Previous work on the optical properties of surface-plasmon-polaritons (SPP) has shown them to be promising candidates for the creation of optical and quantum computers, as well as useful components in the creation of new optical metamaterials. Unfortunately before the potential SPPs can be fully realised several problems of both a technical and a physics nature need to be overcome. In particular, the propagation of light pulses in SPP circuits and films is known to be all severely limited by the effects of attenuation in the metal and material in-homogeneity, while issues of quantum coherence have yet to be properly addressed. The aims of this programme are to investigate the fundamental physics of SPPs so that SPP circuits can be developed for high-speed optical computing. We propose to do this by investigating the behaviour of SPPs at low temperatures and in nano-structured films, while also examining ways in which the SPP waves can be amplified or pumped by stimulated emission from non-linear or luminescent optical materials
Primary investigators
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2009-2012
- Themes:
- Nanoelectronics, Nanophotonics and Biomimetics
- Funding:
- _other
Working in partnership with Carl Zeiss SMT Inc., we are developing the capabilities and applications of the worldââ¬â¢s first commercial scanning helium ion microscope (SHIM)- the Zeiss Orion. The larger mass and therefore smaller de Broglie wavelength of helium ions compared to electrons means that the SHIM suffers less from diffraction effects than a scanning electron microscope (SEM). This, combined with the extremely small and bright source (courtesy of the atomically sharp tip at which helium atoms are ionised), and the small interaction volume of the beam in the sample enables sub-nanometer resolution to be achieved along with a depth of field up to 5 times larger than in an SEM. Our system is equipped with an Everhart-Thornley secondary electron detector, giving outstanding resolution and topographical contrast, and a micro channel plate backscattered ion detector which produces images exhibiting excellent materials contrast. To add functionality, the Orion SHIM can also be equipped with:
-A Gas Injection System (GIS) for material deposition using the helium ion source.
-An energy dispersive backscattered ion detector for compositional analysis, capable of detecting monolayers of material deposited on a substrate.
-A Gatan MonoCL cathodoluminescence system, used for material luminescence studies based on excitation by a charged particle.
The four main areas for investigation are:
1. Ion induced luminescence spectroscopy with the Gatan MonoCL system, including tests on materials known to exhibit cathodoluminescence in the visible to near IR range, e.g. quantum dots, fluorescent dyes, followed by investigations into tagging biological samples.
2. Material modification, including direct sputtering by helium ions and the use of the GIS for deposition and etching.
3. Ion scattering spectroscopy for characterisation of thin films and for small particle compositional analysis.
4. Ion induced patterning (direct write lithography).
In addition, we welcome enquiries from other groups with samples that may benefit from the unique characterisation capabilities that the Orion can offer.
Primary investigators
Secondary investigator
- Prof. Marco Starink
Partner
- Carl Zeiss SMT Inc.
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2004-2010
- Themes:
- Nanophotonics and Biomimetics, Photovoltaics and Energy
- Funding:
- SuperGen
The aims of this project are to investigate the optical properties of metal nanoparticles, to the study the interaction of metal nanoparticles with solar cells, and to optimize this interaction to increase the efficiency of silicon solar cells.
Reducing the thickness of silicon solar cells increases carrier collection and decreases material costs. However, thin layers cannot absorb as much light as thicker layers, and so light-trapping schemes are required to improve absorption. Conventional light-trapping techniques are based on surface texturing, and result. Additionally, these techniques often do not perform well in the near-infrared (NIR), where silicon is most weakly absorbing.
Metal nanoparticles can strongly scatter UV, visible and NIR despite being substantially sub-wavelength in size. The wavelength at which maximum scattering occurs can be tuned by modifying the nanoparticle size, shape and composition. We have studied the optical properties of metal nanoparticles using simulations and experimental methods. To fabricate metal nanoparticles we use top-down techniques such as electron-beam lithography, or bottom-up techniques such as thin-film annealing.
Currently we are investigating the interaction of metal nanoparticles with amorphous silicon solar cells. The optical properties of metal nanoparticles are altered by the presence of the silicon layer, and so we wish to study and optimize this effect. To aid this study we are also investigating the interaction of metal nanoparticles with planar dielectric layers, which may have additional applications such as coupling of light to planar waveguides and improved planar concentrators.
Primary investigators
- Darren Bagnall
- tlt04r
- fd07r
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2009-2011
- Theme:
- Microfluidics and Lab-on-a-chip
- Funding:
- Technology Strategy Board
A microfluidic device that uses single cell impedance spectroscopy is being developed as part of a Point of Care system capable of perfoming a full blood count (FBC) from a fingerprick of blood. In particular, this project focuses on the discrimination of the five different white blood cell types. Cells are introduced to the device and flow at high speed through the detection zone of a pair of microelectrodes, from which the differential signal provides information on both cell size and dielectric properties.
Treatment of whole blood with a lysis solution currently allows differentiation between the three main white blood cell types: granulocytes, lymphocytes and monocytes (see figure). One of the project objectives is to distinguish the less abundant eosinophils and basophils from neutrophils in the granulocyte population. Laser illumination of the cells enables comparison with fluorescence measurements of specific cell markers, the current 'gold standard' of cell identification. The ultimate aim is to produce a low-cost, compact impedance sensor that does not rely on the use of fluorescent labelling.
Primary investigators
- vh
- Hywel Morgan
Secondary investigators
- Nicolas Green
- Professor Donna Davies
- Dr Judith Holloway
Partner
- Philips Research
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2008-2011
- Theme:
- MEMs and NEMs
- Funding:
- EUFP7
Silicon-based Nano-Electro-Mechanical (NEM) sensors are getting increasing interest because of their compatibility with ââ¬ÅIn-ICââ¬? integration as well as high sensitivity to a change in mass. The NEM sensors enable to detect a small amount of biological or chemical molecules thanking to their nanoscale dimensions and sensitive frequency response. This project presents design of a newly-proposed In-Plane Resonant NEM (IP R-NEM) sensor based on a mass-detection principle and discusses its extremely high mass sensitivity in comparison with present-day mass-detection-based biosensors. Our resonator architecture has amplified output signal due to the integrated lateral FET and can be realized by a top-down process on SOI substrates, which is expected to enable monolithic integration of the NEM sensors with CMOS ICs. This project is financially supported by EUFP7 project NEMSIC (Hybrid Nano-Electro-Mechanical/Integrated Circuit Systems for Sensing and Power Managemant Applications).
Primary investigators
- fah07r
- hm2
- Yoshishige Tsuchiya
Partners
- EPFL
- IMEC-BE
- IMEC-NL
- TUDelft
- CEA-LETI
- Honeywell
- Univ. of Geneva
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2009-2011
- Theme:
- Nanophotonics and Biomimetics
- Funding:
- EPSRC
Efficient visible (i.e. Red, Green and Blue) laser emissions are desirable for many applications such as optical data storage, reprographics, RGB colour displays, submarine communications, spectroscopy and biotechnology. These applications would benefit from an inexpensive, low noise, good beam quality and highly stable laser source. There are many different methods in which to achieve a visible laser source, these include nonlinear frequency conversion of high powered lasers, the relatively new process of upconversion and semiconductor lasers using a choice of materials for the blue/green spectrum.
By using standard microfabrication techniques, we propose to fabricate compact, mass-producible, high power, high efficiency visible wavelength lasers based on an upconversion process. An upconversion laser operates on the same principle as ordinary lasers. However, the difference comes with the pumping process. The energy from two or more pump photons is combined to excite the already excited atom to a much higher laser level leading to a shorter lasing wavelength than the pump wavelength when it relaxes to the lower energy level.
However, upconversion lasers require a host with a low phonon energy, otherwise multi-phonon transitions reduce the lifetime of the metastable levels making lasing impossible. Therefore, the objectives of our research are:
ââ¬Â¢ To identify a suitable low phonon host, ââ¬Â¢ Co-dope the host with rare-earth ions: Erbium and Ytterbium, ââ¬Â¢ Fabricate a low loss planar ridge waveguide using the co-doped host material and produce an efficient green laser source.
Once successful, we will further our research using different rare earths to achieve a range of visible laser sources.
Primary investigator
Secondary investigators
- sp3
- Martin Charlton
- Prof. James Wilkinson
Associated research groups
- Nano Research Group
- Optoelectronics Research Centre
- Southampton Nanofabrication Centre
- Date:
- 2001-2010
- Themes:
- Nanoelectronics, Energy Harvesting
- Funding:
- EPSRC
As part of the UK Supergen consortium we are currently performing research into methods of enhancing the performance of silicon based thin film solar cells deposited using PECVD. We intend to achieve this primarily through enhancements in the optical absorption of materials by optimisation of cell design and the inclusion of third generation design features such as plasmonics and intermediate reflecting layers.
Thin film cells are created using an Oxford Instruments SYS100 PECVD reactor which is installed in the department's new cleanroom facility. This reactor provides the the ability to deposit silicon, silicon carbide, and silicon germanium in the amorphous or micro crystalline regime providing the potential to investigate many advanced cell designs and configurations.
Deposited cells are typically characterised using techniques such as spectroscopic ellipsometry, AFM, SEM, QE and IQE measurements, and IV characteristic analysis which are all available in house.
Primary investigators
- Darren Bagnall
- odc04r
Secondary investigators
- mar09r
- mb07r
- pjs05r
- fd07r
Partner
- Pilkington Glass
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Themes:
- Microfluidics and Lab-on-a-chip, Bionanotechnology and Biosensors
- Funding:
- Self funded
We developed a new method for formation of artificial bilayer lipid membranes (BLMs) by the controlled, electrical manipulation of aqueous droplets immersed in a lipid-alkane solution. Droplet movement was generated using dielectrophoresis on planar microelectrodes covered in a thin insulator. Droplets, surrounded by lipid monolayers, were brought into contact and spontaneously formed a BLM. The method produced BLMs suitable for acquisition of electrophysiological data from membrane proteins, and the technique can be extended to create programmable BLM arrays and networks.
Primary investigators
- sa05r
- Hywel Morgan
- Nicolas Green
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Theme:
- Nanophotonics and Biomimetics
- Funding:
- Adventure in Research Grant
Current integrated nano-systems are inflexible due to bulky interfaces, with discrete circuit blocks thus robbing the system of portability. In this research, I propose a nano-device that could be applied to different research disciplines through performing sub task. This would be an extremely attractive concept, as it would enhance the adoption of new nanotechnologies by industry. This system will be small and readily portable and could be used in the field as well as in the laboratory for analysis purposes. This research proposal is aimed at a proof-of-concept study of utilising a novel nano resonant cavity based on photonic crystal and photonic wire technology that will eventually evolve into a monolithic nanoscale integrated ââ¬Ëplug-and-playââ¬â¢ component for a variety of interdisciplinary systems. Applications would include bio-environmental-sensing, optical chip interconnects for a multidimensional nanophotonic-electronic integrated circuit board, light extraction unit, photon-assisted bio-medicine and imaging.
Primary investigator
- Harold M H Chong
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2008-
- Theme:
- Microfluidics and Lab-on-a-chip
- Funding:
- EPSRC
As the oceans play a crucial role in the future of our civilization (natural resource, climate regulationââ¬Â¦), it is important to build very accurate model to predict their evolution. One important part of this model is to know our impact on the environment such as the pollution which can be assessed by knowing the different populations of phytoplankton or algae at different depths. Currently the only solution available on a large scale is to obtain water samples for laboratory analysis which induce many issues of cost, contamination, sample degradation, and poor sample frequency in both space and time. However, if an integrated and small flow cytometer system could be realized, platforms such as Argo floats, AUVs (autonomous underwater vehicle) or gliders could be used to bring the system at different depths and to obtain in-situ measurements. Thus, this part of the project has as an aim to develop an integrated flow-cytometer on chip for in situ particle counting and sampling. The targeted species are phytoplankton with a size in the 2 to 50 õm range. The detection of the different species is realized by measuring the fluorescence and the scattered light of the particles when they are illuminated by a laser in the visible wavelength range. As each particle can have different fluorescence properties and as the scattered light is proportionnal to the size (for small angle) and to the granularity/shape of the particles (big angle), we are able to distinguish them.
Primary investigators
- Hywel Morgan
- Dr Matt Mowlem
- db4
- rz08r
Partner
- National Oceanography Centre (Sensors group)
Associated research group
- Nano Research Group