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445LD with Anamorphic Prisms on a Jayrob DIY

CDBEAM777

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LF, Great...I am just a hobbyist....and now starting to understand some of the basics on optics....and I am sure any optics professional / engineer...would make this comment concerning my scientific method... this from the movie " Forbidden Planet "..."The fool, the meddling idiot! As though his ape's brain could contain the secrets of the Krell!"
But...in our own small way...each of us add to the knowledge base on the form !!
BTW...see the attached pic from Newport optics on Cylindrical lenses...some companies DO make some microlenses....so possibly this MAY be an option ??? Ask your friend about Anamorphic vs. Cylindrical.
But...from what I have been able to determine....both with Anamorphic and Cylindrical lenses....a perfect circularization is not possible....again...what is acceptable ??? Anyone have any opinions on this ?? or...maybe 99% are just fine with the standard aspherical lens in an axis module ??? I am not satisfied with this output. Later...CDBEAM
 

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lasersbee

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Hey... if I could get a 1/4" X 7/8" beam at 45' I would be happy...
Have you tried a lens right after the Prisms to try and focus the
beam from there...:thinking:

I too like the "Trial and Error" method...
:gj:eek:n your last prism setup...

Jerry
 

CDBEAM777

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Thanx Jerry,

Well...More Glass = More transmission loss...even with AR coating....I suppose one could use a anamorphic prism set to diverge the fast axis...then use a second set of anamorphic prisms to expand the slow axis so it is in balance with the fast axis....and IF each set of anamorphic prisms is limited to 3% transmission loss...then that would add up to a 6% loss...Well for me... this would be an acceptable trade off. These ideas are my speculations....and again...I know enough about these optic details to be very dangerous !!

Also the application of cylindrical lenses may be the route to follow. I am under the understanding that Dr. Lava is using this optical set up....and for vector graphics...this may be the ONLY way to go ??? I am reading up about cylindrical lenses...perhaps his " Ape's brain " can figure his way outta a paper bag...haha

Thanx for your interest....Hey...ANY Optical Engineers....feel free to jump into this discussion !!! Later...CDBEAM
 

climbak

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I am an optical engineer, but not by education and I don't deal directly with lens or optical system design. I mostly deal with laser systems and holography. Anyway, it would seem to me that a cylindrical lens pair would be the best way to collimate this diode. would the spot be as small as we'd all like? No. Would the beam be round? No. The divergence could be much more closely matched for the two axes though so there wouldn't be the nasty line. The overall divergence would probably also be better since in general a larger beam waist leads to less divergence. There may be other optics that can do the job as well, but I can't think of any off the top of my head that would be simple or cheap enough for most of us.

I think I am going to design and machine my own host if I ever get around to putting this diode I have to use and I will probably try to use a pair of cylinders to do the job.

Edit: if you really want a roundish beam anamorphic prisms may still be the best method. two pairs of them would probably work well to circularize the beam close to the output, but I think you would still have a different divergence for the 2 axes. If you can find a well matched pair of cylindrical lenses you should be able to get a relatively narrow beam and decent divergence.

All this is also ignoring any power losses as well as the affect of a multimode beam on the ability to properly collimate it.
 
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CDBEAM777

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Thanx Cimbak....Again you have brought great information to the table !!! What would be the typical transmission loss be on a pair of cylindrical lenses ??? I assume they need to be AR coated and should be made from BK7 glass ?? THANX !!!!!!!!!!!!!! CDBEAM
 

climbak

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This is just a guess, but with a nicely AR coated lens made of BK7 or better yet fused silica or quartz, the reflection losses would be under 0.5%. Absorptive losses would vary on thickness but I imagine the lenses could be pretty thin, so no more than 5% loss. Then for 2 lenses you might get 10% loss. Again though with a good lens it could be lower, just not cheap. I think a 10% loss could be done relatively cheaply. If I end up doing my own set up soon I will be looking into this more thoroughly.
 

MISTERWILLING

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Thanx Cimbak....Again you have brought great information to the table !!! What would be the typical transmission loss be on a pair of cylindrical lenses ??? I assume they need to be AR coated and should be made from BK7 glass ?? THANX !!!!!!!!!!!!!! CDBEAM
If you have a week or two to wait, Dr. Lava will be releasing a kit that uses two very small cylindrical lenses. I think you may be able to purchase just the lenses themselves. Keep your out on PL.
 

CDBEAM777

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Mr. Willing....GREAT !!!! I am extremely pleased that you and the Doctor have used very small lenses in your designs....I knew your project was in the works....I was obviously following a parallel track....in a rather delayed fashion !!

Now that I know you are using very small optics...I will not reinvent the wheel...but will await your offering. As I am learning...the selection of the optimal Cylindrical lenses is much more involved than selecting Anamorphic prisms. Will your individual lens size be 10 x 10mm or 20 x 20mm ???? The reason for this question is so I can start to formulate some design concepts working around this footprint information.

I am sure your project has been in the works...likely from the first of this year...I truly appreciate your work and very much look foward to the roll-out !!!.....I will be watching...until then...CDBEAM
 

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