635nm 20mw for 19.95?!

Ebay item 220186884871

I would link to it but for some reason I can't post links. :-?

If that's real, that is a hell of a deal and could result in core-like brightness in red form methinks, assuming you can put the diode in a pointer case.

If you guys think it looks legit, I might get one.

two ebay rules:
1.: ebay+laser = scam! There are a few exceptions to that, but they are scarce.

2.: if it looks too good to be true, it is. From what I can tell, 635nm is only achieved with DPSS, and you wouldn't get a 20mW red DPSS for that price.

I'd say forget it, it's a plain old 650nm.

also you need 10-20 posts to put links up unless a mod removes the limit

I'm afraid you're mistaken, Mr Phil. You may be thinking of 671nm.

Here's a red flag - aperture reads: 635nM 20mW CW CLASS IIIa

Well, I did see the aperture saying 635, but I wouldn't bet too much money on the labels being true, especially with lasers in that price range. I'd rather trust a Noval albel for example than some random ebay label.


About the 635nm: Are you sure? It might of course be that I am messing things horribly up here, so don't mind my talking.
But still, I thought the reason 635 (which allegedly is such a much nicer color) is so rare is because it was DPSS?

philguy said:

Well, I did see the aperture saying 635, but I wouldn't bet too much money on the labels being true, especially with lasers in that price range. I'd rather trust a Noval albel for example than some random ebay label.


About the 635nm: Are you sure? It might of course be that I am messing things horribly up here, so don't mind my talking.
But still, I thought the reason 635 (which allegedly is such a much nicer color) is so rare is because it was DPSS?

Click to expand...

No, 635 nm is still a direct 'injection diode', not DPSS. Pretty much the same recipe is used to make red diodes from 630-670 nm. Perhaps a bit more difficult to make the higher frequencies because the die needs to be under stress, can't remember if it's tensile or compressive.

The only cheap high powered red diodes are those used in DVD players.. just an economy of scale thing. Above about 10-20 mW 635 nm diodes get very pricey, though they can be had. I made a couple of DIY 635 nm pointers a few years back. They are around 20-25 mW.. probably appear as bright as a ~80-100 mW DVD diode (660 nm). It's a nice red, much more orange when compared to the cherry red of a DVD diode. More pink than red, close to HeNe 633nm.

mW per mW a 635nm diode will appear 2-3x as bright as one at 660nm. Just a bias of our eyes.

wow, that is cool! One never stops learning

Is there a (relatively) cheap source of these? Any way of obtaining them? Or is above product already a good deal?

Man, that sounds fun!

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