With the development of femtosecond laser applications such as femtosecond optical comb spectroscopy and femtosecond ranging, there is a growing demand for femtosecond lasers with higher repetition rates. In this paper, the main technologies and technical progress of solid-state lasers and fiber lasers used to generate femtosecond pulses with GHz repetition rate are reviewed. Finally, the latest development trend of GHz lasers is summarized. It provides a reference for the relevant personnel who carry out the research on GHz repetition rate femtosecond lasers later.
