ML520G72 638nm 500mw Diode Group Buy

[valex]

The fast axis of the diode is the smallest close to the diode looking like this: | . But the fast axis is also the high divergent one, so after 30 meters it looks like this ----

With a prism pair you can met the small beam (|) wider like this [] so the divergence gets smaller so you end up with a beam after 30 meters like this - instedd of this ----

With knive edging you just stack the 2 beams as close as possible next to each other like this || after 30 meter it will look almost the same as with only one diode like this ----

With one prism pair you should be able get it down to this -

get it?

Please note, this works with Blue diodes, I have not tested this with the red diodes as we are all waiting for the reds.

yes, that makes sense. I knew the 'thickness' for lack of a better term, flipped at a distance due to divergence, so that makes PERFECT sense. Thank you!

Now as far as the actual mechanical setup to perform the knife edge, anyone have pictures?

[polishedball]

yes, that makes sense. I knew the 'thickness' for lack of a better term, flipped at a distance due to divergence, so that makes PERFECT sense. Thank you!

Now as far as the actual mechanical setup to perform the knife edge, anyone have pictures?

http://www.photonlexicon.com/forums/...ad.php?t=11553

[Doc]

yes, that makes sense. I knew the 'thickness' for lack of a better term, flipped at a distance due to divergence, so that makes PERFECT sense. Thank you!

Now as far as the actual mechanical setup to perform the knife edge, anyone have pictures?

http://www.photonlexicon.com/forums/...chmentid=17617

[edison]

Here,s one

[dave]

Well I got a sample on Friday, and have spent a little time playing round with lenses I have here.. as seem below, the results are a little disappointing. Just a little!!

OK, here goes.

First lens up - Thor C110TME - Focal length 6.24mm

Beam size at aperture, around 5mm by 1mm. drive current, 525ma, output power 375mw.

Second lens up - Creative laser technologies, glass lens, ar coated

Beam size at aperture, about 5mm by 1mm. Drive current 525ma, output power 240mw.

Third lens up - Aixiz glass

Beam size at aperture, about 5mm by 1mm. Drive current 525ma, output power 215mw



Pretty clear the NA of the second 2 lenses is not up to the task, and a lot of that ugly stripe is getting clipped by the lenses.

So with a good lens, who likes 6mrad with no correction? ( I got 2mrad with the same focal length lens with a 445nm diode ) I tried with some prisms, and they work, but the losses are a lot higher than 445nm.

Something else I tried was masking off the lower power fringes along the length of the stripe, leaving only the higher power portion of the beam in a 5 x 1mm rectangle. Unfortunately, there is quite a bit of power in the side fringes. Masking the Thor lens dropped around 150mw off the total power.

Conclusion: Does anybody want a red flashlight? We have one for sale cheap!! Seriously I give up!

[Solarfire]

Correct me if I’m wrong here!


With the Thor lens being the only one to capture the entire beam it appears the uncorrected beam ratio is ≈ 6:1 which pretty much outs prisms for correction due to the angle getting to big (4:1 is pretty much max for prisms with reasonable loss). With cylinder lens a magnification of 5-6 would be required to round things up, the losses would be less but the beam would be 5x5 – 6x5 at the aperture.


At what distance were those spot shots?


Frank

[badger1666]

Hi dave
What was the distance of the second pics with each lens?

[mccarrot]

No offence dave, but wasn't it you who concluded after your first tests with the 445nm diode this diode was useless also?

Looking at your first test results: 1 x 5mm x 6 mrad, tells me a beam of 5x5x1,5mrad is achievable. Now compare this value with 635nm lasers.

Because of the beam profile I think it is possible to knive edge 2-4 diodes without changing the beam specs too much. Ending up with a 2W red with a 9x5mm x 1,5mrad. Sure not perfect but compare it to other solutions.

4 x 635nm flaslight will give you much worse results and 14x 640nm 150mw dioded will cost you a fortune.

So in my oppinioun even with standard lenses this diode is giving you a affordable powerfull red with acceptable beamspecs.

Having this said andy is working on special lenses wich will give much better beamspecs than you have achieved. So maybe its better to keep this diode for a while and first test with andys lenses before selling it cheap.
(I bid 100 USD)

[dave]

O shit, knew I forget something!

All the pics taken at aperture and 10meters respectivly

[dave]

Actually, I don't think I was the one who said the 445nm diodes were useless.

I'm quite happy to be proven wrong here, but the beam quality of these diodes is A LOT worse than the 445nm diodes ( like 3 times the divergence )

Going on my tests you should be able to get 5 x 5 x 1.5mrad, but this would mean masking off the fringes of the stripe, and consequently loosing quite a bit of power. After all optics, you would be doing better with a pair of 642nm diodes.

No offence dave, but wasn't it you who concluded after your first tests with the 445nm diode this diode was useless also?

Looking at your first test results: 1 x 5mm x 6 mrad, tells me a beam of 5x5x1,5mrad is achievable. Now compare this value with 635nm lasers.

Because of the beam profile I think it is possible to knive edge 2-4 diodes without changing the beam specs too much. Ending up with a 2W red with a 9x5mm x 1,5mrad. Sure not perfect but compare it to other solutions.

4 x 635nm flaslight will give you much worse results and 14x 640nm 150mw dioded will cost you a fortune.

So in my oppinioun even with standard lenses this diode is giving you a affordable powerfull red with acceptable beamspecs.

Having this said andy is working on special lenses wich will give much better beamspecs than you have achieved. So maybe its better to keep this diode for a while and first test with andys lenses before selling it cheap.
(I bid 100 USD)