PhD and MSc by research

The Applied Optics Group hosts students studying for 3-year PhD and 1-year MSc (by research) degrees in Physics in the School of Physical Sciences (SPS).

In addition to funded positions, which are advertised when they become available, we welcome applications from self-funded students at any time, and can also support strong candidates in applying for external funding. Various university scholarships are listed on the ‘Find a Scholarship‘ page.

Research areas

PhD and MSc projects are available in a broad range of areas around biomedical imaging and sensing technology, including in optical coherence tomography, photoacoustic imaging, confocal microscopy and endomicroscopy, optical design, light-tissue interaction and modelling, optical sources and fast tunable lasers, signal processing methods and GPU processing. See the research overview and research projects pages for more details.

Research environment

AOG postdocs and research students are all housed in dedicated space in the University’s Photonics Centre, a few minutes walk from the Ingram Building, with all the necessary optics research facilities on hand. The group is highly collaborative; you will be work as part of a friendly international team with a range of expertise. We have weekly group meetings and monthly internal research seminars, as well as regular external speakers to complement the wider School of Physical Sciences colloquium programme. All of our students are expected to regularly attend national and international workshops and conferences, and we often host events here in Kent. A range of training and networking opportunities are available through SEPnet and the Kent Graduate School, and with the agreement of your supervisor, there are opportunities to be involved in outreach and undergraduate teaching. The Kent Postgraduate handbook provides more details on studying for a PhD at Kent.

Application process

Applications are made through the University’s main admissions site, but we prefer candidates to make contact with a potential supervisor (Prof Adrian PodoleanuDr George DobreDr Adrian Bradu or Dr Michael Hughes) to discuss opportunities before applying. If you are unsure who would the best match for your interests, please direct general inquiries to the Head of Group, Prof Adrian Podoleanu. When applying via the admissions site, select either MSc Physics or PhD Physics, and be sure to include the name of your preferred supervisor. You do not need to provide a detailed research proposal but should clearly set out your motivation for obtaining a research degree in applied optics.

Example projects

Some example projects that may be undertaken by self-funded students (PhD or MSc) are below, but a range of other projects can be designed to match your skills and interests, and we will also consider proposals from innovative and highly-motivated students to develop new research ideas which are compatible with our expertise and facilities.

Novel adaptive optics (AO) devices and systems for simultaneous optical coherence tomography (OCT) and AO (Prof Adrian Podoleanu)

A high-performance adaptive optics (AO) system requires a deformable mirror with a large number of elements and large stroke, as well as a sensitive wave-front sensor. Such elements are used in AO for astronomy, but they are very expensive. En-face orientation imaging is exactly what is required for combining OCT with AO for imaging the retina. We are aiming for an OCT orientation which is familiar to ophthalmologists using scanning laser ophthalmoscopy, achievable via en-face OCT. We predict that by incorporating AO elements, the transversal resolution of en-face OCT will become comparable to its depth resolution. Specific skills will be acquired in OCT, AO, and morphology and function of the retina.

Supercontinuum fibre source for OCT and spectroscopy (Prof Adrian Podoleanu)

Supercontinuum generation has long been used as a convenient experimental technique for producing broadband radiation for various spectroscopic applications. The use of photonic-crystal fibres and tapered fibre for generation of supercontinuum emission offers a way to create new broadband sources for spectroscopic and OCT applications. We plan to develop a compact and small-size supercontinuum source for OCT, controlled entirely through an easy-to-use graphical software package. Specific skills will be acquired in fibre optics (technology), lasers, fibre optic amplifiers, photonic crystal fibre, nonlinear fibre optics, general optoelectronics, fibre optic characterisation and testing, and LabVIEW.

Point of care imaging – bringing the microscope to the patient (Dr Michael Hughes)

Microscopy is a vital tool of modern medicine, allowing tissue samples and specimens to be examined in cellular scale detail for diagnosis of a wide range of diseases. Today, almost all medical microscopy takes place in the pathology lab, but you will work in the rapidly developing field of miniature, portable systems for use at the patient’s bedside. You will focus on developing new technology to reduce the size, cost and complexity of these point-of-care microscopes, helping to extend their use, even to low resource settings. You will need to be prepared to work at the interface of physics, engineering and medicine, have or be willing to develop strong practical laboratory and computing skills, and above all have the drive and ambition to find innovative technical solutions to the problems of global healthcare.

Shaping and twisting light with high-speed digital holography (Dr Michael Hughes)

A number of applications of photonics require light fields with the specific amplitude and phase distributions. This can be achieved with spatial light modulators, which provide a high degree of control, but with relatively slow update rates. In this project, you will develop a spatial light modulator using a digital micro-mirror device (DMD), using holography techniques to achieve phase and amplitude control with kHz update rates. This device will then be used for a number of possible applications, including the generation of twisted light (optical vortices with central phase singularities, carrying orbital angular momentum) for micromanipulation, as well as optical phase conjugation for imaging through scattering media or multimode fibres. This project will require a good background in Fourier optics and/or linear algebra as well as interests in scientific computing using Matlab or Python.

Optical Coherence Elastography for cancer detection (Dr Adrian Bradu)

Changes in tissue elasticity are generally correlated with pathological* phenomena. Many cancers, appear as extremely hard nodules which are results of increased cell density. Other diseases involve fatty and/or collagenous deposits which change tissue elasticity. However, in many cases, the small size of the pathological lesion and/or its location deep in the body preclude its detection and evaluation. A plethora of cancer diagnosis methods exist, but most of them require invasive biopsies. These can be time-consuming and cause discomfort to the patient. In contrast, the optical methods are capable of imaging the tissue at the micrometre scale, while optical coherence tomography can provide biopsy without tissue excision. The proposed project is aiming to develop a medical imaging tool, able to produce an image of what tissue ‘feels’ like by evaluating its elastic properties so differentiation between healthy and diseased tissue is possible, but without touch.  The project will involve research activities such as:

  • Signal processing to estimate strain. The technique of elastography will be implemented by placing the tissue under mechanical load and the resulting displacements evaluated using state of the art optical coherence tomography instruments available within the AOG. You will be exploring new algorithms to improve the strain estimation and to remove artefacts from images.
  • Design and implementation of a handheld probe. You will be developing a handheld probe imaging device to allow clinicians to perform elastography measurements on patients. This involves the design of the probe and loading mechanism. The loading mechanism will have to be synchronised with the image acquisition.

The research activities involved in this project will happen at the boundaries of several disciplines such as optics, mechanical systems, imaging, material science, software, medical devices, clinical medicine, etc., hence a fantastic opportunity for you to gain valuable transferable skills. However, it is not a prerequisite for you to be experienced in these fields to undertake the project as you will be given the opportunity to learn these skills during the project. AOG has a team ethos and you will be actively encouraged to work as part of a team.

*pathological = any deviation from a healthy, normal condition

Listening to the sound of light (Dr Adrian Bradu)

Photo-acoustic tomography (PAT) is a hot topic in the biomedical imaging field. It can offer not only structural but also functional information of biological tissues with excellent resolution and high contrast. This is possibly by listening to the sound produced when a laser pulse interacts with the absorbing tissue.  PAT techniques can be applied to the early detection of cancer or examining vascular and skin diseases. The proposed project aims to develop unique multi-modality multi-spectral medical imaging tools able to simultaneously produce PAT and Optical Coherence Tomography images. The project will involve the student in research activities such as:

  • Design and implementation of a multi-modality imaging instrument having at their core the PAT technology. The multi-spectral capability will be ensured by the use of a supercontinuum optical source. The student will develop imaging devices in such a way that the instruments can easily be used in clinical environments (eventually equipping the instruments with a handheld probe).
  • Design and implementation of a hypodermic needle probe for even deeper penetration. The needle will be used within other imaging instruments such as fluorescence or/and polarisation sensitive imaging devices to prove that the mapping of the mechanical properties is accurately done.
  • Signal and Image processing to estimate the elastic properties of phantoms and biological tissues.

The research activities involved in this project will happen at the boundaries of several disciplines such as: optics, mechanical systems, imaging, material science, software, medical devices, clinical medicine, etc., hence a fantastic opportunity for the student to gain valuable transferable skills. However, it is not a prerequisite for the student to be experienced in these fields to undertake the project as he/she will be given the opportunity to learn these skills during the project. The student will embark on highly innovative ideas with high impact potential on the way in which PAT and other optical based methods can be used in intraoperative assessments of various diseases and will be familiarised with the culture of translation of technology from lab to the clinic, that entails interdisciplinary education delivered in interaction with clinicians. This will prepare the student for the growing market of Medical Physics that entails more and more sophisticated equipment.

Developing powerful custom made swept sources for OCT using polygon mirror based wavelength sweeping (Dr George Dobre)

Polygon mirror based spectral filters provide a versatile method of repeated tuning through broadband spectra, resulting in swept-source functionality with diverse possibilities such as the capability to operate in any wavelength range at speeds of hundreds of kHz and the possibility of running several sources from the same polygon mirror element. These aspects make them suitable for experimenting with different settings for OCT imaging in the laboratory.

Investigating polygon mirror swept sources for use in OCT imaging involves the design and alignment of such PM spectral filters in a holistic way, considering a multitude of aspects related to the telescope which serves to direct light from the dispersive element onto the active polygon facet. Research has shown that the parameters of this entire optical system, such as the focal lengths within the telescope, have a significant effect on the bandwidth and linewidth, as well as the maximum power throughput.

The students working in this area will be carrying out both experimental hands-on lab research and simulations such as:

  • Optical design of the telescope optics to minimise aberrations and emphasise key parameters of the optical system, resulting in sharper OCT images.
  • Pushing the boundaries of image acquisition rate.
  • Implementation of a variety of geometries and image optimisation.
  • Software coding to enable image acquisition synchronised with polygon mirror operation.