Generation of low-jitter optical pulses with reconfigurable repetition rates and pulse shape

We demonstrate a method to generate low-jitter optical pulses with reconfigurable repetition rates and pulse shape. The system employs an acousto-optic modulator (AOM) as a pulse picker to divide the frequency from an 80-MHz mode-locked laser. Flexible frequency division is achieved by varying gating signals to control the drive signal of AOM. To ensure long-term stability, the repetition rate of the mode-locked laser, the gating signal, and the drive signal of AOM are synchronized. Hence, the repetition rate of optical pulses can be divided by an integer multiple, which can be as low as 100 kHz. The 1.33 MHz pulses obtained by frequency division exhibit a timing jitter of 99.6 fs. Moreover, time-frequency mapping and waveshape are used to obtain reconfigurable pulse shape. After pulse shaping, the 1.33-MHz signal forms a square pulse with a temporal width of 6.96 ns, and timing jitter of 2.66 ps. Similarly, the 100 kHz optical pulse train can be shaped into a square pulse with a temporal width of 6.46 ns. Moreover, optical pulse frequency agility is achieved with a 12.5 ns minimum period difference while preserving the low-jitter of the original laser source.