title: Investigation on Nyquist pulse generation using a single dual-parallel Mach-Zehnder modulator.
abstract: The generation of Nyquist pulses with a dual parallel Mach-Zehnder modulator (DPMZM) driven by a single RF signal is demonstrated theoretically and experimentally. A complete theoretical analysis is developed and the limitation of the proposed scheme is also discussed. It is theoretically proved that Nyquist pulses with a spectrum of 5 flat comb lines can be generated using a single DPMZM, which is also verified with simulation. 7 flat comb lines in frequency domain can also be obtained if a large RF driving voltage is applied to DPMZM but the generated waveforms won't present a sinc-shape. This scheme is further investigated experimentally. 40 GHz Nyquist pulses with full-width-at-half-maximum (FWHM) less than 4.65 ps, signal-to-noise ratio (SNR) better than 29.5 dB, and normalized root-mean-square error (NRMSE) less than 2.4% are generated. It is found that a tradeoff exists between the insertion loss of the DPMZM and the deviation of generated pulses. The tunability of repetition rate is experimentally verified by generation of 1 GHz to 40 GHz Nyquist pulses with SNR better than 28.4 dB and NRMSE less than 6.15%.
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Jizhao
authors.initials: J
authors.lastname: Zang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Deming
authors.initials: D
authors.lastname: Kong
authors.forename: Jifang
authors.initials: J
authors.lastname: Qiu
authors.forename: Siyuan
authors.initials: S
authors.lastname: Zhou
authors.forename: Jindan
authors.initials: J
authors.lastname: Shi
authors.forename: Jintong
authors.initials: J
authors.lastname: Lin