Single photodiode direct detection system of 100-Gb/s OFDM/OQAM-64QAM over 80-km SSMF within a 50-GHz optical grid

Chao Li,Ming Luo,Shaohua Yu,Xuebing Zhang,Zhaohui Li,Haibo Li,Qi Yang,Wei Li,Rong Hu

doi:10.1364/oe.22.022490

Abstract

We propose a novel guard-band-shared direct-detection (GBS-DD) scheme to improve the receiver spectrum efficiency (SE). The 100-Gb/s signal is modulated by 2 sub-bands, which are assigned onto two orthogonal polarizations. The central wavelengths of the two sub-bands are set as 10.84-GHz frequency space. The two sub-bands are then received simultaneously using a single conventional photodiode (PD) of 40-GHz bandwidth. Only one optical pilot carrier is inserted to beat with the 2 sub-bands on the two polarizations. When the 2 sub-band signal entering into the receiver, the signal-to-signal beat interference (SSBI) terms fall and overlap in the same guard band. As a consequence, the bandwidth usage of the PD is enhanced from 1/2 to 2/3. The 100-Gb/s signal is modulated using orthogonal frequency-division multiplexing based on offset quadrature-amplitude-modulation of 64-quadrature amplitude modulation (OFDM/OQAM-64QAM), and transmitted over 80-km standard single mode fiber (SSMF) within a 50-GHz optical grid. It is shown that the proposed GBS-DD scheme can be implemented by the current commercial optical/electrical devices.

Highlights

With the emergence of internet social networking sites, mobile phones with internet access and expansion of voice and video communication service, the internet has become an indispensable part of people’s daily life
Yan et al have demonstrated a 100-Gb/s optical IM/Direct detection (DD) transmission with 10G-class devices using 65 GS/s Fujitsu high-speed analog-to-digital converters (ADCs) [4]. Such intensity modulation/ direct detection (IM/DD) scheme highly relies on the development of electronics devices/components such as ultra-high-speed ADCs [9] and the transmission distance is highly limited by the fiber chromatic dispersion
To overcome these two drawbacks, another alternative DD scheme, a host of self-coherent system [5,6,7,8] is proposed for short-reach applications since it can significantly lower the expense compared with coherent counterpart while achieving both high data rate and moderate reach

Summary

Introduction

With the emergence of internet social networking sites, mobile phones with internet access and expansion of voice and video communication service, the internet has become an indispensable part of people’s daily life. The required optical bandwidth is more than 600-GHz. In this paper, we propose a novel DD scheme for cost-efficient short reach networks, named “guard-band-shared direct detection (GBS-DD)”, to receive 100-Gb/s optical signal using only one conventional 40-GHz PD within a 50-GHz optical grid.

Results

Conclusion