Soliton mode-locked pulse generation with Polyaniline saturable absorber

We demonstrate the successful mode-locking of an Erbium-doped fiber laser (EDFL) utilizing a Polyaniline (PANI) saturable absorber (SA), resulting in the production of picosecond pulses at a frequency of 1.8 MHz within an elongated ring cavity. The SA is engineered by embedding PANI into Polyvinyl Alcohol (PVA). This conducting polymer-based SA exhibits favorable optical nonlinear properties, boasting a modulation depth of 2.3 %, a saturation intensity of 7.8 MW/cm², and a non-saturable loss of 5.6 %. The laser system generates a conventional soliton pulse train at a central wavelength of 1572.62 nm. The mode-locking operation is sustained within a pump power range from 139.4 to 254.12 mW. The laser also achieves a pulse duration of 3.0 ps and a maximum pulse energy of 0.4 nJ. These findings underscore the effectiveness of the proposed PANI-based SAs, which exhibit comparable properties to currently utilized 2D SAs. The successful mode-locking operation and the promising optical characteristics of the PANI-based SA provide a solid foundation for their potential applications in the realm of ultrafast photonics.