Axicons to combine diodes for a single beam.

[mixedgas]

I've built one, it needs quite a few adjustments.

Steve

[chad]

Mixed, can you post a pic of the axicon and what you have going so far? how big is the optic? is it round? do the facets come to a point or does it have a flat top?

I will fire up solidworks and play with some ideas for machineability and adjustment.

chad

[daedal]

I've built one, it needs quite a few adjustments.

Steve

Agreeing with Chad, please share some pictures of the current setup as I am very curious.

Regards;
DDL

[mixedgas]

The test optic was made out of a piece of austrian crystal by a local glass shop, with 8 sides. The lady who did it made it at 35' because thats what her tooling allowed. So the laser had to come in below the horizon. Its pointed, and the faucets at best gemstone flatness, not optical at all. I used fresnel reflection for the test. It did not have a flat base, she modified a stock piece that is a chandelier decoration. I dropped it into a half inch post holder with some electrical tape for mounting. I stuck it in the optical breadboard of my projector and aligned 3 beams to it, two at right angles and one coming in at roughly 45' from the other side

As her tooling is manually indexed, as she's a artist, not a machinist, the errors are somewhat nasty. She has a masters in fine art,makes mega buck glass art, and this was a waste of her time from her point of view. Since she has other artists in training in her shop, my request to rent her tooling was not granted. Or I would have been back with a rotary table and a borrowed sine plate. We got as far as we did because I once contracted her to make some custom glass for a breast cancer research project, at the old day job.

Because it is not at 45'. the beams develop a nasty oval shape in the test pictures. It not what I'd call a great piece of glass to base a design on, but it only cost 35$ The pointy end is a big mistake, you want the beam up the middle. You want the round spot on the top to be maybe 10% bigger then the diode beam diameter because of wedge effects.

I just obtained some 45' prism blanks that can be cut to true pyramids. There are two PL members with glass grinding capability, one of them a trained machinist. It will happen.

So basing a design on the test glass I have would be a waste. It was kind of like adjusting a melting ice cream cone, because like all artists, she just held it up to a protractor, and used the austrian molded sides to set the faucets around the z axis. Her stuff is mainly to put nice bevels on table glass and thick stained glass. She starts with a industrial belt sander and then goes to a classical glass grinder.

No regrets, because this is how prototypes happen.

If we could find a cnc that we could load a diamond scribe in, perhaps we could make it with thin dielectric mirror stock. Then glue those pieces to a CNCed pyramid. In the long run I think it will be best just to have a optics house in the far east make it,

I would have to drive 5 hours to outside Ft Wayne, but I can borrow a co2 laser there on a xy stage for cutting the glass. However the edges would be trepanned about 2-3 degrees. That seems sloppy. Right now I dont have the gas or hotel money to do Fort Wayne. Thats why I need to get the abs boards done, to start getting the laser "hobby" self sustaining again.

I'll post some pics soon, I didnt take any. I'll have to dig the projector out of the barn and defrost it. When you have a semi photographic memory (yeah, thats how I memorize all this stuff) you don't reach for a camera very often.

Steve

[mixedgas]

News Flash, there is a optics house a hour north of Philly that will quote me small piece work!

Steve

[allthatwhichis]

[chad]

You should move this to the advanced technical thread.

So are you going to do a 4 sided then?

Here is a quick render it is 3/8 diameter and about .5 inch long. Is this what you were thinking?

chad

[mixedgas]

Chad,

yeah, Thats IT. Put a flat on the top for the 5th beam to come up through.

I'll send that to Philly and some other places.

Steve

[mixedgas]

Chad, take a look Edmund Part # K47-237

And then look at K47-628

and then K45-939

You'll get the idea.

Thank you for rendering that!

Steve

[allthatwhichis]

Is it cheaper to coat a glass surface, or machine and polish a small piece of silver? And if silver itself is a really bad idea in and of itself; tell the ignorant one why.