Generation of a 500 GHz optical pulse train by repetition-rate multiplication using an arrayed waveguide grating

In recent work the authors have demonstrated for the first time that upon femtosecond read-out, AWGs can also provide interesting time-domain functionalities, such as generation of isolated bursts of very high repetition-rate pulses. Here, for the first time we report the use of an AWG as a repetition-rate multiplier, producing a 500 GHz continuous pulse train output from a 13.2 GHz repetition-rate short-pulse source. In our experiment, we achieve 2N-fold repetition-rate multiplication by using two outputs of an AWG, each of which provides a pulse spacing reduced by a factor of 2N, but with a 50% burst duty ratio.