Gain Modeling and Numerical Simulation of Fiber Amplifier

 As optical communication technology has been developing fast these years, its application in S-band has been valued by people, especially in the field of WDM/DWDM. The energy structure-e in Tm3+exist the transition which can meet the S-band and S+-band. Although the energy structure of ions are very complex, the fiber amplifier is an important device for the  S+-band optical amplification. And its research will be very significant for further broadening the optical communication bandwidth. Fiber amplifiers have become a new hot spot for optical fiber communication devices. This paper mainly do analysis, simulation and comparison about the semiconductor laser mufti-core pigtail outputting light field intensity, as well as the outputting light field intensity distribution of LD mufti-core pigtail single-lens and dual-lens coupled. This paper analyzes fiber amplifier performance based on the rate equation, transfer equation and simulations.