40-krad/s Polarization Tracking in 200-Gb/s PDM-RZ-DQPSK Transmission Over 430 km

Performance Comparison of Differential 8-Ary Modulation Formats in High-Speed Optical Transmission Systems

“…However, in the case of experimental DQP-ASK, the optimum ratio of the two intensity levels is found to be 4.7 dB. Although approximately 2 dB deviated from the theory, it is consistent with that experimentally reported in [3], [4]. The difference between the analytical and experimental optimum ratio indicates that the experimental phase tributaries of DQP-ASK perform slightly worse than ideal.…”

“…Each phase tributary was measured separately by applying phase offsets to one arm of the DLI ( for DQP-ASK, and for D8PSK), yielding 3 (including the amplitude tributary) and 4 different error rates. By assuming that Gray coding is implemented and that symbol errors only occur between neighboring symbols, the BER of the system is then, assuming the average of these error rates in the case of DQP-ASK [3], [4] and the average multiplied by 4/3 in the case of D8PSK [17], [18].…”

“…For instance, Gnauck et al [1] reported a 1-bit/symbol format, binary DPSK (DBPSK), with the symbol rate of 43 Gbaud (corresponding to 86 Gbit/s in the polarization multiplexed system). Furthermore, B. Koch et al [2], [3] Gbit/s. Moreover, 3-bit/symbol formats, 8-ary DP-ASK (DQP-ASK) and 8-ary DPSK (D8PSK), were shown in [4]- [7], both achieving the same record bit-rate of 240 Gbit/s over a single wavelength with the corresponding symbol rate of 40 Gbaud.…”

A self-coherent receiver for detection of PolMUX coherent signals

“…The first method resorts to an external polarization controller for manually [11,12] or automatically aligning the signal to the receiver polarization axis [13][14][15]. No special signal format is needed.…”

100 krad/s endless polarisation tracking with miniaturised module card

“…Even more importantly, the optical solution consumes less power and can easily be applied to data rates of 200 Gbit/s [2] or higher. For a direct-detection optical polarisation diversity arrangement [3] the latter is not evident.…”