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Osram PL530 - Tiny 530nm OPSL

Alaskan

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Robert/RCB, yep, with 4 to 8 mRad uncorrected divergence out of the PL530, I was thinking the same thing too, using one of those expander lenses, but I have some uber high quality AR coated 25 mm diameter Thorlabs aspheric lenses to try for the collimation, I couldn't use anything less than aspheric for this high quality beam output.
 

Zenodilodon

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Robert/RCB, yep, with 4 to 8 mRad uncorrected divergence out of the PL530, I was thinking the same thing too, using one of those expander lenses, but I have some uber high quality AR coated 25 mm diameter Thorlabs aspheric lenses to try for the collimation, I couldn't use anything less than aspheric for this high quality beam output.
With the expander that comes with the unit you can collimate the beam using a 532nm DPSS collimating lens, it's focus is 6-10mm away from the factory expander.
 

RedCowboy

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With the expander that comes with the unit you can collimate the beam using a 532nm DPSS collimating lens, it's focus is 6-10mm away from the factory expander.
Ok cool, the output is already expanded.....WOW.....this could make a nice tight far field spot. :)

I wonder if there is a higher output version ?


Robert/RCB, yep, with 4 to 8 mRad uncorrected divergence out of the PL530, I was thinking the same thing too, using one of those expander lenses, but I have some uber high quality AR coated 25 mm diameter Thorlabs aspheric lenses to try for the collimation, I couldn't use anything less than aspheric for this high quality beam output.
You could further expand the beam to use your 25mm lens but I would try a standard glass 532 collimator 1st, I bet it will produce a very good beam and tight spot.
 
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Zenodilodon

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Ok cool, the output is already expanded.....WOW.....this could make a nice tight far field spot. :)

I wonder if there is a higher output version ?
It's an 808 pump, and the upside of an OPSL is that it's not to fussy on the pump cause it's doubled off the wavelength coming from the OPSL chip/DBR. With that said if you where careful it is possible to remove the pump diode and fashion a higher output on in place of it. This could be accomplished by a positive meniscus lens in front of the pump so you had space to cool it and get the beam where you want it. It's complicated stuff. Other thoughts are going to be whether or not the tiny optics can withstand higher pumping powers. Maybe they will melt like a muffin in the rain. The output is incredible. my collimating lens is a slight off center, but getting the magic in the tube isn't something I want to go undoing any time soon. The output will be as a DPSS would be.
 

RedCowboy

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I have thought about using a large meniscus lens to bring several beams set around a circle to a variable distance converging point, but before I get off topic........I wouldn't try to overclock the tiny crystals/optics, was wondering if there might be a higher output unit for larger pico projectors....... actually this type could get into the large data projectors or at least those of higher quality, time will tell. :D
 

Alaskan

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Warning: Data dump

I don't see an expander lens build into these little units, just a somewhat weakly collimated output. IMO, for use in a pointer the specified 4 to 8 mRad output divergence needs to be expanded further to get a higher level of collimation to produce a low enough divergence beam. Letting the beam naturally expand before collimation would make a very long pointer, at 8 mRad, the length would need to be like an extra long broom stick at over six and a half feet long to get to about 17 mm diameter before collimation (resulting in ~.47 mRad). That would produce a very low divergence pointer, as most go, but unless you like an uber long pointer, better to use a concave lens in front of it before adding a PCX/plano-convex, or or more ideally, an aspheric collimation lens.

With the 1 mm output beam diameter at the units window, expanding to 20 mm the divergence would be 20 times lower. At that amount of expansion (per the manufacturers 4 to 8 mRad beam divergence specification) the worst case 8 mRad output would then produce a divergence somewhere around .4 mRad, and if 4 mRad output (prior to expansion to 20 mm beam diameter) then close to .2 mRad when expanded that much which is awesome.

I have attached a picture of the PL530 diachi found for the thead as well as some calculations comparing a pointer made with one of these units expanded to 20 mm to a common 5 mm beam diameter 1.4 watt 520 nm much higher divergence pointer which uses a much smaller 6 mm diameter collimation lens. The attachment from laserworld.com shows how much more intensity can be delivered at 8000 meters distance with only 75 mw of output power from the PL530 (exp. to 20 mm) over the far more powerful direct to wavelength laser diode pointer which is running more than 18 times the amount of output power. Keep in mind, the collimation lens is much smaller on the high power pointer which puts it at a further disadvantage, but to sum it up, the far lower output power 75 mw PL530 with a 20 mm collimation lens produces more than 9 times the delivered light intensity at 1500+ meters distant (due to a smaller spot size), compared to the 1400 mw output 5 mm beam diameter 520 nm laser pointer. Note: I would only dare 75 mw if limited duty cycle similar to many DPSS pointers without active cooling at that power, not anywhere close to continuos.

I'm comparing apples with oranges with the different lens diameters, because as for the any laser, changing the beam diameter will change the divergence; larger dia. produces lower divergence, smaller higher. Want lower divergence whether using a direct to wavelength laser diode, DPSS, or one of these OPSL units? Just use a larger diameter collimation lens. However, if using a 6.33 mm diameter aspheric lens which are very common in our pointers, the PL530 will have a worst case divergence of about 1.6 mRad, the NDG7475 1.4 watt 520 nm laser diode about ~2.6 mRad at identical 5 mm beam diameters (for both). Truth is, with that diameter of a lens, neither of those divergence figures are very impressive, but the PL530 still wins by a large margin, especially if the PL530 happens to have the lower possible output divergence of 4 mRad prior to full collimation. In that case, the divergence will be about .8 mRad which is outstanding with only a 6 mm diameter collimation lens. All of that said, using the same diameter lens, the 75 mw PL530 (at a distance of ~1500 meters or greater,) will be about half the intensity of the 18+ times higher power NDG 7475 1.4 watt laser diode.

Using the same lens diameters at maximum power is the real comparison between the PL530 OPSL and the NDG 7475 520 nm laser diode for delivered brightness of the spot. To sum it up:

When using the same diameter collimation lens, if the PL530 is producing the lowest possible specified raw divergence out of the unit, and is set to produce its maximum possible output power of 120 mw (actively cooled with a TEC), the two pointers using identical collimation lenses will produce very close to the same intensity spot in the far distance, so close you could not tell the difference by eye, just a few percents apart. Note: At close distances of 100 meters or less, the higher power NDG 7475 begins to win much faster at producing a brighter spot and does so more and more at shorter and shorter distances, it's only at greater distances the far lower divergence much lower power pointer begins to get closer and closer to the brightness of the higher power pointer, becoming closer and closer at several hundred meters and beyond, at a great distance of 50,000 meters they are very close together for spot intensity when producing 120 and 1400 mw output powers (as if we could see it, not). I imagine at some distance, the PL530 would match and begin to over take, but the online calculator I use to get the figures won't show it.

I'm not an optics professional, so I don't know how low of a divergence we could really get with the optics we commonly use for pointers, but I believe I am in the ball park with these figures.

Online divergence calc: https://www.laserworld.com/en/laserworld-toolbox/divergence-calculator.html#divergence

Got em in the mail yesterday, I want to put these away and not use for awhile, but if someone wants to do a group buy, let's start one, I'm in for a few more so I don't need to touch this pack:

 

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Anthony P

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That is an unusual photo plate you cut for this hologram, Anthony. Have you tried making any reflection holograms yet? They are a bit more involved than transmission ones, but you can view them in ordinary light.
I have made one attempt at reflection type. Tried and epically failed. My set up was the most basic with a single beam through the plate and onto subject... no image at all. I will make further attempts with longer exposure times, and direct lighting of subject instead of just through plate. The fun in an experimental science/ hobby is the experimentation.
Could you please clarify, Paul? "unusual photo plate". These are off the shelf 63x63mm green sensitive from Intergraf VRP-M. Should I try something different?
 

diachi

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I bet you can run the heater on the same 3v

You will want to use a beam expander and collimator lens pair just like the 532nm dpss lasers use, you could likely use the same 532 sourced lenses and set the separation distance to infinity or you could use just a very long focal length lens which looks like what Zenodilodon may have used, however for the best results a concave-convex pair would make the best beam.



Heater voltage is 1.5V-2.0V. Try 3.0V at your own risk.

Not all of them have the output expander lens, mine didn't but another user on Discord did have one on his.
 

RedCowboy

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Heater voltage is 1.5V-2.0V. Try 3.0V at your own risk.

Not all of them have the output expander lens, mine didn't but another user on Discord did have one on his.
Ok so some have an expander lens and some don't, that makes sense and I don't know why I thought it was 3v for the heater unless maybe it was 3v for something else we have heard about lately, anyway it's all good info, Thanks
 

Alaskan

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Holokidd is selling some with expander lenses on them, I bought six from him, but have not received them yet. He said they are glued on and can easily be separated with a razor.
 

paul1598419

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I have made one attempt at reflection type. Tried and epically failed. My set up was the most basic with a single beam through the plate and onto subject... no image at all. I will make further attempts with longer exposure times, and direct lighting of subject instead of just through plate. The fun in an experimental science/ hobby is the experimentation.
Could you please clarify, Paul? "unusual photo plate". These are off the shelf 63x63mm green sensitive from Intergraf VRP-M. Should I try something different?
I just meant that the plate is cut not in a rectangular fashion. It looks like it is two rectangles with the larger on top. I suspect the emulsion is fine for holography. I was wondering if you cut the plate yourself.
 

Anthony P

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I just meant that the plate is cut not in a rectangular fashion. It looks like it is two rectangles with the larger on top. I suspect the emulsion is fine for holography. I was wondering if you cut the plate yourself.
I think what you are seeing as 2 plates is just the shadow from my plate holder. The groove that the plates sit in go up about half the height of the plate. I did not cut them myself. When it comes to glass work of any kind, my years of experience have taught me one valuable lesson... hire someone else to do it!
 

paul1598419

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Oh! You should get a new plate holder. There is no reason for your plate holder to block the light at all. You can likely get something that only holds on the edge. That is what I used when using glass plates.
 

Anthony P

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Oh! You should get a new plate holder. There is no reason for your plate holder to block the light at all. You can likely get something that only holds on the edge. That is what I used when using glass plates.
Apologies if this gets a bit off topic. Here are a couple photos of my plate holder in the daylight. Do you have any thoughts or recommendations?

63406

63407
 

paul1598419

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I always used a plate holder that was one piece. It would hold the glass from the edges because it was spring loaded. The spring was mounted from the bottom. I don't have any examples to show now, but you should be able to find something that won't interfere with the light.
 

Alaskan

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Received the units from ebay seller holokidd with the expander lenses glued on them:

63408
 




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