1.25–2.5 Gb/s Simple Nyquist Transmitters for Coherent UDWDM-PON with Enhanced Spectral Efficiency. Issue 4 (4th July 2018)

• Record Type: Journal Article
• Authors: Velásquez, J. Camilo; Tabares, Jeison; Cano, Iván N.; Prat, Josep
• Is Part Of: Fiber and integrated optics. Volume 37:Issue 4(2018)
• Page Start: 219
• Page End: 228
• Publication Date: 2018-07-04
• Subjects: Beat phase modulation -- coherent detection -- DFB -- directly modulated laser (DML) -- Nyquist shaping -- UDWDM-PON; Fiber optics -- Periodicals; Integrated optics -- Periodicals; Optical communications -- Periodicals; 621.3692
• DOI: 10.1080/01468030.2018.1461281
• Languages: English
• ISSNs: 0146-8030

Abstract

ABSTRACT: We present a coherent ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON) with enhanced spectral efficiency. The benefit of using Gaussian or Nyquist pulse-shaping filters at the transmitter is evaluated through numerical simulations and experiments. The transmitters consist of directly phase modulated distributed feedback (DFB) lasers through beat signals whose duty-cycle and amplitude are digitally adjusted. The results show that transmitting a Nyquist-shaped signal achieves a 25% spectral saving allowing to place 2.5 Gb/s/user data in 6.25 GHz channels. Furthermore, the proposed transmitter tolerates differential link-losses of 15 dB at Rx sensitivity of ‒44 dBm at BER=10 ‒3 with intradyne detection.