P. V. Mamyshev

Pulse-overlapped dispersion-managed data transmission and intrachannel four-wave mixing

We show that strong overlap of adjacent pulses in dispersion-managed return-to-zero transmission reduces pulse-to-pulse interaction and timing jitter. The limiting factors for this pulse-overlapped transmission are the amplitude fluctuations and the ghost pulse generation induced by four-wave mixing between spectral components within a single channel.

Demonstration of massive wavelength-division multiplexing over transoceanic distances by use of dispersion-managed solitons

By combining a special dispersion map that has nearly constant path-average dispersion, a hybrid amplification scheme involving backward-pumped Raman gain, and sliding-frequency guiding filters, we have demonstrated massive wavelength-division multiplexing at 10 Gbits/s per channel, error free (bit-error rate, </=1x10(-9) for all channels), without the use of forward error correction, over greater than 9000 km, using dispersion-managed solitons. The number of channels (27) was limited only by a temporary lack of amplifier power and gain flatness. Terabit capacities are to be expected in the near future.

Soliton collisions in wavelength-division-multiplexed dispersion-managed systems

In dense wavelength-division-multiplexed transmission with strong dispersion management, most pulses inevitably have many partial collisions with pulses of an interacting channel. These partial collisions, in conjunction with the effects of complete collisions, tend to produce unacceptably large timing jitter in high-bit-rate, long-distance transmission. With the use of frequency-guiding filters, however, the timing jitter is dramatically reduced and tends to remain indefinitely clamped to acceptably small levels.

Time-division multiplexing of pump wavelengths to achieve ultrabroadband, flat, backward-pumped Raman gain

We describe a simple scheme, which we call the Raman smart pump, to allow for the achievement of flat gain over broad bands with backward-pumped Raman amplification. The proposed method, based on time-division multiplexing, also removes all interaction among the various pump wavelengths and allows for dynamic gain control through simple electronic means.

Effect of guiding filters on the behavior of dispersion-managed solitons.

We show that guiding filters fundamentally alter the behavior of dispersion-managed soltions by making the pulse energy nearly independent of path-average dispersion (D?) in the neighborhood of D?=0 . This fact enables one to design maps permitting adequate pulse energy with narrow-bandwidth, temporally broad pulses for the attainment of high spectral efficiency and reduced nonlinear penalties in wavelength-division multiplexing.

Dispersion-managed solitons for terrestrial transmission

We describe a scheme involving the insertion of segments of dispersion-compensating fiber, pumped to yield Raman gain, at one or more intermediate points within each 80-km-or-greater span between amplifier huts. With dispersion-managed solitons, the scheme is expected to allow for error-free, many-channel wavelength-division multiplexing, with high spectral efficiency, over transmission distances of many thousands of kilometers.

Guiding filters for massive wavelength division multiplexing in soliton transmission.

In soliton transmission, third-order dispersion of the transmission fibers tends to cause unacceptable variation in the filter strength parameter eta over the wide wavelength bands required for massive wavelength division multiplexing. We show how to vary the mirror reflectivities of etalon filters with wavelength, such that eta , in soliton units, nevertheless remains at the optimal value across the entire transmission band, and we show how to achieve the required R(lambda) accurately and reproducibly by making the etalons from gratings written in fiber.

Experimental Demonstration of Massive WDM Overtransoceanic Distances Using Dispersion Managed Solitons

By combining a special dispersion map having nearly constant path-average dispersion, a hybrid amplification scheme involving backward-pumped Raman gain, and sliding-frequency guiding filters, we have demonstrated massive WDM at 10 Gbit/s per channel, error free (BER ≤1×10−9 for all channels), without the use of forward error correction, over greater than 9000 km, using dispersion managed solitons. The number of channels (27) was limited only by a temporary lack of amplifier power and gain flatness. Terabit capacities are to be expected in the near future.