Probabilistic shaping based on constant composition distribution matching (CCDM) has received considerable attention as a way to increase the capacity of fiber optical communication systems. CCDM suffers from significant rate loss at short blocklengths and requires long achieve high gain, which makes its implementation very challenging. In this paper, we propose use enumerative sphere (ESS) investigate performance for nonlinear channel. ESS lower than same rate, it suitable candidate be...

Fiber nonlinearity has become a major limiting transmission impairment factor. In this paper, we discuss various mitigation techniques in electrical and optical domains. domain, multiple reduced complexity digital back-propagation algorithms were developed, including perturbation back-propagation. One drawback is that they can compensate for intra-channel self-phase modulation (SPM) effects only. The inter-channel fiber be done domain. For example, subcarrier multiplexing (SCM) effectively...

Nonlinear interference (NLI) generated during the propagation of an optical waveform through fiber depends on fourth order standardized moment channel input distribution, also known as kurtosis. Probabilistically-shaped inputs optimized for linear Gaussian have a Gaussian-like distribution with high For channels, this leads to increase in NLI power and consequently, decrease effective signal-to-noise ratio (SNR). In work, we propose kurtosis-limited enumerative sphere shaping (K-ESS)...

Three modulation formats are compared by numerical simulation of highly dense (75-GHz-spaced for 40 Gb/s channel), long-haul (600-1800 km) wavelength division multiplexed systems with three fiber types. Nonreturn-to-zero (NRZ) format, being the most spectrally compact and simplest in transmitter receiver configuration three, seems to be capable enough at shorter transmission distances than 1000 km regardless type. Carrier-suppressed return-to-zero (RZ) tolerant self-phase effect, showed...

We have proposed a dynamically configurable and fast optical impairment model for the abstraction of physical layer, enabling new capabilities such as indirect estimation operating parameters in multivendor networks based on pre-FEC BER information machine learning. is commonly reported by deployed coherent transponders; therefore, this scheme does not increase hardware cost. The estimated can subsequently be used to predict signal quality at receiver not-already-established connections more...

We transmit probabilistic enumerative sphere shaped dual-polarization 64-QAM at 350Gbit/s/channel over 1610km SSMF using a short blocklength of 200. A reach increase 15% constant composition distribution matching with identical is demonstrated.

Four dimensional geometric shell shaping (4D-GSS) is introduced as an approach for closing the nonlinearity-caused gap. This format designed at spectral efficiency of 8 b/4D-sym and compared against polarization-multiplexed 16QAM (PM-16QAM) probabilistically shaped PM-16QAM (PS-PM-16QAM) in a 400ZR-compatible transmission setup with high amount nonlinearities. Reach increase nonlinearity tolerance are evaluated terms achievable information rates post-FEC bit-error rate. Numerical simulations...

Intra-superchannel nonlinear crosstalk affects center subcarriers of multi-carrier superchannels more than the edge subcarriers; its impact on significantly increases with increase number subcarriers. Power pre-emphasis effectively equalizes performance and extends reach by 20%.

We propose a novel technique of balancing dispersion among spans to achieve significantly improved nonlinearity compensation using spectral inversion, which can effectively extend optical reach up 80% for 1 Tb/s DP-16QAM superchannel transmission over non-uniform links in the simulation study.

We experimentally demonstrate the benefit of a quality transmission estimator with learning process for modulation format provisioning. Monitoring BERs provisioned signals enables more efficient assignment format, resulting in 15% capacity increase 6 CD-ROADMs network test-bed.

The performance of enumerative sphere shaping (ESS), constant composition distribution matching (CCDM), and uniform signalling are compared at the same forward error correction rate. ESS is shown to offer a reach increase approximately 10% 22% CCDM signalling, respectively.

Band-trellis enumerative sphere shaping is proposed to decrease the energy variations in channel input sequences. Against shaping, 0.74 dB SNR gain and up 9% increase data rates are demonstrated for single-span systems.

We have compared by numerical simulations the performance of NRZ, CS-RZ and IM-DPSK modulation formats for 480 km 40 channels WDM transmission with SMF NZ-DSF fibers. has shown best tolerance to non-linear effects dispersion both types is an extremely attractive format long-haul Gbit/s systems.

Systematic investigation of XPM impact on QPSK signals reveals that higher symbol rates are advantageous for reducing both intra-span generation and multi-span accumulation phase noise.

We investigated PolMux-RZ-DQPSK signal degradation modes due to PDL and XPM in WDM transmission with co-propagating NRZ signals. SNR XPM-induced polarization dependent phase noise greatly impact system.

We propose a power profile estimator using MMSE, that automatically adjusts the scaling and nonlinear rotation of constellation with complex factor. demonstrate robust performance in simulation experiment, even at higher launch powers.

We analyzed the mechanism of interplay between PDL and fiber nonlinear effects in 112 Gb/s DP-QPSK systems showed that can generate large data-dependent optical peak power variations worsen tolerance cause an additional 1.4 dB Q-penalty.

We show that 32 GBaud single- and multi-carrier DP-QPSK can deliver longer reach for the same capacity as 64 DP-QPSK. However, signal provide 12% than single-carrier

We show significant gain in Virtual Optical Network (VON) capacity by provisioning based on Q-availabilities of optical channels instead fixed Q-margin. The Q-availability is calculated using stochastic simulations GN model.

In this work, we compare the performance of probabilistically shaped (PS) QAM systems with reference uniform under two conditions: (1) for same information rate (IR) and FEC rate; (2) entropy but resulting in different IRs. We demonstrate that unrealistically large system gains improved tolerance to fiber Kerr nonlinearity PS-QAM can be observed second condition due conduct a detailed analysis prove these are solely attributed reduced Also, show first IRs, more realistic shaping achieved...

In this paper we carry out a joint optimization of probabilistic (PS) and geometric shaping (GS) for four-dimensional (4D) modulation formats in long-haul coherent wavelength division multiplexed (WDM) optical fiber communications using an auto-encoder framework. We propose 4D 10 bits/symbol constellation which obtained via end-to-end deep learning over the split-step Fourier model channel. The achieved 13.6% reach increase at data rate approximately 400 Gbits/second comparison to...

Few-mode EDFAs with low channel crosstalk can replace multiple parallel single-mode in fiber trunk lines and networks. Here we proposed a low-crosstalk few-mode EDFA by exploiting the unitary property of coupling matrix symmetric photonic lantern. We experimentally demonstrated 3-channel using retro-reflection 3-mode The small signal gain for all three channels are measured to be larger than 25 dB over entire C-band crosstalks below -10 dB.

XPM impairments on 43 Gb/s single-polarization and dual-polarization RZ-DQPSK signals were compared under co-propagation of 11.1 NRZ channels with direct-detection. The higher symbol rate, format, showed a larger tolerance than the case.