Photon Factory

Laser micro-machining of industrial materials

Supervisor

Claude Aguergaray
Thomas Haase
Jeffery Low
Neil Broderick

Discipline

Photon Factory; Physics; Engineering

Project code: SCI093

Laser micromachining is now used in a variety of industries to produce micro-patterns on material surfaces with a high degree of control. Such processes enable a variety of manufacturing possibilities from hydrophobic surface patterning to improvement in sensor efficiency.

The student will engage with industries (to be disclosed) to manufacture and characterize specialized materials using laser micromachining. Part of this work will involve optimization of methods used within our research group as well as the development of new methods to better meet the needs of our industry partners.

The project provides hands on experience using pulsed lasers for material ablation and use of common profiling techniques, such as optical profiling and scanning electron microscopes, among others.

With this project you will get the chance to learn more about a broad variety of concepts ranging from laser physics and light-matter interaction to surface energies.

Fluctuations in superconductor sandwiches

Supervisor

Ben Mallett

Discipline

Photon Factory; Physics

Project code: SCI094

Superconducting sandwiches are multilayer thin-films of a high-temperature superconductor and a magnetic material. In these sandwiches, interactions between the two layers give rise to qualitatively new properties. In this project, we look at a regime where there are intrinsic fluctuations on second time-scales (at least) in the resistivity. The project will, through careful resistivity measurements in this regime, look to expose any systematics or statistics in these fluctuations characteristic of an electronic state close to criticality.

For students who are interested in:

  • experimental work with electrical measurements, vacuum and low temperatures!
  • using code and statistics to analyze data
  • phase-transitions / statistical mechanics

Blasting away superconductors

Supervisor

Ben Mallett
Steve Wells

Discipline

Photon Factory; Physics; Chemical Sciences; Engineering

Project code: SCI095

This project uses femto-second laser pulses to machine superconductors. Ultimately our lab will make interesting structures and patterns in superconductors, such as superconducting diodes. However, first we must understand the laser-induced damage to the superconductor. To best understand how well the laser machining works, we can measure an extensive property of the superconductor (SC) as we change the effective size of the SC using laser ablation. In particular, we can measure the critical current density, Ic, across a ‘channel’ or ‘bridge’ – a narrow region in the SC film. As the channel is made narrower with laser ablation, the scaling of Ic will reveal the extent of the damage region. This will be combined with SEM and optical profiling measurements.

For students who are interested in:

  • a laser and solid-state physics lab
  • materials processing and characterization

Magneto optical imaging

Supervisor

Steve Wells
Ben Mallett

Discipline

Photon Factory; Physics; Engineering

Project code: SCI096

This project will use magneto-optical imaging (MOI) to image magnetic fields in Fe and superconductors. MOI uses specialised indicator films to rotate polarised light by an amount proportional to magnetic field at each point (the Faraday effect). For the superconductors, the images will be quantified to determine field values, and calculate current in samples including superconducting films, 'bridges' and diodes.

For students who are interested in:

  • optics and electronics
  • magnetism and cryogenics

Raman hyperspectral imaging of skin

Supervisor

Dr Michel Nieuwoudt
Dr Hannah Holtkamp
Professor Cather Simpson

Discipline

Photon Factory; Chemical Sciences

Project code: SCI097

We are seeking a summer student interested in biomedical imaging using spectroscopy. The project will involve creating chemical images of skin using Raman hyperspectral imaging, by recording detailed Raman maps, and processing and analysing the Raman spectra using different classification algorithms in the Matlab chemometric toolbox HYPER-tools.

Skill required

Matlab

Another dimension to ultra-fast time-resolved spectroscopy

Supervisor

Nina Novikova
Ben Mallett

Discipline

Photon Factory; Chemical Sciences; Physics

Project code: SCI098

Here in the Photon Factory, we are adding another dimension to our time-resolved transient absorption spectrometer. This addition will be capable of measuring the refractive index of materials immediately after it has been excited with light. This is done using ellipsometry as an extension to the existing time-resolved absorption (TrA) set-up. The full optical response offers a far richer picture of the physical processes involved in the relaxation from excited to ground states, and this system will be one of the few world-wide capable of doing it. The project will involve working with post-docs in the group to measuring the full, fs time-resolved complex optical response via ellipsometry of Silicon.

For students who are interested in:

  • experimental work with optics and lasers
  • using code (e.g. python) to analyze data
  • light-matter interactions.

Laser Frequency Conversion Setup for Non-linear Raman spectroscopy

Supervisor

Alex Risos
Claude Aguergaray
Cather Simpson

Discipline

Photon Factory; Physics

Project code: SCI099

Coherent anti-Stokes Raman Scattering Spectroscopy (CARS) is an advanced form of classical Raman spectroscopy, using three lasers instead of one. Molecules can be excited into a vibrationally excited state by two laser beams. A third laser beam act as Raman scattering but in the anti-Stokes regime. In order to perform such experiments, we convert our initial laser beam into two more laser beam frequencies. Such frequency conversion is standard in optics and commonly applied in green laser pointers. Here, we need to generate a particular set of two frequencies.

The summer work will thus cover to design a setup that efficiently converts laser frequencies using optical parametric processes under guidance of the supervisor. The student will bring in optics experience in theory including geometric/wave optics and nonlinear optical parametric processes and should pick up new knowledge rapidly using guided self-study in the first weeks.

After the summer project, the student will have gained deep insights into non-linear optics and state of the art spectroscopy and have produced a working experimental setup to convert laser frequencies.

Supercontinuum generation modelling in crystals

Supervisor

Alex Risos
Claude Aguergaray
Cather Simpson

Discipline

Photon Factory; Physics; Engineering

Project code: SCI100

Supercontinuum generation (SCG) in crystals such as sapphire is a common process to transform a narrow band laser beam into white laser light. This is applied in state of the art physics such as extreme ultra violet, sub-femtosecond pulse generation to study electron behaviour or for non-linear spectroscopy applications. However, SCG is inefficient and needs improvement. The student will thus use modern physics such as the non-linear Schrodinger equation or the Unidirectional Pulse Propagation Equation to compute spatiotemporal laser pulse profiles and their propagation in non-linear materials (sapphire). This then, together with the supervisor, is used to find optimised pulse parameters to enhance effectivity and efficiency of supercontinuum generation. The student will learn numerically modelling non-linear optics and interaction with non-linear matter. Specific topics include self-phase modulation and optical Kerr-effects.

Supercontinuum generation through modern beam shaping techniques

Supervisor

Alex Risos
Cather Simpson
Claude Aguergaray

Discipline

Photon Factory; Physics; Engineering

Project code: SCI101

Supercontinuum generation (SCG) in crystals such as sapphire is a common process to transform a narrow band laser beam into white laser light and applied for applications such as non-linear spectroscopy, frequency conversion and ultrashort pulse generation. However, SCG is inefficient and needs improvement. Experimentally, this can be done by focusing a Gaussian laser beam into Sapphire crystals. Alternatively, this Gaussian profile can be manipulated and injected into sapphire increasing the efficacy of generated white laser light. The student will setup an experiment to generate supercontinua by spatially shaping the laser beam profile. Thus, the student learns aspects of non-linear optics, modern spatial beam shaping techniques using high-end spatial light modulators and ultrafast laser technology.