beamsplitters

[glowdye]

I am looking for a non polarizing beam splitter. larger size if possible. can trade high voltage parts such as 10kv .005uf caps, high voltage 2 M Ohm resistors, lots of mosfets, schottkey diodes etc.

 

[nkgamer1990]

arent' all beamsplitters polarized?

 

[diachi]

arent' all beamsplitters polarized?

No, only polarized beamsplitters.

There are also partial reflect mirrors, which are also beamsplitters.

Link to Edmunds with just about everything you'll likely need to know about beamsplitters - also has interesting information about the differences between plates and cubes: https://www.edmundoptics.com/resources/application-notes/optics/what-are-beamsplitters/

 

[Alaskan]

What ratio and wavelength? I am sure you have been looking for them with that in mind. I see NP BS on ebay from time to time cheap, but you have to wait awhile.

OK, I came back to add more, I went looking on ebay, there are lots for good prices but are you looking for a cube, or a plate and what ratio of BS? I have always searched for beam splitter cubes in the past, not plates. I'm finding flat plate beam splitters for good prices. i.e this 30/70 plate: http://www.ebay.com/itm/30R-70T-BK7-Plate-Beamsplitter-50-x-50-x-3mm-1-lot-of-2-pcs-/222403622468

Something like this would be good to increase the power measuring range of a LPM. I saw a 25/75 ratio plate listed too, increase your LPM top end measurement range by 4X with that one. But if all you wanted was to increase your LPM measurement range, stacking a bunch of microscope slides would do that too by a fairly predictable amount due to reflections, if they were flat enough.

What cha building with it, or what application?

 

[CurtisOliver]

I know that, non polarised cubes can be expensive and also have lower power recommendations. I was looking into them in order to combine my NUBM44's together without having a hideous cross shaped beam, and also to allow easier beam correction.

 

[Alaskan]

To avoid the crossed + pattern, OptLasers combines the output of two 638nm laser diodes using a 1/4 wave rotator so when used with a PBS cube, the rectangle pattern produced from each diode fall exactly on top of one another avoiding that pattern. Is that what you were looking into doing, the same thing? Not cheap when adding the cube and the rotator, but nice

 

[CurtisOliver]

Yes, that is what I want to do. I was trying to work out what would be cheaper. A waveplate and pbs, or using a npbs. Thanks Alaskan.

 

[diachi]

Yes, that is what I want to do. I was trying to work out what would be cheaper. A waveplate and pbs, or using a npbs. Thanks Alaskan.

Alaskan bet me to it!

You can't combine beams using a non-polarizing beamsplitter anyway.

 

[CurtisOliver]

Oh, I asked the manufacturer whether it was possible and he stated it was. Just as well I didn't go through with it then.
And yes Alaskan got there first. :na:

 

[diachi]

Oh, I asked the manufacturer whether it was possible and he stated it was. Just as well I didn't go through with it then.
And yes Alaskan got there first. :na:

It'd work, but not in the sense you're thinking.

You'd combine the beams, but you'd still end up with two beams at around the same power as the original beams.

Beam one would pass through say 50% and be reflected 50%. The other beam would have 50% passed and would combine with one half of the other beam (the reflected half), but 50% would be reflected and combined with other half of the first beam.

So it works, just not the way you want.

 

[CurtisOliver]

Er... that is exactly the effect I was going for.
No i'd better stick with a waveplate and a pbs then.

 

[diachi]

Er... that is exactly the effect I was going for.
No i'd better stick with a waveplate and a pbs then.

Yep haha ! Other options are knife-edge (Which is really just stacking the beams next to each other) or a really narrow dichro, like the one used in this thread: http://laserpointerforums.com/f42/combining-two-nubm08-dichro-no-pbs-involved-99830.html

 

[CurtisOliver]

I will try to avoid knife-edging. I want the beams to overlap each other perfectly. That dichro thread was interesting. A good idea. Thanks for your help Diachi. :beer:

 

[Alaskan]

Wish I could find a PBS beam splitter with a hole through it and see if I could coaxially combine three beams. The one going through the hole would need to be a much smaller beam diameter while the other two expanded. Would be kinda weird though, divergences wouldn't match.

 

[CurtisOliver]

I simply wish there was a way of combining many laser beams into one, keeping the original beam specs, therefore avoiding knife-edging.
Your PBS with a hole would be fairly unusual and would lead to a unique beam profile.

 

[Alaskan]

I saw an old post at PL where someone wanted to find one of those, or have one made, but I don't know if they did or not.