Aiming at the reduction of computational complexity of conventional time-domain equalizers in digital coherent receivers, we propose and demonstrate a novel frequency-domain adaptive equalization technique based on the constant-modulus algorithm.
We demonstrate continuously-tunable optical delay using an optical FIR filter consisting of discrete time-delay elements. A 16-tap PLC-based FIR filter having a 10-ps unit time delay enables tunable delay in the range of ± 25 ps.
SUMMARY We design and demonstrate a high repetition-rate similari-ton generation system using normal dispersion fiber amplifiers (NDFA's). We numerically calculate the pulse evolution in NDFA's and clarify the condition to generate similariton pulses in a finite-length NDFA. Then we design the similariton generation system in consideration of the use of… (More)
SUMMARY We analyze the dispersion-managed optical transmission system for the non-return-to-zero (NRZ) pulse format. First, we investigate the physical image of dispersion management by computing small-signal-based transfer functions, and summarize the dependence of transmission performance on system parameters. Next, the Q-map is computed numerically to… (More)
After reviewing the principle of coherent optical modulation and demodulation, we discuss problems of future development of multi-level optical transmission systems, which include multi-level modulation, laser-linewidth requirements, and fiber nonlinearity mitigation.