Linear Er-doped fiber Mamyshev regenerator with high pulse energy generation

High peak power mode locked fiber lasers are effective tools for many applications like optical metrology, biomedical imaging, micromachining and so on. All-fiber architecture and high pulse energy mode locked fiber lasers are very attractive to these applications due to their compactness and robustness. In recent years, an attractive mode-locking scheme based on Mamyshev regenerator was demonstrated to realize high pulse energy mode locked pulse output leading to breakthroughs in the mode locked fiber laser performance. We experimentally demonstrate an all-fiber linear Mamyshev regenerator operating at 1550 nm. Self-phase modulation and off-set spectral filtering provide high peak power pulse pick-up effect in the laser cavity and impel the laser to operate in the mode locking regime. With properly setting of the parameters, the all-fiber Mamyshev regenerator can achieve self-starting of the mode locking easily. No external pulse seeds or auxiliary starting arms are needed for the self-starting of the mode locking, which makes the laser very convenient to operate. Pulses with maximum energy of ~18 nJ and pulse width of 230 fs were achieved. The pulse width almost keeps unchanged with increasing in the pump power and the output power increases almost linearly with the pump power. The spectra from the two outputs with different pump powers were experimentally investigated as well. This high pulse energy Mamyshev regenerator can be used as a high quality and cost-effective laser source for many applications.