• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 27 subscribers
  • Views 540 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

DMD absorption and illumination power density

Coppola Guillaume
Prodigy 10 points
Other Parts Discussed in Thread: DLP7000

Hello,

I am working with a 0.7 XGA 2xLVDS Type-A DMD for beam-shaping purpose in a cold atom physics experiment. The wavelengths I work with are near or above 800 nm.

The informations on maximal light input power I found on www.ti.com/lit/ds/symlink/dlp7000.pdf are : 25 W/cm^2 between 400 and 700 nm, 2 mW/cm^2 for wavelengths under 400 nm and 10 mW/cm^2 for wavelengths above 700 nm.

These values with a very big drop for non visible wavelength seem very strange, and it is very difficult to get an idea of the evolution of the DMD absorption with respect to the wavelength with only three data points.

- Do you confirm the values written above?
- If so, what is the element causing so much absorption above 700 nm?
- In what material are the mirrors made?
- Could you please provide a graph of the evolution of the DMD absorption with respect to the wavelength?
- If this graph doesn't exist, could you at least provide the theoretical absorption of the DMD around 800 nm?

I thank you in advance for your response.
Best regards,

Guillaume Coppola
Laboratoire Kastler Brossel

  • 0
    TI__Expert 6370 points

    Hello Guillaume,

    First, I apologize about the delay, I moved your conversation - we will be better able to address it in this section - and welcome to the E2E community! Now to answer your questions

    1) Yes, I can confirm that the datasheet specifies 10 mw/cm^2 for wavelengths above 700

    2) The restriction above 700 is caused in large part by the AR coating on the window of the DMD. This window is optimized for the visible range.

    3/4/5) The mirrors are (basically) made of aluminum and their reflectivity very closely follows that of bulk aluminum, if you would like to reference a graph of their reflectivity. For information on wavelength transmittance considerations for DMD windows (including graphs), see this application note: http://www.ti.com/lit/dlpa031

    Please let me know if you have any other questions!

    Best regards,

    Trevor