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All Outputs (107)

Spontaneous self-synchronization mechanism for attosecond pulses (2008)
Presentation / Conference
Mcdonald, G., & Christian, J. (2008, August). Spontaneous self-synchronization mechanism for attosecond pulses. Poster presented at National Photonics Conference, Photon 08, Heriot-Watt University, Edinburgh, UK

Ultra-broadband multi-frequency Raman generation is a long-established technique for producing temporal bandwidths that can be of the order of the pump frequency. However, higher-than-optimal intensity beams reduce the bandwidth generated. Many works... Read More about Spontaneous self-synchronization mechanism for attosecond pulses.

Helmholtz solitons: fresh perspectives and new angles in photonics (2008)
Presentation / Conference
Christian, J., Mcdonald, G., & Chamorro-Posada, P. (2008, August). Helmholtz solitons: fresh perspectives and new angles in photonics. Poster presented at National Photonics Conference, Photon 08, Heriot-Watt University, Edinburgh, UK

Spatial solitons are self-localizing optical beams that can evolve with a stationary intensity profile when diffraction is off-set by material nonlinearity. Classic descriptions of spatial solitons [1] involve the paraxial approximation, which can im... Read More about Helmholtz solitons: fresh perspectives and new angles in photonics.

Soliton solutions of the nonlinear Helmholtz equation: propagation properties, interface effects and new families of exact solutions (2008)
Presentation / Conference
Chamorro-Posada, P., Sanchez-Curto, J., McDonald, G., & Christian, J. (2008, June). Soliton solutions of the nonlinear Helmholtz equation: propagation properties, interface effects and new families of exact solutions. Presented at Annual International Conference "Days on Diffraction" 2008, St. Petersburg, Russia

The properties of spatial optical solitons are most often studied using nonlinear Schroedinger (NLS) equations. These model the slow modulation the envelope of a linear wave solution experiences when propagation takes place in a wealky nonlinear medi... Read More about Soliton solutions of the nonlinear Helmholtz equation: propagation properties, interface effects and new families of exact solutions.

Helmholtz solitons: Maxwell’s equations, interfaces, bistability & counterpropagation (2008)
Presentation / Conference
Chamorro-Posada, P., Sanchez-Curto, J., Grikurov, V., McDonald, G., & Christian, J. (2008, June). Helmholtz solitons: Maxwell’s equations, interfaces, bistability & counterpropagation. Presented at Days on Diffraction, 2008. DD '08 International Conference, St. Petersburg, Russia

We give a brief overview of some new results in Helmholtz soliton theory. Firstly, fundamental considerations are made in terms of new contexts for Helmholtz solitons that arise directly from Maxwells equations. We then detail applications of Helmhol... Read More about Helmholtz solitons: Maxwell’s equations, interfaces, bistability & counterpropagation.

Broadband nonlinear optics: fractals, white light and multiplexing (2005)
Presentation / Conference
McDonald, G., Christian, J., Huang, J., Laughton, G., Chamorro-Posada, P., & Sanchez-Curto, J. (2005, February). Broadband nonlinear optics: fractals, white light and multiplexing. Presented at New Trends in Nonlinear Optics, Univesity of Strathclyde, Glasgow, UK

We will present an overview of some recent works that collectively fall under the banner of “broadband nonLinear optics”. Firstly, a generic mechanism for the spontaneous formation of spatial optical fractals has been proposed. Willie’s classic singl... Read More about Broadband nonlinear optics: fractals, white light and multiplexing.

Multi-Turing instabilities and spatial patterns in discrete systems : simplicity and complexity, cavities and counterpropagation
Presentation / Conference
Bostock, C., Christian, J., Leite, A., McDonald, G., & Huang, J. Multi-Turing instabilities and spatial patterns in discrete systems : simplicity and complexity, cavities and counterpropagation. Poster presented at 6th European Optical Society Annual Meeting (EOSAM 2016), Berlin Adlershof, Germany

The spontaneous pattern-forming properties of three discrete nonlinear optical systems are investigated, including the proposal of two new physical contexts for coupled-waveguide geometries. Linear analyses predict Turing threshold instability spe... Read More about Multi-Turing instabilities and spatial patterns in discrete systems : simplicity and complexity, cavities and counterpropagation.

Vector waves with spatiotemporal dispersion and \chi(3) nonlinearity : transformations and relativity, solitons and stability
Presentation / Conference
Carter, L., Christian, J., & McDonald, G. Vector waves with spatiotemporal dispersion and \chi(3) nonlinearity : transformations and relativity, solitons and stability. Poster presented at 6th European Optical Society Annual Meeting (EOSAM 2016), Berlin Adlershof, Germany

A vector model, fully-second-order in both space and time, is proposed for coupled electromagnetic modes in nonlinear waveguides. Our formalism has strong overlaps with the special relativity. Exact two-component solitons are derived, asymptotic a... Read More about Vector waves with spatiotemporal dispersion and \chi(3) nonlinearity : transformations and relativity, solitons and stability.

Dissipative solitons of a spatiotemporal Ginzburg-Landau equation
Presentation / Conference
Cooper, A., Christian, J., Bresnahan, D., McDonald, G., & Chamorro-Posada, P. Dissipative solitons of a spatiotemporal Ginzburg-Landau equation. Presented at Quantum Electronics and Photonics Conference (Photon14/QEP-21), Imperial College London, UK

Diffraction of fractal light by simple apertures
Presentation / Conference
Mylova, M., Christian, J., & McDonald, G. Diffraction of fractal light by simple apertures. Presented at Quantum Electronics and Photonics Conference (Photon14/QEP-21), Imperial College London, UK

We propose and investigate, for the first time to our knowledge, an entirely new regime in wave physics  the diffraction of fractal waves from simple apertures. A selection of new analyses and physical predictions will be given for experimental g... Read More about Diffraction of fractal light by simple apertures.

Spatiotemporal vector solitons in nonlinear optical systems with \chi(3) susceptibility
Presentation / Conference
Ashley, J., Christian, J., McDonald, G., & Chamorro-Posada, P. Spatiotemporal vector solitons in nonlinear optical systems with \chi(3) susceptibility. Presented at 5th European Optical Society Annual Meeting, Berlin, Germany

A new model is proposed for describing coupled optical waves propagating in a system with linear dispersion (both group-velocity and spatial contributions) \chi(3 nonlinear susceptibility. The modulational instability problem is solved in full, and... Read More about Spatiotemporal vector solitons in nonlinear optical systems with \chi(3) susceptibility.

Multi-turing instabilities in Fabry-Perot resonators and discrete microcavities
Presentation / Conference
Bostock, C., Christian, J., McDonald, G., Leite, A., & Huang, J. Multi-turing instabilities in Fabry-Perot resonators and discrete microcavities. Presented at 5th European Optical Society Annual Meeting, Berlin, Germany

We report on research concerning spontaneous spatial fractal pattern formation in passive nonlinear optical cavities (both ring-resonator and Fabry-Pérot geometries). A new model for light propagation inside discrete coupled cavities is proposed... Read More about Multi-turing instabilities in Fabry-Perot resonators and discrete microcavities.

Diffraction of fractal optical fields by simple apertures
Presentation / Conference
Christian, J., Mylova, M., & McDonald, G. Diffraction of fractal optical fields by simple apertures. Presented at 5th European Optical Society Annual Meeting, Berlin, Germany

We propose and investigate, for the first time to our knowledge, an entirely new regime in wave physics  the diffraction of fractal waves from simple apertures. A selection of new analyses and physical predictions will be given for experimental... Read More about Diffraction of fractal optical fields by simple apertures.

Unstable cavity lasers - from kaleidoscopes to snowflakes
Presentation / Conference
Christian, J., Begleris, I., McDonald, G., & Huang, J. Unstable cavity lasers - from kaleidoscopes to snowflakes. Presented at 5th European Optical Society Annual Meeting (EOSAM 2014), Berlin, Germany

The snowflake laser is proposed  a new class of unstable resonator whose feedback mirror has the shape of the von Koch snowflake. Theoretical analysis is undertaken with two-dimensional virtual source theory, and predictions of novel mode patt... Read More about Unstable cavity lasers - from kaleidoscopes to snowflakes.

The spatiotemporal wave equation with a dual power-law nonlinearity
Presentation / Conference
Cowey, R., Christian, J., & McDonald, G. The spatiotemporal wave equation with a dual power-law nonlinearity. Poster presented at Salford Postgraduate Annual Research Conference (SPARC 2013), University of Salford

Solitons and soliton-like emergent phenomena appear ubiquitously throughout nonlinear science. These waves are truly fundamental entities, transcending the physical details of a system and resulting whenever linear dispersion (which tends to broaden... Read More about The spatiotemporal wave equation with a dual power-law nonlinearity.

Spatiotemporal dark and anti-dark solitons in cubic-quintic photonic systems
Presentation / Conference
Cowey, R., Christian, J., & McDonald, G. Spatiotemporal dark and anti-dark solitons in cubic-quintic photonic systems. Presented at Salford Postgraduate Annual Research Conference (SPARC 2013), University of Salford

In a recent publication, Christian et al. [Phys. Rev. Lett. vol. 108, art. no. 034101 (2012)] developed a novel mathematical formalism for describing pulses in generic wave-based systems. When applied to optical geometries, their proposed class of (... Read More about Spatiotemporal dark and anti-dark solitons in cubic-quintic photonic systems.

Helmholtz surface wave propagation along nonlinear interfaces
Presentation / Conference
McCoy, E., Christian, J., & McDonald, G. Helmholtz surface wave propagation along nonlinear interfaces. Poster presented at Salford Postgraduate Annual Research Conference (SPARC 2013), University of Salford

When two dissimilar nonlinear photonic materials are placed together, the boundary between them forms an optical interface. A light beam (typically from a laser source) may then travel along the boundary as a surface wave, remaining trapped within t... Read More about Helmholtz surface wave propagation along nonlinear interfaces.