635 Vs. 650

[Xytrell]

If you went by brightness, they are both of similar prices. For example, a 300mW 635nm costs about as much as 800mW 660nm.

But I like my 635 just fine. It looks like a deep red to me (unless side-by-side with a 660).

[dave]

yes, the 642nm diodes are the way to go, they only have 1mrad divrigence.
http://www.swisslas.ch/he_data/downl...ul_rot__2_.pdf

Main problem is, the 150mW CW diode cost still more than 130 euro's a piece.

So it looks like Swislas is over driving the diodes by quite a lot then, doesn't it..

[FourDee]

it would seem so

[mccarrot]

Yes, but a lot of hobbyist drive 100mW CW 16X DVD burner diodes at 200mW.
This is 100% overdriving with only a little bit shorter live, because in a projector the diode in not driven CW

to run a 150mW CW to 200mW is only 33% overdriving so in a projector it would probbably be no problem.

[keeperx]

i drive my 22x dvd burner diodes at 330mw
i HAVE driven them at 410 before for short burns..
at 250mw, the dvd open cans run well.

maybe i should combine 2 of them to make a big red laser.. oh wait.. i did that already

[kecked]

I have the 642nm diode and it works extremely well but I went back to the open can diodes because I do laser for myself and can see the difference in my white balance.

I combined 2 open can diodes that cost 58.00 with housings and got 400mw of stable 650nm (cooled well). That combines well with 100mw of 532nm green and 200mw of 405nm violet (also combined). Note the 405nm diodes also only cost 58.00. so my total investment in lasers is about the same as I paid for the 642nm red! This setup replaced an ILT argon 175mw and 35mw hene PCAOM combo. ( I LOVE not having the green dot!) PS: it's all in a 12"x18"x6" enclosure and is dead quite.

The actual problem using this type of low power low quality diode laser setup for anything but home use is that the diodes do not overlap well at a far distance. Beyond 30-50 feet, you have a an extremely small 405nm beam, a small 532nm beam , and a huge 650nm beam. In this case of distance, then you need the extra cost of the 642nm diode and really need to consider using higher power matched dpss lasers (2-1 watt 671nm, 1-1 watt 532nm, and 1-1 watt 445nm) for anything commercial in nature.

You might think to use beam expanders on the diodes but that only goes so far to match diversion.

To end this ramble I can only say I can't wait till 445nm comes down in price! It is very nice as a blue and violet gets taxing after a while.

The color difference between 642nm and 635nm in NOT noticable. The difference between 635nm and 660nm is very noticable. The difference between 671nm and 660nm is not noticiable and the diff between 642nm and 660nm is almost as prononced as 660nm and 635nm.

Final word. Unless you put the beams next to each other, you are lying if you say you can tell the difference in a scanned image. It does slightly affect the color temp of the white but that is all.

[keeperx]

my dots are directly on top each other at 100 yards.

[kecked]

So are mine but the diam. of the beams do not match

[tocket]

It might sound odd, but you may want to increase the divergence of your other lasers. Not only could you get a homogeneous beam, but it would also make it safer.

The divergence of my greenie increased after a little accident and while I didn't like it at first I think it's actually good now.

The actual problem using this type of low power low quality diode laser setup for anything but home use is that the diodes do not overlap well at a far distance. Beyond 30-50 feet, you have a an extremely small 405nm beam, a small 532nm beam , and a huge 650nm beam. In this case of distance, then you need the extra cost of the 642nm diode and really need to consider using higher power matched dpss lasers (2-1 watt 671nm, 1-1 watt 532nm, and 1-1 watt 445nm) for anything commercial in nature.

Interesting, I would expect the 532 to have the best beam properties, seeing as it's DPSS. I don't think 405 are particularly good in this aspect; their beam is rather large and divergent, at least with the diodes and lenses I've tried. They're pretty much the same as the red DVD burner diodes.

As for white balance with 642 vs 658 there shouldn't be any significant difference other than 642 being much brighter, so you need less of it. That is according to current color theory, not my observations. You will still get a more natural white with those 658s though, as 400 mW of 658 is slightly stronger than 150 mW of 642.

[allthatwhichis]

I have to argue for 660s, especially the dvd diodes that seem to be dirt cheap now. The beams rival dpss and it looks like combining them isn't too difficult. I took some pictures with my... the camera I bought the boss for Christmas... It shows a clear difference for graphics, although no difference in beams. The lasers are a set of 660s from MechEng3 measuring 310 after the cube and about 275mW after the galvos and a masked CNI 635 measuring about 230 at some point, I think before the galvos... and I have a mask that trims the ebam to jsut the size of the galvo mirrors; I would guess it to measure 150mW. These were measured on daedal's meter before I took the photos.