Dark optical solitons: physics and applications

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

Advanced Optical Modulation Formats

流体力学杂志“Journal of Fluid Mechanics”由剑桥大学教授George Batchelor在1956年5月创办，在国际流体力学界享有很高的学术声望，被公认为是流体力学最著名的学术刊物之一，2005年的影响因子为2．061，雄居同类期刊之首．在它创刊50周年之际，2006年5月JFM出版了第554卷的纪念特刊，其中刊登了现任主编（美国西北大学S．H．Davis教授和英国剑桥大学T．J．Pedley教授）合写的述评：“Editorial：JFM at50”，以JFM为背景，从独特的视角对近50年来流体力学的发展进行了简明的回顾和展望，并归纳了一系列非常有启发性的有趣统计数字．2006年7月21日在剑桥大学应用数学和理论物理研究所（DAMTP）举行了创刊50周年的庆祝会．下午2点，JFM的新老编辑和来宾会聚一堂，Pedley教授致开幕词，其后是5个精彩的报告：The mysterious rattleback and its fluid counterpart（Keith Moffatt），Developments in shear instabilities（Patrick Huerre），Falling clouds（Elisabeth Guazzelli），Ecotectural fluid mechanics（Paul Linden），The success of JFM（Herbert Huppert），最后由Davis教授致闭幕词．

Journal of Fluid Mechanics创刊50周年

The field of nonlinear dispersive waves has developed enormously since the work of Stokes, Boussinesq and Korteweg–de Vries (KdV) in the nineteenth century. In the 1960s, researchers developed effective asymptotic methods for deriving nonlinear wave equations, such as the KdV equation, governing a broad class of physical phenomena that admit special solutions including those commonly known as solitons. This book describes the underlying approximation techniques and methods for finding solutions to these and other equations. The concepts and methods covered include wave dispersion, asymptotic analysis, perturbation theory, the method of multiple scales, deep and shallow water waves, nonlinear optics including fiber optic communications, mode-locked lasers and dispersion-managed wave phenomena. Most chapters feature exercise sets, making the book suitable for advanced courses or for self-directed learning. Graduate students and researchers will find this an excellent entry to a thriving area at the intersection of applied mathematics, engineering and physical science.

Nonlinear Dispersive Waves: Asymptotic Analysis and Solitons

A bound state of temporal solitons in optical fibers is predicted numerically and demonstrated experimentally. It is appropriately described as a pair of bright solitons, bound together by a dark soliton. This structure exists only in dispersion-managed fiber and is different from bound solitons in fiber lasers.

https://lecture.ecc.u-tokyo.ac.jp/~cwpgally/archive/2005winter/references/200510_Molecules_of_Light_original_paper.pdf

Experimental observation of temporal soliton molecules.

Recent Progress in Dispersion-Managed Soliton Transmission Technologies

A novel all-optical modulation-format conversion from nonreturn-to-zero on-off keying (NRZ-OOK) to return-to-zero binary phase-shift keying (RZ-BPSK) is proposed. A Mach-Zehnder interferometric (MZI) wavelength converter consisting of integrated semiconductor optical amplifiers (SOAs) is utilized to implement the proposed format conversion. Error-free operation at a bit rate of 10.7 Gb/s is experimentally demonstrated in order to show the feasibility of the proposed scheme. The received sensitivity of the converted signal is improved by 2.9 dB compared with a back-to-back NRZ-OOK signal at BER=10 -9. In addition, a reasonable dispersion tolerance of the converted signal up to plusmn500 ps/nm is observed. The numerical simulation based upon the carrier-rate equation verifies the experimental results

NRZ-OOK-to-RZ-BPSK modulation-format conversion using SOA-MZI wavelength converter

We propose an all-optical modulation format conversion scheme from non-return-to-zero on-off-keying (NRZ-OOK) to return-to-zero (RZ) multiple-level phase-shift-keying (PSK) based on nonlinearity in optical fiber. The proposed conversion scheme is numerically investigated and experimentally demonstrated. We experimentally demonstrate error-free operation of NRZ-OOK/RZ- binary PSK conversion at 10.7 Gb/s. The operation of the NRZ-OOK/RZ-quadrature PSK conversion is shown by eye opening after balanced receiving at a symbol rate of 10.7 Gsymbol/s. In addition, we demonstrate the feasibility of the modulation format conversion from NRZ-OOK to RZ-8-levels PSK by numerical simulation.

All-optical modulation format conversion from on-off-keying to multiple-level phase-shift-keying based on nonlinearity in optical fiber.

Current status and the future perspective of digital coherent technology for optical fiber and radio-over-fiber (RoF) transmission systems will be reviewed. For the starter, we will review two key digital coherent techniques; the coherent receiver and compensation techniques for the fiber nonlinearity-induced impairments. Next, we will present a commercial deployment of 100 G digital coherent long-haul optical fiber transmission system and the R&D challenge to 400 G and beyond transmission systems. Finally, we will turn our focus on digital coherent RoF transmission systems. We will introduce an ongoing government-funded R&D program in Japan, entitled “Agile deployment capability of highly resilient optical and radio seamless communication systems.” It was initiated after the disaster in Japan in March 2011, aiming at optical fiber and millimeter-wave-band radio seamless transmission system. It would be a good use case of cutting-edge radio-over-fiber technology for an immediate social need.

Digital Coherent Technology for Optical Fiber and Radio-Over-fiber Transmission Systems

We describe the principle of a novel quantization scheme for all-optical analog-to-digital conversion. The proposed quantization is realized by slicing the supercontinuum spectrum with an arrayed waveguide grating. We conducted a proof-of-principle experiment of an optical three-level thresholding process and successfully demonstrated a two-bit optical quantizer, which shows the feasibility of the proposed scheme.

Akihiro Maruta

Papers

Recent Progress in Dispersion-Managed Soliton Transmission Technologies

NRZ-OOK-to-RZ-BPSK modulation-format conversion using SOA-MZI wavelength converter

All-optical modulation format conversion from on-off-keying to multiple-level phase-shift-keying based on nonlinearity in optical fiber.

Digital Coherent Technology for Optical Fiber and Radio-Over-fiber Transmission Systems

A novel quantization scheme by slicing supercontinuum spectrum for all-optical analog-to-digital conversion