Guilin Sun
Ansys Employee

I just found your post which is in the wrong forum. Lumerical has dedicated English, Chinese and Korean forums:

https://forum.ansys.com/forums/forum/discuss-simulation/photonics/

https://forum.ansys.com/forums/forum/discuss-simulation/photonics/photonics-chinese/

https://forum.ansys.com/forums/forum/discuss-simulation/photonics/photonics-korean/

Next time please post in the proper forum in order to get quick reply.

A short reply is: simple change the "coupling coefficient".

https://optics.ansys.com/hc/en-us/articles/360036618733-Waveguide-Coupler-C-INTERCONNECT-Element