To help us solve your issue as quickly as possible, please provide the following information:
1. What device are you trying to simulate? Include diagrams if available.
I am trying to simulate a bent waveguide in Lumierlcal mode
2. What results are you trying to obtain? Be as specific as possible.
I am trying to obtain the mode mismatch loss between a circular bend and a straight waveguide.
3. Description of the problem or issue.
I am trying to find the largest radius that is required for two-mode mismatch losses of 0.1%. In other words, what is the radius that will result in two mode mismatch losses (between the 90 degree bend and the two waveguides intersection) that will result in 0.999 transmission. The waveguide dimensions are 500x220 nm strip silicon waveguide buried in Silica cladding, and the mode is the fundamental TE. I did this simulation 3 years ago and the answer was 10 microns. I think even last year that answer was 10 microns. I did this simulation last week and the answer was 8.5 micron. I am wondering if something has changed in terms of the waveguide center offset in the latest version, or am I doing something wrong?
4. Lumerical product and software version.
Release: 2019b r6, Version: 7.14.2088
5. Please attach your simulation files, including any logs.