REAM intensity modulator-enabled 10Gb/s colorless upstream transmission of real-time optical OFDM signals in a single-fiber-based bidirectional PON architecture

Reflective electro-absorption modulation-intensity modulators (REAM-IMs) are utilized, for the first time, to experimentally demonstrate colorless ONUs in single-fiber-based, bidirectional, intensity-modulation and direct-detection (IMDD), optical OFDM PONs (OOFDM-PONs) incorporating 25km SSMFs and OLT-side-seeded CW optical signals. The colorlessness of the REAM-IMs is characterized, based on which optimum REAM-IM operating conditions are identified. In the aforementioned PON architecture, 10Gb/s colorless upstream transmissions of end-to-end realtime OOFDM signals are successfully achieved for various wavelengths within the entire C-band. Over such a wavelength window, corresponding minimum received optical powers at the FEC limit vary in a range as small as <0.5dB. In addition, experimental measurements also indicate that Rayleigh backscattering imposes a 2.8dB optical power penalty on the 10Gb/s over 25km upstream OOFDM signal transmission. Furthermore, making use of on-line adaptive bit and power loading, a linear trade-off between aggregated signal line rate and optical power budget is observed, which shows that, for the present PON system, a 10% reduction in signal line rate can improve the optical power budget by 2.6dB. © 2012 Optical Society of America

Field-Trial of Machine Learning-Assisted Quantum Key Distribution (QKD) Networking with SDN

We demonstrated, for the first time, a machine-learning method to assist the coexistence between quantum and classical communication channels. Software-defined networking was used to successfully enable the key generation and transmission over a city and campus network

Key performance indicators for elastic optical transponders and ROADMs:the role of flexibility

Flexible optical networks will provide the required service diversity to manage unpredictable traffic patterns and growth. However, a key challenge is to quantify flexibility in order to indicate the associated performance of individual components and subsystems required to support networks and correlate it with other figures of merit. Measurable key performance indicators will aid the process towards the design and deployment of cost effective and efficient optical networks. Moreover, the design and placement of network elements within a network influences the resultant network-wide flexibility and performance. In this paper, we highlight critical design parameters for key optical components, optical transmission and switching subsystems using flexibility as an additional figure of merit. We derive models to measure the flexibility of key optical components, optical transmission and switching subsystems based on entropy maximization. Using these models, we evaluate flexibility and design trade-offs of the presented enabling technologies with other key performance indicators such as spectral efficiency, lightpath reach, total capacity, normalized cost, connectivity and others. This study provides an advanced and more informed set of design rules that quantify and visualize the different degrees of flexibility of enabling technologies and associated performance based on required specification and/or functionality