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How big is too big? Maybe this one is? Doesn't matter trinh hong phuoc will build it :)

Alaskan

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Here's one of the choices I have to pump with the FAP800's to produce 1064 nm.



Edit: The challenges with this is requiring two inputs or two FAP's and the output is not centerline, mirrors can work wonders though, at a price.
 
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steve001

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Steve, the PCX lens has a FL of close to 100 mm, the negative lens is the back half of a Sanwu 3.3x beam expander. I don't know its FL, Trinh engineered the BE on this unit. Weight about 20 pounds with batteries inside, right now it's only a hand held unit but I suppose I could build some kind of mount which looks like a big hand with motor actuators and turn this into a piece of modern art?
Looking forward to seeing what the divergence will be.
 

Alaskan

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Why build my own? The power level I want as well as the portability would be extremely expensive to buy from a commercial manufacturer, but finding surplus parts, not such a bad deal, but be prepared for a lot of cost and time involved to do so.

 

Alaskan

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Ha, I know that very well.... This is a bear of a project, I might not be able to tame this beast on batteries alone, but fun to try. If it won't tame at 10 watts doesn't mean it won't at 5. I don't expect a long duty cycle, no way that will happen, but it might be good for a few minutes at a time which is all I want. It's all about expectations brother, I understand the difficulties and likely outcome for this project but I'm going to try for 10 watts peak turbo mode for however long it can produce it anyway.
 

Snecho

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Sorry, didn't mean to step on any toes. Hey. he said laugh at it and that's what we're doing. :)
Should beat the pants off a NUBM44 pointer or my old ghetto monster, wouldn't you agree?

It is not a hand held pointer you sillies, it's a battery operated portable lab laser, or will be. Although you can hold it by cradling in one arm and steering with the other as with many other lab lasers too, unless a weakling. Just looking at this thing gives me super powers!

Edit: If too heavy you can use the smaller of the two... No wait, you don't have one... even better probably don't want one which is fine with me, there can only be one largest laser pointer in the world! It's so big no one dare compete (that's what she said too).

It's not the size that matters, it how you use it :)
 
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Gabe

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Sorry, didn't mean to step on any toes. Hey. he said laugh at it and that's what we're doing. :)
Oh yeah nah no I was laughing at it too, I meant that anybody holding that thing is gonna feel like a god, no worries :)

Alaskan, sorry because I know essentially nothing about pumped lasers and anything else really that goes into this project so I’m hoping you can enlighten me. What am I looking at in the photo you posted, what components do what and how will they play a role in the build? Thanks :)
 

Alaskan

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This project is to do something outlandish, hopefully resulting in a high power DPSS but other than that for portable use on batteries it’s a bit of a ruse just for fun. I have seen candlepowerforums members build some flashlights this big and laughed at those (see below for an example of an oversized flashlight), high time we had a laser pointer contender! Thing I haven't told you yet about this project is later I will remove the stick, put feet on the cylinder and use it as a table top laser with a more capable power source for the pump diode(s) as well as cooling so I can run the output higher. I am looking for a way to use a single FAP800 for battery use at half output (for normal output mode) and then two FAP800's at near full output when on the bench power supply.



Right now there are no components inside at all, just a large deck of aluminum inside to mount parts to. However, good news is I already have the main components including the complete sets of optics from several Coherent 532 nm lasers I purchased from the surplus laser parts market which originally could produce much more than 10 watts of 532 nm green to mount inside. That is why I’m hopeful I can get this to produce some number of DPSS watts output. I also have a new old stock 50 watt FAP800 for a Avia laser as a zero time pump for the YVO4 and several more with time on them which still produce good output.

Even at this mass of aluminum the challenges will be heat management as well as power supply current limitations when on battery which will limit the output power of this unit. The end lens is not the first collimator, it is a beam expander.
 
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Alaskan

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I didn't mean 30 watts, just the beam specs themselves should be similar.

Here are some of the YVO4 crystals from high power Coherent lasers I have collected over the years. Most of them are in gold plated copper mounts with TEC's. I have over 25 mounted in heat sinks and lots of singles, so ready to start building soon. I also have lots of non-linear crystals and the ovens for them not shown in this photo, I wouldn't attempt this build without plenty of options for parts.







The bottom photo is of a YVO4 I received this week, that particular seller doesn't know how to pack well, it was a replacement for one which had the TEC broken due to poor packing and this one too now has a ding on the top due to his terrible packing along with the FAP he sent together with it. Dinged but both still usable, disappointing though.

Nd:YVO4 is the most efficient laser host crystal for diode pumping among the current commercial laser crystals, especially, for low to middle power density. This is mainly for its absorption and emission features surpassing Nd:YAG.

The Nd:YVO4 has a broader absorption bandwidth at the pump wavelength when compared with Nd:YAG. The pump absorption bandwidth is 2.4 to 6.3 times that of Nd:YAG. This property means more efficient pumping and a broader range of diode specifications. Also, The Nd:YVO4 laser will maintain a strong single line emission and since vanadate crystal is uniaxial, it will produce only polarized laser output, thus avoiding undesired birefringent effects.





You can see from the above graph curves, to produce an output at 1064 nm the ND:YVO4 can be pumped with 808 as well as visible wavelengths and a long stretch of wavelengths into Near-IR. The disadvantage of using YVO4 is due to its relatively low heat transfer characteristics making pushing it too hard a problem and heat sinking techniques of paramount important to keep from destroying the crystal. That's why I'm not going to engineer my own heat sink or cooling for this type of crystal and use pre-engineered modules with heat sinking and TEC intact. That said, the reason I want to use the ND:YVO4 instead of a ND:YAG is the efficiency of converting 808 nm IR into 1064 nm for SHG conversion to 532 nm green is much greater using the YVO4.
 
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