Benny Mikkelsen

Bio: Benny Mikkelsen is an academic researcher from Alcatel-Lucent. The author has contributed to research in topics: Optical amplifier & Wavelength-division multiplexing. The author has an hindex of 24, co-authored 51 publications receiving 2455 citations.

Intra-channel cross-phase modulation and four-wave mixing in high-speed TDM systems

Abstract: A comprehensive numerical and experimental study of 40 Gbit/s RZ transmission is presented which reveals two new forms of nonlinear interactions that limit the speed of high-speed systems. Both limitations originate from nonlinear interactions among neighbouring bits. The first interaction involves cross-phase modulation and leads to timing fluctuations while the second interaction originates from four-wave mixing and leads to the creation of shadow pulses.

Integrated tunable fiber gratings for dispersion management in high-bit rate systems

Abstract: Dispersion management is becoming paramount in high-speed wavelength-division-multiplexed lightwave systems, that operate at per-channel rates of 40 Gb/s and higher. The dispersion tolerances, in these systems, are small enough that sources of dispersion variation, that are negligible in slower systems, become critically important to network performance. At these high-bit rates, active dispersion compensation modules may be required to respond dynamically to changes occurring in the network, such as variations in the per-channel power, reconfigurations of the channel's path that are caused by add-drop operations, and environmental changes, such as changes in ambient temperature. We present a comprehensive discussion of an emerging tunable dispersion compensating device, based on thermally actuated fiber gratings. These per-channel devices rely on a distributed on-fiber thin film heater, deposited onto the outer surface of a fiber Bragg grating. Current flowing through the thin film generates resistive heating at rates that are governed by the thickness profile of the metal film. A chirp in the grating is obtained by using a thin-film, whose thickness varies with position along the length of the grating in a prescribed manner; the chirp rate is adjusted by varying the applied current. The paper reviews some of the basic characteristics of these devices and their implementation, in a range of different applications, including the mitigation of power penalties associated with optical power variations. We present detailed analysis of the impact of group-delay ripple and polarization-mode dispersion on systems performance, and present results from systems experiments, that demonstrate the performance of these devices at bit rates of 10, 20, 40 and 160 Gb/s. We also discuss advantages and disadvantages of this technology, and compare to other devices.

100 Gbit/s All-Optical Wavelength Conversion with an Integrated SOA Delayed-Interference Configuration

Abstract: First all-optical 100 Gbit/s wavelength conversion employing cross-phase modulation is demonstrated with a recently introduced completely integrated and packaged delayed-interference configuration.

DWDM 40 G transmission over trans-Pacific distance (10,000 km) casing CSRZ-DPSK, enhanced FEC and all-Raman amplified 100 km UltraWave/spl trade/ fiber spans

Abstract: We demonstrate error-free dense-wavelength-division multiplexing (DWDM) transmission of 40 40-Gb/s channels with 100-GHz spacing over 10 000 km dispersion-managed fiber using carrier-suppressed return-to-zero differential-phase-shift keying (CSRZ-DPSK), enhanced foward-error correction, and all-Raman-amplified spans with 100-km terrestrial length.

100 Gbit/s all-optical wavelength conversion with integrated SOA delayed-interference configuration

Abstract: The authors report all-optical 100 Gbit/s wavelength conversion employing cross-phase modulation for the first time

Capacity Limits of Optical Fiber Networks

Abstract: 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.

Optical phase-shift-keyed transmission

Abstract: Differential-phase-shift keying (DPSK) has recently been used to reach record distances in long-haul lightwave communication systems. This paper will review theoretical, as well as implementation, aspects of DPSK, and discuss experimental results.

Roadmap on silicon photonics

Abstract: Silicon photonics research can be dated back to the 1980s. However, the previous decade has witnessed an explosive growth in the field. Silicon photonics is a disruptive technology that is poised to revolutionize a number of application areas, for example, data centers, high-performance computing and sensing. The key driving force behind silicon photonics is the ability to use CMOS-like fabrication resulting in high-volume production at low cost. This is a key enabling factor for bringing photonics to a range of technology areas where the costs of implementation using traditional photonic elements such as those used for the telecommunications industry would be prohibitive. Silicon does however have a number of shortcomings as a photonic material. In its basic form it is not an ideal material in which to produce light sources, optical modulators or photodetectors for example. A wealth of research effort from both academia and industry in recent years has fueled the demonstration of multiple solutions to these and other problems, and as time progresses new approaches are increasingly being conceived. It is clear that silicon photonics has a bright future. However, with a growing number of approaches available, what will the silicon photonic integrated circuit of the future look like? This roadmap on silicon photonics delves into the different technology and application areas of the field giving an insight into the state-of-the-art as well as current and future challenges faced by researchers worldwide. Contributions authored by experts from both industry and academia provide an overview and outlook for the silicon waveguide platform, optical sources, optical modulators, photodetectors, integration approaches, packaging, applications of silicon photonics and approaches required to satisfy applications at mid-infrared wavelengths. Advances in science and technology required to meet challenges faced by the field in each of these areas are also addressed together with predictions of where the field is destined to reach.

Coherent detection in optical fiber systems

Abstract: The drive for higher performance in optical fiber systems has renewed interest in coherent detection. We review detection methods, including noncoherent, differentially coherent, and coherent detection, as well as a hybrid method. We compare modulation methods encoding information in various degrees of freedom (DOF). Polarization-multiplexed quadrature-amplitude modulation maximizes spectral efficiency and power efficiency, by utilizing all four available DOF, the two field quadratures in the two polarizations. Dual-polarization homodyne or heterodyne downconversion are linear processes that can fully recover the received signal field in these four DOF. When downconverted signals are sampled at the Nyquist rate, compensation of transmission impairments can be performed using digital signal processing (DSP). Linear impairments, including chromatic dispersion and polarization-mode dispersion, can be compensated quasi-exactly using finite impulse response filters. Some nonlinear impairments, such as intra-channel four-wave mixing and nonlinear phase noise, can be compensated partially. Carrier phase recovery can be performed using feedforward methods, even when phase-locked loops may fail due to delay constraints. DSP-based compensation enables a receiver to adapt to time-varying impairments, and facilitates use of advanced forward-error-correction codes. We discuss both single- and multi-carrier system implementations. For a given modulation format, using coherent detection, they offer fundamentally the same spectral efficiency and power efficiency, but may differ in practice, because of different impairments and implementation details. With anticipated advances in analog-to-digital converters and integrated circuit technology, DSP-based coherent receivers at bit rates up to 100 Gbit/s should become practical within the next few years.

Advanced Optical Modulation Formats

Abstract: Fiber-optic communication systems form the high-capacity transport infrastructure that enables global broadband data services and advanced Internet applications. The desire for higher per-fiber transport capacities and, at the same time, the drive for lower costs per end-to-end transmitted information bit has led to optically routed networks with high spectral efficiencies. Among other enabling technologies, advanced optical modulation formats have become key to the design of modern wavelength division multiplexed (WDM) fiber systems. In this paper, we review optical modulation formats in the broader context of optically routed WDM networks. We discuss the generation and detection of multigigabit/s intensity- and phase-modulated formats, and highlight their resilience to key impairments found in optical networking, such as optical amplifier noise, multipath interference, chromatic dispersion, polarization-mode dispersion, WDM crosstalk, concatenated optical filtering, and fiber nonlinearity