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FrozenGate by Avery

Do the Dr. Lava optics correction lenses provide any beam expansion/mrad improvement?

Joined
Jun 12, 2010
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I'm curious if the little corrective optics that DrLava sells have any beam expanding caractaristics to help improve divergence. does this just make the fat & slow axis divergence closer... or does ti increase divergence on both axis as well? Wat are the focal lengths? Do they have an AR coating? http://hacylon.case.edu/ebay/laser_diode/Lenses.php

I'm not sure if I want to build a beam expander or a corrective optics module.
 





As I understand it, the lenses increase the diameter of the fast axis and therefore decrease the divergence of the fast axis.
 
From what I've read, Dr. Lava's cylindrical correction optics are designed to work after an aspheric collimator.
As Cyparagon pointed out, it expands the fast axis to match the slow axis to reduce divergence.

They are AR coated for broadband IIRC and will work with the 638nm 500mW diodes as well.
 
Well hopefully they will be available soon, I put a order in 4 months ago and I'm still waiting...
 
Well hopefully they will be available soon, I put a order in 4 months ago and I'm still waiting...

I last heard from Dr. Lava on the 11th of Nov. - apparently the manufacturer had to re-coat some of the lenses.

Dave
 
On the 10th of Nov Dr. Lava said that, though he said it would only take a extra week. My Hands are getting cold at the stall of my project :-(

Edit:

Got them a few days ago :-)
 
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Sorry to necropost, but I thought that would be a lesser offence than starting a new thread for this -

I'm looking for the PDF of the instructions that come with these Dr. Lava optics. I have the optics, but I've lost the printout, and there was some good concise info about positioning these correctly. Can anyone point me in the right direction? The PDF doesn't seem to be up on his site.
 
They're cylinder lenses, right? The easiest way would be to place the expanding lens in front of the laser, and move the other lens around until you get the right spot size.
 
Did I include that instruction sheet with them?

I thought I did..

I believe the only thing you really need to be aware of, is that the beam enters the smaller optic. The beam (being best focused to infinity via first set of optics- 405-G1 or aiXis multi elements) being oriented like [], and the lens oriented like [] also.

Then I believe it said it would be a 10mm separation between the first lens and the larger lens. I do not know if that was an "on center" distance, but its a safe assumption.

Just remember, its just beam expander for only one aiXis of the beam, so naturally while looking down at the assembly from an aerial view, you should be able to see the curvatures of each element.

Precision is key, on center alignment is critical. Develop some kind of solid mounting setup once you've got it to work.

Hope this helps. :)
 
That's what I remember the page saying also - but I lost it during my move.

What's driving me nuts, is that it seems like it would be more logical to orient the beam like = and then the lens like this []. That way you would be converging the width of the beam (if viewed from above) with the first lens, and then *stopping* the convergence and making the beam parallel (if viewed from above) with the second.

[DIODE] === |) > |( ---------------------
 
speaking of beam correction and all, Any got a link to a set of telescopic optics to make the beam on a 8 laser array would be?
4 and 4 with a cube + telescopic optics should make for a decent beam.
 
Except then the divergence would be terrible on both axes.

I'm not arguing that you're wrong (I'm sure you're right), but I'm not quite getting it. It seems to me that you should be able to get one axis perfectly parallel and thin with the Aixiz lens, and then use one of corrective optics to converge the other axis down to a small diameter, and then the other corrective optic to stop the convergence of that axis and make it too parallel. It seems like the corrective optics would do nothing to the axiz that had already been made thin and parallel by the Aixiz lens, because the corrective optics are cylindrical lenses.

I guess I'm having a lot of trouble visualizing this. I'm very visual, and it's pretty tough for me to grasp the the angles/axes involved without seeing something visual.
 
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Here's what I'm stumped on:

The instructions basically tell us to put the FAST (wide) axis vertical, and use the corrective optics to expand the SLOW (thin) aixz out to the same width, for a square output result.

Why not put the SLOW (thin) axis vertical, and use the corrective optics to shrink the FAST (wide) axis down to the same width, for a square output (but a much tighter resulting beam).

Exact same concept, but more desirable result, no?
 


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