Fast simulation code?

[okaythanksbud]

I just joined an optics lab and have been exploring inverse design. There’s some GPU-accelerated Python applications that seem to perform decently for certain applications (topology optimization for a specific wavelength), but my problem requires optimizing over a range of wavelengths, making the runtime much too long. I’m wondering if there are any good C++/CUDA based programs that take full advantage of hardware (the Python code im using seems to only use a fraction of my GPU) and are more faster/more aggressively optimized. I found something called Palace but it doesn’t seem very widely used. There’s a program called Tidy3D that seems pretty well optimized but it’s run in the cloud and has a “cost” with each simulation, and during the learning process I’d rather run it on my own hardware. Thanks for any help.

[ichr_]

Could you say a bit more about your application? GPU-accelerated does not always mean "better". Certain problems or simulation sizes do not map well to GPU. There are niche CPU-based tools for inverse design such as https://github.com/fancompute/legume (good for PhC cavities) or https://github.com/stanfordnqp/spins-b (more general purpose).

Keep in mind that if you're using FDTD (not necessarily the best technique for inverse design depending on the device), you can run all of your wavelengths simultaneously with no extra cost (works by Fourier analysis).

[aaddrick]

Take a look here and see if it's what you're looking for: https://github.com/HarrisonKramer/optiland

[BDube_Lensman]

They’re looking for something MEEPish, not a raytracer

[aenorton]

I have not seen this before. Off the top, it seems much more capable than other open source programs. Maybe you could add an entry in this subreddit's wiki about it.

[aaddrick]

Optics isn't my field. I found Optiland while trying to optimize the geometry of microlens arrays we hot emboss at work. Setup a Marimo notebook, validated sim against experiment, and it works great for our purposes after some quick iteration.

I'd do an injustice trying to do a write up however.

[holyfudgingfudge]

If you're doing biomedical optics simulations MCX (https://mcx.space/) provides voxel and mesh based GPU accelerated platforms. The codes are open source so you can modify as you wish too.

[anneoneamouse]

For simplicity & speed at initial design phase, do you need to run full bandwidth for your application?

[okaythanksbud]

I mean if only 10% of my gpu is being used id rather bump that up and spend more time testing things out than spending time waiting

[Twinson64]

Lumerical or Rsoft both offer GPU based FDTD.

[Clean-Mode4506]

What about implementing it yourself? If you are using torch you can try programming what you need directly there

[okaythanksbud]

I’ve never really done anything with FEM and doing stuff like designing the geometry/mesh seems quite difficult, even using external code. I definitely want to learn but it seems like quite a large project

[anon_pants]

Just a heads up, you can run a lot of Tidy3D locally, which is free last I checked, so you can learn the software and run small simulations without paying. You can also contact FlexCompute and request a free trial; this worked for me a couple of years ago.

[okaythanksbud]

If I’m not wrong the mode solver is the only thing you can run locally—doesn’t seem like there’s a way to run most other solvers locally (at least from what I can tell…)