Gain clamping performance of Hafnia-bismuth-erbium co-doped fibre amplifier using lasing controlled structure with FBG

In this study, the gain clamping performance of Hafnia-bismuth-erbium co-doped fibre amplifier (HB-EDFA) using a lasing controlled structure with fibre Bragg grating (FBG) pair is presented. First, the gain and noise figure (NF) characteristics of a bidirectionally pumped HB-EDFA with very short lengths of heavily doped fibre are presented regarding its critical design parameters such as HB-EDF length, pump power, input signal power and signal wavelength. Then, the gain clamping performance of a bidirectionally pumped HB-EDFA having a C-band FBG pair with Bragg wavelengths of 1534 and 1542 nm is experimentally analysed. A good gain clamping capability was obtained using the proposed bidirectionally HB-EDFA design which has resulted in a dynamic signal input power range of 25 dB at 16 dB signal gain for 1.6 m HB-EDF length, and a wider dynamic signal input power range of 30 dB at 10 dB signal gain for 1.1 m HB-EDF length.