Can splash be removed, or "blocked"

[Darkarmyofone]

I was just wondering if there is ANY way at all to eliminate the outer splash of my red 300mW. its absolutely horrible... and i have seen peoples lasers project ONLY a perfect dot...with a TINY bit of surrounding reflection as all lasers do.

Could anyone enlighten me on the subject... thank you in advance

Dark

 

[Cyparagon]

This is done with an aperture cap like you see on the end of most pointers. Some people don't like that on DIY pointers because it hinders access to the focusing ring.

 

[Meatball]

doesn't darkhorse make those?

 

[Darkarmyofone]

can someone post a pic maybe?

 

[pseudolobster]

Either clean your lens, or build some sort of cap that has a narrow hole in it which blocks the splash and only lets the beam through.

 

[Darkarmyofone]

hrm... does that "easy focus adapter" that jayrob sells do this? the little metal thing that makes it easier to focus, and gets glued onto the end of the lens.

 

[ElektroFreak]

Nah, that won't work. If you're talking about long-die red diodes, they project a dot with a line through it. That much is normal. An acrylic lens will also add a bit of splatter noise unless you get a particularly good, clean one. The best results that I've had as far as a clean dot have been while using an Aixiz glass lens assembly. The output is a perfect dot with the line, but no splatter. To get rid of the line, you'd need a small blocking aperture right at the beam exit.

 

[LarryDFW]

Darkarmyofone;

First of all, make sure the diode window is clean.
(I have some cleaning procedures in my Lens Assy. for sale thread)

Second, take a look at the thin stainless apertures in the various sleds.

They are usually right after the BR diode in the optical path.

I have a new lens assembly which can accomodate an aperture.

LarryDFW

 

[Darkarmyofone]

larry,
I read your thread about the cleaning methods, and i did just that. isopropyl alcohol right? then wet microfiber, then dry mircrofiber? i think thats what it was.

anyways, i have noticed a major difference in the two acrylic lenses i just obtained. one had an open back "looks melted open though... was used with an LOC" and the other had only a small hole at the back of the lens...

now i've seen jayrobs and someone elses optic tests where they say "all acrylic results were with the back OPENED" im assuming this is what he was refering to?

the things is the splash on the open lens is MASSIVE. while i only have a dot and line with VERY light splash around the second lens dot.

my goal is to have nothing but the dot. I know its a pain... but could someone like post a link to a device or something that would help me accomplish this? and yes i know i need glass lenses, meredith lens "OFR's" is in my future.

 

[Kenom]

What your talkin about is relatively easy to do. See the die on a laser diode (now this is just going to be a general statement of understanding not total truth) is 2 layer of material and in the center of that material is where the laser emits. (picture below provided by shore laser) anyway, this light is extreme and has a tendency to follow optical paths. The junction of the 2 layers is such a place, and so it emits off to the side of the entire junction (I've marked it in green). Thereby creating your "wings" or line emitting off the side of the dot. You can see this more clearly here: http://laserpointerforums.com/laser_pointer_forums_3/forum/showpost.php?p=527872&postcount=296

In order to get rid of that. You need to create essentially a limited window that is going to "cut" off anything you don't want to emit out. I've created an image to illustrate how to go about doing that by creating a smaller exit aperture. The larger aperture allows the wings to be emitted out to whatever your pointing at, while the smaller aperture ends up cutting those wings off. I've left the wings on the smaller aperture to demonstrate how only the center beam is allowed to exit.


I hope this helps clear up where these wings come from, and how to eliminate them.

 

[rog8811]

I found a nut (as in a nut from a nut and bolt) that was a press fit into the the chrome bezel, in front of the lens, of an Aixiz worked well.
You need to paint the inner thread of the nut with matt black paint to stop random reflections.

Regards rog8811

 

[Darkarmyofone]

wow... that was about the most thoural explanation ever kenom lol. so if im working with a closed can diode... i could just VERY CAREFULLY make the window smaller by placing a small ring of something overtop of it? im assuming this is what you meant. or when you said aperture did you mean the diode window, or the end of the lens?

but thank you all so much for the help. i hate splash so much, i always thought the wings were from the two slits in the lens so you can adjust it with a screwdriver or w/e. but now i know better. i'll do my best to give this a shot, does anyone know what i should use ?

rog, thats a good idea, you mean finding a really thin nut "almost looking like a washer maybe..." and press it "ontop" of my lens, without damaging it of course, thus slimming the aperture?

i hope im understanding this right, im all up for learning, and really appreciate the time you guys take to help me out. thnx

Dark

 

[ElektroFreak]

The only issue you may run into is the fact that the "wings" come from a nearly microscopic point source just like the main dot. Unless you place the aperture a ways down the beam path (maybe 2-3" from the main emitting aperture) you'll have a VERY hard time getting the aperture size just right. The "wings" diverge faster than the main beam, and at the aperture they are indistiguishable from the main beam itself. After an inch or two the wings will have diverged enough that an aperture could be made with little difficulty. If you're thinking of doing this to a pointer you will need to extend the length of the pointer by a few inches.

 

[rog8811]

almost looking like a washer maybe

No I just used a standard thickness nut.
I added a plate with a small hole to my white laser, it gets rid of a red halo as the red beam is very much messier than green or BR.
You can see it next to the spiro motor in this photo.

Regards rog8811

 

[Darkarmyofone]

yeah it was supposed to be for a pointer, so i guess scratch that, i'll just deal with it. sounds like allot of work, and i hate splash...but not THAT bad lol. thx guys

 

[rog8811]

yeah it was supposed to be for a pointer, so i guess scratch that

That was just to show the idea, experiment! It is the only way to find out what works.

Regards rog8811