In an erbium-doped fiber amplifier(EDFA), erbium ions act as a three-level system. Therefore, much higher pump energy is required to achieve the population inversion in an erbium-doped fiber(EDF). This higher pump energy requirement complicates the efficient design of an EDFA. However, efficient use of the pump power can improve the EDFA performance. The improved performance of an EDFA can be obtained by reducing the doping radius of the EDF. A smaller doping radius increases pump–dopant interactions and subsequently increases the pump–photon conversion efficiency. Decreasing the doping radius allows a larger proportion of dopant ions,which are concentrated near the core, to interact with the highest pump intensity. However, decreasing the doping radius beyond a certain limit will bring the dopant ions much closer and introduce detrimental ion–ion interaction effects. In this Letter, we show that an optimal doping radius in an EDF can provide the best gain performance. Moreover, we have simulated the well-known numerical aperture effects on EDFA gain performance to support our claim.
Chinese Optics Letters
support from King Fahd University of Petroleum and Minerals(KFUPM)
King Abdulaziz City for Science and Technology(KACST)via KACST-TIC in Solid State Lighting(Nos.EE2381 and KACST TIC R2-FP-008).
Corresponding author:Md.Ziaul Amin,firstname.lastname@example.org;corresponding author:Khurram Karim Qureshi,email@example.com;corresponding author:Md.Mahbub Hossain,firstname.lastname@example.org