My First IR Build

[Deleted member 49011]

Does anyone have a picture of this grin lens output from a multi-mode diode? Does it need to be rotated to work?

HMike

Hey i have a grin lense on my 3 watt diode , do u want pics ? or are you on about the one on this thread ?

 

[Hemlock_Mike]

Ion -- If you have a picture, I'll look at it.
I think you said it works well with the multimode C-mounts. I do see above a comment that you like it. Guess I'll order one. There don't seem to be many experimenters on here.

HMike

 

[Crazy Jay]

Meatball that's perfect for a multi-mode diode and it's less than 1 mm thick. So after it goes through the lens, you can then use a typical collimating lens?

 

[Hemlock_Mike]

CJ -- These cost a few bucks but from what I read, the GRIN is worth it.
Fortunately, I have the tools to machine a mount. It might take some messing with glass to find a coll. lens.

HMike

 

[Crazy Jay]

CJ -- These cost a few bucks but from what I read, the GRIN is worth it.
Fortunately, I have the tools to machine a mount. It might take some messing with glass to find a coll. lens.

HMike

That would be good for the 444nm multimode laser that one guy is selling on ebay

 

[Hemlock_Mike]

CJ ---
The ones I see in Edmonds are rated at 670, 810 and ~1,400 nM. I don't know how these would work at 444 nM. I think these are somewhat "tuned" by index of refraction and length. Coatings can also play a roll in efficiency.
I'm hoping the one I get actually works!

HMike

 

[Crazy Jay]

CJ ---
The ones I see in Edmonds are rated at 670, 810 and ~1,400 nM. I don't know how these would work at 444 nM. I think these are somewhat "tuned" by index of refraction and length. Coatings can also play a roll in efficiency.
I'm hoping the one I get actually works!

HMike

I hope so too. The information will be valuable that's for sure. And if you don't get it right the first dozen times ... well it's like Edison said “We now know a thousand ways not to build a light bulb”

 

[Meatball]

We can't forget that the GRIN appears to be used as a compact- simple to mount lens for correcting the fast axis. We will still need a cylinder lens to get a focused dot.

I suggest that we use a very short focal length cylinder lens after the grin. This may allow for a nice bi-concave lens to completely collimate the beam to infinity. This may allow for more "pointer" use.

If we used a regular plano- convex lens after the cylinder- after the focused point, then we the diode could be focused to burn a bit better...

One of these methods works well for HIGH power reds, and the other method works well for IR diodes. It will be much more difficult to completely correct output into a round dot. We may still be seeing a lot of rectangle and square beams...

 

[Hemlock_Mike]

I ordered a 670 nM GRIN today. Likely another frustrating experiment but always interesting. I hope to use this on my 1 W c-mount but I will likely be maching a bunch of "stuff" for it.

HMike

 

[Deleted member 49011]

Hey , Hemlock_Mike


This is the best pics i can get , u can just abot see the lense and the second pic is the out put from it , it was burning the black material

 

[Hemlock_Mike]

I'm planning in an aluminum disk with a #50 hole in it to mount the GRIN. What glue if any are you using? I don't want it too permanent -- yet.

HMike

 

[Deleted member 49011]

I'm planning in an aluminum disk with a #50 hole in it to mount the GRIN. What glue if any are you using? I don't want it too permanent -- yet.

HMike

Hey , i got this out of a pre made laser head , no sure of the glue but its white in colour ,

 

[Parabola949]

Sorry I've been gone so long. jay, I still want to send you my lens to see if you can come up with something. Although I am still confused- I hear some places the GRIN is placed on the diode vertically, and others say horizontally.... ?!?!??!? which one is it?

 

[jayrob]

Quite honestly I have no idea...

I mentioned that I would gladly try and make a washer type piece for mounting it centered in the module. But that was assuming that it would mount vertically...

Did they send a data sheet?

 

[Hemlock_Mike]

Jay --

From what I gathered from Edmonds, It appears that the GRIN is mounted VERY close to the emitter and the beam travels through it on the long axis.

HMike

 

[jayrob]

And these diodes that I bought (shown in this thread), have a window. So the die is down in there a ways...