445nm beam combining

Hello all. I am new user here on forum but checking the site for a bit longer :wave:

Already 7 years I am trying to understand laser as it is from the elementary physics of laser diodes to exact application and it's all possible abilitties of use in daily life and also in research.

I am about to start one ''bigger'' project that will combine three beams from 3x-3,3w 445nm laser diodes into one beam.

And here are the two things I need to have clear before starting:
1, If the cube to combine beams has dimenssions 12,7mm (0,5'') what cooling of this crystals is needed ?
2, What power can I expected from the three combined beams if the single one's 3w of optical power ?

Thanks in advance for answers. (Please excuse my English).

I assume by cube, you meam a polarizing beam splitter. Combining optics don't need cooling.
Basides that, PBS cubes can only combine 2 beams (of opposite polarization). To combine 3 beams you would need to either knife edge all 3, or knife edge 2 and then combine it with the 3rd via the pbs. I suggest just knife edging, it will be a lot simpler.
Refer to this thread: http://laserpointerforums.com/f51/reference-guide-how-combine-lasers-77449.html

Thanks for info and for the link..very nice guide.