Philip St. J. Russell

Bio: Philip St. J. Russell is an academic researcher from Max Planck Society. The author has contributed to research in topics: Photonic-crystal fiber & Photonic crystal. The author has an hindex of 47, co-authored 356 publications receiving 16560 citations. Previous affiliations of Philip St. J. Russell include University of Southampton & University of Erlangen-Nuremberg.

Coherent octave-spanning mid-infrared supercontinuum generated in As2S3-silica double-nanospike waveguide pumped by femtosecond Cr:ZnS laser

Abstract: A more than 1.5 octave-spanning mid-infrared supercontinuum (1.2 to 3.6 μm) is generated by pumping a As2S3-silica “double-nanospike” waveguide via a femtosecond Cr:ZnS laser at 2.35 μm. The combination of the optimized group velocity dispersion and extremely high nonlinearity provided by the As2S3-silica hybrid waveguide enables a ~100 pJ level pump pulse energy threshold for octave-spanning spectral broadening at a repetition rate of 90 MHz. Numerical simulations show that the generated supercontinuum is highly coherent over the entire spanning wavelength range. The results are important for realization of a high repetition rate octave-spanning frequency comb in the mid-infrared spectral region.

Transmission filters based on periodically micro-tapered fibre

Abstract: Summary form only given.We have demonstrated a micro-taper based long-period grating with very narrow bandwidth optical response of 7 nm and extinction >20 dB. The wavelength response and bandwidths can be redesigned by choosing appropriate periods and grating lengths.

Optically induced creation, transformation, and organization of defects and color centers in optical fibers

Abstract: Over the past five years, a color-center model for the dynamics of the absorption induced in germanosilicate fibers upon exposure to blue/green light has been under development at Southampton. This model is introduced and its predictions used for the first time to test our proposed Kramers-Kronig mechanism for the concurrent refractive index changes induced in the visible and the infrared. It is found that the predicted color-center population changes in the UV are insufficient to explain these refractive index changes. A possible alternative model, based on density changes in the glass triggered by color-center formation, is assessed experimentally and analytically. The implications of this result to photonically driven self-organization in fibers is briefly assessed, and reference made to recent experimental results.

Scaling rules for high quality soliton self-compression in hollow-core fibers

Abstract: Soliton dynamics can be used to temporally compress laser pulses to few fs durations in many different spectral regions. Here we study analytically, numerically and experimentally the scaling of soliton dynamics in noble gas-filled hollow-core fibers. We identify an optimal parameter region, taking account of higher-order dispersion, photoionization, self-focusing, and modulational instability. Although for single-shots the effects of photoionization can be reduced by using lighter noble gases, they become increasingly important as the repetition rate rises. For the same optical nonlinearity, the higher pressure and longer diffusion times of the lighter gases can considerably enhance the long-term effects of ionization, as a result of pulse-by-pulse buildup of refractive index changes. To illustrate the counter-intuitive nature of these predictions, we compressed 250 fs pulses at 1030 nm in an 80-cm-long hollow-core photonic crystal fiber (core radius 15 µm) to ∼5 fs duration in argon and neon, and found that, although neon performed better at a repetition rate of 1 MHz, stable compression in argon was still possible up to 10 MHz.

Cavity Optomechanics

Abstract: We review the field of cavity optomechanics, which explores the interaction between electromagnetic radiation and nano- or micromechanical motion This review covers the basics of optical cavities and mechanical resonators, their mutual optomechanical interaction mediated by the radiation pressure force, the large variety of experimental systems which exhibit this interaction, optical measurements of mechanical motion, dynamical backaction amplification and cooling, nonlinear dynamics, multimode optomechanics, and proposals for future cavity quantum optomechanics experiments In addition, we describe the perspectives for fundamental quantum physics and for possible applications of optomechanical devices

Photonic crystal fibers

Abstract: Photonic crystal fibers guide light by corralling it within a periodic array of microscopic air holes that run along the entire fiber length Largely through their ability to overcome the limitations of conventional fiber optics—for example, by permitting low-loss guidance of light in a hollow core—these fibers are proving to have a multitude of important technological and scientific applications spanning many disciplines The result has been a renaissance of interest in optical fibers and their uses

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fiber grating sensors

Abstract: We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors.

Supercontinuum generation in photonic crystal fiber

Abstract: 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.