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Thread: Super-continuum fiber laser

  1. #21
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    Jim--they say that these fibre lasers are very efficient and due to the amount of surface area, heat dissipation is not a problem. I believe I read that the lasing takes place in the very center of the fibre.

    Steve

  2. #22
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    Quote Originally Posted by yaddatrance View Post
    I believe retail on the tapered fiber is only about $3-5k... If you add a nice surplus pump system for $20k, then you could build this (to professional specs) at home for $25k-ish... If you're not picky about the output, then I'd guess homebuilt for $10k...
    Yadda, what do you know about these things? Do you know how they work?

  3. #23
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    Hi guys,

    A standard pump laser would be a Coherent Mira at 800nm w/ 50fs pumping.

    The raw fiber, while attractively priced would be somewhat painful to align.
    (Think walking mirrors on a gas laser, only this time through fiber...)
    There are companies which make premade "tubes" w/ the appropriate mirrors
    aligned and installed.

    One caveat is that you'll be looking at using a faraday isolator off the
    pump laser (like the 1/4 plate splitter, but more useful and more expensive)

    I can draw more useful information if you want...

  4. #24
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    Cool stuff!!

    "how would you color modulate it?

    I would guess you could use a standard pcaom. The driver would have to be different. you would have to make a frequency agile single channel pcaom driver, and a circuit that could convert from discrete RGB values to a linear true white spectrum.

    oooh! It gives me goose bumps thinking about it. Imagine color mod from uv to nir!!

    chad

  5. #25
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    Thanks for the info Yadda.
    First off, I don't have that kind of money for a Ti:sapphire laser
    Second, I don't guess a bare 808nm diode work for this application?(cant pulse it fast enough and wrong wavelength?)
    How do you reckon Sumita does it with a blue laser? You think it's a femtosecond pulsed? I did find this>
    FEMTOWHITE 800 - nonlinear supercontinuum device

    The FEMTOWHITE 800 is a polarization-maintaning supercontinuum device for use with 800 nm femtosecond lasers. It contains 12 cm highly nonlinear, polarization-maintaning photonic crystal fiber with zero dispersion at 750 nm. The fiber ends are sealed and mounted in quartz ferrules, which are PM aligned to a line on the end of the device. The nonlinear fiber is mounted in a robust aluminum housing which can be easily mounted on a translation stage. The device features build-in beam expansion at the end facets, facilitating easy coupling and a high damage threshold.

    The supercontinuum device has an outer diameter of 25 mm (~1 inch), and is compatible with opto mechanics from e.g. Newport and Thorlabs.
    Advantages

    - Optimized for 800-nm-range femtosecond pumping
    - Polarization maintaining
    - Zero dispersion at 750 nm
    - Sealed and cleanable end-facets
    - End-facet beam-expansion
    - Highly nonlinear photonic crystal fiber technology
    - Robust 25 mm (~1") aluminum housing
    - Compact: only 12 cm (4.7“) in length
    - Compatible with standard holders
    - Maintenance free

    Performance

    The FEMTOWHITE 800 is the equivalent to a nonlinear subassembly, and consequently, the performance of the device depends on the pump source. Below is shown a representative output spectrum from the PM fiber pumped by a 50 fs Coherent Mira laser at 800 nm.
    Recommended Setup

    Below is a schematic of the recommended setup for supercontinuum generation using the FEMTOWHITE 800. The fs pulses from the laser are launched through a Faraday isolator to avoid back reflections from the other optics and the FEMTOWHITE 800. For best performance (i.e. shortest pulses and highest peak power) it is recommended to use a prism compressor to compensate for the dispersion in the telescope optics and the microscope objective. As the FEMTOWHITE 800 is polarization-maintaining, polarization control should be used to align the pump light polarization to one of the major axis in the device. Rough alignment can be accomplished using the guide line engraved on the end-facet of the device. Fine-tuning should be done by monitoring the degree of polarization of the output from the FEMTOWHITE 800. The device can also be used with unpolarized pump sources at the expense of slightly less broadening and randomly polarized output. Coupling into the device is best realized with a 40X or 60X achromatic microscope objective.

    Datasheet

    Download datasheet for the FEMTOWHITE 800

  6. #26
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    ...and third
    Are all of these fiber lasers (white continuum or otherwise) pumped by fs lasers?
    Thanks Yadda
    Steve

  7. #27
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    This looks fun>
    Photonics Research | September 2006
    VECSEL Generates Watt-Level Blue-Green Output
    Intracavity second-harmonic generation produces 1.3 W at 488 nm.
    http://www.photonics.com/content/spe...rch/84253.aspx
    Attached Thumbnails Attached Thumbnails PRVESCEL_Fig1.jpg  

    Last edited by steve-o; 03-06-2007 at 05:08. Reason: added link

  8. #28
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    As soon as VECSELs become available, we got it made!
    Quote:
    Researchers in the UK and Finland have fabricated what they believe to be the first high-power vertical external cavity surface-emitting laser (VECSEL) to emit directly at visible wavelengths. (Optics Express 13 77)

    Red VECSEL

    The VECSEL emits continuous wave and according to the authors currently produces a maximum output power of 390 mW at 674 nm with an M2 of 1.05. However, the team believes that power scaling to in excess of 1W is possible in the near future. What’s more, the device was tunable by 10 nm around 674 nm.

  9. #29
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    Fiber laser progress thru the last few years:
    Attached Thumbnails Attached Thumbnails watt levels per year.jpg  


  10. #30
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    You could most certainly make a pump from an 808 diode, but you'd have to cool it quite a bit to drop the nm down... you're better off with a 798nm or similar and letting it run warm... diodes generally have no problems being pulsed. The only difficulty is measuring such small pulses, you would at the very least need a scope. Though I've seen successful (and scary) nails on a spinning platter used to provide "optimal" pumping of nitrogen lasers, which might work if you're feeling terribly ghetto... (Not that I'd recommend it)

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