Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Optimization with the Eigenfrequency Study Step

Please login with a confirmed email address before reporting spam

I am trying to perform an optimization within the Eigenfrequency study step to optimize the Q/V (Quality factor/mode volume) ratio for a specific mode of a Photonic Crystal.

It seems to run successfully for gradient-free optimization algorithms like the Nelder-Mead Method but I would like to run an optimization for multiple control variables and a shape optimization (for the shape of the holes in the crystal) using the free shape domain (and free shape boundary).

When I change the optimization algorithm to a derivative-based one, like MMA, I cannot select the 'eigenfrequency' study step inside the 'evaluate for' parts of the optimization study (it just says 'none'). Additionally, when using free shape domain/free shape boundary in a shape optimization, the gradient-free solvers do not seem to be compatible with this.

The questions I have are:

1) Is the Eigenfrequency Study step not compatible with derivative-based Optimization algorithms?

2) Is shape optimization, with the free shape domain/free shape boundary, only compatible with derivative based solvers?

3) Is there/are there ways to perform the shape optimization (using free shape domain etc) and gradient based optimization of the Q/V ratio (which requires the eigenfrequency) in COMSOL?

Many thanks,

Angus


0 Replies Last Post 06.04.2021, 09:57 GMT-4
COMSOL Moderator

Hello Angus C

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.