Automated Start-Up and Extinction Dynamics of a Mamyshev Oscillator Based on a Temperature-Dependent Filter

Mamyshev oscillators (MOs), which are based on an effective saturable absorber that arises from offset spectral filtering, are a new type of mode-locked fiber lasers, but experimentally verifying the theory of the evolution of various dynamic characteristics of optical pulses in MOs has remained a major challenge due to the lack of appropriate filters and the means of real-time, single-shot experimental measurement. Here, the starting, extinction, and output dynamics of MOs are studied by designing and using a special temperature-sensitive band-pass filter, whose central wavelength can be continuously and accurately adjusted with temperature. The entire automated evolution of light pulses in the MO from start-up to stable operation and then to extinction can be observed continuously by adjusting only the filter's temperature. What is more interesting is that the start-up and the extinction processes are mirror symmetric, and both of them experience a double Q-switching state. Further research has shown that the maximum filter interval corresponding to MO self-starting is related to the pump power and that the bigger the pump power, the wider the filter interval. By gradually changing the interval between the two filters, the various output characteristics of the MO are also systematically studied.