Optical gating of an electro-optic frequency comb for pedestal suppression and 8-fold repetition-rate division

We demonstrate an optical pulse gating technique for pedestal suppression and wide-range repetition-rate variation in a 20 W, 8 GHz all-polarization-maintaining fiber (PMF)-based electro-optic (EO) comb system operating at 1030 nm. The sinusoidal phase modulation of the EO comb generates higher-order dispersion that becomes dominant at outer spectral components. Since a grating-pair compressor compensates only the group delay dispersion, the residual higher-order dispersion manifests as pedestals that degrade temporal pulse quality. By applying a < 50 ps temporal gate at 8 GHz, the pulse energy ratio of the compressed pulse was enhanced from 84.0% to 97.3%, achieving a nearly Fourier-transform-limited pulse duration of 1.90 ps. Simultaneously, varying the gating period enables repetition-rate division from 8 GHz down to 1 GHz. The average output power remains constant at 20 W with corresponding pulse energies up to 20 nJ. The output power stability remains within 0.42% rms over one hour across the tuning range, confirming robust operation. This platform offers a single-system solution for systematic optimization of intra-burst parameters in GHz burst laser processing.