Problem AC characteristics of semiconductor laser in ADS

I simulate a circuit model of semiconductor laser in ADS, the DC characteristic is ok ,but the AC characteristic is not right. I feel confused about this phenomenon.What is the possilbe reason? How to debug this kind problem? Could someone give me any guidance?


Thanks!

Can not understand what problem is !
U'd better post your picture .

Thanks for your reply.

I have solved the problem by myself. I want to build a circuit model for semicinductor laser in ADS. The reason of my problem was that the model has multiple soultions, and in AC analysis, the outcome is in not in the desired solution regime.I transformed the model and the problem has been successfully solved.

Thanks a lot for your attention!