This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DLP6500FLQ: Request for Technical Assistance - DMD Module V-6501 Distortion Issue

Part Number: DLP6500FLQ
Other Parts Discussed in Thread: DLP6500FYE

Dear Sir/Madam,

I hope this message finds you well. I am reaching out to request your assistance with an issue I am experiencing related to the DMD module V-6501, purchased from Vialux.

Upon using the DMD chip (DLP6500FLQ, Type A DMD) under an fs laser source with a repetition rate of 1kHz, I noticed a distinct alteration in the DMD window. Specifically, the window appears less transparent, exhibiting a round shape that shifts and quivers every few seconds, resulting in flickering and significant distortion of the output light. Intriguingly, this effect is reversible; once the laser is off, the DMD window regains its transparency and flatness.

The problem seems to surface when the laser power is around 200mW or above, with the laser beam size approximately 1cm. Reducing the laser power alleviates the effect but does not completely eliminate it. Notably, this issue does not appear to be linked to the DMD pattern.

For context, we previously utilized other DMD 6500 modules (DLP6500, chip type of DLP6500FYE) from TI and did not encounter this issue, even at a laser power of up to 3W. I noticed from the technical data that the window thickness differs between the two modules (3mm for Type A DMD and 1mm for DLP6500FYE), and they utilize different types of glass (Corning 7056 for V-6501 and Corning Eagle XG for DLP6500FYE).

Despite studying the thermal evaluation data from TI, the temperature increase seems to remain under the threshold for my experimental condition.

Given the critical role this high-speed DMD module plays in our optical system, it is crucial for us to understand how to utilize it properly with the fs laser. I would greatly appreciate any insights, suggestions, or potential solutions you could provide. If necessary, I can furnish additional details for your reference.

Thank you so much for your attention to this matter. I eagerly anticipate your response.

  • Hello Wenqi,

    We are already in communication with ViALUX that makes this module.  With that said, there are a number of items of information that will be valuable to know.

    Are you operating the DLP6500FLQ in exactly the same way (optically) that you were operating the DLP6500 FYE.

    Please provide the following information so that our optics team can evaluate what might be going on:

    • Pulse energy 
    • Pulse duration
    • Spatial profile of the pulse - i.e is it Gaussian, or a flattop.
    • Is the 200 mW the time averaged power?
    • Wavelength of the laser

    We await your responses so that we can determine how to proceed.