My First IR Build

IR glasses have been ordered...

If I can find the lens, then I can start experimenting with it perfectly centered with a machined holder of some kind.

Man, those guys on e-bay are selling the lens as a lens specifically made for an 808 IR diode... It says 'double convex' if that matters...

Unless you absolutely have to have it portable, I'd go with a cylinder lens, works like an FAC, except not as tiny or hard to find, I think Chris had some at one point, am unsure if he still does.

Hmmm...

Well I guess I'll sleep on it for now. (time to hit the sack)

Really appreciate all your guys' input!

Hey Jay....

as was stated earlier... you have a Multi-Mode IR Laser Diode...
it is comprised of several laser dies side by side giving you an
output beam profile like this --> -----
The ends of the beam profile (fast Axis) spread out at a large angle
while the thickness of the beam spreads out a lot less (slow Axis)....

If your LD had a FAC lens glued to the Die.. (which can be done
with a microscope and expersise in doing it) it would look like the
1st photo in the link in Post #15... like this--> ■
and spreads out almost equally on both the Horizontal (fast Axis)
and Vertical (slow Axis) directions..

An LD with a FAC lens (Fast-Axis Collimation) is easier to focus and
can be done with a Convex lens... (like the O-Like IR Labbys that we
have in the shop).

IIRC... an LD without a FAC would need a cylindrical Lens at a distance
from the LD. There was a member (sbdwag) that did some experiments
with a 2 Watt IR LD and those lenses... Here is a link and a Video that
shows the Cylindrical Lens he used and the distance he needed to mount
his...

http://laserpointerforums.com/f40/808nm-2w-c-mount-first-shots-video-43406.html#post572738

BTW... LDs with FAC lenses are more expensive...

Here some quick info on FAC Lenses and a supplier (maybe)...

ACL - FAC lens


Jerry

Very informative!

Thanks Jerry, I'll check it out!

Hey Jay, still messing around my diode, but did find this older post on the forums:
http://laserpointerforums.com/f40/1w-808nm-burns-less-then-loc-46148.html

Take a look- has some good info about different lens near the end


Other than that, I have looked all over the place, and can't find a price quote on a FAC lens anywhere....

I think a cylinder lens would be a cheaper and easier way to simply correct the fast axis. Cylinder lenses can be small enough to fit inside just about any laser module. The laser modules that produce a "line", normally use a simple cylindrical lens to spread out the dot in one dimension. Used correctly, I'm sure something similar will be able to correct the same line back into a dot.

BUY LASERS NOW!

here's another old post that may help
http://laserpointerforums.com/f40/need-some-advice-my-1w-808nm-laser-build-46455.html

I was just on ebay looking at that same exact 1W IR diode...If you find a solution...let me know. I thought it would be a normal, single unit laser. But I guess from what I'm reading, its not.

@jayrob
The major problem is that not all light from diode can go trough lens.

You should use FAC to correct fast axis, or you need very short FL lens (Aixiz lens have FL of 5mm that is still not enough to collect all light from diode) , or you can use big lens with bigger FL.

lasersbee said:

Collimation) is easier to focus and
can be done with a Convex lens... (like the O-Like IR Labbys that we
have in the shop).

Click to expand...

I talked to Susie and she told me that they only use 16mm aspherical lens that has FL of 33mm. She didn't mention anything about correcting optics.

When I get the time, I'm going to be experimenting with different lens. But I have definitely found all this to be true- while testing, I used a simple Aixiz acrylic lens in it's module, I'm not sure how many of you have one of these. The entry on the lens is covered by plastic, and is only (i'm guessing here) 2mm wide, and when placed roughly 3 or 4mm from the diode, the laser burns a line into the plastic. I'm going to guess that only 30% of the laser is actually making it into the lens, maybe less. I need to find a cylindrical lens that can be placed directly on the diode, which can then focus the laser into the second lens. The fun part will be getting the distance perfect... especially when I just don't have tools for cutting the module. As I get around to it, I'll let everyone know what's going on.

EDIT:
I would like to add that even though a small amount of the laser is even being focused, It burns about the same is the minimag hack did. I would definitely like to see how well it would work with 100% of the beam being focused in....

Take a look at this topic:
http://laserpointerforums.com/f40/need-some-advice-my-1w-808nm-laser-build-46455.html

There we were discussing about the same problem...

Tried cylinder lens, tried another lens before aixiz lens....nothing worked well.

At the end I decided to use normal glass aixiz lens with some modification.





I have made the lens segments facing the other way and then turned the whole assembly around, effectively bringing them closer to the laser diode itself.
To collect even more light I drilled assembly a bit so lens is more exposed to the diode.

To make it focusable with Aixiz ring I extended brass assembly with small piece of plastic lens holder.

I think that is the cheapest way to get more light out of module.

Would anybody be able to give advice on the diameter of cylinder lens needed for this 9mm diode? Or a good guess?

Here is a source: (the largest diameter shown is only 1.8mm)
Gradient Index (GRIN) Rod Lenses - Edmund Optics

I was thinking of trying number NT64-526...

Any thoughts?

By the way, I also emailed a few requests to several companies about this diode and the needs... Hopefully will get a response soon.

Also got some software that is supposed to help with optic design and simulation... I'll see how that goes though.

In fact, as soon as I posted this, I got a reply lol



Thanks for your request. Can you please give us some more information on the diode itself? Do you have perhaps a data sheet of the diode?

In detail we need to know:
What is the divergence of the diode in fast-axis?
What is the intended collimation quality respectively what divergence and beam width do you intend to achieve after collimation of the fast-axis?
Are there any geometrical constraints which limit the height of the lens?
How do you intend to fix the lens (bottom-tab, side-tab)?
What length of the lens do you need?
Best regards
Volker


Not sure how to answer all these questions lol

I already tried to get a data sheet from the seller with no success...