Generation and characterization of burst modes in passively mode-locked lasers with internal Fabry–Perot cavities

The generation of burst pulses in a multi-pass passively mode-locked laser is systematically explored. We exploit intracavity mirrors with different thicknesses to serve as reflected Fabry–Perot (RFP) cavities in laser resonators. Using a RFP cavity with the thinnest optical thickness, we can generate picosecond optical burst pulses with the highest intra-burst pulse rate of 33.12 GHz. The maximum output power of 2.6 W is obtained at an incident pump power of 11.9 W. We further develop an analytical model which considers the RFP effects to manifest the first-order autocorrelation and spectral behaviors in experiments. The agreement between theoretical analyses and experimental explorations provides the feasibility to flexibly manipulate the burst modes in practical applications.