No abstract

In this paper, we real-time transmitted 32 ´100-Gb/s PM-QPSK modulated signal over 2,080-km standard single mode fiber (SSMF) using coherent detection based on 100G transponder with 31.78 Gbaud/s. 32 WDM channel sources are generated by a single laser source on a 32 GHz grid and yield a spectral efficiency of 3.11 b/s/Hz.

Broadband SONET (Synchronous Optical Network), SDH (Synchronous Digital Hierarchy), and ATM (Asynchronous Transfer Mode) are widely deployed in public and private networks. OC-48/SDH-16 equipment of 2.5 Gbit/s and high speed network components beyond 2.5 Gbit/s are gaining popularity in various B-ISDN systems. Wavelength chirping of laser diode (LD) creates a hurdle in Gbit/s directly modulated optical transmitter design. Practically, transmitter consisting of a narrow linewidth LD source and an external electro-optic modulator (EOM) can provide a minimum chirping effect and is suitable for multigigabit transmission.1,2 Currently, the typical drive voltage of 3 GHz LiNbO3 EOM is about 3~4 V at 1310 nm. Therefore, the required high speed electronic drive circuits are costly and thus limits the mass deployment of the external modulated transmitter modules. In this paper, we report the demonstration of a low drive voltage (Vx = 1.7 V) EOM with optical modulation bandwidth of 5 GHz.

No abstract

Abstract. We propose a bidirectional radio over fiber ( RoF ) system for simultaneous generation and transmission of amplitude shift keying (ASK), optical carrier suppressed amplitude shift keying (OCS-ASK) and frequency shift keying (FSK) signals based on one single-drive Mach-Zehnder modulator (MZM). The feasibility of the proposal is verified by experiments and error-free performances are achieved for all the data.