July 7, 2023 at 3:13 pmAndy LiSubscriber
I have recently been working with Lumopt to design a 2D (FDTD) topology-optimized wavelength demultiplexer in silicon. However, I am noticing a significant difference in the performance of two simulated devices which should have identical performance.
The first is the output of Lumopt, as shown below. This device has been fully binarized (no index values between silicon and oxide).
This device has the transmission spectrum shown below:
However, this has the transmission spectrum shown below:
As you can see, the spectrum is blue shifted by about 20 nm. By changing the FDTD mesh settings to use a uniform 20nm mesh (which the original device was optimized for) and aligning the mesh exactly with the device, the blue shift is reduced but still exists at about 5 nm. I have an optical index monitor on the entire device which shows no difference between the two devices. In both cases, I am using 2D FDTD simulation with PML boundaries.
Thanks for any help you can provide.
July 7, 2023 at 6:51 pmGuilin SunAnsys Employee
Thank you for raising this question. As your test shows, results strongly depend on the mesh accuracy. and the geometry its self might have slight diference, as the GDS is represented by polygons. You may need to have the index data after simulation, and get their differece to see if the difference is exactly the same.
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- “Import optical generation” or “delta generation rate”?
- Why am I getting “process exited without calling finalize”, and how do I fix it?
- Using a license file on a new license server
- Ansys Insight: Diverging Simulations
- Error: addfdtd is not a valid function or a variable name
- Questions about the calculation of the cross-polarization conversion efficiency of metasurface
- Error on Lumerical device
- Ansys Insight: About override mesh in FDTD: its use and settings
- Finding your Ansys (or Lumerical) account number
- Lumerical – error message when trying to open from Linux terminal
© 2023 Copyright ANSYS, Inc. All rights reserved.