DLP651NE: DMD

Ok this is how you go to get the fill factor: do on-state and adjust the gap and size to get same pitch  but put micromirrors at +12 degree and incident beam at 24 degree as follows:

Hello Babak,

Thank you for reaching out on E2E, we are working with the team to answer your questions.

Best,

Aaron

Guys any update? Appreciate any input.

Hi Aaron... Kind follow up. Any update on answer to my questions. Appreciate your input. I am waiting for answer for my questions above

Hi Aaron,
Thank you for your responses. You answered all my questions. Except there is discrepancy between size 0.5um gap in flat-state and fill factor of 94% considering 7.6um pitch, 100% mirror reflectivity and on-state scenario. With this arrangement, I will get %93.377 ~%93.4 and not 94% accuracy. I am kindly being such a stickler as the gap size is effective in diffraction modeling losses for us. We are aware of tolerance +/-1 degree on mirror tilt. But that does not affect the tolerance in fill factor or gap.

- Could you please either discuss with your colleges the 94% accuracy tolerance or, confirm the 0.5um gap. Please do not close the case as I will be using a 7000X microscope to measure the gap directly to verify. I trust your input on 0.5um or what you re-find/re-confirm on exact size of the gap. I will be going to verify this by next Thursday.

- Additionally we want to know what the size of pivot hole in middle of mirror is. We need to model it to see how much light we are losing. 
- Is middle pivot hole being all scattered/lost light? Thanks for answering this last question too.

Thank you.

Babak

Hello Babak,

We utilize 26 degrees in our modeling and this is why we show a 94% fill factor. The calculations of fill factor will rarely match exactly with the actual performance of your system, each part has many variables that cannot be controlled in production. This can already be seen in the +/- 1 degree tilt angle.

You can measure the gap visually if you would like. 

I will have to go back with the team to confirm the pivot hole size.

Best,

Aaron

Thank you, Aaron,
I understand.
Thanks for asking about the pivot hole
Could you please also find out the micro mirror thicknesses as I am modeling diffraction pattern using zemax Lumerical software. If you can guess the reflectivity of micromirror sides (top is known), I appreciate it too. 
then we can close this case.
thanks
Babak

Hello Babak,

Could you please advise the extent of the effort of modeling?

The reflectivity of the micromirror sides is the same as the top, I will follow up with the team about the others.

Best,

Aaron

Thank you for reflectivity....
I will be doing a full diffraction model using Lumerical connected to zemax. We are losing lots of power out of DMD and we must find out why. It is not a matter of efficiency for us. It is a matter of heat management in a small compartment which leads to mechanical tolerance swing and light loss at target.
knowing the thickness helps. The pivot hole can help or be adjusted as % reflection from surface. We are so close to plug these realistic dimensions into my model and go from there. I guessed thickness to be half the gap based on my optical microscope and SEM photos of DMD floating on web googling it. but I prefer to have correct numbers than guess and estimate. Thanks so much for all your support. I appreciate it. 
Babak

Hello Babak,

The team would like to take this discussion off of the public forum here and hold a quick meeting with you. Our members have experience with this modeling strategy and we'd like to understand more how to help.

Thank you for the questions!

Aaron