35 citations · 89 across the 12 of their papers we have counts for
13 papers
Simultaneous Recovery of Dielectric Constants, Photoelastic Constants, and Strain Profiles from Picosecond Ultrasonic Echoes
Richard Wiltshaw, Motonobu Tomoda, Osamu Matsuda +3
Light reflected from a deforming solid depends on boundary motion and strain-induced modulation of the dielectric response. For a propagating acoustic field, scattering from differ…
Reconfigurable topological valley-Hall interfaces: Asymptotics of arrays of Dirichlet and Neumann inclusions for multiple scattering in metamaterials
Richard Wiltshaw, Henry J. Putley, Christelle Bou Dagher +1
We study two-dimensional periodic metamaterials in which idealised cylindrical inclusions are modelled by boundary conditions. In the scalar time-harmonic setting, the background f…
Fabry-Pérot quasinormal modes for topological edge states
Marc Martí-Sabaté, Benjamin Vial, Richard Wiltshaw +2
Topological waveguides supporting quantum valley Hall interfacial states confine waves to interfaces and, due to topological protection, are resistant to backscattering even in the…
Dispersion relations of generalized one-dimensional phononic crystals
Mario Lázaro, Richard Wiltshaw, Richard V. Craster +1
We present a comprehensive method for determining {both exact and approximate} dispersion {relations} for one-dimensional {resonant phononic} crystals, applicable to a wide range o…
Wave propagation in beams with multiple resonators: conditions for weak scattering and the Born approximation
Mario Lázaro, Richard Wiltshaw, Richard V. Craster +1
This work reports the conditions under which weak scattering assumptions can be applied in a beam loaded by multiple resonators supporting both longitudinal and flexural waves. The…
Platonic quasi-normal modes expansion
Benjamin Vial, Marc Martí Sabaté, Richard Wiltshaw +2
Elastic wave manipulation using large arrays of resonators is driving the need for advanced simulation and optimization methods. To address this we introduce and explore a robust f…
Analytical approximations for multiple scattering in one-dimensional waveguides with small inclusions
Mario Lázaro, Richard Wiltshaw, Richard Vaughan Craster +1
We propose a new model to approximate the wave response of waveguides containing an arbitrary number of small inclusions. The theory is developed to consider any one-dimensional wa…
Analytical solutions for Bloch waves in resonant phononic crystals: Deep subwavelength energy splitting and mode steering between topologically protected interfacial and edge states
Richard Wiltshaw, Jacopo Maria De Ponti, Richard Vaughan Craster
We derive analytical solutions based on singular Green's functions, which enable efficient computations of scattering simulations or Floquet-Bloch dispersion relations for waves pr…
Octet lattice-based plate for elastic wave control
Giulia Aguzzi, Constantinos Kanellopoulos, Richard Wiltshaw +3
Motivated by the importance of lattice structures in multiple fields, we investigate the propagation of flexural waves in a thin woven plate augmented with two classes of metastruc…
Acoustic topological circuitry in square and rectangular phononic crystals
Nicolas Laforge, Richard Wiltshaw, Richard V. Craster +6
We systematically engineer a series of square and rectangular phononic crystals to create experimental realisations of complex topological phononic circuits. The exotic topological…
Hybrid topological guiding mechanisms for photonic crystal fibers
Mehul P. Makwana, Richard Wiltshaw, Sébastien Guenneau +1
We create hybrid topological-photonic localisation of light by introducing concepts from the field of topological matter to that of photonic crystal fiber arrays. S-polarized obliq…
Asymptotic approximations for Bloch waves and topological mode steering in a planar array of Neumann scatterers
Richard Wiltshaw, Richard V. Craster, Mehul P. Makwana
We study the canonical problem of wave scattering by periodic arrays, either of infinite or finite extent, of Neumann scatterers in the plane; the characteristic lengthscale of the…
Tunable three-way valley Hall energy-splitter: venturing beyond graphene-like structures
Mehul P. Makwana, Gregory J. Chaplain
Strategically combining four structured domains creates the first ever three-way topological energy-splitter; remarkably, this is only possible using a square, or rectangular, latt…