Welcome to the Microphotonics and Photonic Crystals Website! |
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 Group Photo 2008
 Group after playing football 2008
 Mel and Thomas using the state-of-art e-beam lithography system
 Part of the team inspecting a Photonic Crystal
 The group enjoy a game of volleyball during the 2008 Away Day
 The 2008 Away Day venue
 Some of the group relaxing while at the 2008 Away Day
 Microcogs, built to create an optically powered micropump
 Schematic of Four-wave mixing, two input waves combine to create a third output wave
 Demonstration of an intelligent fire-alarm system using multiple Specks formed into a SpeckNet
 Photonic Crystal cavity, enhanced to provide a high-Q
 Photonic Crystal waveguide fabricated in a silicon membrane
 Schematic of pulse compression using a Photonic Crystal coupled-cavity waveguide
 Close-up image of microcogs (coloured for clarity)
 A Photonic Crystal switch with a human hair to demonstrate scale
 Fabrication of Photonic Crystal switch (inverse colours)
 Photonic Crystal waveguide interesting fabrication error
 Field of Splitring resonators
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Group Photo 2008
Group after playing football 2008
Mel and Thomas using the state-of-art e-beam lithography system
Part of the team inspecting a Photonic Crystal
The group enjoy a game of volleyball during the 2008 Away Day
The 2008 Away Day venue
Some of the group relaxing while at the 2008 Away Day
Microcogs, built to create an optically powered micropump
Schematic of Four-wave mixing, two input waves combine to create a third output wave
Demonstration of an intelligent fire-alarm system using multiple Specks formed into a SpeckNet
Photonic Crystal cavity, enhanced to provide a high-Q
Photonic Crystal waveguide fabricated in a silicon membrane
Schematic of pulse compression using a Photonic Crystal coupled-cavity waveguide
Close-up image of microcogs (coloured for clarity)
A Photonic Crystal switch with a human hair to demonstrate scale
Fabrication of Photonic Crystal switch (inverse colours)
Photonic Crystal waveguide interesting fabrication error
Field of Splitring resonators
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The focus of the group is on functional nanostructured photonic devices. We are the leading planar photonic crystals research group in the UK and amongst the leaders worldwide. We have been active for over a decade and have made some pioneering demonstrations, such as the first demonstration of a two dimensional photonic bandgap in a semiconductor waveguide (Nature 1996), demonstration of the superprism effect (2002) and the lowest loss photonic crystal waveguide in Europe (2006) and the first demonstration of pulse compression in phtonic crystal waveguides (2003). Current interest focuses on the dispersive properties of photonic crystal waveguides for dispersion compensation, slow light and wavelength control. Slow light is a particularly exciting area of research as it allows us to build efficient optical switches, low power optical devices and optical buffers/memory. These effects are explored in the EUFP6 Splash project, led by St Andrews and the UK Silicon Photonics project.
Our Biophotonic research area aims to use the sophisticated technology developed for the fabrication of photonic crystals and lasers in a different context, namely micro-manipulation and sensitive detection for biomedical applications. Integration of optoelectronic and microfluidic concepts result in novel lab-on-a-chip concepts. (see Monolithic integration of optical traps and microfluidic channels research project)
The development of optical interconnects is our contribution to the pan-Scottish Speckled Computing network. Here, we aim to use low-power, microscale lasers and LEDs to communicate between and locate "Specks" i.e. mm-size self-contained processing units
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Photonic Crystals |
Photonic Crystals are wavelength scale, periodic, dielectric microstructures. Their periodic patterning creates photonic band gaps which forbid the propagation of light through the structure. The periodicity couples forward- and backward-travelling waves inside the Photonic Crystal (PhC), causing a net cancellation of the optical field. PhCs therefore insulate photons in a manner similar to which electrons are insulated in a semiconductor crystal. |
The group have worked on a wide variety of planar PhC elements, building discrete components for integrated optical circuitry. Even more important however is the ability to control the speed of propogation of light in Photonic Crystal waveguides. We aim to take advantage of the strong temporal dispersion of 2D PhC waveguides for pulse delay lines and dispersion compensation. The first 2D planar PhC superprism demonstrated in 2002 takes a step towards producing much more compact spatially dispersive elements, with improved resolution.
Slow Light in Photonic Crystal Waveguides |
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Miniaturised optical switch exploiting slow light effects in order to reduce the switching length 40-fold to 5 µm for a given refractive index shift of 4x10-3 |
Speckled Computing |
SpeckNet was set up in 2003 to look at creating a distributed sensor network, made up of so called Specks. The SpeckNet group at the University of St Andrews is one of many groups within the SpeckNet consortium distributed over five Scottish Universities including Edinburgh, Glasgow, Strathclyde and Napier. |
Specks will be minute (around 1mm cubed) semiconductor grains that can sense and compute locally and communicate wirelessly. Each Speck will be autonomous, with its own captive, renewable energy source. Thousands of Specks, scattered or sprayed on to the person or on to surfaces, will collaborate as programmable computational networks called SpeckNets.
At St Andrews we are working on the optical components for SpeckNet with particular interest in optical beamsteering and triangulation. |
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Array of microemitters used to communicate between Specks |
Biophotonics |
Microfluidics is becoming an increasingly important part of MEMS research with areas such as ‘Lab-on-a-chip’ and ‘microTAS’ growing in size and scope. We aim to combine our abilities in microfabrication with expertise in micromanipulation from the Optical Trapping group at St Andrews to allow us to create novel devices and perform research of an international standard in these areas. A current project is the integration of microfabricated monolithic lasers with micro channels to allow on-chip optical tweezing. This would allow the mass fabrication of devices that could use optical trapping for pumping, sorting or detection of biological specimens in a ‘Lab-on-a-chip’ enviroment. |
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One of the projects is the simulation, fabrication and testing of microgears that can be controlled via form birefringence. These gears could be used to power a micromachine such as a micropump.
All-optical control of microfluidic components using form birefringence
S Neale, M MacDonald, K Dholakia and T F Krauss
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News |
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Jobs |
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Form birefringent microcogs. |
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