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

This paper gives the 2010 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. The 2010 adjustment takes into account the data considered in the 2006 adjustment as well as the data that became available from 1 January 2007, after the closing date of that adjustment, until 31 December 2010, the closing date of the new adjustment. Further, it describes in detail the adjustment of the values of the constants, including the selection of the final set of input data based on the results of least-squares analyses. The 2010 set replaces the previously recommended 2006 CODATA set and may also be found on the World Wide Web at physics.nist.gov/constants.

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CODATA Recommended Values of the Fundamental Physical Constants: 2006

The rise in output power from rare-earth-doped fiber sources over the past decade, via the use of cladding-pumped fiber architectures, has been dramatic, leading to a range of fiber-based devices with outstanding performance in terms of output power, beam quality, overall efficiency, and flexibility with regard to operating wavelength and radiation format. This success in the high-power arena is largely due to the fiber’s geometry, which provides considerable resilience to the effects of heat generation in the core, and facilitates efficient conversion from relatively low-brightness diode pump radiation to high-brightness laser output. In this paper we review the current state of the art in terms of continuous-wave and pulsed performance of ytterbium-doped fiber lasers, the current fiber gain medium of choice, and by far the most developed in terms of high-power performance. We then review the current status and challenges of extending the technology to other rare-earth dopants and associated wavelengths of operation. Throughout we identify the key factors currently limiting fiber laser performance in different operating regimes—in particular thermal management, optical nonlinearity, and damage. Finally, we speculate as to the likely developments in pump laser technology, fiber design and fabrication, architectural approaches, and functionality that lie ahead in the coming decade and the implications they have on fiber laser performance and industrial/scientific adoption.

High power fiber lasers: current status and future perspectives [Invited]

The history, fabrication, theory, numerical modeling, optical properties, guidance mechanisms, and applications of photonic-crystal fibers are reviewed

Photonic-Crystal Fibers

A review on the latest developments on graphene, written from the perspective of a chemist, is presented. The role of chemistry in bringing graphene research to the next level is discussed.

The chemistry of graphene

This paper presents a novel design and performance analysis of a multiple output wavelength composite Raman fiber converter. The converter comprises two sections: (1) phosphosilicate and (2) germanium (Ge) doped fiber sections. The characteristics and performance of the converter are analyzed by using numerical modeling techniques. The optimization of key parameters is performed to ensure the highest conversion performance. An overall conversion efficiency of 28% is achieved. The characteristics of the optimal regime are also analyzed. The optimal regime is rather tolerant to the deviation of key parameters from their optimal values.

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Multiple output wavelength composite Raman fiber converter

A qualitative analysis of a planar Bragg waveguide is done using coupled wave theory and rounded permittivity profile of the multilayer cladding Explicit formulae for trapped mode field distribution, ohmic and radiation losses are derived from the simplified dispersion equation Practical estimates of the waveguide parameters are given

Qualitative theory and modeling of hollow Bragg waveguides

Structure of hermetic-tin coatings of superhigh strength silica glass fibers

We have studied the influence of cross-sectional structure and bends on optical cross-talk in a multicore fibre. A reduced refractive index layer produced between the cores of such fibre with a small centre-to-centre spacing between neighbouring cores (27 μm) reduces optical cross-talk by 20 dB. The cross-talk level achieved, 30 dB per kilometre of the length of the multicore fibre, is acceptable for a number of applications where relatively small lengths of fibre are needed. Moreover, a significant decrease in optical cross-talk has been ensured by reducing the winding diameter of multicore fibres with identical cores.

Influence of fibre design and curvature on crosstalk in multi-core fibre

Summary form only given. The cascaded Raman fiber lasers pumped by Nd or Yb fiber lasers are effective tools for generating high-power cw radiation at wavelengths 1.24 and 1.48 /spl mu/m. However, germanosilicate fibers have a small Stokes frequency shift of 440 cm/sup -10/. This leads to the necessity of using the third and sixth Stokes orders to obtain the radiation with the wavelengths of 1.24 and 1.48 /spl mu/m correspondingly. Because of this, the structure of a cascaded Raman fiber laser consists of three and six pairs of Bragg gratings for 1.24 and 1.48 /spl mu/m. Besides the complexity and high cost of such cascaded Raman fiber lasers, the conversion efficiency is reduced with the growth of the Stokes order. The best option is a fiber with a large enough Stokes frequency shift to obtain 1.24 and 1.48 /spl mu/m radiation corresponding to Stokes lines of low order. A phosphosilicate fiber satisfies this requirement.

E. M. Dianov

Papers

Multiple output wavelength composite Raman fiber converter

Qualitative theory and modeling of hollow Bragg waveguides

Structure of hermetic-tin coatings of superhigh strength silica glass fibers

Influence of fibre design and curvature on crosstalk in multi-core fibre

Phosphosilicate fiber: simple high-power cw 1.24- and 1.48-/spl mu/m Raman lasers