title: Complex modulation and detection with directly modulated lasers.
abstract: Due to the chirp effect, the modulation information is carried by both intensity and phase of the optical signal generated by a directly modulated laser (DML). Compared to the signal recovery based on intensity alone, the receiver sensitivity is significantly improved when phase is also involved for signal recovery. In this paper, we provide thorough analysis of two schemes to recover the directed modulated signal based on the combined information of intensity and phase. The intensity and phase combined recovery for polarization-division-multiplexed (PDM) directly modulated signal is demonstrated for the first time, achieving a data rate of 40 Gb/s over a transmission distance of 160 km. Compared with the conventional intensity-only recovery, the receiver sensitivity is improved by 5.5 dB and 10 dB respectively by using two intensity and phase combined recovery schemes.
authors.forename: Qian
authors.initials: Q
authors.lastname: Hu
authors.forename: Di
authors.initials: D
authors.lastname: Che
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Yuan
authors.forename: Qi
authors.initials: Q
authors.lastname: Yang
authors.forename: William
authors.initials: W
authors.lastname: Shieh