2D Grating Coupler Orientation in FDTD Solutions

[kar3]

I am using the 2D grating coupler design given by Lumerical (https://kb.lumerical.com/en/pic_passive_grating_coupler_2d.html)

I want to orient the fiber given in the model from the XY plane to the XZ plane.
There is no ‘rotation’ option as given for the grating coupler structure.

Could someone please let me know how I can achieve this rotation?

Thanks!

[nlui]

In 2D simulations in FDTD Solutions, the structure is always taken to be infinite and uniform in the z-dimension so it wouldn’t be possible to use a 2D simulation to simulate the case where the fiber is oriented in the XZ plane. Instead, you would need to use a 3D simulation like in the 3D grating coupler example here:
https://kb.lumerical.com/en/index.html?pic_passive_grating_coupler_3d.html

[engwong]

Hi kar3,

If you are simulating a 2D design, the fibre MUST be oriented in the XY plane. What you can do is put the grating in a ‘structure group’, and then rotate the structure group in the x-axis by -90 degrees. This should get the relative orientation of the grating coupler to the optical fibre right.