Dear Knowledge Exchange Community,
I am trying to simulate simple waveguide structures with regards to effective refractive index (and its derivatives) over a specific wavelength range (0.7-1um). To do so I use the “Frequency analysis” solver. I am interested in the fundamental TE-like mode. For some reason the mode seems to get confused with a more confined TM-like mode half way through the wavelength-sweep. This of course affects the effective refractive index and especially its derivatives.
Why is this occurring, and is there a way to solve this or omit the problem?
Attached is a pdf with screenshots of the “Frequency analysis” window and the Lumerical MODE file.
Thank you for your time!