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Thread: Laser Simulator?

  1. #1
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    Default Laser Simulator?

    Hello all!

    I am hoping that someone here can do better than Google, and get me really what I am looking for.

    I am making a fairly heavy request, but I know what I am looking for has to exist somewhere.

    I am looking for a software that will allow me to basically play in my own cavity/resonator sandbox.

    The ability to:
    Customize mirror RoC, customize reflectivity at chosen wavelengths (doesn't need to go to decimals), customize position on more than a straight linear plane (Z-Folds, bow-tie rings, etc).
    Test cavities with gain mediums and NLOs with my chosen properties (or preloaded works too).
    Custom input wavelength with geniune "life-like" interference with other optical properties of the cavities (gain mediums, NLOs, mirror reflectivity, etc).

    Basically, I want to open it up, and be able to build a cavity for 561nm, optimize it, and then do the same for 488nm.

    When you're working on a budget, you don't get to "plug-n-play" certain optics hoping they will work. Also, if I ever need something custom, this will help me optimize what I need for a later project.

    It also gives me brain food. I learn by DOING. I can remember almost EVERY simulation I've done since the faux-Mars landing I did in elementary. It's just how I am. This will be an amazing learning tool for me.



    I have seen a few of these around. Expensive software meant for universities and such. Though they generally come with massive packages for spot and beam characteristics, mode monitoring, and just other "modules" that I do not need. I basically need a frequency generation simulator. I've seen packages that have this, but I don't need the other 80% of the package. It's just clutter to me.

    If anyone can help me find me some good software to do what I need, please, let me know. I am very anxious to get clicking away in something like this.
    Only an electron wiggler like you would resonate at 30cm.

  2. #2
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    Default

    I won't be of much help, but I do remember a link for a programm called HNLO (?) circulating around here, maybe someone can point you to it?

    and then something like the usual google flood of irrelevant links https://www.google.gr/?gfe_rd=cr&ei=...avity+software
    "its called character briggs..."

  3. #3
    mixedgas's Avatar
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    SNLO for the crystal sanity check. PSST! for the cavity.

    PSST is a linear modeler, but you can insert rods (called a lens duct) to simulate the Vandate thermal lensing etc. You can mentally fold the cavity in PSST. What I mean by that, is that the fold has a minor impact at first. It mainly affects beam shape in a highly stable cavity.

    What you want to do are "ABCD" matrices for modeling the optics. Silfvast's book covers them. Other books cover them better. Using ABCDs is the hand method.

    Maybe ask the guys who sell LASCAD for a 30 day demo? Explain why you want it. Tell them you are considering a career in lasers, they might just help. Otherwise its 1/6th of a yearly salary for the basic program.

    Demand Scarcity applies to Laser Simulation code, there is little demand, so its expensive.

    UPDATE: LasCad has a restricted demo. I'd see how long before it times out before I download it. I'd still email them first.

    REFS:

    http://www.rp-photonics.com/abcd_matrix.html

    Folded Resonators are first covered in:

    H. Kogelnik and T. Li, “Laser beams and resonators”, Appl. Opt. 5 (10), 1550 (1966)

    This has come up before:
    http://www.photonlexicon.com/forums/...lator-software

    Weartronics is still around.....

    I did find one ABCD calculator/spreadsheet on line.

    Steve
    Last edited by mixedgas; 08-21-2014 at 06:07.
    Qui habet Christos, habet Vitam!
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    I have psst! and have fiddled with it a bit. A very nice program. The one thing it did not do was allow me to change reflectivity of mirrors/crystals at chosen wavelengths, and show what effect those changes had on the output.

    I have not heard of SNLO. I will look it up, hopefully it is free. I've only had a few hours of "play time" with PSST!, so I am still working out the kinks. Learned how to emulate a Z-fold using a lens to create two foci. Was not sure what the lens ducts did. I tried adding them, and trying a couple things, they never really had an effect on the cavity, so I brushed them aside as "useless". I will pry a bit deeper and see what I can find out. Most of my time was trying to find the most "complicated" cavity I could create. Managed to pull off a dual concave, 4 lens setup resulting in a very narrow waist for crystal pumping. About as far as I got.

    A did download a lot of apps/software that just turned into linear cavity testers. Most of which had awful GUIs. One even opened up new windows for item selection, properties, etc. half in one monitor, and half in the other (dual monitor setup here). Though, they did all have "ABCD" matrices. I had NO IDEA what that even was, or could be. I will deeper into that as well.

    I sent a couple emails. Found some AWESOME programs, but they all looked too good to be free. All request for a price, education software. The ones with price listed exceeded $1000 with only one or two exceptions. I looked into LASCAD, Cavity Cave (or something like that), Virtual Labs, Lab View, WinLase, and many more.

    I got a trial for VirtualLabs LightTrans trial. The brief description includes some neat stuff. I'd imagine that these websites would be more inclined to help an intellectual with a lust to learn. However, that being said, it's an ever changing world out there ...

    Thanks for the tips, I now have a few more tabs open. Hope to really get cookin tonight

    ~Reeber

    PS - Pardon the possibly incorrect use of effect/affect, it's been some day.
    Last edited by SoulFeast; 08-21-2014 at 12:46.
    Only an electron wiggler like you would resonate at 30cm.

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    Man, I really want to slide in some wise crack about a video projector here but I just can't come up with a good one.

  6. #6
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    A wise crack about a video projector??
    Only an electron wiggler like you would resonate at 30cm.

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    Yeah, whatever the crack may be, it will be a bright one!







    (Well brighter than a laser crack anyway. )

  8. #8
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    A big downside to all this is that LightTrans has a sort of user friendliness that makes Photoshop look like MS Paint...

    A billion new functions, and no idea what I am doing.

    On the upside, I have about 2000+ solid materials to make my laser mediums out of, on the downside, I can't find the right Yttrium. They have about a dozen different Yttriums, none are orthovanadate, or sluminum garnate.

    I did not expect this to be such a struggle.

    Also, SNLO is not working for an unknown reason. I'll play with it when I can.
    Only an electron wiggler like you would resonate at 30cm.

  9. #9
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    First calculate your gains and losses intracavity. The KTP crystal sucks power out of the system, it is a loss, for example. Then start playing with optics.
    Most designers of simple lasers try to make the pump spot size smaller then or equal to the desired mode volume of the laser.

    So if you want a 0.5 mm Green beam, you would aim for a 0.4 mm 808 nm spot size that has a long volume in the rod.

    Then the thermal lensing comes into play, and that is where you need the modeling software.

    If the laser was pulsed where the 55% green conversion is obtainable, you know you have a 55% loss intra-cavity that you know you need to overcome. In reality KTP in CW is probably going to be ~25-30%.

    Siflvast's book covers estimating your gains and losses, and I know you have a copy.

    Barkhousen's criteria for oscillation has to be met, which says gains must exceed total losses and you need positive feedback phase shift.

    I need to set up a FTP some how so you can have access to some YAG design PDfs. I cant post them publically, due to copyright.

    Steve
    Qui habet Christos, habet Vitam!
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    When I still could have...

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