N G van Kampen 1981 Amsterdam: North-Holland xiv + 419 pp price Dfl 180 This is a book which, at a lower price, could be expected to become an essential part of the library of every physical scientist concerned with problems involving fluctuations and stochastic processes, as well as those who just enjoy a beautifully written book. It provides an extensive graduate-level introduction which is clear, cautious, interesting and readable.

https://iopscience.iop.org/article/10.1088/0031-9112/34/4/040/pdf

Stochastic Processes in Physics and Chemistry

A topical review of numerical and experimental studies of supercontinuum generation in photonic crystal fiber is presented over the full range of experimentally reported parameters, from the femtosecond to the continuous-wave regime. Results from numerical simulations are used to discuss the temporal and spectral characteristics of the supercontinuum, and to interpret the physics of the underlying spectral broadening processes. Particular attention is given to the case of supercontinuum generation seeded by femtosecond pulses in the anomalous group velocity dispersion regime of photonic crystal fiber, where the processes of soliton fission, stimulated Raman scattering, and dispersive wave generation are reviewed in detail. The corresponding intensity and phase stability properties of the supercontinuum spectra generated under different conditions are also discussed.

Supercontinuum generation in photonic crystal fiber

We describe a method to estimate the capacity limit of fiber-optic communication systems (or ?fiber channels?) based on information theory. This paper is divided into two parts. Part 1 reviews fundamental concepts of digital communications and information theory. We treat digitization and modulation followed by information theory for channels both without and with memory. We provide explicit relationships between the commonly used signal-to-noise ratio and the optical signal-to-noise ratio. We further evaluate the performance of modulation constellations such as quadrature-amplitude modulation, combinations of amplitude-shift keying and phase-shift keying, exotic constellations, and concentric rings for an additive white Gaussian noise channel using coherent detection. Part 2 is devoted specifically to the "fiber channel.'' We review the physical phenomena present in transmission over optical fiber networks, including sources of noise, the need for optical filtering in optically-routed networks, and, most critically, the presence of fiber Kerr nonlinearity. We describe various transmission scenarios and impairment mitigation techniques, and define a fiber channel deemed to be the most relevant for communication over optically-routed networks. We proceed to evaluate a capacity limit estimate for this fiber channel using ring constellations. Several scenarios are considered, including uniform and optimized ring constellations, different fiber dispersion maps, and varying transmission distances. We further present evidences that point to the physical origin of the fiber capacity limitations and provide a comparison of recent record experiments with our capacity limit estimation.

Capacity Limits of Optical Fiber Networks

Real and Complex Analysis

Squeezed states of the electromagnetic field have been generated by nondegenerate four-wave mixing due to Na atoms in an optical cavity. The optical noise in the cavity, comprised of primarily vacuum fluctuations and a small component of spontaneous emission from the pumped Na atoms, is amplified in one quadrature of the optical field and deamplified in the other quadrature. These quadrature components are measured with a balanced homodyne detector. The total noise level in the deamplified quadrature drops below the vacuum noise level.

Observation of squeezed states generated by four-wave mixing in an optical cavity

We present a method for the accurate prediction of BER in nonlinear systems, taking into account the temporal correlations of the nonlinear interference noise and incorporating the effect of an adaptive receiver.

Correlations and phase noise in NLIN-modelling and system implications

A scheme to realize phase-sensitive amplification of light using a nonlinear coherent coupler is proposed Squeezed-light generation with low pump power and short interaction length is possible with this technique

Parametric amplification and squeezed-light generation in a nonlinear directional coupler.

We review the modeling of nonlinear interference noise (NLIN) in fiber communications, focusing on the accurate extraction of the NLIN variance, the dependence on modulation format, the role of nonlinear phase-noise and the existence of temporal correlations. We show ways in which temporal correlations can be exploited for reducing the impact of NLIN, and discuss the prospects of this procedure in future communication systems.

http://ieeexplore.ieee.org/iel7/6949035/6963816/06964231.pdf

Nonlinear interference noise in WDM systems and approaches for its cancelation

We characterize the joint two-time statistics of the polarization-mode dispersion (PMD) vector. Good agreement with experimental PMD measurements taken on an installed system is achieved. The results can be used to obtain the temporal evolution of the average penalty of a system close to an outage condition.

Statistics of the polarization mode dispersion dynamics.

The quantum theory of noise in a chain of gain–loss elements is reviewed. A new derivation is given of the characteristic function of the photon-number distribution at the output of a long amplifier chain. The results of the quantum theory are compared with those of the semiclassical theory, and it is shown that in most practical cases the semiclassical theory gives an excellent approximation of the full quantum result. It is shown that transparency sets a fundamental limit on the maximum distance over which a signal can be transmitted and hence on the maximum spacing between regenerative stations. An analytic estimate of this limit is given.

Antonio Mecozzi

Papers

Correlations and phase noise in NLIN-modelling and system implications

Parametric amplification and squeezed-light generation in a nonlinear directional coupler.

Nonlinear interference noise in WDM systems and approaches for its cancelation

Statistics of the polarization mode dispersion dynamics.

Quantum and semiclassical theory of noise in optical transmission lines employing in-line erbium amplifiers