Cheap way to combine two red beams?

[ReNNo]

I want to combine beams from two red lasers so I can get enough red light to use it in laser scanner.

What would be the cheapest way to do it?
Is there any optics in sleds that can do that job? (I played with some optics from sled but couldn't find any useful for this use)

If not, do I need beam splitter (50/50) to combine beams, if yes, where can I buy beam splitter for cheap?


I don't want to open another thread for this question, but maybe someone can help.
Dichros for combining beams can be found on O-Like but I also want dichro holders.
O-like sells holders but they are not adjustable and it can be pretty difficult to combine beams.
I need holders with screws for fine adjustment and I don't know if anyone sells them for cheap.
The cheapest I could find was about 35USD.

 

[Grix]

There is a broadband coated PBS cube in KES bluray sleds, if I recall correctly.

 

[ReNNo]

There are one smaller and one bigger PBS in KES-400A sled.

But none of them won't work for combining two red beams.
And both PBS are smaller than 5mm beam that means power leaking.

 

[ReNNo]

---bump---

 

[ElektroFreak]

I want to combine beams from two red lasers so I can get enough red light to use it in laser scanner.

What would be the cheapest way to do it?
Is there any optics in sleds that can do that job? (I played with some optics from sled but couldn't find any useful for this use)

If not, do I need beam splitter (50/50) to combine beams, if yes, where can I buy beam splitter for cheap?


I don't want to open another thread for this question, but maybe someone can help.
Dichros for combining beams can be found on O-Like but I also want dichro holders.
O-like sells holders but they are not adjustable and it can be pretty difficult to combine beams.
I need holders with screws for fine adjustment and I don't know if anyone sells them for cheap.
The cheapest I could find was about 35USD.

You can knife-edge the beams using a turning mirror from a sled. Also, you can get red coated PBS cubes fairly cheaply from laser-wave, ebay,, and I think optotronics has a fairly big one here: Optotronics Product Details

 

[ReNNo]

You can knife-edge the beams using a turning mirror from a sled. Also, you can get red coated PBS cubes fairly cheaply from laser-wave, ebay,, and I think optotronics has a fairly big one here: Optotronics Product Details

I tried turning mirror but it can only reflect red beam and almost none of light goes trough it.

It all looks expensive for my low-budget scanner build.
Cheapest PBS I can find is on surplus shed.


Now I'm more worried about dichro and PBS holders.
O-like sells holders but without adjustment screws.
I have no idea how to align beams.
It could be easy to align beam horizontally but how to do it for vertical alignment?
Only if I bend O-Like holder...

 

[BShanahan14rulz]

I tried turning mirror but it can only reflect red beam and almost none of light goes trough it

Yes, the mirror is used to reflect the red beam.

If you use the edge o the mirror, you can shine another red beam right next to the mirror. The light won't combine, but it will create one spot, more or less.

Imagine using the mirror as a PBS cube, but instead of light going through the mirror, you send light around it. If you align it just right and use the right edge of the mirror, you will end up with a continuous beam.

Check out http://laserpointerforums.com/f50/my-take-quad-red-52626.html for a visual representation.

Edit: not "MY" take, Andy_Con's take. And if you are just using 2 diodes, you can forego the first mirror, just put the diode there pointing in the direction of the final beam. This would "combine" 2 diodes' output using only 1 mirror.

Vertical adjustment shouldn't be too much of an issue if everything is right-angles. I guess you could put a fold or two of aluminum foil under the mount to tilt it, if you find you need vertical adjustment. or you could create your own adjustment mount for the mirror mount.

 

[ReNNo]

Wow, he did great job.
This technique is amazing.

But when I want to combine two beam with edge of one mirror it makes beam 10x5mm.
To correct it I need two additional lenses. And even after correction beam is not perfect.

Hmmm, I think this is not right way to combine two beams.

For combining 4 beams it would be good technique because you get square beam.

 

[ReNNo]

I decided to use beam splitter.
This one on Surplusshed look good.

15MM COATED CUBE BEAMSPLITTER - Surplus Shed

Can this work to combine two red beams? Would it be efficient?

 

[BShanahan14rulz]

I'm not too experienced with beam splitters, short of knowing basically what they do. I've heard they can be somewhat less efficient than mirrors, but that the end result is much more desirable because rather than putting two beams next to each other to form one beam, you are putting two beams in the same space.

We should let someone with more experience chime in.

Edit: It's hard to tell. Some beam splitters seem to split beams while others can split or combine, depending on the diode orientation. This one looks like it splits a beam 50/50 more or less, depending on the wavelength. I dunno if this can be used to efficiently combine beams.

Most of the ones people use here are polarizing beam splitters that will reflect one polarization while transmitting another. Check out the wikipedia article on beamsplitters for more information on the different types.

 

[ReNNo]

I'm not experienced with beam splitter neither.
That is why I need someone experienced to tell me if this 19USD beam splitter is good for combining two red beams.

 

[Bionic-Badger]

Well I just ordered the 20mm one. I'll see how it works with some laser pointers or something (no real mounting apparatus at the moment). I've been wanting to do some beam combining too.

 

[ReNNo]

OK, then I'll order 15mm cube and see how it works.

 

[HIMNL9]

Uhm, one thing that surplusshed site don't say ..... are these ones POLARIZED beamsplitter, or simple diffraction beamsplitters ? .....

Cause, if it's just a diffraction beamsplitter, it can be used for split a beam, but NOT for join two of them (same as for the dichroic beamsplitters and 50% mirrors), where instead, if they are polarized ones, they CAN be used for combine two beams .....

 

[jaycey]

Heres my take on the dual red... http://laserpointerforums.com/f48/pain-beam-combining-i-see-red-54506.html

 

[ReNNo]

Uhm, one thing that surplusshed site don't say ..... are these ones POLARIZED beamsplitter, or simple diffraction beamsplitters ? .....

Cause, if it's just a diffraction beamsplitter, it can be used for split a beam, but NOT for join two of them (same as for the dichroic beamsplitters and 50% mirrors), where instead, if they are polarized ones, they CAN be used for combine two beams .....

That is what I'm afraid.

P.S. Payment sent for PBS

@jaycey
Wow, that is exactly what I want to do...

So... I need to make holders with adjustment screws....
I'll try.