A5060970330- Near-Field Optical Microscopy
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Laser-induced spectroscopy and plasma
- Orbital Angular Momentum in Optics
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- X-ray Diffraction in Crystallography
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Optical Coatings and Gratings
- Atomic and Subatomic Physics Research
- Advanced Electron Microscopy Techniques and Applications
- Computational Physics and Python Applications
- Diamond and Carbon-based Materials Research
- Machine Learning in Materials Science
- Quantum many-body systems
- nanoparticles nucleation surface interactions
- Radioactive Decay and Measurement Techniques
- Plasmonic and Surface Plasmon Research
- Crystallography and Radiation Phenomena
- Surface Roughness and Optical Measurements
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Nuclear Materials and Properties
University of Oxford
2018-2023
International Atomic Energy Agency
2017
Delft University of Technology
2015-2016
A fast noninvasive method based on scattering from a focused radially polarized light to detect and localize subwavelength nanoparticles substrate is presented. The technique relies polarization matching in the far field between scattered spurious reflected fields. Results show localization uncertainty of ≈10^{-4}λ^{2} possible for particle area ≈λ^{2}/16. effect simple pupil shaping also shown.
Abstract The advent of x-ray free-electron lasers has enabled a range new experimental investigations into the properties matter driven to extreme conditions via intense x-ray-matter interactions. femtosecond timescales these interactions lead creation transient high-energy-density plasmas, where both electrons and ions may be far from local thermodynamic equilibrium. Predictive modelling such systems remains challenging because different at which thermalize, vast number atomic...
Electron-ion collisional dynamics is of fundamental importance in determining plasma transport properties, nonequilibrium evolution, and electron damage diffraction imaging applications using bright x-ray free-electron lasers (FELs). Here we describe the first experimental measurements ultrafast impact ionization resonant core-hole spectroscopy a solid-density magnesium plasma, created diagnosed with Linac Coherent Light Source FEL. By resonantly pumping 1s→2p transition highly charged ions...
We present experimental observations of K_{β} emission from highly charged Mg ions at solid density, driven by intense x rays a free electron laser. The presence indicates the n=3 atomic shell is relocalized for high charge states, providing an upper constraint on depression ionization potential. explore process state relocalization in dense plasmas first principles using finite-temperature density functional theory alongside wave-function localization metric, and find excellent agreement...
The development of high-brightness free-electron lasers (FEL) has revolutionised our ability to create and study matter in the high-energy-density (HED) regime. Current diagnostic techniques have been very successful yielding information on fundamental thermodynamic plasma properties, but provide only limited or indirect detailed quantum structure these systems, how it is affected by ionization dynamics. Here we show electronic solid-density nickel, heated temperatures 10's eV femtosecond...
Spot size reduction is demonstrated by printing focused spots from amplitude-modulated radially polarized light at the wavelength λ = 405 nm on a photoresist. Amplitude modulation realized ring illumination and application of an optimized amplitude distribution function. implemented via spatial modulator, which followed specially designed radial wire grid polarizer to obtain high-quality light. Comparison between full modulated apertures written photoresist performed. Rigorous simulations...
Conventional solid-density laser-plasma targets quickly ionize to make a plasma mirror, which largely reflects ultra-intense laser pulses. This Fresnel reflection at the plane boundary wastes our e orts laser/solid interaction, and limits target heating nonlinear generation of high-energy electrons penetrate inward. One way around this dual problem is create material with an anisotropic dielectric function, for instance by nanostructuring in such that it cannot support responses generate...
Closed formulas are presented for the electromagnetic field of given power in lens pupil, which maximizes longitudinal electric when focusing through an interface at arbitrary depth along optical axis. The optimum pupil is found to be a continuous, monotonously increasing function radial coordinate, differs considerably from commonly used annular illumination. Several cases fields and focused shown different materials, NA, depth. Also, effect absorbing media considered.