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ArcticMyst Security by Avery

Building my own DPSS yellow

LSRFAQ

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Depends if you have 24-seven access to a very good, very large milling machine such as a Bridgeport. Large means stiff, as making tiny parts demands a high quality machine with little vibration or drift. This is not something that you can easily do with a tabletop mill.

If you have that, you can build decent green DPSS.

The only problem with building a yellow from the many published scientific papers is the cost of one-off sets of optics, and Chinese quality control.

The issue that would confound most beginners is getting the crystal orientation right, along the axis, with respect to polarization.

The second issue is suppressing 1064, while balancing which one of the three close together 112X nm lines lase. 1064 has about nine times the gain of 1121, so the laser will want to jump to 1064.

The third issue is getting the coatings right , to suppress 1064, 1328, and enhance 561 and 112X.. Then tuning the intracavoty etalon to select the brightest 1120 line in the F manifold,of which there are three or four.

I have four sets of 1121 optics laying around, two LBO doubling crystals, and two rods coated for 1121 with side pumping. I have four pairs of optics coated transmit > then 60% 1064 nm, while lasing 1121, with 1% T on 1121 to allow for alignment. I will be, some day this summer, milling the mounts on my Bridgeport. My rods are rectangular, so I'm side pumping. The rod is coated enhance 1121 and 561, reject 1064 at both ends... Those do not grow on trees, and mine are medical surplus.

None of that is for sale. Unless your name is Krazer, and that is only for one spare line selecting high reflector, as he outbid me on one of the rods.. At least I think he did..


I'm trained in DPSS and Lamp Pumped Lasers, so I'm not too worried about making a V fold cavity. I am concerned about adding a Q-Switch to make sure I get what I want.

Current plan is 20-30 watts of 808 side pump for 2 watts out at best, probably half that amount of yellow, on a good day.. I'd be darn happy to see 100 mW at first...

It took three years of patiently shopping Ebay to find what I needed... locating the right yellow medical system to search for took a while, and I've only gotten spares, never a complete unit.

BTW, Rotate type Two KTP for SHG of green about 4 degrees and it works for 561 with large losses... But you need a q-switched source of 112X to really make that shine..


However buiding a green is much easier. One watt hybrid crystals (KTP bonded to Vandate or Yag) that require little alignment are cheap, 175$ or less. I can get that going with a drill press and some carefully selected aluminum and copper stock. No mill needed.

I've aligned OPOs with two non-linear crystals and seven intracavity optics, so this should not be too bad, but I do expect a full weekend of alignment.

I guess I'm a laser professional, but I don't see this as laser based rocket science... I do see it as a final exam for a journeyman machinist, which I am not. As milling perfectly squared 2 mm slots in copper with just enough slack to get the indium foil in will be an issue. I'm blessed in that I do not care about the size of the final product. Thank God my employer asked me if I wanted the mill when they trashed it. Even then it cost a fortune to have it professional moved, and I paid scrap value for the weight of the metal.

To the guy who started the thread. Start with Nitrogen, usually you can get that going on your second attempt at building one. Once you get the hang of that, DPSS is not too bad.

DPSS Green is not difficult. Most are built by Chinese laborers who had high scores on national tests but were not selected for college. They put them together with scraps of tinfoil for alignment shims... PDF plans for scientific grade green are easy to come buy if you have a friend at a college. Heck the Chinese optics companies all coat the same optics sets to the same informal national standard design for each power level.

As for building lasers, Most dream, but some dare to do, and even if they fail, the journey can be a reward. However persistence, a budget, patience. making intra-personal connections, and expecting some failure is required.

Nine out of ten people reading this thread would not call, and request a quote for the crystal set... They just assume... It never ceases to amaze me.

Steve
 
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SyKo

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This really isn't possible, unfortunately. The process is too complicated and too precise to be done without specialized equipment. It is almost impossible to build a DPSS 532 on your own, let alone a yellow. :(

Why is this common thought around here? i swear i am missing something but i've had alot of success ripping apart many a helpless green modules and mixing and matching their diodes and crystals, sure it may be hard to get a precise 532nm output but as far as getting a ir diode to spit out 532nm when accompanied by the right crystal it doesnt seem all that difficult?

Mind you i am yet to blow up a cheap ebay pen crystal by pumping it with multiple watts of IR.
 

LSRFAQ

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Why is this common thought around here?

Mr. Syko, I rarely give rep. In fact I hate rep systems... However...

Plus one! Audace, Encore Audace! Toujours l'Audace!

Dead DPSS are useful for something once you have enough of them.

5 - 20 mW hybrids, are what, 20$ on Ebay if you dig hard enough... While crystal sets with pump diodes cost more then a 100 mW completed module, there is a great deal of satisfaction in getting one going. Especially if you cheat and use some MM1 mounts.

But you do need a really good 175$ pair of laser safety glasses while doing so.. Ones that cover 808 and 1064.

Steve
 
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SyKo

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Why is this common thought around here?

Plus one! Adace, Toujours l'Adace!
Dead DPSS are useful for something once you have enough of them.

5 - 20 mW hybrids, are what, 20$ on Ebay if you dig hard enough...

But you do need a really good 175$ pair of laser safety glasses while doing so.. Ones that cover 808 and 1064.

Steve

Yeah i swear my vision is already a little off due to this hobby...
 
D

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Why is this common thought around here? i swear i am missing something but i've had alot of success ripping apart many a helpless green modules and mixing and matching their diodes and crystals, sure it may be hard to get a precise 532nm output but as far as getting a ir diode to spit out 532nm when accompanied by the right crystal it doesnt seem all that difficult?

...

Agreed IDK why people say its impossible I have dinked around with DPSS
I don't understand How to properly align the vandidate/yag but the doubler is not that hard (mostly because you can see the output)
I have build several green lasers from scratch using composite Crystals. As well as successfully realigned a few. Heck I Rebuild a protera wich is Inner cavity direct doubled. I see people post that statement Its impossible all the time and it drives me nutz. Is it difficult yes, Dangerous yes, Impossible NO

Mind you i am yet to blow up a cheap ebay pen crystal by pumping it with multiple watts of IR.

Ill admit I did that with a 50mW pen I swapped the dead diode It was one of the easy ones where the diode was held in with a threaded ring. well usually when you swap them you have to roate the diode untill you find a spot with decent output. Not this one.
No matter what orientation Beautiful TEM00 best I Had seen for that style Module. So wile testing the laser using a bench supply and a diode socket I decide since I'm already getting 50mW of green and my diode is not at full power lets push it a bit higher. Well Bad mistake I put a burn between the crystals -_-.
 
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Super helpful. You really seem to know your stuff. I'd love to try my hand at it sometime, but by the time I have that kind of time and money yellows will probably be a dime a dozen. Can't wait for that day, still, i'd like to make my own DPSS sometime
 




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