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Here are some close measurements of a lens I cannot locate where to purchase from. Anyone seen one like it? It is one piece...no glued up lens...but may have to go that route...AR coated as well. I will indent this lens ...as with a press as it has drove me nuts trying to find one like it...one piece lens that is.
Edmunds has Drum lenses on page 69. They come in CC and Plano/C. They are machined spherical lenses. Prices of course are welllllllll Edmunds!!!!
HMike
Buying quality is like buying oats.
You can buy fresh, clean oats for which you will have to pay a fair price.
Or you can buy oats that have already been through the horse.
That comes a little cheaper.
OBTW this is not quite a drum lens...
ME3 ---
Edmunds says they are drum lenses. That is spherical lenses ground into a cylindrical shape.
Now my question of the day ---- I have an FAP800 module. It has an internal bar emitter fiber coupled to a front circular coupler. When focused, I see about 19 dots of light, each fiber. I can't focus it to a dot and a columator gives me the same "picture" at distance.
Is there an optic which will combine all those dots into a point? I was considering the sphere followed by a columator but there may be other options. A grin has too small an input unless it follows the sphere.
HMike
The lens in EO is a drum lens for sure...the lens I have is extreme convex on one end and concave on the other....if a rework of a drum lens was cost effective, it may be possible. As far as the fiber output....the coupling is done with a pair of ball lenses , like this...... fiber end , ball , ball, fiber end= >00< . So you are getting close to getting a collimated beam from fiber in your process of thought. I would get hold of some of the free optics software and see what it looks like in the program. Experimentation is cheap there.I will investigate the use of the plano/convex lens with a different aspheric...it may work with a different combination and distance apart.
If you plan to make green with that thing....I have the waveplate you will need to pump Yag with if you don't use PM fiber.
Thanks Mike ---
I've tried many lens combos but always get the dot pattern at focus........ I'm looking to get an output which will focus to a dot at distance using other optics. It will light up a green set of crystals easily! I have 2 of these 808 FAP's.
HMike
The FAP I have is meant to be fiber coupled. They use this coupling to homigionize the pump power then collimate/shape the output to pump with.
There is no magic way to fix something like this. Think of it like a projected image ( the diode bars) you can zoom in or out, change focus, but you always have the image of the diode bars. The same problem we are all having with the big blues.
ME3: If you can't find anything off the shelf and need something custom and want to pay for it, go here: http://www.rainbowoptics.com/
chad
Chad ----
The modules I have were used IIRC as power for etching something. That to me means that they can be focused to a dot. I am seeing the "points" image as you say but isn't there a homogenizer optic to pull it together?
HMike
Not that I know of, (and I don't claim to be an expert). The cheapest and easiest way I know of is coupling to a fiber. The only other theoritical way I can think of to do it is to focus into a small ~ 800um diffuse piece of glass then image that and collimate. Doing this would be hugely lossy.
The fiber serves two purposes, first it mixes up the diode output and second it offers a convenient beam delivery method. The fiber is part of the design. The fap is not able to deliver a nice tem00 beam directly out of the aperture. That is why It comes with a SMA fiber connector.
chad
I appreciate the help here guys ---
Seems to me that the dual sphere arrangement >00< would still give me the dot pattern when focused at say- 10 feet. How about adding a piece of fiber in the middle? >0-0< It would need to be able to handle ~ 12 Watts. I'm afraid a GRIN is too small.
HMike