Little update : I received the LENS-27, installed them, passed a lot of hours trying to get the best alignment of the 4 beams, and now I finally obtained a relatively good beam data : total is 2x4mm, but the most power concentration should be on an even smaller surface
Also I developped a small TEC driver, it's the lil board on the top of the module. It's adjusted for 20°C +-1°C, and seems to works well, despite it's only an on/off circuit with constant current source.
And maybe I should consider an external driver case, as all these boards take a lot of place...
Ah and about the power, I obtain a nice 1.2 watt after all the optics, with 350mA per diode, I'm quite happy