My latest creation, 445nm corrected.

Its been a good fight to get these 445nm LD's beaten into submission :banghead:

My latest attempt while waiting on my Lava optics was to try a heavy loss
setup with an anamorphic prism pair.

In addition to the prisms, I also tried using a tunnel like aperture after the optics,
which further dropped the output.

I guess it comes down to raw power vs beam quality.. I'm now leaning at beam
quality, and severe loss. I just cant stand a flat beam....

Pic# 3 is approx 6 inches from the lasers, and pic# 4 is approx 20ft.

In both pics there is a comparison raw beam from a separate module running
at the same output at high current. Low current in the 445's only masks the
'ugly mode' which is seen when running near 1W.

I've also noticed that with the prism pair, there is a stray beam which I cannot
seem to get rid of. My guess is that the anomalies that are seen with the 445's
have found a way to also make it into a second 2-5mW beam. I'm trying to
eliminate this beam, but so far, not even the smaller aperture will do the trick.

It is not noticeable in these pics, and the cam is viewing through a filter. The low
power from this second beam is easily filtered...




The output is adjustable on this labb'y from 40mW up to 575mW.

Hey it's an improvement. What kind of power loss are You seeing?

Those are some decent results! Like the case.. looks like a B&W tek 473nm casing, awesome fit.

I like the looks of your dot. Are you planning on doing another with Dr Lavas optics once they come in?

The case is the B&W / CNI... I plan on a similar build with Lavas optics as well.

The losses are in the range of 300mW or so. Before the optics is close to 1W
if I put the aperture on, the dot and beam are totally round, but this is because
of severe clipping plus the prisms, and even more loss.

The beam looks really nice even with the losses. The problem is, the LD has
to work overtime to get good results and remain a class 4 at the same time.

Im planning a 3W handheld with lavas optics, as they will fit a portable a bit
better. Trying to fit the prisms in a heatsink would require too much room. They
also have to be offset from the laser module, which requires a wider heatsink.

With the cylindrical optics, I plan on combining 2-3 beams in a single host,
and should still be able to keep it relatively small.

300mw is a significant loss. Lava's Lenses hopefully will not give that much of a drop.

Its a big power loss, but also a great improvement in beam quality - difficult trade off!

I wonder how the corrected beam compares to a PBS combined dual-445 though. That obviously gives a + shaped beam profile, but that my still look better than the stripe from a single diode... and nearly double the power

There have been issues when trying to combine these via pbs cubes.. Turns out its not very efficient either.

PBS Cubes and 445nm Diodes......

Benm said:

Its a big power loss, but also a great improvement in beam quality - difficult trade off!

I wonder how the corrected beam compares to a PBS combined dual-445 though. That obviously gives a + shaped beam profile, but that my still look better than the stripe from a single diode... and nearly double the power

Click to expand...

Im actually working with knife edging over a PBS with the 445's. It makes more sense
in that the beams are so flat out of the LD and collimator, there is almost no point
in using a cube...

Putting 2 or more beams side by side, and then through the prism pair, or lava optics,
may be a better solution.

I say this because the output beam before the secondary optics become almost
oval on their own. The two flat spots act as if they are correcting themselves
as far as shape goes. The only remaining problem from there is the rapid divergence.
Correct that with the prisms, and I think the beam will look really nice.

I have to play around with the dual setup and hopefully can get some pics up tonight.
I already have a 2 array and 3 array labby's sitting on my bench. Just have to run
them through the prism pair and see what happens. My guess is that the beam will
look better than using a PBS.. I could be completely wrong, but the 445's seem to
lend themselves to the knife edging setup better than LD's that are single mode.

The only thing with knife edging, is that alignment may be a bit more difficult.

Very nice work!!

wannaburn said:

Im planning a 3W handheld with lavas optics, as they will fit a portable a bit better. With the cylindrical optics, I plan on combining 2-3 beams in a single host, and should still be able to keep it relatively small.

Click to expand...

I really looking forward to seeing this!! :drool:

Kevlar said:

Very nice work!!



I really looking forward to seeing this!! :drool:

Click to expand...

Thanks :beer:

When you see the 3W's you will also have a chance to own one..

They will be limited edition depending on how hard the cylindrical optics
will be to get after the first ones land...

The problem is, I am waiting for a big order from DX, and cant begin the
heatsinks until the optics and the hosts get here. The optic mounts are
going to be milled into the heatsink, and have no idea of the layout yet op:

Here's a (probably) dumb idea, if you're going to combine 3 445 diode's outputs, why not just rotate the diodes/modules in their mounting heatsinks so the beams all rotate their fast axes into a kind of star pattern like an asterisk...

So instead of " - " you get " * ".

Granted, now the fast axes will be spreading just as fast in all directions, and can't be corrected other than focus (unless you correct all three fast axes before combining, which is triple the optics needed...) but if the goal is a round dot more than keeping the divergence tight, that might be a simple way to produce a nearly symmetrical spot, disregarding any other factors.

AJ_Dual said:

Here's a (probably) dumb idea, if you're going to combine 3 445 diode's outputs, why not just rotate the diodes/modules in their mounting heatsinks so the beams all rotate their fast axes into a kind of star pattern like an asterisk...

So instead of " - " you get " * ".

Granted, now the fast axes will be spreading just as fast in all directions, and can't be corrected other than focus (unless you correct all three fast axes before combining, which is triple the optics needed...) but if the goal is a round dot more than keeping the divergence tight, that might be a simple way to produce a nearly symmetrical spot, disregarding any other factors.

Click to expand...

The only problem there is, to get the beams as tight together as possible, I have found it best to have them 'standing' side by side. If you rotate the modules they will hit the mirrors more like > l/ < rather than > ll <.

This means to get them as close as possible you will end up clipping the edges of the beam...

With 'knife edging' you want them as parallel and close together as you can get them. Once the combined beams pass through the prism's or cylindrical optics, the beam gets even more tighter together.. No matter what shape or orientation they are in, the dot becomes so small, I doubt there would be any noticeable difference other than less power loss.

I didn't get a chance last night, but will tonight to pass a 3W knife edged module through the prism pair and see if there are any undesirable results.

Extremely nice work on those correction optics +1

Yay! wow that 3W would be awesome
but how would you power such a monster and the host would be huge wouldn't it?

Very impressive work, for me personally power is nowhere near as important as quality and I'll be emulating elements of your design when I get some time and money to play with my A-140 445 build.

I reckon for a scanner setup what you've done there is near enough to perfect to be useful, what do you think?

Burnsy said:

Extremely nice work on those correction optics +1

Yay! wow that 3W would be awesome
but how would you power such a monster and the host would be huge wouldn't it?

Click to expand...

Im waiting on some amc7135 boards as well as the new host bodies :banghead: I hate waiting... These drivers are LDO and should do fine with say 2 LD's and 2 7135's hooked 1 per LD.

Cooling will be the factor im most concerned with.. The hosts I ordered for the 3W is a monster, so heat and duty cycle
should be reasonable..

jupiter8 said:

Very impressive work, for me personally power is nowhere near as important as quality and I'll be emulating elements of your design when I get some time and money to play with my A-140 445 build.

I reckon for a scanner setup what you've done there is near enough to perfect to be useful, what do you think?

Click to expand...

Considering even with the losses, the shape of the beam can be tamed quite easily. The divergence has yet to be measured, but at 20ft the dot looks like a 12x 405 :eg:

Aside from a small stray beam (still have to get rid of) the beam is perfect. Im hoping that
the same results can be had with 2 and 3 diode arrays.

Realistically, I dont see it to be a problem other than loss, and the extra heat from an array.

I like to think of this setup as a pseudo DPSS, in that im putting 1W in and getting near 600mW out corrected... Even in terms of DPSS, this would still be ridiculous efficiency.

Its looking promising indeed :beer: