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Thread: Spectrometer for measuring 808nm diode efficiency and wavelength shifting.

  1. #1
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    Question Spectrometer for measuring 808nm diode efficiency and wavelength shifting.

    I looked up if there were a few threads related to this question but was wondering if anyone has ever tried one of those lower cost spectrometers.

    The application where I want to use it is measure the wavelength shift and normal wavelength of a listed 808nm diode to see how much of the light is actually in or around 808nm. I hear stories of ebay sellers selling 808nm diodes that aren't actually 808nm so a lot of the energy available for say a DPSS blue or green is lost because of it, not just that but off course there is also a shift in wavelength when overdriving those diodes or when cooling them more significantly. I am aware DPSS is mostly on it's way out but I still see value in the knowledge myself of building a 532nm sometime for fun and have the proper eye protection to do so.

    I have little applications where I actually want to use an spectrometer so I cannot justify the cost of a high-end one but was wondering if the lower cost spectrometers do the job once calibrated using a fluorescent light and using some lasers of various wavelengths.

    I was mostly looking at this mini usb spectrometer: (https://www.ebay.com/itm/Mini-USB-Sp...YAAOSw4GVYMJIf) which may do the job once calibrated using a fluorescent light and some lasers to get it sort of within a nm or so?
    I was looking into surplus units but wasn't lucky to find those. I am aware that you can make your own by making a slit and using a prism or grating combined with a camera with the IR filter taken out but a pre-made product that will likely be on the same level might be an easier solution.

    Would love to hear if it's even worthwhile looking at. I was really wondering if there is something out there that just does what I need for this particular application.

  2. #2
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    I have cheap idea. 808nm dichro filter. If you can put it in the beam it should pass most of the beam if it’s 808nm. I think 2nm wide is common.

    https://www.semrock.com/FilterDetail...=LL01-808-12.5

    I’m sure cheaper can be found. Spectrophotometer might be cheaper than that filter. I’m betting you can find one by taking a cheap green laser pointer apart.

    To calibrate. Use a hene tube. Lots of known lines.

  3. #3
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    Quote Originally Posted by kecked View Post
    I have cheap idea. 808nm dichro filter. If you can put it in the beam it should pass most of the beam if it’s 808nm. I think 2nm wide is common.

    https://www.semrock.com/FilterDetail...=LL01-808-12.5

    I’m sure cheaper can be found. Spectrophotometer might be cheaper than that filter. I’m betting you can find one by taking a cheap green laser pointer apart.

    To calibrate. Use a hene tube. Lots of known lines.
    dont have a hene but do have an argon/krypton. Should be the same deal.

  4. #4
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    Should work. Just look at those specs. If they work amazing deal.not sure the resolution but at those prices why not try.

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    Quote Originally Posted by kecked View Post
    Should work. Just look at those specs. If they work amazing deal.not sure the resolution but at those prices why not try.
    it says the accuracy is less then 3nm.. im not sure if that better calibration reduces this.. i messaged them asking about the different slit sizes and they offer 500 lines and 1000 lines.. maybe they can advice based on my application.

  6. #6
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    Bought one of those spectrometers a year ago... Haven't used
    it yet.

    Lousy build quality. The Labels were applied crooked.
    It uses a slit held in place with scotch tape...
    It has a plastic eBay Diffraction Grating in font of a USB Board
    Camera. Nothing else in the Box.

    Jerry
    See the LaserBee II and all other LaserBee LPM products here....
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  7. #7
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    Thank you. Saved me bothering.

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