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Slepian eigenvalues as tunnelling rates (2022)
Journal Article
Creagh, S. C., & Gradoni, G. (2023). Slepian eigenvalues as tunnelling rates. Annals of Physics, 449, Article 169204. https://doi.org/10.1016/j.aop.2022.169204

We calculate the eigenvalues of an integral operator associated with Prolate Spheroidal Wave Functions (or Slepian functions) by interpreting them as tunnelling probabilities in an analogous quantum problem. Doing so allows us to extend a well-known... Read More about Slepian eigenvalues as tunnelling rates.

Acoustic radiation from random waves on plates (2022)
Journal Article
Mohammed, N. M., Creagh, S. C., & Tanner, G. (2022). Acoustic radiation from random waves on plates. Journal of Physics A: Mathematical and Theoretical, 55(39), Article 394004. https://doi.org/10.1088/1751-8121/ac8c08

Controlling and simulating the sound radiating from complex structures is of importance in many engineering applications. We calculate the radiated acoustic power from plates with diffuse bending vibrations. We characterise the diffuse field by a two... Read More about Acoustic radiation from random waves on plates.

Wireless power distributions in multi-cavity systems at high frequencies (2021)
Journal Article
Adnan, F., Blakaj, V., Phang, S., Antonsen, T. M., Creagh, S. C., Gradoni, G., & Tanner, G. (2021). Wireless power distributions in multi-cavity systems at high frequencies. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 477(2245), Article 20200228. https://doi.org/10.1098/rspa.2020.0228

The next generations of wireless networks will work in frequency bands ranging from sub-6 GHz up to 100 GHz. Radio signal propagation differs here in several critical aspects from the behaviour in the microwave frequencies currently used. With wavele... Read More about Wireless power distributions in multi-cavity systems at high frequencies.

Tunnelling around bends—Wave scattering in curved shell structures (2020)
Journal Article
Mohammed, N. M., Creagh, S. C., & Tanner, G. (2021). Tunnelling around bends—Wave scattering in curved shell structures. Wave Motion, 101, Article 102697. https://doi.org/10.1016/j.wavemoti.2020.102697

A ray dynamics describing wave transport on curved and smooth thin shells can be obtained from the underlying wave equations via the Eikonal approximation. We analyse mid-frequency effects near the ring frequency for curved plates consisting of a cyl... Read More about Tunnelling around bends—Wave scattering in curved shell structures.

Diffraction of Wigner functions (2020)
Journal Article
Creagh, S., Sieber, M., Gradoni, G., & Tanner, G. K. (2021). Diffraction of Wigner functions. Journal of Physics A: Mathematical and Theoretical, 54(1), Article 015701. https://doi.org/10.1088/1751-8121/abc72a

We describe the contribution of diffractive orbits to semiclassical approximations of Wigner function propagators. These contributions are based on diffractively scattered rays used in the geometrical theory of diffraction (GTD). They provide an exte... Read More about Diffraction of Wigner functions.

Nearfield acoustical holography – a Wigner function approach (2020)
Journal Article
Ramapriya, D. M., Gradoni, G., Creagh, S. C., Tanner, G., Moers, E., & Lopéz Arteaga, I. (2020). Nearfield acoustical holography – a Wigner function approach. Journal of Sound and Vibration, 486, Article 115593. https://doi.org/10.1016/j.jsv.2020.115593

We propose to use Wigner transformation methods as a tool for propagating measured acoustic signals from and towards a source region. We demonstrate the usefulness of the approach both for source reconstruction purposes and as a stable numerical simu... Read More about Nearfield acoustical holography – a Wigner function approach.

Modeling propagation in large deformed step-index fibers using a finite operator method (2019)
Journal Article
Kumar, D. S., Creagh, S. C., Sujecki, S., & Benson, T. M. (2019). Modeling propagation in large deformed step-index fibers using a finite operator method. Journal of the Optical Society of America B, 36(5), 1208-1221. https://doi.org/10.1364/josab.36.001208

© 2019 Optical Society of America. A finite operator model is applied to the propagation of light in deformed step-index fibers. The distribution of the light captured by the fiber from an arbitrary initial excitation is illustrated in the phase spac... Read More about Modeling propagation in large deformed step-index fibers using a finite operator method.

Analysis of Nonstationary Emissions for Efficient Characterization of Stochastic em Fields (2018)
Conference Proceeding
Baharuddin, M. H., Smartt, C., Maricar, M. I., Thomas, D. W., Gradoni, G., Creagh, S. C., & Tanner, G. (2018). Analysis of Nonstationary Emissions for Efficient Characterization of Stochastic em Fields. In 2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE) (208-213). https://doi.org/10.1109/EMCEurope.2018.8485104

A statistical approach using field-field correlation functions which is obtained from two-probe time domain measurement is used to characterize the radiation from complex devices. The time-frequency analysis provided by the measurement data has shown... Read More about Analysis of Nonstationary Emissions for Efficient Characterization of Stochastic em Fields.

Near-Field MIMO Communication Links (2018)
Journal Article
Phang, S., Ivrlac, M. T., Gradoni, G., Creagh, S. C., Tanner, G., & Nossek, J. A. (2018). Near-Field MIMO Communication Links. IEEE Transactions on Circuits and Systems I: Regular Papers, 65(9), 3027-3036. https://doi.org/10.1109/tcsi.2018.2796305

© 2004-2012 IEEE. A procedure to achieve near-field multiple input multiple output (MIMO) communication with equally strong channels is demonstrated in this paper. This has applications in near-field wireless communications, such as Chip-to-Chip (C2C... Read More about Near-Field MIMO Communication Links.

Near-field scanning and propagation of correlated low-frequency radiated emissions (2017)
Journal Article
Gradoni, G., Madenoor Ramapriya, D., Creagh, S. C., Tanner, G., Baharuddin, M. H., Nasser, H., …Thomas, D. W. (2017). Near-field scanning and propagation of correlated low-frequency radiated emissions. IEEE Transactions on Electromagnetic Compatibility, 60(6), 2045-2048. https://doi.org/10.1109/TEMC.2017.2778046

Electromagnetic radiation from complex printed circuit boards can occur over a broad frequency bandwidth, ranging from hundreds of MHz to tens of GHz. This is becoming a critical issue for assessment of EMC and interoperability as electronic componen... Read More about Near-field scanning and propagation of correlated low-frequency radiated emissions.

Theory and numerical modelling of parity-time symmetric structures in photonics: boundary integral equation for coupled microresonator structures (2017)
Book Chapter
Phang, S., Vukovic, A., Gradoni, G., Sewell, P., Benson, T. M., & Creagh, S. C. (2017). Theory and numerical modelling of parity-time symmetric structures in photonics: boundary integral equation for coupled microresonator structures. In Recent Trends in Computational Photonics. Springer Nature

The spectral behaviour and the real-time operation of Parity-Time (PT) symmetric coupled resonators are investigated. A Boundary Integral Equation (BIE) model is developed to study these structures in the frequency domain. The impact of realistic gai... Read More about Theory and numerical modelling of parity-time symmetric structures in photonics: boundary integral equation for coupled microresonator structures.

Wigner-Function-Based Propagation of Stochastic Field Emissions from Planar Electromagnetic Sources (2017)
Journal Article
Gradoni, G., Arnault, L. R., Creagh, S. C., Tanner, G., Baharuddin, M. H., Smartt, C., & Thomas, D. W. (2018). Wigner-Function-Based Propagation of Stochastic Field Emissions from Planar Electromagnetic Sources. IEEE Transactions on Electromagnetic Compatibility, 60(3), 580-588. https://doi.org/10.1109/TEMC.2017.2738329

© 1964-2012 IEEE. Modeling the electromagnetic radiation from modern digital systems - acting effectively as extended stochastic sources as part of a complex architecture - is a challenging task. We follow an approach here based on measuring and prop... Read More about Wigner-Function-Based Propagation of Stochastic Field Emissions from Planar Electromagnetic Sources.

Modelling chaos in asymmetric optical fibres (2017)
Conference Proceeding
Kumar, D. S., Creagh, S., Sujecki, S., & Benson, T. M. (2017). Modelling chaos in asymmetric optical fibres. In 2017 19th International Conference on Transparent Optical Networks (ICTON) (1-5). https://doi.org/10.1109/ICTON.2017.8024908

A ray dynamical approach is developed for the study of large-core asymmetric step index fibres (SIF), especially those made from chalcogenide glasses (ChGs) which can exhibit very high refractive index, large numerical aperture, and which are transpa... Read More about Modelling chaos in asymmetric optical fibres.

Propagating wave correlations in complex systems (2016)
Journal Article
Creagh, S. C., Gradoni, G., Hartmann, T., & Tanner, G. (2016). Propagating wave correlations in complex systems. Journal of Physics A: Mathematical and Theoretical, 50(4), Article 45101. https://doi.org/10.1088/1751-8121/50/4/045101

We describe a novel approach for computing wave correlation functions inside finite spatial domains driven by complex and statistical sources. By exploiting semiclassical approximations, we provide explicit algorithms to calculate the local mean of t... Read More about Propagating wave correlations in complex systems.

Theory and numerical modelling of parity-time symmetric structures in photonics: Introduction and grating structures in one dimension (2016)
Book Chapter
Phang, S., Benson, T. M., Susanto, H., Creagh, S. C., Gradoni, G., Sewell, P. D., & Vukovic, A. (2016). Theory and numerical modelling of parity-time symmetric structures in photonics: Introduction and grating structures in one dimension. In A. Agrawal, T. M. Benson, R. De La Rue, & G. Wurtz (Eds.), Recent trends in computational photonics (161-205). Springer. https://doi.org/10.1007/978-3-319-55438-9_6

A class of structures based on PT PT-symmetric Bragg gratings in the presence of both gain and loss is studied. The basic concepts and properties of parity and time reversal in one-dimensional structures that possess idealised material properties are... Read More about Theory and numerical modelling of parity-time symmetric structures in photonics: Introduction and grating structures in one dimension.

Parity-time symmetric chain resonators (2016)
Conference Proceeding
Phang, S., Vukovic, A., Creagh, S., Gradoni, G., Sewell, P., & Benson, T. M. (2016). Parity-time symmetric chain resonators.

A simple tight-binding model to study the band-structure of an infinite length Parity-time (PT) symmetric chain of resonators is presented in this paper. In the talk, we will investigate the impact of having a structure of finite length and consider... Read More about Parity-time symmetric chain resonators.

Localized single frequency lasing states in a finite parity-time symmetric resonator chain (2016)
Journal Article
Phang, S., Vukovic, A., Creagh, S. C., Sewell, P., Gradoni, G., & Benson, T. M. (2016). Localized single frequency lasing states in a finite parity-time symmetric resonator chain. Scientific Reports, 6, Article e20499. https://doi.org/10.1038/srep20499

In this paper a practical case of a finite periodic Parity Time chain made of resonant dielectric cylinders is considered. The paper analyzes a more general case where PT symmetry is achieved by modulating both the real and imaginary part of the mate... Read More about Localized single frequency lasing states in a finite parity-time symmetric resonator chain.

A phase-space approach for propagating field–field correlation functions (2015)
Journal Article
Gradoni, G., Creagh, S. C., Tanner, G., Smartt, C., & Thomas, D. W. (2015). A phase-space approach for propagating field–field correlation functions. New Journal of Physics, 17, Article 093027. https://doi.org/10.1088/1367-2630/17/9/093027

We show that radiation from complex and inherently random but correlated wave sources can be modelled efficiently by using an approach based on the Wigner distribution function. Our method exploits the connection between correlation functions and the... Read More about A phase-space approach for propagating field–field correlation functions.

Threshold manipulation in parity-time symmetric microresonator chain (2015)
Conference Proceeding
Phang, S., Vukovic, A., Creagh, S., Benson, T. M., Gradoni, G., & Sewell, P. D. (2015). Threshold manipulation in parity-time symmetric microresonator chain.

This paper analyses the eigenfrequencies of an infinitely long chain of microresonators with PT symmetry. The results show that the depth of modulation of the real part of the refractive index can be used to control the threshold point of the PT stru... Read More about Threshold manipulation in parity-time symmetric microresonator chain.

Parity-time chain of whispering-gallery mode resonators (2015)
Conference Proceeding
Phang, S., Vukovic, A., Creagh, S., Benson, T. M., Gradoni, G., & Sewell, P. D. (2015). Parity-time chain of whispering-gallery mode resonators.

The paper analyses the dispersion characteristics of an infinitely long PT chain made of whispering gallery resonators with gain/loss modulation. The results show that the appearance of the threshold breaking point depends not only on both of couplin... Read More about Parity-time chain of whispering-gallery mode resonators.