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Fiber and laser beams [TO MANY PICS]

FireMyLaser

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It's been a while since I posted some pics...

Optical trapping, it does this so easily with this lens. If any lager particle happens to float by it gets caught!


Shorter focal point lens from my dead x-125.


Add the fiber, just before the focal point. The fiber is from some sort of home equipment (dunno what) that I cut and treated the ends myslef.






The raw output at the other end of the fiber.


Collimated by an aixis lens.


IRL its not diffused like in the picture, it's a perfect filled circle with no diffused edges.


Here I added a long focal point lens from a video camera, and collimated the beam even more. Still pretty divergent tho.








Destroying a CD.





Just some different colours. *clickable*







Two short vids.


 

diachi

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Gosh darnit! That looks pretty awesome, I'd love a fibre setup. May need to get round to making one ! ;) Looks awesome man :)
 
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Nice! You've demonstrated that using a fiber is a GREAT way to get nearly perfect TEM00 output from a diode.
 
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Yeah but I find it impossible to get a laser beam out of it. The beam was ~20mm in diameter ans had a divergence of ~15 mRad(!):barf:
Homemade RGV-lab laser.​


With the right optical combination, you could get a good beam, but most of the time this effect is used to counter the lousy pump beam profiles from diode bars. If you couple the entire output of a 20W bar into a fiber, you can then focus the fiber output into a crystal and get a very clean output since the pump input has a smoothed beam profile.


 

FireMyLaser

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One question, what happens to the polarization in the fiber? Does it get totally mixed up everywhere?
 

Gryphon

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That was insane how you were able to re-collimate it back into a beam, although it did kinda look like the ouput of a spot light
 
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Nice! You've demonstrated that using a fiber is a GREAT way to get nearly perfect TEM00 output from a diode.
Actually, it is a way to get round output, but not TEM00, that is a flat top profile with more or less even intensity throughout the beam.
 

FireMyLaser

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Single mode fiber you say? ;)

Btw, you work for Lumileds, can you spot one of the company products above? (actually there's two but only one is sorta obvious)
 
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You have done it again LEGO's & LASER's you never quit amazing me with your build skills, I'll just bet you could pull something laser off even on a deserted island huh LOL
can't wait to see a laser beam come out the other end when you get the right lens.
say are the fibers in your bundle made from glass ? or a resin type. thanks for sharing !
 

FireMyLaser

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It's some sort of resin core. I pealed off the jacket with an exacto knife and carefully heated up the end-tip close to a flame to make it crystal clear and smooth. It took me like 3-4 attempts at each end to success. It had to get very hot and soft, but that' right on the edge to catch fire... so it was pretty difficult.
 
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bobhaha

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WOW whats the output of that laser? I'm guessing 6x? that looks really nice and round, man good job!! i would love to see that in person.. never seen a laser over 200mW in person, it will be a great experience, once i have enough money for my own 6x or 8x build!!

good job -Adrian
 
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Actually, it is a way to get round output, but not TEM00, that is a flat top profile with more or less even intensity throughout the beam.

That's true. TEM00 does require the intensity to be brightest in the center of the spot and less so around the edges, but fiber-coupling does remove pretty much all the bad features of diode output.
 

diachi

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WOW whats the output of that laser? I'm guessing 6x? that looks really nice and round, man good job!! i would love to see that in person.. never seen a laser over 200mW in person, it will be a great experience, once i have enough money for my own 6x or 8x build!!

good job -Adrian

IIRC it's a 6x ( maybe PHR, can't remember ) + a LOC + the DX 35 green module all using modified LM317 drivers that support TTL modulation. Does around 400mW of near white.
 




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