Physics

Design of real-time photoacoustic imaging system

Supervisor

Jami Shepherd

Discipline

Physics

Project code: SCI006

Photoacoustic (PA) imaging is an emerging medical imaging technique which harnesses the strengths of both optics and ultrasound. Pulses of light travel centimeters deep into the body, where the light is absorbed by blood to create an ultrasonic source. Our group is developing a real-time PA imaging systems to measure blood flow in the body.  

The student will work on design and optimisation of this system, including designing a custom imaging probe and programming the acquisition system. Experiments will be carried out to optimise light delivery first in phantom models, and finally in vivo. The student will gain experience with the pre-clinical field of PA imaging as well as experience programming an ultrafast ultrasound system. Experience programming in MATLAB (or Python) is preferred. 

Optical and photoacoustic measurements of bovine cortical bone

Supervisor

Jami Shepherd

Discipline

Physics

Project code: SCI007

Current photoacoustic (PA) imaging systems are limited to soft-tissues and cannot image inside of bone. The goal of this project is to determine the optimum optical wavelength for generating PA waves inside of bone. The student will first complete optical absorption measurements of bovine bone samples, followed by quantitative photoacoustic amplitude measurements. The student will gain experience with biomedical optical measurements as well as all-optical photoacoustic imaging.

Weird explosions and the even weirder stars that precede them

Supervisor

Dr Heloise Stevance
A. Prof. Jan Eldridge

Discipline

Physics

Project code: SCI008

Carl Sagan said “We are made of star stuff”. That stuff is often released into space via very powerful stellar explosions, which usually mark the end of the life of rare and massive stars. Over the past couple of decades, astronomers have discovered a large variety of explosions, most of which are not yet fully understood.

One of the ways we can try to understand how stars explode is by studying their neighbours and their surounding. This is done by comparing images and spectra taken with large telescopes to computer simulations.

In this project you will use state-of-the-art models to help us better understand the stars that give rise to some of these explosions. The project is based on questions that are extremely relevant to the current state of the field and the results will likely be used in a future peer-reviewed journal article.

Requirements: An interest in Astronomy and understanding how the Universe works. Some coding experience, especially with Python.

Gas sensing with Si Terahertz (THz) micro-resonators

Supervisor

A-Prof R Leonhardt (ext 88835)
Dominik Vogt

Discipline

Physics

Project code: SCI009

THz radiation (0.5THz=0.6mm) can be used to detect fundamental absorption resonances of gases like N2O (or other greenhouse gases). The project consists of designing a high quality disc-shaped Silicon whispering-gallery mode resonator (~ 0.1mm thickness, ~ 6mm diameter), characterising the transmission characteristics of this resonator, and measuring the additional absorption when this resonator is placed in a gas cell filled with N2O, and finally determine the concentration of N2O. The project is mainly experimental, and you will learn how to use an advanced THz set-up that acts as a spectrometer with a very high resolution. If you are interested, contact me for a tour of our lab.

Simulation of integrated Terahertz (THz) components

Supervisor

A-Prof R Leonhardt (ext 88835)
Dominik Vogt

Discipline

Physics

Project code: SCI010

THz radiation (0.5THz=0.6mm) will at some stage replace the current systems (~30GHz) to enable ultra-fast WiFi. To do so, circuits based on Si technology that can handle THz radiation have to be developed. This project is aimed at designing relatively simple components like waveguides, splitters, and filters for this new technology. The simulations will be mainly performed using the commercial sofware COMSOL. The challenge will be to limit the computing time for these 3D simulations. Initially some calculations will be performed in 2D to get an overview about different approaches. The overall aim is to design a ‘circuit’ that can be implemented on a Si wafer, and then used for characterisation in our THz Lab. If you are interested, contact me for a tour of our lab. 

Design and implementation of novel Terahertz (THz) micro-resonators

Supervisor

A-Prof R Leonhardt (ext 88835)
Dominik Vogt

Discipline

Physics

Project code: SCI011

High quality (Q) factor THz resonators that work by total internal reflection are a recent development in THz spectroscopy. Because of the large wavlength (0.5THz=0.6mm), the concepts/possibilities are different to resonators used in the visible or IR region. Up-to-now only very simple designs like a ‘sphere’ and a ‘disc’ have been studied. One aim is to find a design that results in even higher Q factors. In the project you will explore different designs (e.g. ‘double disc’) numerically, and if a design looks promising you will implement it, and experimentally characterise it using the sophisticated set-up in the THz Lab. This project will therefore be a mixture of simulations and experimental work. If you are interested, contact me for a tour of our lab.

Nano-optical chatline for atoms

Supervisor

Maarten Hoogerland

Discipline

Physics

Project code: SCI012

The project involves experiments with supercold atoms, trapped on the surface of an optical nanofibre. These atoms may emit single photons into the nanofibre, which in turn may be picked up by other atoms. The project aims to establish entanglement between different atoms using this mechanism. You will be part of the research team working on this, using single photon detectors, a lot of optics and fibre optics, and computer control to work on a project on the foundations of quantum mechanics.

Ultracold atoms in flatland

Supervisor

Maarten Hoogerland

Discipline

Physics

Project code: SCI013

This project involves ultracold atoms, that are trapped in a sheet of light, so that they are only free to move in two dimensions. The atoms are loaded from a Bose-Einstein Condensate, and are thus have long deBroglie wavelengths, longer than the wavelength of light. We aim to generate arbitrary potentials for these atoms using a DMD (digital mirror device, a million microscopic mirrors that can be addressed with microsecond precision), and study vortices and flow in this quantum fluid. You will be working as part of the research team, working with optics, lasers and computer control. 

Primordial Black Holes, Dark Matter and Future Astrometric Surveys

Supervisor

Richard Easther

Discipline

Physics

Project code: SCI014

This project will examine whether future space-based astrometric surveys (successors to the GAIA mission) have the potential to constrain scenarios in which the dark matter fraction of the universe consists of primordial black holes with masses similar to that of small asteroids. Such objects could induce small transient changes in the positions of background stars via the gravitational deflection of starlight as they pass through the outer solar system, which would be potentially detectable by sophisticated astrometric surveys. The project will involve determining the expected frequency of near-transits of stars by these hypothetical black holes and the corresponding deflections in stellar positions, and assessing whether this strategy provide a workable approach to constraining a galactic population of small primordial black holes. Students should be familiar with Python, physics and mathematics. Detailed knowledge of relativity is not required. 

Optical frequency combs in ultra-high Q microresonators

Supervisor

Stuart Murdoch (Rm 303.503)

Discipline

Physics

Project code: SCI015

An optical frequency comb is an ultra-precise spectroscopic ruler that allows the measurement of optical frequencies with unprecedented levels of accuracy. These combs are now used in a myriad of applications ranging from extra-solar planet detection to optical telecommunications. Their discovery was awarded a Nobel prize in 2005. Optical microresonators are tiny optical cavities that can trap light for extended periods of time allowing for highly efficient nonlinear interactions. New research has shown that under the correct conditions optical microresonators can produce high-quality frequency combs. This opens up the possibility of new chip-scale comb devices. The Auckland group has considerable experience in both the theory and experimental investigation of microresonator frequency combs. The successful candidate will work with our group on topics based around the theory, fabrication, and experimental implementation of new microresonator based comb designs.

Widely tunable microresonator parametric oscillators

Supervisor

Stuart Murdoch (Rm 303.503)

Discipline

Physics

Project code: SCI016

Optical microresonators are tiny optical cavities that can trap light for extended periods of time allowing for highly efficient nonlinear interactions. Recent work, by our group, has shown that under the right conditions these devices can efficiently generate light at new wavelengths far from the original pump frequency. So far we have been able to demonstrate over an octave of narrowband tunability in these devices, with the output light tunable in wavelength from 1095 to 2539 nm. We now wish to push the performance of these devices even further and generate signals in the spectroscopically important ‘molecular fingerprint’ region around 3 um. The successful candidate will work with our group on the experimental and theoretical realisation of these exciting new devices.

Bacterial characterisation using optics and microfluidics

Supervisor

Cushla McGoverin
Dr. Frédérique Vanholsbeeck
Ayomikun Esan

Discipline

Physics

Project code: SCI017

In this project, the student will work with an optical set-up that collects fluorescence spectra from bacteria. Hence, the student completing this project will develop skills with optics, microfluidics and microbiology. The lab work will be completed in the biophotonics laboratory of the physics department (City campus) and the PC2 lab of the Molecular Medicine and Pathology department (Grafton campus). Previous experience in an optics or biology/chemistry laboratory would be great but is not necessary. 

Optical Tweezers

Supervisor

Cushla McGoverin
Dr. Frédérique Vanholsbeeck
Craig Steed

Discipline

Physics

Project code: SCI018

The Biophotonics laboratory in the physics department is interested in using optical tweezers for the manipulation of bacteria. The initial phase of this project requires the assembly of an optical tweezing set-up and the student would be involved in this assembly. The student will develop skills with optics and learn about optical tweezers. Previous experience in an optics laboratory would be great but not necessary. 

Developing a polarisation sensitive OCT system to retrieve sample optical axis and measure the vitreous humour

Supervisor

Dr. Frédérique Vanholsbeeck
Magdalena Urbanska
Dr Marco Bonesi
Matt Goodwin

Discipline

Physics

Project code: SCI019

This project is based on polarisation sensitive optical coherence tomography (PS-OCT), an interferometric technique that allows high resolution in vivo imaging and identification of the sample optical axis. The student will learn about the technique of OCT and will adjust an existing OCT system to be polarisation sensitive. They will characterize the system and test it on a few samples.

High resolution Optical coherence tomography for optical biopsies

Supervisor

Dr. Frédérique Vanholsbeeck
Dr Marco Bonesi
Mykola Zlygostiev

Discipline

Physics

Project code: SCI020

This project is based on optical spectral domain coherence tomography (SD-OCT), an interferometric technique that allows high resolution in vivo imaging. The student will learn about the technique of OCT and how to analyse images to extract more information than just the structure of the sample. The aim of the project is to develop an ultra broadband OCT system using a commercial spectrometer to attain ultrahigh resolution (less than 1 micron). 

Antarctic snow and the weather systems of the Southern Ocean

Supervisor

David Noone

Discipline

Physics

Project code: SCI021

Intense low-pressure systems of the Southern Ocean give rise to heavy precipitation on the Antarctic coast. These systems also transport pollutants to the otherwise pristine polar environment. This project aims to use a novel set of atmospheric composition data collected in Antarctica with estimates of airflow in the southern ocean to link snowfall amounts with the source of pollutants. Familiarity with atmospheric sciences, and some experience with scientific computing (e.g., with python) will be needed.

Satellite remote sensing of clouds and water vapor

Supervisor

David Noone

Discipline

Physics

Project code: SCI022

Water vapor is the most abundant greenhouse gas and the movement of water around the planet is a driving factor in controlling the climate. The interplay between atmospheric circulation and water vapor causes precipitation. This project aims to use satellite remote sensing for the New Zealand and the pacific region to evaluate the processes associated with convective clouds. Familiarity with atmospheric sciences, and some experience with scientific computing (e.g., with python) will be needed.

Rainforests and rainfall

Supervisor

David Noone

Discipline

Physics

Project code: SCI023

It is thought that rainforests help create the rainfall that they rely on. The feedback is due to evapotranspiration from the trees that gives rise to subsequent rain. The goal of this project is to combine estimates of transpiration rates with measurements of the atmospheric composition to deduce what fraction of precipitation is due to vegetation. Familiarity with atmospheric sciences, and some experience with scientific computing (e.g., with python) will be needed.

Drop Impacts and Capillarity

Supervisor

Geoff Willmott

Discipline

Physics

Project code: SCI024

Experimental projects are available to study microscale liquid dynamics using high-speed photography (producing cool slow-motion videos). We are particularly interested in drop impact experiments, in which drops collide with solid surfaces. Fluids of interest include partially dried dairy products, and ferrofluids which produce ‘spiky’ magnetic instabilities. Surfaces may be patterned in order to control the spreading, splashing and rebounding of the drops. A project could also focus on development of image analysis techniques. 

Projects are suitable for students from any quantitative science / engineering background, and can be aligned with industrial (real-world) applications. Skills developed will include experimental methods for materials science, and understanding of fluid dynamics.

Lab website

Nanofluidics and Active Matter (Theory / Modelling)

Supervisor

Geoff Willmott

Discipline

Physics

Project code: SCI025

Project(s) will develop and use computational and/or theoretical models in the fields of (i) nanofluidics or (ii) active matter. In nanofluidics, liquids are confined to spaces on nanometre length scales. Modelling will be used to guide experimentalists working with nanopores and nanopipettes. Active matter involves collections of interacting, moving particles such as swarms and flocks. Here, the system to be studied is a large collection of asymmetric ‘Janus’ nanoparticles. Especially suitable for students with some computational / numerical experience.

Lab website