High-frequency, stable optical pulse generation using two-section passively mode-locked semiconductor diode lasers

Passively mode-locked semiconductor lasers are compact and reliable pulse sources, but they have the drawback of relatively high timing jitter levels. We propose to control the pulse generation from a passively mode-locked semiconductor laser by using a Q-switching laser with a repetition rate equal to the fourth sub-harmonic of the cavity round trip of the modelocking laser. Jitter levels are reduced from 9 to 4 ps.