Amplification of high repetition-rate, picosecond laser pulses using a zig-zag slab configuration

•With the continual development of laser-based applications, there is growing demand for laser sources with high pulse energy, pulse durations in the picosecond range and with high repetition rates. These sources are particularly important for applications such as laser ignition, laser processing of materials and supercontinuum generation. While it is possible to generate high repetition rate, picosecond pulse duration emission from passively q-switched microchip lasers, the maximum pulse energy is limited and must be amplified.•In this work we undertake comprehensive theoretical modelling of the characteristics of the seed beam as it is injected into the amplifier slab, and we model the expected amplification characteristics of the system. This theoretical modelling is supported by a comprehensive experimental investigation of the system performance and optimization.•With this MOPA system design, we demonstrate a maximum amplification factor of ∼90 times and generate amplified seed laser output with a pulse energy of 99.58 mJ, and a pulse duration of 491 ps at a repetition rate of 200 Hz.