Demonstration of an ultra-high frequency picosecond pulse generator using an SBS frequency comb and self phase-locking

Abstract

We propose a method to generate phase-locked pulses in the picosecond regime by using Stimulated Brillouin Scattering (SBS). The phase-locked comb is generated using only long length of fiber and a single frequency CW pump laser. We show that there is a phase relationship between multiple Stokes peaks in a cavity, which directly leads to pulsing without the need to add a mode-locking component. This generates highly coherent pulses in the order of ~10 ps. The repetition frequency, which is very stable is in the order of tens of GHz, is based on the SBS frequency shift and has a linear dependence with temperature (1 MHz/°C). Such a laser could therefore be used in high-speed optical clocks and optical communication system. This system allows the pulses to be generated at any wavelength by simply changing the pump wavelength.