Improved multi-channel multi-carrier generation using gain-independent multi-channel frequency shifting recirculating loop

We propose and experimentally demonstrate an improved scheme to generate optical frequency-locked multi-channel multi-carriers (MCMC), using a gain-independent multi-channel recirculating frequency shifter (MC-RFS) loop based on single sideband (SSB) modulation. We re-build the RFS structure with better performance. By using MC-RFS loop, we can generate N-channel subcarriers each round trip without interference. These subcarriers of each channel are stable and frequency-locked, which can be used for multi-channel WDM source. The dual-channel RFS loop is carried out for demonstration in our experiment with dual-carrier source. Using this scheme, we successfully generate 62 frequency-locked subcarriers with 25-GHz frequency spacing in 2 channels and each channel has 31 tones.