Nickel nanoparticles‐based saturable absorber: Toward compact multiwavelength Yb‐doped fiber pulsed lasers near 1 μm region.

We experimentally demonstrate a compact pulsed dual‐wavelength Ytterbium‐doped fiber laser (YDF) based on Nickel nanoparticles (Ni‐NPs) as a Q‐switcher and optical stabilizer. By integrating the Ni‐NPs saturable absorber (SA) in the cavity, and adjust the 975 nm diode pump power to 185 mW, a self‐starting passively Q‐switched was generated at a central wavelength of 1038.5 nm. By exploiting the extra high nonlinearity of Ni‐NPs, the homogenous gain broadening of the YDF oscillator can be suppressed. Consequently, at a pump power of 195 mW, a stable dual‐wavelength passively Q‐switching laser has been generated at room temperature without any intracavity spectral filters or modulation elements. As increases the pump power up to the maximum value of 288 mW, the Ytterbium‐doped fiber laser observed that the smallest pulse width, the maximum repetition rate, and the maximum pulse energy of 1.44 μs, 100.1 kHz, and 4.45 nJ, respectively. The Ni‐NPs SA proof its potential in generating multiwavelength pulsed laser in the 1 μm region for different photonic applications. [ABSTRACT FROM AUTHOR]