Exploiting the FM-to-AM conversion to generate high-contrast picosecond laser pulses

In this work, we simulate and demonstrate experimentally a new approach to generate picosecond laser pulses. This technique is based on optoelectronic FM-to-AM conversion: a transient radiofrequency phase modulation is applied on a continuous-wave fiber laser otherwise blocked by a bandstop filter. By leveraging the ability of modern electronic amplifiers to generate high voltage swings values on a short timescale, the presented setup induces a large and brief excursion out of the filter, hence generating 18 ps pulses with a time contrast of 38 dB. Detailed simulations pave the road toward pulses shorter than 1 ps by using an optimally shaped RF response.