Auto bias control and bias hold circuit for IQ-modulator in flexible optical QAM transmitter with Nyquist filtering.

An Auto Bias Control (ABC) technique for the IQ-modulator of a flexible optical QAM transmitter is described. This technique can support various optical QAM signal formats with Nyquist filtering and electronic dispersion pre-compensation. 16, 32 and 64-QAM signals (21 Gbaud) are successfully generated, and all bias voltages are held to their optimum value even when signal format is changed.

Experimental demonstration of arrayed optical amplifiers with a shared pump laser for realizing colorless, directionless, contentionless ROADM.

We propose arrayed optical amplifiers that share a single pump laser with the aim of realizing full-add/drop colorless, directionless, contentionless ROADM nodes and demonstrate its feasibility in experiments. The experimental results show that the fabricated arrayed optical amplifiers can be made to correspond properly to wavelength path reconfigurations by adjusting a splitting ratio of the variable splitter between the pump laser and eight EDFAs, and cause no significant penalty for 128-Gbit/s PDM-QPSK signal transmission.

Statistics and performance under combined impairments induced by polarization-dependent-loss in polarization-division-multiplexing digital coherent transmission.

Two-dimensional statistics and Q-penalty performance under the combination of two major impairments induced by polarization-dependent loss, namely level imbalance and loss of orthogonality between polarization-multiplexed tributaries, for a polarization-division-multiplexing digital coherent transmission at over 100-Gb/s are presented for the first time to estimate the outage probability needed for designing the system.

Experimental demonstration of multi-degree colorless, directionless, contentionless ROADM for 127-Gbit/s PDM-QPSK transmission system.

We experimentally demonstrate the feasibility of a multi-degree colorless, directionless, and contentionless (C/D/C-less) ROADM node composed of high port count wavelength-selective switches and transponder aggregators using silica-based planar lightwave circuit technology. The experimental results show that the introduction of a C/D/C-less function to a multi-degree ROADM node induces no significant penalty in a 127-Gbit/s PDM-QPSK signal transmission.