A simple approach to start Mamyshev oscillator at 1030 nm utilizing a saturable absorber mirror

We demonstrate a simple method to start Yb fiber Mamyshev oscillator by adding a saturable absorber mirror (SAM) in an optical path at a bandpass filter reflection. At first, to achieve the starting of Mamyshev oscillator using SAM, by injecting a seed pulse from outside the cavity, an output coupling, a transmitted central wavelength between offset bandpass filters, and a pump LD power are explored to start the Mamyshev oscillator. Then, preserving the above-mentioned three parameters in the cavity, we exchange a fiber-cabled mounted SAM for the seed pulse output FC/APC connector. After that, the Mamyshev oscillator immediately started by turning on the pump LD. To understand the starting dynamics of this approach, we capture the pulse resolved spectrum in an initial stage of the pulse formation of Mamyshev oscillator by time-stretch spectroscopy. Before starting Mamyshev oscillator, a signature of the Q-switch pulse is observed in the 2D color plot imaging of the pulse-resolved single-shot spectrum. When a strong amplified spontaneous emission is input to SAM, a Q-switch pulse is created, and then this Q-switch pulse circulates in the cavity. This Q-switching pulse plays a role in the seed pulse to start the Mamyshev oscillating. We believe this simple approach is one of the efficient techniques for starting the Mamyshev oscillator.