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solar light to laser beam ? Answered

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Hello,
would it be possible to concentrate solar light so to form a laser beam ?
In other words would it be possible to apply laser light principles to basic solar light with the help of optics of some sort ?



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veloci8 (author)2016-09-03

So if i am not late... I am trying to do the same thing now but with normal light (flashlight....), so as I understood this. You need to place 2 magnifying glasses, so that the light from the first is fully concentrated (when the dot is smallest), then it needs to pass through the second magnifying glass. And then it should be converted in a laser or a concentrated beam...

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Downunder35m (author)veloci82016-09-03

Maybe you should read up on the definition of LASER.....
Light Amplification by Stimulated Emission of Radiation....
Three vital parts are missing in your concept:
Amplification, Stimulation and Emission.
Without that all you get is a focussed beam of plain and normal light.

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Kiteman (author)veloci82016-09-03

Concentrated beam, yes. Laser, no. Read the other comments for reasons why.

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twitt50 (author)2016-04-08

It will work, but the question I have is what type of laser are you thinking about developing? You can easily make Light Emitting Diodes (LED) which is a low power laser. If you are looking to make high power laser then you will need lots of money and a lab. This will take a lot of research...I worked on all types of lasers in the mid 1990's when Optics were 1st becoming popular....fun stuff!

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bulwynkl (author)2015-05-06

so, I've been thinking about this too - because the Israeli military have done this... Taken sunlight, focused it, and fed it down an optic fibre to use as a medical cutting tool. circa 2003. http://www.israel21c.org/technology/scientists-har...

Wanting to do something like this at home is an interesting exercise. First thing to realise is that the sun is not a point source - it subtends about 1/2 a degree in the sky, so the minimum sized spot you can get with a lens or parabola depends entirely on the focal length of the primary lens. You can't get a more tightly focused beam with lenses than that. What you need (open to suggestions) is a way of feeding the entire focused beam into an optic fibre. - the scales are quite different. A 1m lens might focus down to a 1cm spot - sufficient to melt copper at 80kW/m^2, but that's rather large compared to the core of an optic fibre - e.g. communications fibres have a core ~9 um

I've been contemplating a internal reflection concentrator - simplest of which would be a cone of glass mirrored on the outside, possibly partially mirrored on the inside (light goes in, does not come back out.).

this would potentially take the focused beam down to ~1mm^2, or a bit smaller with acceptable loss - suspect energy densities at this point are sufficient to melt most things... and I still haven't reached the size of a typical fibre - any finer and we start running into precision issues beyond the home hobbyist as well. Not to mention that bubbles in the glass start to be a problem at this sort of scale too.

Are there larger optic fibres we could consider at this point?

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bulwynkl (author)bulwynkl2015-05-06

OK, so the problem isn't as bad as I thought... multi-mode power application silica fibres have a core ~500um... http://www.newport.com/Multimode-Fibers,-Power-Del...

worst case, feed a lot of small lenses into a bunch of fibres and combine into one fibre/MUX

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Zergling_pack (author)2010-07-01

laser-> L.A.S.E.R. -> light amplification by stimulated emission of radiation 1 key feature of the laser is you get ONE and only ONE wavelength produced by the laser. Your lens system is merely increasing power/intensity at a given location, while a laser does have a high intensity it isn't a concentration like a lens is doing. But as suggested there's much simpler solutions to your lighting a room scenario.

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SolarFlower_org (author)2010-06-29

Sunlight covers a huge range of frequencies, laser is by definition just one. Also there's something about their waveforms being synchronised, hence the term 'coherent' but I can't be bothered wikipediaring that just now.

I actually designed an optical device which will do exactly what you're wanting; collimate an arbitrary light source into a tight beam, but haven't got around to seeing if it works outside of my computer. I'd need to get it machined or 3d printed. Might get around to it some day.

The results I was getting from my optical previs software were a blowout of about one meter per kilometer. ie a 1mm beam would be 10 cm at 100 meters. And there's no real upper cap on how much power you could put through the thing (depending on the materials used), so it could make a pretty lightweight and cheap 'laser' cutter.

I originally started thinking about it for similar reasons to you; sending energy around, but it's not really practical. To light a room you'd need at least 50 watts of white light, and even the loosest of beams with that much power would cut through almost any material on earth. Or bird, frisbee, trampolining child etc.

Maybe look into liquid core light pipes. I made one out of silicone tube and mineral oil, but the silicone scatters the light too much. Teflon FEP or AF 1800/2400 apparently works pretty good, but is a little tricky to get hold of. Not impossible tho.

Good luck!

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nutsandbolts_64 (author)2010-06-05


Have you checked my post down there lately? If not, then I'll say the single word you want that answers your question.

*drum roll*

YES!!! (as explained in my very long discussion with critterfluffy).

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gabdab (author)2010-03-27

I am aware of the 'reflective aluminum pipe from the roof down to your room' solution ,but it is limited to under roof rooms mostly.
Other solution seems to be to use plastic fiber optics to transfere light from a solar concentrator (on the roof) to rooms ( distance or fiber optics length is limited in this case to 200 mts more or less).
So I was wondering it laser could be a viable option is some border cases like covered greenhouses or else..
Diamonds would be cool but maybe you would be burning off some satellite here and there occasionally with a 'death ray' sort of thing.

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nutsandbolts_64 (author)gabdab2010-05-26

 lol, diamonds? people would steal the very thing that gives you light! anyways, is this thing what you're talking about or something what you intend to use the laser thing for? 

Yellow=light/sun
red=optical fibers
black thing to the left=parabola
black thing to the right=rough representation of a house

Try using extremely thin nylon (fishing line, only a bit thinner). Cool that down using a sort of heat sink system. Try fiberglass. Just get the individual strands on fiberglass and line 'em up and insulate. 

Or you can just get a really long shiny-in-the-inside pipe that'll go down to the 1st floor. Of course, that involves putting holes in there. I just saw your objectives so uh I'm gonna list down viable things here.

Goal 1: Transmitting light from place to place as a laser beam. 
Check out the forum link I just put up there.

Goal 2:Lighting a room with the beam by aiming it on some sort of diffuser.
I'll get another image for that! <insert more elevator music> Okay, I got it.

I hope you're satisfied. If you're gonna bring up anything about my forum topic, post it in my forum topic.

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lemonie (author)gabdab2010-03-27

Hi,

  What do you want to do - is this a question about moving sunlight around for lighting a room, or do you want a concentrated energy-beam for some purpose?

L

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gabdab (author)lemonie2010-03-27

..I am looking into:
- transmitting light from place to place as a laser beam
- then lighting a room by directing laser beam onto a light diffuser of some sort.

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lemonie (author)gabdab2010-03-27

You want a "light-pipe", or you want solar-powered lights. It's like that.

L

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nutsandbolts_64 (author)2010-05-26

 I posted a forum topic about this. It's titled incorrectly due to the fact that we didn't put any filters in there to make the light monochromatic, but that's too easy so that's okay (for now). 

As I recall a laser is a device that sends out a monochromatic beam of light. Time out, I'll check the dictionary again (insert elevator music here). Okay, "A device that produces a monochromatic, coherent beam of light". Hmm, we achieved the "coherent" part, now we have to go on the "monochromatic" half of it. It's time to get some filters... when classes resume that is(our school bookstore sells cellophane and lots of other things, so it's pretty much my supplier)... 

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user

 For your information, "laser" stands for "Light Amplification by Stimulated Emission of Radiation". I know you're not stupid. I'm just clarifying for anyone who's wondering "what does laser stand for?". Let's see. "Stimulated Emission of Radiation" is done by the Sun already (correct me if I'm wrong). "Light Amplification" is done by our little device described in my forum (again, correct me if I'm wrong). By my understanding, "Stimulated Emission of Radiation" is supposed to amplify light. You know what, I'm getting confused. Let's just stick to what a laser is and not what it stands for. I feel like I'm gonna get a headache sooner or later.

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gabdab (author)2010-03-26

So it would be possible to transmit solar light from a distant location as a laser , using sunlight as an optical pump ?
I was thinking for example about transmitting solar light inside a room from a roof.

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kelseymh (author)gabdab2010-03-26

That would be a foolish waste of resources.  You lose a lot of efficiency in the pumping, and you don't gain anything transferring energy via a coherent beam versus any other form of light.  Light is light is light.

Just use a reflective aluminum pipe from the roof down to your room.  You can buy them commercially, or make one yourself.

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gabdab (author)kelseymh2010-03-27

I guess a laser beam is meant to travel farther than a non coherent beam .. that would be usefull if you want to transfer light in an open space for example not loosing intensity.

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kelseymh (author)gabdab2010-03-27

Nope.  A laser will travel exacty as far as a non-coherent beam which has been similarly collimated.  And lasers do lose intensity, at 1/r2, just like any other form of radiation. 

They appear more intense at larger distances because you don't normally deal with intense collimated sources.  You're comparing that laser pointer spot with an ordinary flashlight (which emits over 4pi), and so of course it looks different.

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gabdab (author)kelseymh2010-03-29

How do you generate a collimated (like laser) non-coherent beam ?
Might this be the case of two facing parabolic mirrors (large one concentrating inside smaller one)?

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Kiteman (author)gabdab2010-03-26

That's nothing to do with lasers.

It is possible, and frequently done, to "pipe" light into rooms from roof-top lenses.

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gabdab (author)gabdab2010-03-26

.. would a low sunlight intensity work as well as a strong one , where it worked at all ?

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NachoMahma (author)2010-03-26

.  Laser light is coherent light. Sunlight is not (as far as I can tell). I don't think you can "cohere" light by using just lenses. But I'm no expert, don't try any dangerous experiments based on what I just said.
.  Came across this solar pumped laser while getting the coherent light link.

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gabdab (author)NachoMahma2010-03-27
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lemonie (author)2010-03-26

I think you need a whole load of diamonds, placed on a carefully designed reflector. You'd want it somewhere close to the equator, a small island off the coast of Thailand perhaps?

L

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kelseymh (author)2010-03-26

You should research what a laser is and how a laser works.  You could use concentrated sunlight as an optical pump for a laser.

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