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Thread: Best NLO for SHG of 946nm?

  1. #1
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    Default Best NLO for SHG of 946nm?

    Hi everyone,
    I'm thinking about starting a bit of a challenging project. I want to try to build a 473nm laser from scratch. I realize this wont be a 'super laser' or anything, but even if I can get 1mW of 473 I'd be satisfied. Most likely, this laser wont be used for anything, but is more of just a fun experiment and project to work on for a while.

    YES I realize this will be a tough project and yes I realize it is more than likely that I will never see any blue out of the laser without hours and hours of alignment and tinkering, but I still want to see what I can come up with.

    That being said, I'm wondering which NLO I should use for creating 473nm light. I guess I'm wanting to know which would be the easiest and most 'forgiving' to work with. The two I hear of most often are LBO and BBO.

    Also I'm wondering what kind of pump may be the easiest to work with. Should I just use a c-mount and try to focus the direct output into the yag or should I try a fiber coupled unit?

    Any thoughts would be appreciated.

    Thanks!!

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    Wow ! I have competition.....I have done it....lot of time.....and experimenting. But when you see the beam.....that's when all is OK. I would strongly suggest LBO. BiBo is great if you can get the temp to hold within .1 deg. Any more sway in the temp from here and the walkoff angle will change up to 3 deg. plus it is only good for a little over 200mw from what I have read. Be sure your Yag is coated for for the 1319 and 1064 bands on S1. Do NOT buy a "kit" off e-bay. Some one said that this set I have came from there.NOT. I have direct access to the manu from the same company that CNI and a lot of other laser manu's get them from. They are NOT Casix either. Do your research on Sam's faq until you reach the end of all you can find there....not much on the 473 stuff..do a study of resonator designs and setups..then give me a call.
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

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    I guess finding casually an AR-coated 1319nm,1064nm Nd:YAG material will be hard. I'm planning same experiment but using a slanted rod (brewster cut). However the cut angle is for 1.06um, I hope to run it without AR coating at 946nm. The next problem is buying mirrors ... AR@1064, 1319, HR@946 with longer that 50mm radius, maybe flat.
    For the SHG I'm planning to use the LBO from China set (2x2x10mm)
    Piotr.K

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    It may prove rather hard to get the 946nm line out of that xtal...the brewster cut is killing it. It would be better to get external cavity mirrors and facet the brewster away. This would allow ........

    HR S1 Flat
    946,473nm ,HT 1319,1064,808.
    S2 AR 946 , 473nm

    OC Plano concave
    Roc of 50 to 100
    S1 HR 946 HT 473nm
    S2 AR 473nm
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

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    Default Yag and LBO still the best for 473?

    a couple of years after and with new crystals coming up. i'd like to ask...


    is the yvo4 better than yag for this application? is BiBo still unsuitable and one should stick with LBO?


    and the thing nagging me the most: Anything appearing for SHG of 1270nm or any similar red? I'd even consider THG or anything to get DPSS red. Which NLO for this?

  6. #6
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    and the thing nagging me the most: Anything appearing for SHG of 1270nm or any similar red? I'd even consider THG or anything to get DPSS red. Which NLO for this?[/QUOTE]


    ND:YAG is best for 473, but you can do better with the THG to the 453 using vandate.

    As for the other lines in the F1 manifold, if its easy, the Chinese laser companies do it. Go look at the relative gains for each line, you'll be shocked how low they are compared to 1064. 1121 is about the longest line other then the 13XX stuff that has any gain.
    I have a doubling crystal for 661. It sets on the shelf.

    Before you buy any crystal, download SNLO freeware and check what the vendor tells you Phi and Theta are. I've gotten burned before, getting remarked crystals that do not work at a given wavelength.

    Steve

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    Thumbs up

    thanks a lot for the info steve
    looks like i have some studying to do. definately cheaper than actually buying and trying with NLOs

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    Has anyone else looked into using Yag for a big red? Start off with a standard end pumped 808nm rod and collimation system. Using .04% doped ND:Yag in a rod form, HR and OC coated for the 1319 nm band, then a waveplate to remove anything that spilled over the OC outside of the 1319 band. Then the beam would enter a LBO substrate crystal for a SHG frequency of 659nm employing an OC of near ROC-50mm. This will work on paper....and should in reality. This is the easiest way I have found to get at real red power without building thin disc lasers which are not very stable at extreme temps and power levels...though very scalable. Besides the complexity of the optics to build a thin disc setup alignment will be a royal pain due to thermal expansion rates. Any one want to help me find some optics? I have looked at building this more than I will admit. Should be good for near 20-25% eff. Plus the added bonus of a killer beam profile....only downside is DPSS lag time. What do you think about it?
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

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    I actually looked into doing the 1121 line for yellow with lamp pumped, to the point of having my xtal math confirmed and quoting the crystals.

    I have been in the room with a red modded KTP532

    I gave a set of flashlamp pumped pulsed 13xx line optics to a friend. He has offered them back.

    I bought the red KTP crystal, medical surplus, and confirmed the coatings on a spectrometer.

    So sorta, just not diode pumped.

    Steve

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    Quote Originally Posted by mixedgas View Post
    I have been in the room with a red modded KTP532
    Was this using Nd:YAG for 1319nm and LBO for 659nm? Do you have any clue of the efficiency (or power output) that was achieved? This is an interesting modification that I have modeled before. Unfortunately 1319nm is a weak transition in Nd:YAG to begin with, SHG efficiency in LBO is worse than in KTP, and the perceived brightness of 659nm is much lower than 532nm. However, I would still be very interested to speak with anyone who has actually done this.

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