Members of the Photonic Sensors and Imaging Theme
Theme Leader: Frederique Vanholsbeeck
Investigators: Keith Gordon, John Harvey, Justin Hodgkiss, Jari Kaipio, Rainer Leonhardt, Jevon Longdell, Rainer Künnemeyer, Eric Le Ru, Brendan McCane, Igor Meglinski, Roger Reeves, Mike Reid, Harald Schwefel, Cather Simpson, Kasper van Wijk, Jon-Paul Wells, Peter Xu
The imaging and sensing theme aims to produce the next generation of sensors and imaging systems needed for scientific and industrial applications. This will be done by extending our understanding of the basics of the way light and sound interact with matter and then using this to construct new sensors and imaging systems that solve specific problems in 3 fields: biomedical, geophysics and primary industries. Our experimental work will be supported by strong theoretical and numerical models. Our research will be guided by the need of our scientific and industrial collaborators. Our goal is to produce accurate, minimally invasive, in situ and in vivo, cost effective sensing and imaging techniques. Regular meeting will be organised to coordinate efforts between the team members. For each technique we consider, we will advance the field and seek potential commercialisation. Most of our modelling software as well as some of our data will be made available online for the benefit of the scientific community.
Project (SI1) Optical Coherence Tomography and Acousto-Optic Imaging
We will investigate the limits of optical coherence tomography (OCT) and its complementarity with acousto-optic (AO) techniques. These techniques open the way for functional imaging by using the information resulting from the interaction between the sample and the probing wave (be it sound or light). Our project will span both fundamental and applied aspects with a strong theoretical backbone. Our goal is the holy grail in imaging: real time, non-invasive, label-free sample recognition and characterisation with high spatial resolution. New contrast agents will be investigated such as chromatic dispersion, speckle and Doppler OCT for OCT and dispersion length mapping for AO imaging.
Project (SI2) Non Invasive Biomedical Imaging and Sensors
We exploit the techniques described in (SI1) for specific applications in the biomedical area. First, based on a Monte Carlo model we recently developed, we will deliver an online computational research tool for imitation of 2D/3D OCT-based images of human skin, connective tissues, and other biological materials of interest.
Project (SI3) Remote Sensing and Imaging for Geophysical Applications
The field of optical remote sensing is not limited to biomedical applications. Here we plan to apply our technology to rock and climate physics. Our rock physics research helps to address pressing energy and environmental issues. Recent work by the team focuses on the connections between important chemical reactions in the subsurface (for example, during CO2 sequestration), and the imprint of these reactions on elastic (seismic) waves probing the earth.
We will also use highly stable ring laser small gyroscopes to determine the length of day (which in turn is required to maintain the GPS). In addition, the larger version of these lasers makes powerful and very sensitive seismographs and we will use them to detect variation in the earth rotation
We aim to realize the for the first time 3D seismic mapping using data from gyroscope lasers. We also plan to develop a laser-based strain meter for broad-band characterization of the elastic properties of rocks.
Project (SI4) Improved Sensors for NZ Primary Industries
We are working to create the next generation of photonic sensors that are uniquely adapted to the needs of NZ and have the potential to be a niche high-technology high-value export industry in their own right. An example is the detection of previously unknown substances, such as contaminants in biological samples like milk, which requires the development of new techniques and instruments. We propose to develop 4 complementary approaches that could ultimately be combined to offer a complete range of sensors for the primary industry to detect bacteria, adulterants or the origin of the components. The techniques we are working with are fluorescence, mass spectroscopy, and near-IR, mid-IR, Raman and low frequency Raman spectroscopies.
Additionally, using new contrast agent in fluorescence, we will investigate how biological processes can be monitored. This will be done in collaboration with microbiologists and using contrast agent such as ZnO and lanthanide doped nano particles.