it.