600mW Yellow Laser Build

[HydroSean]

So I just purchased these dichroic mirrors (link) to build a high power yellow laser by mixing red and green laser light. Here's a picture of what I hope will work, please let me know if you see any flaws

So which red wavelength should I get 650nm or 638nm? Also what about the green wavelength, 520nm or 532nm? I noticed in jayrobs tutorial here (link) he used 650nm and 532nm. Would it be the same if I used 638nm and 520nm? Also should I use the 3-element lens or G-2 lens?

 

[diachi]

I'd use 520, red wavelength doesn't matter much - you just need a little less power for 638. Reasoning for 520 is that the beam diameters will be a better match. Otherwise you end up with a yellow beam that has a red outline.

Edit: May also want to get some small mirror mounts to make life easy.

 

[HydroSean]

So should I get the 3-element lens then? They have a tighter beam spot right? Or possibly make an entry hole to shape the beam into a circle?

 

[diachi]

So should I get the 3-element lens then? They have a tighter beam spot right? Or possibly make an entry hole to shape the beam into a circle?

Get whatever lenses will match beam diameter the best, and get diodes that can be matched well too, that way further correction shouldn't be needed, unless you just want to improve beam quality.

As for shaping the beam, it doesn't work like that. You either need a cylinder pair or an anamorphic prism pair, and perhaps a spatial filter. The problem is that MM diodes have different divergences on either axis, so if you used a circular mask to shape the beam the divergence on either axis wouldn't change and you'd still end up with a stripe. The spatial filter clears up aberrations surround the beam. You can live without that.

Bragg Spatial filter (we usually use pinholes, but the result is the same):

 

[HydroSean]

Oh looks like I'll need that anamorphic pair of lenses. Got a link for a good deal?

How about this one?

 

[BobMc]

So I just purchased these dichroic mirrors (link) to build a high power yellow laser by mixing red and green laser light. Here's a picture of what I hope will work, please let me know if you see any flaws

So which red wavelength should I get 650nm or 638nm? Also what about the green wavelength, 520nm or 532nm? I noticed in jayrobs tutorial here (link) he used 650nm and 532nm. Would it be the same if I used 638nm and 520nm? Also should I use the 3-element lens or G-2 lens?

Best wishes with your build. Looking forward to the finished post. 600mw's of yellow should just be awesome. Fingers on the :drool: button!