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

Index profile grading and elimination of the central dip have yielded the lowest loss ever reported for modified chemical vapor deposition-made highly GeO/sub 2/-doped single-mode fibers (1.33 dB/km at 1550 nm for /spl Delta/=2.9%). Investigation of the angular distribution of scattering has shown that much of the optical loss in such fibers is due to anomalous scattering. This scattering arises in the region of the central dip in the refractive index profile and at the core-cladding interface.

On the origin of excess loss in highly GeO/sub 2/-doped single-mode MCVD fibers

Characteristics of one-cascade (106 ⇒ 124 µ m) and two-cascade (106 ⇒ 124 ⇒ 148 µ m) phos- phorus-doped fiber Raman lasers are studied The cavities of both lasers are formed by Bragg gratings written directly in the active fiber Double-cladding Yb 3+ and Nd 3+ ion fiber lasers with λ ~ 106 µ m were employed for pumping These lasers were pumped, in their turn, by diode laser arrays with λ ~ 098 µ m (Yb) and λ ~ 081 µ m (Nd) The efficiency of the one-cascade laser with an unprecedentedly short length of 50 m was as high as 65% with 48-W pump radiation applied to the input of the laser The maximum efficiency of the two-cascade Raman fiber laser was 40% Gratings directly written in the active fiber reduced concentrated losses in laser cavities, which allowed the laser length to be decreased and the lasing threshold power of Raman fiber lasers to be low- ered

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Highly efficient one- and two-cascade Raman lasers based on phosphosilicate fibers

A new method is proposed for fundamental soliton train generation from a CW double-frequency signal. This scheme uses multisoliton precompression in a fibre with sharply increasing dispersion followed by adiabatic compression in a dispersion decreasing fibre.

High repetition rate CW fundamental soliton generation using multisoliton pulse compression in a varying dispersion fibre

A long period fibre gratings written in phosphorous doped fibre using CO-laser exhibited a high resistance to a thermal decay. Adiabatic mode field converters fabricated in P-doped fiber by heat treatment in electric arc discharge possess high mode expansion ratio and low losses.

http://ieeexplore.ieee.org/iel4/5897/15800/00732615.pdf

Long-period fiber gratings and mode-field converters fabricated by thermodiffusion in phosphosilicate fibers

The properties of IR emission centers are investigated in Bi-doped Mg-Al-silicate glasses having moderate melting temperatures to be fabricated by routine melting in alumina crucibles. The quadratic concentration dependence of absorption in the visible range indicates that the considered optical centers can be Bi2 dimers forming in a balanced chemical reaction in the glass melt. Their formation enthalpy is evaluated from their concentration variations with the synthesis temperature. The high (up to 85% at low concentrations) luminescence quantum yield and wide emission spectrum makes this glass a promising material for tunable lasers.

E. M. Dianov

Papers

On the origin of excess loss in highly GeO/sub 2/-doped single-mode MCVD fibers

Highly efficient one- and two-cascade Raman lasers based on phosphosilicate fibers

High repetition rate CW fundamental soliton generation using multisoliton pulse compression in a varying dispersion fibre

Long-period fiber gratings and mode-field converters fabricated by thermodiffusion in phosphosilicate fibers

The IR emitting centers in Bi-doped Mg-Al-Si oxide glasses