title: Optical transmitter for 320-Gb/s PDM-RZ-16QAM generation using electrical binary drive signals.
abstract: We propose a new 16QAM optical transmitter based on a combination of a dual-drive Mach-Zehnder modulator (DD-MZM) and a dual-parallel Mach-Zehnder modulator (DP-MZM) with electrical binary drive signals. For 16QAM generation, two arms of DD-MZM are independently driven by two different binary data, and consequently, the DD-MZM produces an offset square 4QAM of the 16QAM constellation. This 4QAM signal is then switched over other quadrants through a typical QPSK modulation scheme by the following DP-MZM, and resulting in 16QAM. By using the proposed transmitter together with a digital coherent receiver, we successfully demonstrate the 224-Gb/s and 320-Gb/s PDM-RZ-16QAM systems. Their OSNR sensitivities at 3.8x10(-3) BER are observed to be 19.8 dB and 23 dB, respectively.
authors.affiliation: KDDI R&D Laboratories Inc., 2-1-15 Ohara, Fujimino, Saitama, 356-8502 Japan. hchoi@kddilabs.jp
authors.forename: Hyeon Yeong
authors.initials: HY
authors.lastname: Choi
authors.forename: Takehiro
authors.initials: T
authors.lastname: Tsuritani
authors.forename: Itsuro
authors.initials: I
authors.lastname: Morita
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation*; D055096:Optical Devices; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*