Hybrid nanocomposite film provides FWM and Fabry Perot Filter: Towards multi-wavelength fiber laser generation in 1 μm region

We report on the demonstration of a multi-wavelength ytterbium-doped fiber laser (YDFL) by exploiting a nanocomposite film to act as both a Fabry-Perot (FP) filter and a nonlinear material inside the ring cavity. The proposed filter is formed by combining an FP structure based on a large core diameter single-mode fiber (SMF) with a nanocomposite film. The nanocomposite film was prepared by coating gold nanostars with zinc-oxide nanorods/multi-walled carbon nanotubes (ZnO-NRs@Au-NSs/MWCNTs) embedded into polyvinyl alcohol (PVA) polymer. Moreover, the fabricated hybrid nanocomposite film exhibits a high nonlinear optical response that fulfilling the requirement to induce the FWM effect employed to suppress the mode-competition. Four lasing lines of uniform power-symmetry distribution with a spacing of similar to 160 GHz have been generated by appropriately adjusting the pump power strength to 230 mW. The results suggest that ZnONRs@Au-NSs/MWCNTs nanocomposite film could be a promising filter for stable multiwavelength generations at room temperature.

Automated summary

The study demonstrates a multi-wavelength ytterbium-doped fiber laser using a nanocomposite film as both an FP filter and a nonlinear material inside the ring cavity. By embedding gold nanostars with zinc-oxide nanorods/multi-walled carbon nanotubes in a PVA polymer, the hybrid nanocomposite film exhibits a high nonlinear optical response. This enables stable and symmetric generation of multiple wavelengths in the laser system.