Building your own 473nm laser from 808 using an LBO

[3ricj]

Hi there folks,

First post.

I've been researching the feasibility of building DIY style a high-powered 473nm laser.

It would seem that you can pump a ND:YAG and an LBO set using an 808 laser to get an nice 473nm output.

There exists some (somewhat cheap) crystals for doing this:

http://cgi.ebay.com/ND-YAG-and-LBO-s...QQcmdZViewItem

Questions: Has anyone done this on a DIY scale? What sort of input power do you expect these sorts of crystals and lenses can handle? I assume active cooling via a TEC will be required... and that the mounts for these little crystals will need to be effective heatsinks. I'm only expecting 10% effiency out of this system, so I'd like to pump it with as much power as I can. Something on the order of 1-2 watts, which is really cheap using 808 lasers.

How does one safely & accurately focus these parts? Do they need to be positioned within one wavelength or something?

Assuming I make this work, I will publish detailed information on how to build one of these.

Cheers,
-3ricj
HackerbotLabs

[keeperx]

MechEng3 is your best bet in that department..

[allthatwhichis]

Greetings! Welcome to the forum... Start your reading... here:

http://www.photonlexicon.com/forums/...ead.php?t=5628

http://www.photonlexicon.com/forums/...ead.php?t=5685

http://www.photonlexicon.com/forums/...ead.php?t=6695

http://www.photonlexicon.com/forums/...ead.php?t=6941

Good luck!

[mixedgas]

Start with a two crystal green to get a idea of what you need to do.
High power home made green is a better idea.

Blue is not easy, it requires really good temperature controls and good machining. Temperature control is more about good mechanical engineering then electrical engineering. It has been my experience that low cost foreign crystals are just not a good idea for blue. It has also been my experience that good blue often does not come from a simple 4 element linear cavity.

mecheng will possibly jump in here, but this is not one you want to attempt unless you have easy milling machine access.

BOB when he ran NML told me he needed to hold .001" C at the doubling crystal for blue, now that was 10 years ago and things in the pump diode department have improved a great bit, but it still takes some really good engineering.

If I had my choice between building a glass medium sized hene tube from scratch vs a blue DPSS, I'd take the Hene.

Steve

[3ricj]

Greetings! Welcome to the forum... Start your reading... here:

Thanks for the info... looks pretty hard core.. but from reviewing those posts it's not clear to me that anybody has gotten it to work yet. heh. Also, the costs quickly exceed the cost just to purchase one... plus endless amounts of time. This might not be a good direction for me. heh.

Anyway, thanks so much for the info, I will keep researching. I just got first light on my galvo... only green is online now, but have a bunch of parts in the mail to give me a 405/650/532 "RGV" setup. None of my drivers are 'analog', so I'm going to have to build my own drivers for the lasers I have. This will also help with color balance, I assume.

Has anyone tried to use a webcam to assist with color calibration? Seems like it might be doable. ...

[3ricj]

mecheng will possibly jump in here, but this is not one you want to attempt unless you have easy milling machine access.

I have a mill/lathe/laser cutter/3d printer.. so that's not a problem. Most of these parts will need to be machined vs. 3d printed, which makes me sad.

[MechEng3]

Dont give up so easy...but I hate to be the one to let you know that you will be doing very well to get any more than 3% conversion. I have a set of Xtals here with a 3 watt pump...just under 100mw a little overdriven in the amperage. The TECs need to be close...a 10 Ohm thermistor will take care of sensing...one big mistake I made was not having the thermistor almost touching the LBO. I have this one torn down for a higher power pump diode and a different set up for beam correction lenses. I am convinced that cylindrical lenses are the way to go here....after a FAC lens of course. It just works and is adjustable. I would try and get at 150um pump spot for that YAG if you get them. As for the TEC controllers....old Lasever driver for the TEC on the diode with a Flexmod driver inside....a Wavelength Electronics HTC-1500 controls LBO temps. Most of the hydrothermal LBO will lase at room temps....but really do their thing when the right temp is reached...depending on the cut usually around 29.6 deg C. It can be done.....there is knack to getting the optics close befor installing the SHG xtal. Please do some reading on Sam's laser FAQ. Then get into a good laser theory or design book. If you have the mill you can get the mounts and optics holders made easy. Yeah you can buy one for a little more than it will cost you....but the learning experience....priceless.

[Laser Ben]

I have a mill/lathe/laser cutter/3d printer.. so that's not a problem. Most of these parts will need to be machined vs. 3d printed, which makes me sad.

You can 3D print a full prototype if you would like!

[Laser Zone]

So what do they use for a 10 watt blue dpss .

[mixedgas]

So what do the use for a 10 watt blue dpss .

the only commercial high power solid state blues that are not diode array, are usually femtosecond systems, ie the Zeiss/Jena pulsed systems, although OPSL are coming on strong but not quite up there yet. These systems cost 6 or 7 figures.

blue is still a pain in the neck any way you go.

Steve