Experimental demonstration of flexible bandwidth networking with real-time impairment awareness

We demonstrate a flexible-bandwidth network testbed with a real-time, adaptive control plane that adjusts modulation format and spectrum-positioning to maintain quality of service (QoS) and high spectral efficiency. Here, low-speed supervisory channels and field-programmable gate arrays (FPGAs) enabled real-time impairment detection of high-speed flexible bandwidth channels (flexpaths). Using premeasured correlation data between the supervisory channel quality of transmission (QoT) and flexpath QoT, the control plane adapted flexpath spectral efficiency and spectral location based on link quality. Experimental demonstrations show a back-to-back link with a 360-Gb/s flexpath in which the control plane adapts to varying link optical signal to noise ratio (OSNR) by adjusting the flexpath's spectral efficiency (i.e., changing the flexpath modulation format) between binary phase-shift keying (BPSK), quaternary phase-shift keying (QPSK), and eight phase-shift keying (8PSK). This enables maintaining the data rate while using only the minimum necessary bandwidth and extending the OSNR range over which the bit error rate in the flexpath meets the quality of service (QoS) requirement (e. g. the forward error correction (FEC) limit). Further experimental demonstrations with two flexpaths show a control plane adapting to changes in OSNR on one link by changing the modulation format of the affected flexpath (220 Gb/s), and adjusting the spectral location of the other flexpath (120 Gb/s) to maintain a defragmented spectrum. (C) 2011 Optical Society of Americ

Experimental Demonstration of a Variable Bandwidth, Shape and Center-Frequency RF Photonics Filter using a Continuously Tunable Optical Tapped-Delay-Line and Having an Optical Output

Abstract: We experimentally demonstrate the RF photonics filter using optical tapped delay line based on an optical frequency comb and a PPLN waveguide as the multiplexer. RF filters with variable bandwidth, shape and center-frequency are implemented. OCIS codes: (060.4370) Nonlinear optics, fibers, (070.4340) Nonlinear optical signal processing. 1

Experimental Demonstration of Robustness and Accuracy of an MZI-based OSNR Monitor under Transmitter Drift and Reconfigurable Networking Conditions for Pol-Muxed 25- Gbaud QPSK and 16-QAM Channels

Abstract: We experimentally demonstrate the robustness of an MZI-based OSNR monitor under reconfigurable network and transmitter drift. The monitor calibration factors for 25 Gbaud PM-QPSK signal are stored after assembly and applied to study the accuracy of the OSNR monitoring unit when different changing scenarios outside the monitor occurred. OCIS codes: (060.2360) Fiber optics links and subsystems; (060.4257) Networks, network survivability 1

Experimental Demonstration of All-Optical Phase Noise Mitigation of 40-Gbits/s QPSK Signals by Mixing Differentially Delayed Nonlinear Products

Abstract: We propose and demonstrate an all optical phase noise mitigation scheme by mixing differentially delayed nonlinear products. For 40-Gbits/s signals, phase squeezing results in phase noise range reduction of around 50 % and 1.5 dB OSNR gain at BER 10-5. OCIS codes: (070.4340) Nonlinear optical signal processing; (060.2360) Fiber optics links and subsystems 1