For sake of simplicity, let's talk about 1 diode. I understand that 2 cylindrical lenses are required as it's essentially 2 individually emitted beams which need correcting, but I'm trying to visualize where you would place any common-size cylindrical lenses in your proposed arrangement. Could you possibly provide a simple drawing, with some respect given to component scale, so I could attempt to imagine such a setup in something semi-portable? Thanks
Forget about anything semi portable. I was thinking as application for projector systems. Due to the required 90 degree alignment offset required to feed a PBS cube (and the real estate needed for setting up bounce mirrors to achieve that 90 degree offset) you're going to be hard pressed to craft together anything that doesn't require two hands to hold if you're going for a portable unit. This isn't something that could be packaged as tightly as CDBEAM's combiner creations.
Without a drawing should be enough to picture what to do. Diode->collimator->C-lens pairs as close to the collimator as possible, ideally the first lens of the pair will be touching the first lens of the other pair and they will be offset in their angle at the same angle the beams are offset from one another emitting from the diode. That is, each beam from the diode will be entering the first c-lens with the lenses angled such that the beams will be entering the lens straight, just as you would on a normal, single beam diode. Imaging the hands of a clock at say, 9:20. Except the hour and minute hands are the same size and they're not hands on a clock at all.. instead they are the top surface of the C-lenses that you are looking directly down on. 9:20 was just to visualize those lenses as a slight angle offset to match what the angular offset of the beams themselves might be. In this example, the diode itself would be somewhere in the 7:00 region firing upwards towards 1:00. The laser diode itself is located as far away as necessary from the center of the clock's hands to allow the center of each beam to strike the center of each lens, and the angle of the lenses to one another in this example matches the offset of each beam such that the beams are entering their respective lenses square to each lens.
The rest of the C-lens setup is as normal, so now you have corrected beams at a slight offset, the same angle they've been to one another as always. Pick one of the two beams and have it enter a PBS cube a short distance away, perhaps 8 inches of travel from the output of the c-lens, to give you some room to work on the other beam. Now you must use bounce mirrors on the other beam to set it up such that will enter the other side of the PBS cube, so this will likely require the first mirror to deflect the beam in a way that it increases the angle the two beams are relative to one another, then a second bounce mirror angled and positioned so it's aligned with the input of the PBS cube. Before entering the PBS cube, one of the two beams will need to pass through t wave rotator plate to change the polarity of beams relative to one another so the PBS can do it's job. Otherwise, if you don't use a wave rotator, you would need to rotate one of the entire beams to achieve the needed polarity angle to required by the PBS cube.
Not only is this not possible without separate diodes (usually one diode module is rotated in it's heat sink to achieve 90 degree rotation if a wave rotator is not available) it would also result in a "+" shaped output which, of course would.. suck. The wave rotator allows the beams to enter the PBS cube and overlap one another so the output is the two beams combined and perfectly overlapped. So now you have your corrected beam which is actually both beams overlapped and almost twice as bright as each of the beams before they were combined.
Now you have defeated the dual beam nuisance and forced it to be a single beam, and corrected it to boot.
This means that what will happen is a few days after finishing this project, a new red diode will be released that has a single emitter with a higher output than your corrected combined beams. This new diode will cost the same or less than your dual beam diode and won't require the $120 in two c lens sets, $ in front surface bounce mirros, $ in PBS cube and $$$ in wave rotator costs.
Thank your for your contribution! This is the driving force behind all new diodes and we're glad you took one for the team. The diode puppeteers are sick, sick people indeed, and watching you sink all that effort and money and time in to achieving a decent high output was the perfect moment to release the 4 watt single emitter they've had behind their backs this whole time, simply so they could watch your spirits be crushed and love for life be dissolved.
Damnit, it would have been easier to draw the thing
I'll draw it sometime in the next hour or two. I've spent enough time writing this and I have things on my mind that are more interesting to do for the moment
