Optimizing multi-pass amplifier in a virtual chirped pulse amplification system

Abstract This article presents a detailed simulation study of a multi-pass amplifier in the chirped pulse amplification (CPA) system using Lab2 femtosecond virtual tools in LabVIEW to model and optimize the pulse amplification process. The virtual experimental setup includes Gaussian pulse generation, pulse stretching using an Offner-triplet stretcher, multi-pass amplification, and final pulse compression using a double-grating compressor. Various multi-pass amplifier configurations (4-pass, 8-pass, and 12-pass) are simulated, and their effects on pulse amplification, phase stability, and energy gain are analyzed. The study demonstrates that the 8-pass configuration achieves the most optimized performance in terms of energy gain, spectral and temporal stability, and pulse duration, providing a more balanced pulse compression. Diagnostics via frequency-resolved optical gating confirm these results, showing that the 8-pass Amplifier delivers shorter pulse durations (∼36 fs) and better phase control compared to the 4-pass and 12-pass amplifiers, which experience higher nonlinearity and less stability. The article underscores the critical role of compressor grating separation in minimizing pulse duration and optimizing laser performance. Using the Lab2 virtual tools in LabVIEW, this simulation provides valuable insights into the dynamic optimization of multi-pass amplifiers in CPA systems.