Enhanced nonlinear effect for generation of both bound state solitons and harmonic mode-locking with high signal-to-noise ratio based on crossed bandpass transmittance filters

As an emerging laser architecture, Mamyshev oscillators have great potential for high-average-power and large-pulse-energy ultrashort pulse generation and offer an excellent platform for exploring nonlinear dynamics arising from their high nonlinear phase accumulation ability. This study demonstrates various bound state solitons, including dual- and multi-pulse states, in a nonlinear enhanced Mamyshev laser in the 1 μm wavelength regime. Furthermore, harmonic mode-locking up to the seventh-order (∼116.88 MHz) with a signal-to-noise ratio (SNR) above 70 dB is achieved through intracavity nonlinear control, birefringence optimization, and careful gain management. To the best of our knowledge, this is the highest SNR obtained in a harmonically mode-locked Mamyshev laser. The realization of diverse bound state solitons evolving into harmonic mode-locking provides valuable insight into the nonlinear dynamics of Mamyshev lasers and stimulates the discovery of new phenomena to advance fundamental science and laser technology.