635nM or 637nM which is better

[BruceLavender]

Hi All,
I know this topic is probly been discussed here before, which is better. I have been offered a RGB laser with a 635Nm red but I have heard the the diameter of the beam is much bigger 2.5mm -3mm against 1mm for the 637nM ?

[taggalucci]

Typically a 637nm laser module has better beam characteristics than 635nm ones. It will depend on the supplier and how well made and aligned the individual diodes are.

What power are you after?

[lilylin]

the 637 is better than the 635.But at the same time,637 is much more expensive than the 635

[edison]

635 is crap. 638nm is allot better but it can be used mainly for beamshows. 637nm single modes give the best beam after stacking but you need to stack 6 of them versus 2 of the 638nm diodes. But the 638,s need beam correction. 638,s are the poor mans red. I rather choose 500mw single mode and have the better quality beam then high power worse beamspecs of a 1 watt 638nm setup. If you stack 6 single modes you need a very stable stacking system to keep them alligned though.

It all depends what quality and what budget people have. Most people in the hobbyworld choose multimode because it is cheaper and its relatively easy to build it. Want have the best of the best you need to spend more but you will get over the cost of a single mode module in time but if you go for cheap then it you will get haunted by the poor quality and keeps irretating you. At least for me because i want to have things perfect when it comes to lasershows.

[norty303]

The more expensive one will always be better.

If the cheaper one was the best option, you simply wouldn't see the more expensive one offered for sale (nobody in their right mind would buy it). Simple economics.

[Bradfo69]

Thanks for the question and particularly, thanks edison for the clearest answer I've heard. I was going to post something similar just a day or two ago. I've still occasionally had a hard time wrapping my head around 635, 637,638, 640, 642 and the differences.

Real 640 if I understand correctly has the best beam and is the MOST expensive although I've also heard it said that some companies call their products 640 when they are really 642. I "think" I heard that Kvant even switched from making 640 to making 642.

I also understand 635 is huge, almost like 650 big (but brighter) so, it may be taking over as the red of choice in the cheaper Asian projectors.

[edison]

Most chinese companies use 638nm but they don,t use correction optics. That way a european setup with corrective optics is better. Have a look here:

http://www.photonlexicon.com/forums/...wanna-have-red

638nm with about 1mrd divergence and 4x4.5mm at aperture. I have them also in RB modules with 650mw max and 1 watt blue

[edison]

Most chinese are now starting to use 638nm because of the brightness but they don,t use correction optics. That way a european setup with corrective optics is better. Have a look here:

http://www.photonlexicon.com/forums/...wanna-have-red

638nm with about 1mrd divergence and 4x4.5mm at aperture. I have them also in RB modules with 650mw max and 1 watt blue

[norty303]

Real 640 if I understand correctly has the best beam and is the MOST expensive although I've also heard it said that some companies call their products 640 when they are really 642. I "think" I heard that Kvant even switched from making 640 to making 642.

Brad, as far as I think I've understood it over the years, 640 and 642 are all the same thing. All direct injection diodes have a +- on the wavelength, so one diode could be 640 and one 642 and one 638 out of the same batch. I'm pretty sure that my Laserwave '640' module uses the same diodes as Kvant used in their '642' module.

Just like we see 445 blue advertized as 450nm sometimes - I believe they are still talking about the same diodes.

I think any of the diodes that we know of that are referred to as between 635nmnd 642nm could all feasibly produce any wavelength in that band if the tolerances and other variables like temperature were in the right direction.

The only truly accurate way to describe them (I think) is to reference the diode part number.

[Bradfo69]

Maybe DTR or someone who deals in them could jump in and answer that.

I have some unbuilt edison designed products floating around - a dual, a couple quads (although one is loaded with blue - I've just never set up a driver for it yet) and my thinking, based on this thread is to do a module with some of the single mode Mitsus to go in my graphics box project and then, maybe set up the dual with a couple of the Mitsu 500mW 638's.

I need to actually get my sh!t together and start attemping to mess with these and learn somthing. I've got too many "diode module building" parts laying around, with good intentions and no follow through.