Numerical study of passively mode-locked fiber optical parametric oscillators by self time-lensing

The recent development of fiber mode-locked lasers with fiber parametric gain has opened up an intriguing field of ultrafast pulse generation. Thanks to the tunability of the parametric gain in optical fibers, the gain media of mode-locked lasers are no longer limited to the choice of rare-earth-doped fibers. In our previous study, optical time-stretch was introduced into the cavity of a fiber optical parametric oscillator as a temporal diffracting distance to overcome localization of the parametric gain. The implementation of the diffracting distance for pulse stretching and compression relied on two dispersive elements with opposite sign dispersion. In this context, we propose a new design of passively mode-locked fiber optical parametric oscillators with only a single mono-dispersive element. We utilize the parametric process as a time lens at which the spectral components of the two oscillating parametric sidebands are phase-conjugated in the temporal domain. This allows both mode-locked sidebands to oscillate and switch periodically inside the fiber cavity with only a single dispersive element. We numerically simulate the pulse generation of this switching mode-locked fiber parametric oscillator. (C) 2019 Optical Society of America