5 mm PBS cubes are cool. Really.

[The_Doctor]

I have several of them. If you want one, make me an offer I like, and I'll send it once I get paid. I'll leave it to people here to decide what they think is a sensible offer, just be aware that I will accept if I like it, otherwise not. I won't be selling these on eBay, I'm not a business, I can't be doing with risking penalisation for multiple sales of similar items, and their final value fees are a nuisance too. Besides, how many general eBay diode laser buyers even know what a PBS will do for them? I could spell it out and most might still be wondering what the point is..

The cubes were made for ABSee Laser of Germany, for use in their multi-diode red lasers. AR coated for 650 nm, 5 mm on each side. As a guide, I tested a cube: 122 mW Source, 106 mW 87% Transmission, 112 mW 92% Reflection. This isn't as good as Edmund Optics can sell you, but it's a LOT cheaper. Bear in mind theirs are specified at 635 nm, they won't do as well at 658 nm so these are a good alternative.

As I said in the subject, they ARE cool. If you are capable of mechanical construction, a 5mm cube should be plenty big enough, you won't need 15 mm across if you're not trying to do what Arctos do. You could send three beams parallel and in same polar plane, into the cube, for six out, on one common axis, and 5 mm IS plenty. If ABSee Laser could do this, so can you.

I'll admit that this is something I haven't done. It's one of many projects I never followed through. I can help though, I did go as far as making some tiny kinematic mounts in brass, which would work with these, so I can advise buyers to some extent, as others here can too. I can also post a Sketch-Up model that will show precise dimensions, etc.. I'll do this if I get some interest.

I have about 30 (I think 32 or 33) of these cubes. If I like an offer I'll accept it. Can be made openly here, or via PM. On receiving payment I'll send the cube(s) within a day or two at most of cleared payment. Once they're gone, they're gone, but there are enough for a serious project here, or several sales of built modules.

[The_Doctor]

Bumpity.

Give it some thought.. I think the only reason ABSee Laser quit was because they'd have fallen foul of the Arctos patent, nothing wrong with these small PBS's for private builds of lasers though.

I really don't know why people seem to insist on large ones anyway. You have to get two beams to cross in a tiny region, to make a cube work. If your beams are 3mm wide or less, a 5 mm cube is plenty! Unless you're using Arctos style arrays or have very clumsy fingers, I can't see why 15 mm is needed. Imagine a dual diode laser the size of a matchbox. With one of these, you could do it.

[allthatwhichis]

I need big optics... It is a personality flaw.

[stanwax]

my DVD dual red is combined using a 5mm cube from an old samsung dvd player. Its just the right size and no need for all that excess.

Rob

[The_Doctor]

I need big optics... It is a personality flaw.

They look nice. But once the thing is built I want to see the output.. Also, the smaller the assembly, the cheaper it is to make it stable, so long as making its parts doesn't get expensive. I like a 5mm PBS for the same sorts of reasons people like 5mm scan mirrors. Best performance comes when they're no bigger than they have to be.

[allthatwhichis]

It is not for looks, although big optics do look cool to me... I am still a n00b in my opinion; alignment is still a bitch and I like the "space", kinda like a safety net. I have only combined my first set of reds a couple of weeks ago. I am not sure I would have gotten it done so fast with the 5mm, and probably would have killed one with back reflection. One day I am sure I will use a 5mm, but for now... bigger is safer.

[The_Doctor]

Ok. Though I guess a small cube on a slightly larger mount might work. The thing with a really tiny mount is the moves to steer it can make it move too much. Or be too inaccurate. I never finished my project so I don't really know. Jem's opticians' screws take care of the fine movements but my design might be unstable because the kind of ball-joint used in larger mounts isn't there. But I reckon it's still ok, just not as large or linear range of control as might sometimes be wanted. You'll get used to small, if you have a go. I used to think that hand soldering SMT parts was impossible, especially the finest pitches on IC's but there is always a way, and what's more, a simple one. The trick is to work with existing conditions, not against them. Trying to dominate with our wishes and ideas is where we get in a mess. We can still get what we need, just maybe not the way we want. Another thing about small, I remember some Chinese saying about fishing (as done with a spear, I think) When aiming for the fish, aim for the eye. Meaning it's just as easy to be accurate as inaccurate, given the same means to try, and you're more likely to get the fish. Odd that the saying hadn't a word to say about refraction in the water, but never mind.