Department of
Mechanical, Materials and Manufacturing Engineering
   
   
  
 

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Angela Seddon

Professor of Inorganic Materials, Faculty of Engineering

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Expertise Summary

 

Angela Seddon holds the Chair in Inorganic Materials at Nottingham University, UK. From October 2007, she will additionally hold the award of Royal Academy of Engineering / Leverhulme Trust Senior Research Fellowship. She heads up the Novel Photonic Glasses Group and the over-arching Advanced Materials Research Group at Nottingham. Experimental facilities,housed in the Wolfson Centre for Materials Research, are world-class. The aim of her research is to bring understanding to how the nano- and micro-structureof special glasses influence glass optical properties and ultimate optical device performance and she has published over 140 research papers. The laboratory facilities at Nottingham University for synthesising and fabricating these glasses include a class 10,000 cleanroom Fab. Lab., housing a customisedHeathway tower for drawing novel optical fibres and novel processing facilitiesfor making planar, small-scale waveguides.

High-silica glasses are known for their excellent linear optical properties and are, for instance, the material of choice for long haul optical fibres. Novel inorganic-compound glasses such as heavy metal halides, oxides and oxyhalides, and chalcogenides, are based on more weakly chemically bonded lattices than silica. These novel glasses are therefore rather less chemically and mechanically robust than silica glass. Onthe other hand, they offer far more optical versatility than silica glass including: windows spanning the near-ultraviolet to far-infrared; large solubility of active rare earth dopants; low phonon energy for greater efficiency of radiative transitions; large linear and nonlinear refractive indices;high third order nonlinear optical susceptibilities; nano-glass-ceramicformation; great photosensitivity and a large acousto-optic effect. Being glasses means that compositions are not fixed to a single stoichiometry but almost infinitely variable, allowing the possibility of tailoring optical properties to suit, such as for all-optical switching, amplification, sources, sensors, memory, interconnects and photonic and electronic integration. Also inorganic compound glasses are generally isotropic hence optical orientation is not a problem compared to crystallinematerials.

Recent achievements of the Novel Photonic Glasses Group at Nottingham University include showing that erbium III doped into nano-glass-ceramics exhibits the broadest emission reported to date, to our knowledge, at 1.55 micron wavelength compared to when doped into other hosts. In addition, the doping levels achieved are ~ 100 x that in contemporary EDFA (erbium doped fibre amplifiers). Hence the doped nano-glass-ceramics have potential as next generation micro-amplifiers of far greater system flexibility than current amplifiers for telecom. systems.

Photonic and electronic integration on a single chip demands innovative, flexible fabrication technologies. Over thelast few years we have demonstrated for the first time that hot embossing of novel inorganic-compound glasses successfully produces waveguides and other features to better than 0.1 µm -scale definition. We have recently demonstrated monomode rib waveguides made by the hot embossing route. These are the basic building blocks of photonic integrated circuits.

We are developing low optical loss, novel glass optical fibres for the infrared for power delivery and sensing for instance for medical surgery and diagnoses, respectively.

Research Summary

Angela Seddon holds the Chair in InorganicMaterials at Nottingham University, UK. From October 2007, she will additionally hold the award of Royal Academy of Engineering / Leverhulme Trust Senior… read more

Selected Publications

Current Research

Angela Seddon holds the Chair in InorganicMaterials at Nottingham University, UK. From October 2007, she will additionally hold the award of Royal Academy of Engineering / Leverhulme Trust Senior Research Fellowship. She heads up the Novel Photonic Glasses Group and the over-arching Advanced Materials Research Group at Nottingham. Experimental facilities,housed in the Wolfson Centre for Materials Research, are world-class. The aim of her research is to bring understanding to how the nano- and micro-structure of special glasses influence glass optical properties and ultimate optical device performance and she has published over 140 research papers. The laboratory facilities at Nottingham University for synthesising and fabricating these glasses include a class 10,000 cleanroom Fab. Lab., housing a customised Heathway tower for drawing novel optical fibres and novel processing facilities for making planar, small-scale waveguides.

High-silica glasses are known for their excellent linear optical properties and are, for instance, the material of choice for long haul optical fibres. Novel inorganic-compound glasses such as heavy metal halides, oxides and oxyhalides, and chalcogenides, are based on more weakly chemically bonded lattices than silica. These novel glasses are therefore rather less chemically and mechanically robust than silica glass. On the other hand, they offer far more optical versatility than silica glass including: windows spanning the near-ultraviolet to far-infrared; large solubility of active rare earth dopants; low phonon energy for greater efficiency of radiative transitions; large linear and nonlinear refractive indices; high third order nonlinear optical susceptibilities; nano-glass-ceramic formation; great photosensitivity and a large acousto-optic effect. Being glasses means that compositions are not fixed to a single stoichiometry but almost infinitely variable, allowing the possibility of tailoring optical properties to suit, such as for all-optical switching, amplification, sources, sensors, memory, interconnects and photonic and electronic integration. Also inorganic compound glasses are generally isotropic hence optical orientation is not a problem compared to crystalline materials.

Recent achievements of the Novel Photonic Glasses Group at Nottingham University include showing that erbium III doped into nano-glass-ceramics exhibits the broadest emission reported to date, to our knowledge, at 1.55 µm wavelength compared to when doped into other hosts. In addition, the doping levels achieved are ~ 100 x that in contemporary EDFA (erbium doped fibre amplifiers). Hence the doped nano-glass-ceramics have potential as next generation micro-amplifiers of far greater flexibility than current amplifiers for telecom. systems.

Photonic and electronic integration on a single chip demands innovative, flexible fabrication technologies. Over the last few years we have demonstrated for the first time that hot embossing ofnovel inorganic-compound glasses successfully produces waveguides and other features to better than 0.1 µm -scale definition. We have recently demonstrated monomode rib waveguides made by the hot embossing route. These are the basicbuilding blocks of photonic integrated circuits.

We are developing low optical loss, novel glass optical fibres for the infrared for power delivery and sensing forinstance for medical surgery and diagnoses, respectively.

Department of Mechanical, Manufacturing and Materials Engineering

The University of Nottingham
University Park
Nottingham, NG7 2RD


telephone: +44 (0) 115 95 14081