Design of a dual-channel modelocked fiber laser that avoids multi-pulsing

Multi-channel modelocked lasers and their design have attracted much attention. Here, we use the Swilt-Hotienberg equation to study dual-channel simultaneous modelocking (DSML) in a fiber laser. When a quartic filter is added to the laser cavity, the stable dual-channel simultaneous modelocking can be obtained for a given filter bandwidth when frequency separation, omega(s), is less than a calculated threshold, omega(th). When omega(s) > omega(th), a multipulsing instability occurs. We use a linear stability analysis to determine the limit that the multi-pulsing instability imposes on DSML, and we propose a cavity design that avoids the multi-pulsing instability. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement