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Solar-powered laser (supposedly)

 I was in this other forum about the Mythbusters' "Archimedes' Death Ray" thing. Our discussion went off topic, so I made another topic! According to Google, a laser is a device that produces monochromatic, coherent beam of light. We have established the coherent part of it by focusing the Sun's energy on point which has a mirror so theoretically, that focused part of the beam should reflect off the mirror. Our design(s) is/are based on multiple parabolas (or Fresnel lenses) to collect and focus light. The light is in turn reflected off mirrors to be combined on a mirror (or lens) which will be used to aim the light to the target. Unfortunately, I forgot the "monochromatic" part of the laser, but that's not a problem. All we have to do is put filters on our parabolas. That should be a cool enough part to filter the light without melting the filter(s) itself / themselves. What would be an idiotic thing to do is put the filter right in front of the last mirror, because it would melt it (unless off course, that filter was a pane of glass). 

 Any suggestions/comments/design ideas please put them up here. If your idea is just downright stupid (sorry, I don't know what else to use (other than idiotic, or crazy, actually crazy's better than stupid (back to topic))). If it is stupid, I will not use offensive words against you (unless you were swearing on my face); you will, instead, be facing the following words: "Sorry, your (insert suggestion/comment/idea) is not feasible. Please try again". I know it's a bit funny; part of it is for your entertainment, part of it is for your knowing. Again, please post any suggestion, comment, or ideas. By the way, if it's only a bit stupid, you won't be needing to face the words...

Have a nice day!




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nutsandbolts_64 (author) 6 years ago
Update: construction stalled. Must wait a few more months.
nutsandbolts_64 (author) 7 years ago
Update: Construction of the small-scale prototype will begin on June 15.
Here is a really good tool to play with basic optics principles:
http://dev.physicslab.org/asp/applets/opticsbench/default.asp

It seems you are having some trouble with it which is understandable.  The only reason I know anything is because I spent semester learing it with a teacher.  If you have any questions feel free to ask.

PS: The dots on the lenses are the focal points.  See what happens when you a lens with a long focal length and one with a short focal length and overlap them together.  What you see is the principle we are trying to exploit.
nutsandbolts_64 (author)  critterfluffy7 years ago
 Got it. 
optics.JPGoptics 2.JPG

Also notice that the smaller the ratio between the focal length of the two the tighter the beam gets.  It doesn't matter how big the lenses are, all that matters is the ratio of the two foci.

nutsandbolts_64 (author)  critterfluffy7 years ago
 I noticed that. Now, all I need to do is persuade beehard44 to collaborate on the construction of a prototype solar laser (if he believes that it's gonna work at all). I'll design the parabolic collectors. The other half of the setup would be designed at a later date. 
So how are things going?  Just thought I would check up since we haven't talked in a while.
nutsandbolts_64 (author)  critterfluffy7 years ago
 My friend here (beehard44) is diverting me away from getting my parabolas. My sister used up all the ink last night so I guess I'm getting another ink cartridge (to print out the parabolas of course). I just discovered my current coil of galvanized wire won't stand up to the weight of the parabola support structure, and it was the last coil in that hardware store... Other than that, I'm about to begin construction of the small scale version (after my Aikido session today at 2:30 pm GMT+8)
Sounds like you have been busy.  For the small scale are you going to go with parabolos for the collectors or fresnel lenses?  Fresnels would likely be cheaper but I am not sure.
nutsandbolts_64 (author)  critterfluffy7 years ago
 During the proof of concept test, I have had mixed results. 

Result 1: I accidentally turned it into a projector.
Result 2: I accidentally turned it into a microscope
Result 3: Got it finally focused, but I didn't expect this to happen! (queue image)

Position 1: Shone the light at the magnifying glass. Focused perfectly!
Position 2: Hit the mirror at that point
Position 3: it just got dispersed! 

I believe we can solve the dispersal problem with another lens at position 3. At that point we're back to square 1! If that's the problem then that means that your design would look like image 2. What I don't get about your design is the final lens. My other test suggests that if a(n) (ordinary) lens has a light source coming in at an angle, that focused light would be on an angle. I'll test again. Confirmed... We need an unusually shaped lens to counteract what we see here. I'll come up with something sooner or later.
disperse.JPGarchemedes deathray.JPG
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