Fig. 1. Schematic of optical chirp polarity LFM signal generator

Fig. 2. Schematic of MZM1 and MZM2 output signals under different baseband inputs

Fig. 3. Schematic of MZM3 output signals under different baseband inputs. (a) 0 bit; (b) 1 bit

Fig. 4. Time-frequency curves of positive chirp and negative chirp signals

Fig. 5. Comparison of time-frequency curve of baseband input signal and output signal

Fig. 6. Communication receiving structure of the proposed scheme

Fig. 7. Simulation results of output spectra of MZM3 under different baseband inputs. (a) For bit 0; (b) for bit 1

Fig. 8. Simulation results of input and output signal spectra. (a) Input chirp signal; (b) output signal

Fig. 9. Time-domain waveform and time-frequency curve of the output signal. (a) Time-domain waveform; (b) time-frequency curve

Fig. 10. Time-domain waveforms and time-frequency curves of output signal after tuning. (a) Time-domain waveform after the first tuning; (b) time-frequency curve after the first tuning; (c) time-domain waveform after the second tuning; (d) time-frequency curve after the second tuning

Fig. 11. Autocorrelation spectra of different signals. (a) Input chirp signal; (b) output signal

Fig. 12. Ambiguity functions and－3 dB equivalent lines in the frequency range of 1624 GHz. (a) Ambiguity function of triangular wave FM signal; (b) ambiguity function of single chirp signal; (c) triangle FM signal contour, the inset is－3 dB equivalent line; (d)－3 dB contour of single chirp signal

Fig. 13. Matched filtering result of triangular wave FM signal

Fig. 14. Simulation results of communication function of proposed scheme. (a) Baseband input waveform; (b) time-frequency curve of output signal; (c) dechirp result at the receiving end