Simulation and Algorithm Optimization of a Bismuth-doped Optical Fiber Amplifier for the U-band (1650-1700 nm)

Abstract

Based on the current situation of tightening capacity of fiber optic communication systems, it has become a necessity to find new technologies to expand the range of bands for commercial fiber optic amplifiers. With the research on ytterbium, neodymium, erbium, and thulium ion-doped optical fibers in recent years, the short wavelength region (1100-1550 nm) band of optical communication has been developed, but doped optical fiber amplifiers in the long wavelength region (1650-1700 nm) are still immature. The paper reports the simulation and algorithmic optimization of a bismuth-doped optical fiber amplifier. Referring to the realistic experimental parameters, the theoretical optimal gain of 54.2697 dB was obtained by setting the center wavelength of 1550 nm pump source, 200 mW pump energy, and the center wavelength of 1650 nm signal source. Further, an adapted fiber length of 1 m and a doping concentration of 4.0248×10²⁴ m^-3 for the approximate optimal gain were obtained by the optimization algorithm. Moreover, the differences between the two optimization algorithms are compared and the reasons for the differences in the results are briefly analyzed.