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An optical accessory option question.

steve001

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The other day I asked Podo this question.
Hello Podo. As you know, all or nearly so these diodes have rectangular or oval beam profiles. Have you considered an optional accessory that could accommodate a cylindrical lens or lenses to shape these beams to a more desirable rounder beam shape?
Podo replied:
We could probably make such accessory but there doesn’t seems to be a demand for it so...
After reading this my question is this. If an accessory option was offered that would round the beam to a more circular profile would you buy such an option? If so why? If not why not?
 

Benm

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Do you mean corrective optics that change the fast-axis divergence to get it close to the slow-axis by expanding the beam in one plane but not the other?

Those are available, mostly as either sets of cylindrical lenses or prism pairs.
 

steve001

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Do you mean corrective optics that change the fast-axis divergence to get it close to the slow-axis by expanding the beam in one plane but not the other?

Those are available, mostly as either sets of cylindrical lenses or prism pairs.
Of course. I know they are available, but not as something off the shelf one can simply attach to a Sanwu laser. At this time a custom lens mount would be required. Their lasers are of *modular construction so it would be rather easy to make such an option without retooling the basic design. To be a bit more precise in my description, this optional lens mount would be an attachment made by Sanwu containing a cylindrical lens that could be screwed on to their lasers.

*The Challenger series would be the best choice for this option.
 

Cyparagon

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It isn't something most people care about or even notice. What you're describing is a single-axis beam expander, which would be rather expensive, be orientation-critical, would not be cross-compatible with all models, add substantially to the size of the device, and reduce power.

I'd never buy one, personally.
 

CurtisOliver

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I don't know if enough people would buy them to make it viable as a Sanwu product. As Podo himself has stated
... but there doesn’t seems to be a demand for it so...
Also I have to agree with Cyparagon. Each diode has different beam specs meaning a different adaptor would be needed.
If you want one, the best option is make your own.
 

paul1598419

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I have C lens pairs, but wouldn't want to buy a laser from Sanwu with a pair attached. I prefer to build my lasers over buying prefabricated ones. I don't see a lot of people interested in getting these at the price point they would end up at.
 

Encap

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It isn't something most people care about or even notice. What you're describing is a single-axis beam expander, which would be rather expensive, be orientation-critical, would not be cross-compatible with all models, add substantially to the size of the device, and reduce power.

I'd never buy one, personally.
Agree.

I don't know if enough people would buy them to make it viable as a Sanwu product. As Podo himself has stated

Also I have to agree with Cyparagon. Each diode has different beam specs meaning a different adaptor would be needed.
If you want one, the best option is make your own.
Exactly, Curtis.

Would not a viable product accessory for hand held lasers for several real reasons already mentioned above.

That nobody offers same and what the reality of the market for and legality selling of hand held lasers really is in the world pretty much tells the tale. As Cyparagon has said "It isn't something most people care about or even notice."
Would be expensive and the majority of people who might want one would probably not want to spend the money.

We a lucky to have 2 manufacturers that offer beam expanders at relatively low cost. Keep in mind most people buying hand held lasers just want to push a button and see a light and have no other real reason, interest, or purpose for owning a laser.
 
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Benm

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That'd probably be the reason indeed - just lack of demand.

Perhaps it would be possible to build and aftermarket corrective optic cap that you could attach to the front of such a laser, but you'd have to get the exact distances and orientation right for it to work really well.

The problem is that it will never be as good as a single mode diode though. I suppose that people that just want raw power (to set things on fire for something) do not care that much about optical properties, and people that like clean optics just have to settle for the lower output of single mode diodes.

That 'lower' figure depends on distance though, if you get something 100 mW single mode 1 mrad unit and look into it from a kilometer away that will be brighter than a 5W laser with 5 mrad divergence of the same wavelength.
 

steve001

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That'd probably be the reason indeed - just lack of demand.

Perhaps it would be possible to build and aftermarket corrective optic cap that you could attach to the front of such a laser, but you'd have to get the exact distances and orientation right for it to work really well.
Not when using one lens to correct the fast axis. A round plano-concave cylindrical lens mounted flat side facing the diode would work. They're much easier to postion compared to other shape cylindrical lenses. That would create a square(ish) beam that at any distance increases the power density making the beam look like what we typically imagine a laser beam to be - pencil thin streak of light.
The problem is that it will never be as good as a single mode diode though. I suppose that people that just want raw power (to set things on fire for something) do not care that much about optical properties, and people that like clean optics just have to settle for the lower output of single mode diodes.
Consider a blue 4w laser which has a rectangular beam shape. With a cylindrical lens taming the fast axis you've improve the esthetics. Meaning at any distance the terminal spot will look round not bar shaped.

My purpose for starting this thread is as stated, but also to get old members and newbs especially to appreciate not only raw output power but to consider the beam esthetics that likely drew us to lasers in the first place. Perhaps such thinking appreciation could create demand.
 

Benm

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I guess it could among laser enthusiasts that really care about beam profiles and such. Surely taming that multimode laser into producing more of a square than a line at larger distances (say 100 meters) is an attractive thing to do, and i've tried it myself with prism pairs and such. That approach works, but it wasn't really handheld compact to say the least ;)

It also will not be a very thin beam at all - what you essentially do is beam expansion in one direction so you get less divergence in that direction. This makes the output pattern into a square of sorts, but as wide as the line pattern was before applying the correction.

You cannot have both: if you want lower divergence you need to make the beam diameter larger. That said a corrected beam that is something like 1x1 cm fat with low divergence is still better than the line from an uncorrected multimode to me... but perhaps only to me and very few other people.
 

steve001

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I guess it could among laser enthusiasts that really care about beam shape. That said a corrected beam that is something like 1x1 cm fat with low divergence is still better than the line from an uncorrected multimode to me... but perhaps only to me and very few other people.
Yup.
 

CurtisOliver

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I particularly like corrected beams too, so it isn't like there aren't people that would appreciate it. It's just there isn't enough people to justify making a new product. As an idea, I like it. Just unfortunately from a business point of it isn't practical to pull off.
 

steve001

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I particularly like corrected beams too, so it isn't like there aren't people that would appreciate it. It's just there isn't enough people to justify making a new product. As an idea, I like it. Just unfortunately from a business point of it isn't practical to pull off.
I measured the inside diameter of the Challenger ll optical pathway. It has a diameter of a bit over 9mm. A single positive cylindrical lens might just fit.
 

paul1598419

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How so? Can you make just one of the lenses do the same job as a pair? It seems the first lens expands the one axis and the other collimates it. Unless you are talking about a totally different lens.
 




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