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3D render of 445nm diode laser running at 1.3W

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Hi folks, thought y'all might like this. I did something like this back when I first got my Leadlight green pointer, years ago and found it very interesting how clean the somewhat oval dot was when translated into a 3D height map. I've been doing A LOT with my scary high power 1.3W 445nm build, and of course it was inevitable that I'd want to view and document the profile of the "dot" at a distance.

For this experiment, I set up the laser in a semi darkened room, and focused the "dot" so that it was as perfect as I could achieve at 30ft away using the normal Aixiz 405nm for 12mm housings optics. I set this up to strike a sheet of common white printer paper taped to the side of a box, and set up a camera to take photographs as straight on to the beam as I could get. I quickly found what I already knew - that the "dot" isn't a dot at all, but more of a short line. Interestingly enough, wave interference (best guess) causes it to appear as a double line with a darker band in the center, and multiple encircling bands of weaker beam surrounding those. Each of the two centermost "dots" measured approximately 15mm long by 2 - 3mm wide, and were fairly clean rectangles given the distance involved.

To do the rendering, I clamped the power switch on the laser so that I could walk to the target and observe the "dot" close up, and then I took several photographs. I picked the best of the photographs of the "dot", and used it as a "displacement map" in Lightwave 3D v9.3. I then used the original photograph as a texture map to give it it's proper character as a blue laser dot. The result allows you to see better how the beam strength varies across the profile, as if it were a hill that you could walk around and study the shape of.

Needless to say, it's not a very dotlike structure. I'm used to diode lasers being distorted, but these blues are very non dotlike at any kind of a distance. From these basic observations, I was able to deduce beam dimensions for any given distance, assuming low air distortion and pure linearity with distance vs. scale, and found that at several hundred feet, the "dot" would approach 400mm long and 80mm wide, pretty interesting. Someday if I can ever find the proper environment to test this in, I'll have to actually try it. :beer:



BTW, I believe the source of this laser diode is an A130 projector, if anyone wants to know.
 

weeba2kv

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( it's not a very dotlike structure )

Ehmm if you turn the lens a lilbit you already can see it's far from a nice round dot.
These 130 140 diodes are totally not good for making a beam show , just a fun toy.
 
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Yes, which is why early in the post, I stated:

I quickly found what I already knew - that the "dot" isn't a dot at all, but more of a short line.
This wasn't to find out if the beam profile had a round, pretty quality to it. It was to see what the beam profile would look like at a long distance.
 

Prototype

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( it's not a very dotlike structure )

Ehmm if you turn the lens a lilbit you already can see it's far from a nice round dot.
These 130 140 diodes are totally not good for making a beam show , just a fun toy.
Actually, the 445nm diodes are great for laser shows.
 

Eudaimonium

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Nice render.

Could I kindly ask you for just the bump map used ? I could use it as output mapping of light for my own 3D laser diodes.
 
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Knowing nothing about laser shows except that they generally are accompanied by music, I can't of course comment to the effectiveness of these blues as show diodes... However, I must say, they certainly have the power and you can't ask for an easier, cheaper blue laser source. I think they're freaky pretty streaking up into the night sky in clear air, let alone helped by a little smoke.

Eudaimonium, I have no problem atall with that... Here is the source photograph that I used for displacement mapping. Displacement mapping is different from bump mapping because it actually changes the object mesh, but I should think it would work fine as a bump map anyway. Note that I didn't bother grayscaling it when I used in in LW, used it just as is and it worked just fine. It could be that the dynamics would change a bit if it WAS converted to grayscale. I imagine it would depend on the way the program handles values in the image.



Oh, also please note that I applied considerable blur to the image IN LIGHTWAVE because the grain of it was causing major mesh tears as was. It might look a little jagged unless you do something similar.
 
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Eudaimonium

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Oh, no need to convert it ?
Try this:


This my attempt at taking picture of diode output. Without lens, about 2 meters away from wall. Or so.
 
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Interesting... Until now I somehow missed the fact that the raw emission from the bare diode is in fact doubled in the center. Here's what mine looks like with no lens, projected onto my washing machine at about two feet... Probably kind of a stupid move because #1 I didn't wear my goggles for the shoot and #2 the surface isn't exactly matte. Note that it is very sharply defined at the ends - you can clearly see where the diode can or the housing or both or something is clipping the light at the ends:



Lol I see I also got misc reflections in the shot, nice work Rick...
 




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