Demonstration of Multiple Kerr-Frequency-Comb Generation Using Different Lines From Another Kerr Comb Located Up To 50 km Away

On-chip Kerr frequency combs are potentially promising to enhance many applications because of their broad-band operation and chip-scale integration. Such combs offer various mutually coherent optical carriers that can potentially be used as both coherent light sources and local oscillators in optical communications. In this paper, we experimentally demonstrate multiple Kerr frequency comb generation using different lines from another Kerr comb located up to 50 km away. Different master comb lines after fiber propagation can be individually selected to pump distinct microresonators to generate slave combs with different repetition rates. An approximately 20 kHz linewidth can be obtained for the beat notes of the master and remote slave combs. Furthermore, results show that the linewidths of the slave comb lines almost remain the same as that of the master comb pump. A pump light with an optical signal-to-noise ratio of beyond 23 dB is required for slave comb generation. When serving as local oscillators, the slave comb lines have a smaller variation of frequency error than the comb lines generated by an independent unstabilized laser.