Hello ​​​​​​​suhwan,

Did you find out anything related to your question, I am also interested in answer to your question

Hi Suhwan and Önder,

Just to chime in -- Suhwan, other than the operands you mentioned, are you also using something like the Optimization Wizard to generate merit functions? I would imagine that using only the operands you’ve defined in the merit function may give the optimization some issues, especially if your design is in a space where the MTFS/T operands may be in a “noisy range,” where there is no clear direction for your variables to change toward to get an overall better result on those operands. Typically operands like the ones you listed are included in a merit function which also has something from the Optimization Wizard. In addition, the stage you are at in the design can inform what criterion you evalute (early stages probably want to look at just RMS spot size until it behaves well, then you can turn to RMS wavefront and eventually MTF).

In fact, we do have the Contrast Optimization setting which is related to optimizing on MTF, but it doesn’t perform an MTF computation directly. Rather, it evaluates some phase difference in your pupil based on your desired spatial frequency you’re interested in controlling. This is because generally something like phase/spot size play more nicely in optimization as opposed to just MTF operands.

Lastly, I am sure that adequate sampling of your pupil/field of view is crucial, especially if you’re dealing with compact imaging systems like mobile phone lenses. If you’re dealing with something like high order aspheres, you’ll want to be sure that the Optimization Wizard samples the pupil at a high enough resolution. For instance, we have the following comments in our Help File at “The Optimize Tab (sequential ui mode) > Automatic Optimization Group > Optimization Wizard > Pupil Integration Settings > Gaussian Quadrature ”

Below are a couple of other articles that may interest you regarding optimization:

• Optimizing for MTF performance using Contrast Optimization
• Designing for as-built performance with High-Yield Optimization

Let us know if you have any more questions here!

Thanks for your reply.
Currently I do not directly control the MTF through the operand MTFT/S. When MTFT/S is used, the performance is often worse. So, by changing the weight of SPOT SIZE, WAVEFRONT and the aberration operand, I am trying to get the desired target value.

Hi Suhwan,

Thanks for your added post here, and apologies for the delay in my getting back to you on this. It sounds like you’ve been using a combination of operands to get closer to your desired performance. For MTFS/T, I do think those values are best suited for either monitoring the performance at certain spatial frequencies or when you are very close to a final design. As far as other operands are concerned, I think we have discussed the most pertinent ones in depth, but adjusting the weights is another factor I hadn’t brought up before. I think typically if the spot performance is good enough, you can usually replace those operands with wavefront operands to be your new metric of image quality (as better wavefront performance would generally indicate improved MTF performance), but I suppose you could always adjust the weights so that the spot operands are less impactful to the optimization but still considered at some level.

Let us know if you have any more questions, and thanks again for your post!