Frequency comb selection enabled flexible all optical Nyquist pulse generation

In this paper, we propose and experimentally demonstrate flexible all optical Nyquist pulse generation enabled by frequency comb selection with cascaded intensity modulators and tunable optical band-pass filters. Cascaded intensity modulators are used to generate frequency-locked optical comb with flat amplitude and linear phase with up to 15 tones. Arbitrary frequency comb selection based on tunable optical band-pass filters allows the control of the pulse width and repetitive period of the high quality sinc-shaped Nyquist pulse. The optical spectra of the selected 3 and 7 tones frequency comb and the corresponding time-domain waveforms are measured in experiment and simulated by software, respectively. Experimental results conform well to the simulation results which verifies the feasibility of our scheme. The scheme we propose is with excellent flexibility in Nyquist pulse generation and is suitable for high capacity optical transmission system.