Easy Solution for Beam Improvement of 445nm Diode

[foulmist]

I think I found a very simple and easy solution for those who don't like the "Bar Like" output of the 445nm diodes - like me

This is the original beam after a 3 Element AR Coated Glass Lens...

This is the NEW BETTER BEAM

and there is how I did it...
First I got out my diode heatsink with driver and I had to transfer it to my newly made (almost the same) heatsink... This took me almost 2 hours!!! I had to be very very careful and I had made the bed for the diode a little narrower, so I had to manually widen it with a file by hand til it got to be just about right for a tight press fit

NEXT I won't bother you with the process this is the final assembly missing just one "secret" piece !

SO I have made the hole a little shorter for the diode bed and the lens here isn't pressed all the way... No worries I fixed it with a little of thermal silicon it took me another 20minutes to align it perfectly! -

and VOALA I know this isn't a perfect circle again.. but I like the improvement VERY VERY MUCH! I also know that there is a loss in power too ... but ... "I have no lust for power!!" :na: well actually I do but I can live with that

ok some more pics (these are all taken with my phone so ignore the quality)

When getting it focused closer to infinity ... it gets even better

and now.... the moment I know you all have been waiting for... how about some juggling

the secret lens is just a bi-concave 5mm expanding lens for 532nm laser

you can find these in any DPSS module or order some from eB@Y
It goes right after the diode(on top of it) and then the focusing lens

thanks for watching I am so happy I didn't destroy my laser
and It still burns like crazy YEAH

 

[ARG]

Wow! That's a big improvement! Thanks for sharing the tip +1

How much power is lost from this?

 

[foulmist]

Wow! That's a big improvement! Thanks for sharing the tip +1

How much power is lost from this?

I can't actually tell.. I don't have a LPM.. don't have the money yet

 

[weeba2kv]

Now try a 638 red diode

 

[foulmist]

Now try a 638 red diode

I actually have a couple of those for 635nm but I don't have a diode YET!

 

[InfinitusEquitas]

+rep and thanks for sharing.

Wonder if a similar approach was taken with one of these: mini B - 445nm 100mW Pocket Low Power Blue Laser Pointer

Definitely looks like the same dot profile to me.

 

[foulmist]

+rep and thanks for sharing.

Wonder if a similar approach was taken with one of these: mini B - 445nm 100mW Pocket Low Power Blue Laser Pointer

Definitely looks like the same dot profile to me.

hmm I don't know about them but I think mine looks a little better :san:

 

[Things]

+rep and thanks for sharing.

Wonder if a similar approach was taken with one of these: mini B - 445nm 100mW Pocket Low Power Blue Laser Pointer

Definitely looks like the same dot profile to me.

That looks like a single mode diode to me. No beam correction needed for single mode diodes usually.

 

[Bionic-Badger]

I wonder about the losses too... is it just blocking off the edges like those circular light blockers on the cheap red laser lenses?

 

[foulmist]

I wonder about the losses too... is it just blocking off the edges like those circular light blockers on the cheap red laser lenses?

the lens itself expands the raw output. without the focusing lens it just looks as a bigger raw output. and that is being focused into the 3element lens.

 

[lasersbee]

I wonder about the losses too... is it just blocking off the edges like those circular light blockers on the cheap red laser lenses?

Yeah... I agree... It looks like 40-60% of the beam could
blocked and missing. It would take a power measurement
before and after the mod to really know...

The beam does look better...if power is not important like
foulmist said


Jerry

 

[foulmist]

Yeah... I agree... It looks like 40-60% of the beam could
blocked and missing. It would take a power measurement
before and after the mod to really know...

The beam does look better...if power is not important like
foulmist said


Jerry

Jerry I have you targeted! I mean I will buy a LPM from you but I don't know when exactly! I can tell you the exact losses then

 

[lasersbee]

Jerry I have you targeted! I mean I will buy a LPM from you but I don't know when exactly! I can tell you the exact losses then

LOL..... we'll be here when you are ready...

Jerry

 

[honeyx]

Let me guess. The collimating 3 element lens is designed to exactly catch the wider edges of the beam at its edges. By using a expanding lens the whole beam is streched more so the wider edges hit the housing of the 3 element lens and the narrower edges are closer to the glas edges.

So you got the same effect like using a circular light blocker with the same or even more looses but just a thicker beam diameter.

 

[jeffreythe00]

This is KOOL! I await lpm results! I'd be really disappointed if it were only clipping the edges though. Either way it doesn't look to be the case. Awesome result! +1 when I can!

 

[DrSid]

IMHO this increases aperture, thus reduces divergence. Somehow this has more effect on fast axis.
I've noticed something similar when playing with beam expander on 445. With larger aperture the beam seems much better. This may be the same thing, just nicely packed.