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DLP650LNIR: AR Coating Thickness

Jejomar Ildefonso
Expert 8590 points
Part Number: DLP650LNIR
Other Parts Discussed in Thread: DLP4500NIR, DLPC350

Hi Team,

Our customer is considering to use the DLP650LNIR in the 2500nm wavelength. They are aware that the DMD was only specified at 2000nm and would like to simulate the transmission tradeoffs at 2500nm. They've noted that the visible coatings on Corning 7056 show ~70% transmission - this kind of transmission is acceptable in their application so they're assuming the DLP650LNIR would also work fine. Would it be possible to get the layer thicknesses of the AR coating for them to simulate the behavior beyond 2000nm?

Thanks!


Kind Regards,

Jejomar

  • 0
    TI__Mastermind 43135 points

    Jejomar,

    I will have to consult with the DMD team to see if we can provide this information or whether it is considered proprietary.

    However, in my estimation the diffraction efficiency at 2500 nm may start to reduce the efficiency also.

    Fizix

  • 0 in reply to Fizix
    Prodigy 30 points

    Hello Fizix,

    We are now considering DLP4500NIR with DLPC350, since this has a more suitable AR coating with transmission of 93% up to 2500 nm. Thus, I would like to change the question to what are the layer thicknesses of DLP4500NIR, so that I could simulate its behaviour beyond 2500 nm.

    I am also curious about the reduced diffraction efficiency at these wavelengths. Could you elaborate on this? In particular, how much do you estimate that there is a reduction in the efficiency as we move to these longer wavelengths (neglecting the window transmission losses), e.g. up to ~2800 nm?

    Best regards,

    Samu

  • 0 in reply to user6413458
    TI__Mastermind 43135 points

    Hello again Samu,

    I am still trying to get an answer as to whether this is proprietary information.

    Just for clarification, you are asking only for the DLP4500NIR AR coating thickness, not for the coating stackup.  Is that correct?

    Fizix

  • 0 in reply to Fizix
    Prodigy 30 points

    Hello Fizix,

    Whatever data you can share, preferably the thicknesses and materials of each individual layer. If that is not possible, then the materials used, the number of stacks, and/or the thickness of the entire AR coating.

    Samu

  • 0 in reply to user6413458
    TI__Mastermind 43135 points

    Hello again Samu,

    Again, sorry for the longer than usual wait on this.  We had to review our agreement with the manufacturer.  

    Unfortunately upon review, any information about the AR coating, including thickness, etc. . . is considered proprietary and cannot be shared!

    There is nothing that prevents using some kind of measurement to determine the thickness, but TI cannot share information about the coating other than the window transmittance values already published on ti.com

    Fizix

  • 0 in reply to Fizix
    Prodigy 30 points

    Hi Fizix,

    That is unfortunate. We are going for DLP4500NIR at any case, since its AR coating is as close to our operating wavelength (2.5 µm - 2.6 µm) as we can get with TIs DMDs. Obviously not expecting 100% optimal performance, but hopefully it will not prove disastrous due to e.g. extremely low diffraction efficiency.

    Would be nice to get data for +2.5 µm wavelengths in the future. Of course 2.5 µm - 3 µm is a difficult wavelength range to work with due to strong H2O and CO2 absorption bands.

    Samu

  • 0 in reply to user6413458
    TI__Mastermind 43135 points

    Samu,

    I agree it is disappointing.

    Please let us know what you end up measuring in efficiency for your operation.

    Fizix