Design, optimization, and analysis of thulium-doped optical fiber amplifiers for E-band communication

A thulium-doped (Tm3+) optical fiber amplifier (TDFA) module operating in the E-band is proposed. The bandwidth limitation inherent in E-band amplifiers employing rare-earth element doping is mitigated through the utilization of the amplifier module designed with a parallel combination of the two TDFAs. The performance of the amplifier is effectively analyzed through the optimization of parameters including TDF length, Tm3+ density, doping-radius of Tm3+, numerical aperture, and input signal power to the TDFAs. An average gain of 37.12 dB and a noise figure <3.93 dB are obtained in the wavelength region of 1412 to 1460 nm with a maximum of 41.54 dB at 1432 nm having a moderately uniform gain. The impact of the nonlinear ion–ion interaction mechanism (IM) on the signal is also investigated for the designed amplifier module. Having obtained the optimized parameter set, the percentage increase of 0.029% and decreases of 0.043% in the signal gain at the wavelengths of 1420 and 1448 nm, respectively, are obtained considering the IM effects.