Evaluation of the Coherent Artifact in Ultrashort Laser Pulses using D-Scan and Its Application to Broadband Fiber Lasers

In most techniques used for the temporal characterization of high-repetition rate ultrafast lasers, the resulting measurement is usually integrated over a large number of pulses. Shot-to-shot fluctuations within the pulse train are therefore averaged in the acquisition. These variations may be of a different nature depending on the laser source and the nonlinear processes involved. In previous works, some of these techniques were tested through numerical simulations and their sensitivity to this phenomenon — known as the coherent artifact — has been analyzed by adding random phases to the pulses and by introducing multiple pulse instabilities in the pulse train [1–3].