Tunable ultra-flat optical-comb-enabled, reconfigurable, and efficient coherent channelized receiver.

In this Letter, based on two advanced tunable ultra-flat optical frequency comb generators (T-FOCGs), a coherent channelized receiver with high channelized efficiency and reconfigurability is proposed. In the T-FOCG, the number of 1 dB comb lines increases with the gain, but the optical power of these 1 dB comb lines has almost the constant variance. In the proposed scheme, one optical carrier can support four sub-channels. Meanwhile, the number and bandwidth of sub-channels, as well as the bandwidth and center frequency of an original broadband signal, are all tunable. In this Letter, we verify the feasibility of the coherent channelized receiver by channelizing a 4 GHz signal with a 20 GHz center frequency into four 1 GHz sub-channels, and the reconfigurability is demonstrated by channelizing a 10 GHz signal with frequencies from 18 to 28 GHz into five 2 GHz sub-channels. Moreover, the error-vector magnitude curves of the directly received and the channelized quadrature amplitude modulation (QAM) signal at different amounts of beat noise are compared.