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Will my plan work for laser modding?

L

Laserz4sale

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I want to make a optical tip or something to put onto my 100mW green to focus the beam to a even smaller dot (not by using a magnifying glass) I want to be able to turn the focal point into a beam so i can light matches or pop balloons from a farther distance. Here is my design:
laserdiagram.jpg

If this is possible, can you give me a shopping list or something and a "how to" to make it?
Thanks
 





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BKarim

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this is not possible: the beam will always diverge. the thiner the beam is , the more diverging it will be
 
bobhaha

bobhaha

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You may want to look into a Beam expander.... it increases beam size but decreases divergance, therefore allowing you to burn/pop balloons at longer distances. From what I have gathered, if your laser focuses at 0.5 feet a 10x beam expander will increase the focal point to 5 feet... I could be wrong however, so wait for some one to confirm this.

This will give your desired affect, except beam diameter will be larger, not smaller...

hope that helped :D - Adrian
 
KiLLrB

KiLLrB

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you have to pick a happy balance. I believe the saying is you cant have your cake and eat it too.
 
L

Laserz4sale

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bobhaha said:
You may want to look into a Beam expander.... it increases beam size but decreases divergance, therefore allowing you to burn/pop balloons at longer distances. From what I have gathered, if your laser focuses at 0.5 feet a 10x beam expander will increase the focal point to 5 feet... I could be wrong however, so wait for some one to confirm this.

This will give your desired affect, except beam diameter will be larger, not smaller...

hope that helped :D - Adrian
Click to expand...
But if it increases beam size, it will be weaker right?
 
KiLLrB

KiLLrB

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Laserz4sale said:
But if it increases beam size, it will be weaker right?
Click to expand...

Not weaker just spread out and weaker per sq. mm... read some of the stickies we have to learn about divergence and beam diameter ;) also sams faq is another good place to look for info on lasers
 
L

Laserz4sale

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What if i connect my laser to the opposite end of a beam expander? will that make the beam size smaller?
Oh and btw, can i make my own beam expander? I have plastic lenses i can use if needed. If i want to make my divercence on my O-like module better, can i use a flat head screw driver and turn it a little at a time and shine it like 50 feet away and have a friend stand at other side and tell me if the dot is good? That way, i can keep the dot very small from far away
And when i use a lens you find in front of a disposable camera, it can focus the laser to a fine point for burning. That makes it have BAD divergence. At 10 feet, the dot is like 6 inches already
 
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MickyP

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If you use a singlesided convex lens to focus the beam to a point, and then use a singlesided concave lens of the exact and opposite focal length of the first convex lens, placed at the point where the beam focuses, you will get the laser beam reduced in diameter.

However, you will always get divergence to some degree.
Trying to get this setup "just right", especially regarding the refractive index's of the two lenses required (thus characteristics) and also the micrometer adjustments, is very difficult and requires some study to get the measurements just right.

Another method of shaping beams (and able to compress a beams dimensions) is by using optical "wedges". Google it and get studying. You will need two sets of wedges (four total) to reduce the beam in both directions. Both of these solutions is not something that is simple or easy to do in pointers, its more done in larger labratory type laser heads.

If you do manage pull this off, you may find the gains you get due to condensed beam size will be lost by the inherent losses through the lenses or wedges.
Do post your results if you get something working though.
 
L

Laserz4sale

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MickyP said:
If you use a singlesided convex lens to focus the beam to a point, and then use a singlesided concave lens of the exact and opposite focal length of the first convex lens, placed at the point where the beam focuses, you will get the laser beam reduced in diameter.

However, you will always get divergence to some degree.
Trying to get this setup "just right", especially regarding the refractive index's of the two lenses required (thus characteristics) and also the micrometer adjustments, is very difficult and requires some study to get the measurements just right.

Another method of shaping beams (and able to compress a beams dimensions) is by using optical "wedges". Google it and get studying. You will need two sets of wedges (four total) to reduce the beam in both directions. Both of these solutions is not something that is simple or easy to do in pointers, its more done in larger labratory type laser heads.

If you do manage pull this off, you may find the gains you get due to condensed beam size will be lost by the inherent losses through the lenses or wedges.
Do post your results if you get something working though.
Click to expand...
il try this. I hope this works:thanks:
 
B

BKarim

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a condensed beam will have very great divergence, and you will not be able to pop anything
 
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