“Optical PAM4 transceiver” in the case library

- January 3, 2024 at 2:52 am
  
  pengzheng97
  Subscriber
  
  Hi, I met a problem when I learn the case ""Optical PAM4 transceiver" in the case library"
  https://optics.ansys.com/hc/en-us/articles/360042322694-Optical-PAM4-transceiver
  I add an "Optical Oscilloscope" as the picture to view the optical signal after pam4 modulation, and I noticed the signal have some problems: There will be some overshoot at the edge of the modulated signal strength change, resulting in some "spikes" in the signal. Is this correct? Is there any way to reduce this?
  Thanks, wish for your reply :)
- January 3, 2024 at 7:44 pm
  
  GWANG
  Ansys Employee
  
  Hi pengzheng97,
  
  Thank you for the post. This effect of spikes is normal and you can add a filter after the modulator to remove this effect.
  
  Hope this can help.
  - January 8, 2024 at 8:46 am
    
    pengzheng97
    Subscriber
    
    您好，谢谢您的回复，我试着加了几个optical 滤波器，它们会将整个信号的波形都改变，请问该用什么滤波器，怎么设置才能只滤掉这种过冲的peak呢？
  - January 10, 2024 at 1:49 am
    
    pengzheng97
    Subscriber
    
    Hi,Guanhui Wang, is there any method to solve the problem? Or any other way to modulate PAM4 signal withou these overshooting peak.
    Really need your help, wish your reply, thanks