collimated multiple lasers

mattmagic100 said:

It can be done - Life long experimenter

rog made a white pointer by combining a red, green, and blue laser in the kes-400aa(?) sled and the optics inside. check out his website.

Click to expand...

Yes, but there is just a pair of things that you have not considered, i think.

First, the second cube of that sled is apparently not a polarizer, but just a splitter / joiner

second, that goal was not to add power to power, but to add 3 different wavelenght.

So, let me do an example ..... first is a polarized joiner, that join red and blue in h and v polarization schemes, and get a nagenta beam with 2 polar planes ..... that, passing through the second cube, got splitted in 2, and at the same time, added with 50% of the green beam, also this splitted in 2, like in the attached image .....

I never seen that assembly working (mean, the unit powered up and the beams paths inside the cubes), but i bet a beer that my theorical model is near enough the reality

it's difficult combine more than two lasers of the same wavelength using a PBS ... you can use the knife edge mirror method. But this method is certainly not easy and usually requires other optics after the PBS in order to get a relatively nice beam. There are a few other ways that are possible but they are also difficult.

Regards,

Adam

You (and by "you" I mean all you folks asking why more than one PBS wont work) really need to read up on what polarization is and then you will understand why using more than one PBS wont work

If you combine a red and a green beam, you combine their powers as well, of course.

Combining beams is only possible if they differ in some characteristic. What you then need is a material that transmits one type of beam and reflects the other. For different colors (wavelength), you use a dichroic mirror (and as long as the wavelengths are sufficiently far apart, you can add more); while for two beams of the same wavelength, you use the polarisation as the distinguishing mark. After the combination, that trick doesn't work any more because you can only have two independent polarisation planes and they're now both "occupied", no way to sneak in a third.

^ Uh, yes, you can ..... you only need a polarized combining TESSERACT ..... (J/K, sorry, can't resist )

Now how could I have overlooked that?!?

so I am guessing using quarter wave rectifying layer material in the polarizing process would have zero effect or are they already being used and tuned to the frequency of the laser to ensure low loss of power? can you point everyone to a good article (science article) that explains more about the polarization process, I know that general polarizers are usually a metal of some sort that is then heated and stretched so that the metal forms micro filaments that the light striking it caused a back lash creating a field between the filaments, (iodine used in vinyl is what they use for the 3D glasses you see in old school 3D movie theaters) and then you can use a filament molecule like polycarbonate, that gets its strength as a polymer by being stretched over and over while hot and layered (for bullet proof glass) thus creating chains all running the same direction of the polycarbonate molecule, in an aligned fashion, so if you put it between two polarizers, instead of getting a black to clear reaction as you rotate them against each other, you get a color change effect going between a red and blue with green and yellow phases, though using lexan you never get the UV spectrum in the rotation process since lexan blocks all uv both A and B spectrums, you can see what I am talking about in my video,


(the material used in the video is a sheet of lexan from Home depot and two sheets of polarizing film from the front's of LCD screens.)


that being said, I would love to read up more on polarization as I know I barely know anything about it.

Here are some reference photos of knife edge arrays.

Diagrams - Album on Imgur

Commercial eightonlight modules using knife edging - Album on Imgur

red diode knife edging - Album on Imgur

If you want a pointer, I suppose you could fit two diode array in a large host.
https://www.youtube.com/watch?v=53GJJHwQ8BA

Wear eye protection when working with lasers, especially adjustable mirrors.

by the way the reason I even came to this thread is because I saw the first image (in the OP) in a google search on combining multiple lasers together as one laser. I am very grateful I read the whole thread lol, it would have sucked to try and combine 6 laser together only to find out the cubes were not able to do such a thing lol. the glass dividers in a 3LCD projector are some interesting tech but my design I am working on requires the ability to use UV light in a projector, so this info is invaluable, again thanks to everyone who posted here not only clearing up what is a bad idea but also the originator of the bad idea so I did not have this idea and not have the benefit of the advice of those that had the facts on everything involved to not use this idea lol. I would think with higher powered lasers being so cheap, two beams should be more than enough for most people. two of the higher multi watt 445nm lasers combine together just sounds completely insane lolol

very glad google reintroduced me to this forum, I only wish I could remember my login details from way back then lol

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