SPM is unobvious when input optical power is less than 0 dBm, and when input optical power is greater than 0 dBm and less than 12 dBm, SPM weakens the GVD effect and extends the transmission distance.

• 入纤功率在0-12 dBm时,SPM效应减弱了色散效应的作用,延长了系统的受限距离;