Generation of dark solitons in Er-doped fiber laser based on ferroferric-oxide nanoparticles

The study presents the dark solitons generation in Er-doped mode-locked fiber laser based on ferroferric-oxide (Fe₃O₄) nanoparticles. The D-shaped fiber deposited with Fe₃O₄ nanoparticles is used as the birefringence and nonlinearity device. The dark solitons with repetition rate of 13.5 MHz are obtained in the pump power of 350 mW. The bright-dark soliton pairs are also observed by properly adjusting the polarization state at the pump power of 400 mW. The results in this paper demonstrate that Fe₃O₄ nanoparticles are the promising materials for generating dark solitons in fiber lasers.