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Thread: "unknown" YVO4 crystal

  1. #1
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    Default "unknown" YVO4 crystal

    Hi to all!

    i have this brand new YVO4 crystal... I know it was made for some Spectra Physics - JDSU laser. I also know that it has all necessary coatings for 532 (if coupled with an appropriate ktp). I know that the doping level is 1,2% (which is kind of strange to me given the dimensions of the crystal which are 4mmx4mm by 8mm long)

    this is mounted on some sort of mount which is 5cm round and 5cm high, it has an NTC embeded and two water cooling sockets at the bottom

    so, anybody got any idea where this was supposed to be used? the crystal is the middle of the three circles shown below









    "its called character briggs..."

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    oh well, i thought that watercooling and yvo4 could make this easier to identify.

    it looks very similar to the ones below, and some of them are used in a "spectra physics millenia" 532, the head uses a closed loop chiller system, that's why the inlets are for

    http://cgi.ebay.com/ND-YVO4-Vanadate...#ht_500wt_1156

    http://cgi.ebay.com/ND-YVO4-Vanadate...#ht_500wt_1156

    http://cgi.ebay.com/Nd-YVO4-Crystal-...#ht_3374wt_905

    any ideas if i am right? and any suggestions of a matching ktp? or pump diode power?

    i think 1,5% doping is a bit to high, for me to just shine 10w of 808 on the rock
    "its called character briggs..."

  3. #3
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    I don't know much about end-pumped vanadate in regards to doping levels, etc. but I believe Millennia are end-pumped with somewhere around 40-80W of 808. The laser is pumped by "Prolite" FC diodes, which show up on Ebay occasionally (the shiny FCBars with armored cables).
    You'll probably want a >7mm KTP for it - 3x3x8 would be a good size. An LBO would probably work too. Either way, MAKE SURE IT IS CUT FOR SHG. There's lots of THG/OPO stuff on Ebay - not phase-matched for the 1064->532 conversion!
    It'll be mildly expensive (a good price for a 40W FCBar on Ebay is somewhere in the vicinity of $150), the crystals are a pain in the ass to find, and the optics are even harder to find as you'll need a matched set for green, but it'll make for a nice project
    And oh, I recommend Koechner's "Solid State Laser Engineering". Great book.

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    hey, thanks for the feedback!!
    "its called character briggs..."

  5. #5
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    Most older Millis are pumped by two fiber launched pump diodes from opposite directions.

    The vandate is cut for about a 35'-45' (guessing) angle of incidence for the lasing light, as its a "X" or crossed cavity.

    Its been three years since I have had my hands on one, so memory is sketchy.

    Steve

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    thanks for the input steve!
    wow.. x cavity... so i've got more than i can chew with this one. def out of my league (which is lower than junior high school league). the most i could manage, would be to pump it with a low power 808, run it through a ktp and see what happens

    does anybody have any sort of schematics for such a cavity? or any pics of a millenium internals?

    or better still, does anybody have a use for this so i can send it over?
    "its called character briggs..."

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    Default I have one of these

    Hello,

    I have one of these crystals or at least very similar. Mine is square actually but the mount is quite the same.

    I read this post with interest as I don't know much about this crystal. I would like to produce 1064nm output. I am more interested in IR than visible since this would be to try some LIDAR applications and IR has much better penetration in the atmosphere than green.

    However I am wondering how to put things it practice as I just have the crystal in its mount and a pump diode...
    - does it need the HR and OC mirrors or are the surfaces of the crystal already coated for that purpose?
    - someone said there is an angle of attack for pumping that is not on the axis of the crystal (35 or 45 degrees apart) because it comes from an X cavity. How is this supposed to work?
    - for the moment I have a 1.2W max 808nm pump diode, is it sufficient? I would also like to try to pulse the crystal by modulating the pump diode with a sawtooth waveform around the lasing threshold of the crystal. This is supposed to work and give decent pulses.

    Thank you and best regards,
    Edouard.

  8. #8
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    Just because it looks thr same doesn't mean its the same sort of crystal; many laser firms used this sort of crystal in a similar mount. Can we have more info? Where you got it, etc? Did the seller tell you it was a Millenia crystal.

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    hey edouard, happy that my post was of interest to someone. not sure i can provide much help though.

    i sent bwang all the info i had on this one, but we could not get to a conclusion. so best of luck with your search. in any case, feel free to use this thread and post pics of your own crystal in case something interesting turns up
    "its called character briggs..."

  10. #10
    mixedgas's Avatar
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    Edouard,

    The sawtooth trick works for very short rods, there are other ways, some not too expensive. Lets see a picture and dimensions of yours, from that, and a guess at the ND concentration, we can calculate your lasing threshold. and perhaps what optics you need.

    1064 is easy to obtain.

    What kind of LIDAR do you wish to do, what distances?

    Steve

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