Erbium-Doped Self-Similar Fiber Laser with a Prism-Based Spectral Filter

Mode-locked fiber lasers are widely used due to their compactness and ability to generate ultrafast optical pulses. In normal-dispersion fiber lasers, including dissipative soliton (DS) and self-similar (SS) regimes, intracavity spectral filtering is essential for achieving stable pulse evolution. Spectral filters based on diffraction gratings have been widely employed for this purpose. In contrast, prism-based spectral filters provide an attractive alternative, offering lower insertion loss and improved robustness against environmental contamination. Furthermore, compared to grating-based counterparts, they allow for a larger intra-cavity beam size. In this work, we demonstrate an erbium (Er)-doped SS fiber laser operating at 1550 nm that incorporates a prism-based spectral filter. The prism-based spectral filter successfully maintains SS pulse evolution in the normal-dispersion cavity for stable mode-locked operation.