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

The evolution of reflectance spectra is recorded during Bragg gratings heat treatment in hydrogen atmosphere at a pressure of 8 MPa and temperatures up to 600 °C. 'Type I' and 'type IIA' gratings written in germanium- and nitrogen-doped-silica-core fibers are investigated. (2 pages)

http://ieeexplore.ieee.org/iel5/10509/33317/01576449.pdf

Behaviour of in-fibre Bragg gratings in hydrogen atmosphere at elevated temperature

Quantum yield of the luminescence radiation emitted from the metastable state of Nd 3+ in silicate glasses and Y 3 Al 5 O 12 crystals

Computer modelling of light propagation in optical fibres formed by vacancies in two-dimensional periodic lattices is performed using the MIT Photonic-Bands package to calculate fully vectorial definite-frequency eigenmodes of Maxwell's equations with periodic boundary conditions in a plane-wave basis. The lattices consist of cylindrical holes in bulk glass or of glass tubes with the holes and gaps between the tubes filled with air. Single-site hexagonal and square lattices, often studied both theoretically and experimentally and used in manufacturing silica glass-based photonic crystal optical fibres, are considered. The calculations are carried out for the 80TeO2–20WO3 tungsten–tellurite glass-based fibres with the refractive index frequency dispersion taken into account. The numerical solutions are analysed by the effective mode area approach. The modelled dependences of fundamental mode dispersion on geometrical parameters of the fibres are used to suggest tungsten–tellurite photonic crystal fibres of several types for parametric devices.

/pdf/computer-modelling-of-tungsten-tellurite-photonic-crystal-52y8wldmte.pdf

Computer modelling of tungsten–tellurite photonic crystal optical fibres for parametric fibre devices

The differential mode attenuation αm(λ) in the spectral region of OH absorption (1.2-1.6 μm) has been studied in SiO 2 /GeO 2 core graded-index fibres. It was found that the mode attenuation due to OH absorption K m (λ) at 1.39 μm had its maximum in the fibre core centre. The comparison between the calculated and measured K m (λ) at this wavelength could be used for the determination of OH-ion distribution profile in optical fibres.

Mode attenuation at 1.39 μm in graded-index fibres

We report a Raman laser with an output power of 4.2 W at 2.1 μm based upon a 75 mol.% GeO2 doped fiber pumped with CW Thulium doped fiber laser. Potential of 2.3 μm operation is discussed.

E. M. Dianov

Papers

Behaviour of in-fibre Bragg gratings in hydrogen atmosphere at elevated temperature

Quantum yield of the luminescence radiation emitted from the metastable state of Nd 3+ in silicate glasses and Y 3 Al 5 O 12 crystals

Computer modelling of tungsten–tellurite photonic crystal optical fibres for parametric fibre devices

Mode attenuation at 1.39 μm in graded-index fibres

2.1 μm CW Raman source in GeO 2 fiber