Reply To: Designing a single mode fiber

[Guilin Sun]

Ｉbelieve that two modes you get are correct: they are degenerated TE and TM modes. Their mode profile is the same with the same neff. If you use some  kind o fsymmetry BCs, one will disappear. For example, you can use xmin anti-symmetric, and ymin symmetric. You can check the SMF example.