solar coupled optical fiber

[swamidog]

when i'm not busy with my multiple day/evening/night jobs, i do professional photography. many of the photos i sell are framed in custom made barn board frames that i decorate with pieces of cactus skeletons and other desert artifacts.

i've been slowly assembling a cnc system for burning designs into the frames. for personal reasons, it would be very satisfying to use solar coupled fiber instead of lasers to do the actual burning.

there are number of references to solar surgery experiments on the net: http://physicsworld.com/cws/article/news/17238, but i don't have the equipment necessary to build the device.

anyone interested in collaborating with me on this?

[dnar]

Mate, if you lived closer than 10,000 miles I would be in!

You might want to checkout some of the current sky lights they fit to office buildings. Some include sun tracking. It could provide the basis for a good collector/collimator.

Sounds like a fun project! You could boast owning the worlds largest laser! Sol has plenty of life left in him too.

[aromaru]

I don't know if this should be considered out of anyone's budget; this appears to be an interesting alteration on the increasing in popularity solar oven.

A square meter of surface area is around one kW, minus the loss from your aperture, reflecting surface and optical fibre, You don't have to go all out to obtain a similarly functional unit.

For your parabolic reflector, I present a great source on all things in solar cooking: http://solarcooking.org/plans/parabo...flat-sheet.htm
The most over board you might go is using mylar for that 98,8 percent efficiency, but the shiny side of aluminium foil is sufficient for cooking a roast; in fact, the only place you'd want to spend good money on is the fiber itself.

While the, err, emitter can be focused with a lens and closed with a mirror, it would probably be wise to include a capping system for your collector.

[swamidog]

I'm thinking about picking up one of these as my collector:


http://cgi.ebay.com/ws/eBayISAPI.dll...m=180661512191

I don't know if this should be considered out of anyone's budget; this appears to be an interesting alteration on the increasing in popularity solar oven.

A square meter of surface area is around one kW, minus the loss from your aperture, reflecting surface and optical fibre, You don't have to go all out to obtain a similarly functional unit.

For your parabolic reflector, I present a great source on all things in solar cooking: http://solarcooking.org/plans/parabo...flat-sheet.htm
The most over board you might go is using mylar for that 98,8 percent efficiency, but the shiny side of aluminium foil is sufficient for cooking a roast; in fact, the only place you'd want to spend good money on is the fiber itself.

While the, err, emitter can be focused with a lens and closed with a mirror, it would probably be wise to include a capping system for your collector.

[aromaru]

As I mentioned, the money you'd want to spend would more so be in the fibre than the mirror. Thirteen inches is mighty small, and I don't know if your senior membership has allowed you to notice a certain love of excessive power among some groups, but for that US$70, you could DIY a mighty sized dish AND cover it with mylar.

Then again, if your only use is to do burning art, that might be sufficient. I'd still think saving money on the DIY method would be a good idea, but at least work out what your temperature would be before picking a size.

I'd hate the idea of spending Benjamin after shipping, only to wind up hovering over an area longer than you'd prefer.

[swamidog]

True. I'm more concerned with the fiber/coupling part of the problem than the collecting.

As for excessive power I'm marking wood and leather, not cinder blocks... But there's always something to be said for turning power down.. I have a ex-medical 20 watt co2 laser if i really need to ramp things up, but i really dont think i need much power out of the fiber.

I don't want to use sunlight to save money. If I was penny pinching, I'd use a half watt 405 diode. I want to use sunlight because is satisfying on artistic and spiritual levels for me.

As I mentioned, the money you'd want to spend would more so be in the fibre than the mirror. Thirteen inches is mighty small, and I don't know if your senior membership has allowed you to notice a certain love of excessive power among some groups, but for that US$70, you could DIY a mighty sized dish AND cover it with mylar.

Then again, if your only use is to do burning art, that might be sufficient. I'd still think saving money on the DIY method would be a good idea, but at least work out what your temperature would be before picking a size.

I'd hate the idea of spending Benjamin after shipping, only to wind up hovering over an area longer than you'd prefer.

[aromaru]

One advantage of a DIY system is making adjustments inexpensively. The other half of that experimenting is applying the idea to other things you might find interesting in the future.

The acrylic system in your link is effective for cooking food, with tracking parabolics being as warm as a traditional oven, but your idea involves changing the focal point to another reflector which will send that light into the open end of some fiber by way of another lens and mirrored cone, I'm guessing. Refining all this could be frustrating, but so can experimenting from the DIY reflector; however, if you damage the acrylic dish in working on your refinements, this could lead to a new source of frustration.

The advantage in starting with a pre-made system is the time saved on not working on the reflector. If that's all you're interested in saving is that time at the sacrifice of experience and some cash, I certainly wouldn't stop you if I was hanging over your shoulder while bidding/buying on eBay. I, personally, like to break cheap things I've made myself.

My concern on cost is merely what seems like unnecessary expense in acquisition rather than a reference to any overall lifestyle assumptions. Solar ovens aren't expensive, which is part of why I brought it up in response to your starting post, the other, obviously, being that the surgical device itself appears to share much of their physics; otherwise, there are tons of power generation techniques that focus on curved surfaces for concentrating the Sun's output to everything from a single stirling engine, to heat storing media and even thermal transporting fluid similar to liquid cooling of a surface.

[allthatwhichis]

My cousin and I are currently working on a solar powered Sterling engine using old satillite dishes with mirrored surfaces. For your purpose you could use a frensel lense. I'd think you could use a ball lense after the frensel to go to the fiber coupler.

I agree, using the sun for anything can be spiritually forfilling.

[mixedgas]

Skip the lossy fiber, not enough of that 1 Kw per meter is visible or near IR. Coeleostats are your friends. Probably easier, too.

Here is a small, simple, Coeleostat:

http://touro.ligo-la.caltech.edu/~jkern/Personal/images/01.jpg

A bit more ambitious Coeleostat:

http://nsokp.nso.edu/mp/images/slide7.jpg




Steve

[aromaru]

While absorption loss can be significant in optical fiber, making free space a preferred routing method, you can't seriously be recommending the primary structure actually be a Coelostat, just the idea of mirrors and lenses for transmission of the concentrated light off the focal mirror, right? Otherwise, that's a lot of precision optics and solar tracking to implement for what is, ignoring the structural theory, still a solar oven.

I know you're not talking about diffraction limiting and evacuated and extended focal lengths, but to goto a coelostat would seem, I don't know, a might aggressive?

[mixedgas]

Aromaru, I seem to be as 'Crazy as a frog of foxes". However, except when I'm violating Clarke's first law, I'm usually pretty good at what I do. You may wish to quietly inquire from other PLers what I did for a living before the economy went south. I used to be very, very, good at what I did.

A look at a 6200 Kelvin spectrum for a black body compared to the adsorption curve of fused silica fiber might be in order. He can't afford a broad spectrum chalcogenide fiber. I can get him some huge medical fibers, but he can't make the required spot size to match the NA.

Relax,

Swami knows enough about optics to mock up what he's trying to do before he knocks a hole in his roof. Besides, he'll call my best friend, and they will go out in the desert and drink after they try this.

Chris,

If you can find a old Super-Trouper based on carbon arc (Possibly converted to xenon at one time), you might be amazed at the pyrex long focal lenses in the long throw versions, These can be had for the asking in many major cities as they are replaced with Xenon, Halide, and LED. You just want the lenses in their mounting rings, ditch the arc and body. I pulled a set out of two scrapped Troupers on campus a few years ago. They make nice burners.

Electronic Goldmine had some huge plastic 4 foot square Fresnels with 13 foot focal lengths about 3 years ago, They were not hot sellers. They might still have some. We bought one at the lab for a project, and got "burned" because Goldmine was "optomystic" (pun intended) on the focal length.

One meter square front surface mirrors show up in dead projection TVs by the road, all the time.

Remember to use a assist gas and fume evacuator, pine tar fumes are nasty.

Have fun,

Steve

[Laser Wizardry]

Relax,

Swami knows enough about optics to mock up what he's trying to do before he knocks a hole in his roof. Besides, he'll call my best friend, and they will go out in the desert and drink after they try this.


Steve

Beer: check

Lasers: check

Desert: check

Swami?

[swamidog]

I called you last week about it . I'm spending the week hunting for arrow heads and dinosaur bones in colorado/utah.

When I'm back, I'll grab the lumia box, the digerido, and meet you in the desert.

Beer: check

Lasers: check

Desert: check

Swami?

[sugeek]

I called you last week about it . I'm spending the week hunting for arrow heads and dinosaur bones in colorado/utah.

When I'm back, I'll grab the lumia box, the digerido, and meet you in the desert.

I'll be there Friday with Fieldmax and PM1K in hand .

-Adam

[swamidog]

i haven't had any free time to dedicate to this project, but i stumbled across this incredible inspiring site today:

http://thisiscolossal.com/2011/06/markus-kayser-builds-a-solar-powered-3d-printer-that-prints-glass-from-sand-and-a-sun-powered-laser-cutter/

this guy built a sun tracking concentrator that fuses sand.. magic!