Replacement Laser for Holographic Fabrication of Photonic Crystals

Lead Research Organisation: University of Oxford
Department Name: Oxford Physics


This grant proposal is intended to enable us to buy a replacement for a laser system. The laser has been troublesome in the past and is getting worse - it has been unusable for two months, and in that time the manufacturer has not been able to suggest how it might be returned to use. The laser is essential to our research - without a replacement we cannot continue with a project already funded by EPSRC which is described below.Photonic crystals are optical materials with regular, repeated, wavelength-scale microstructure. Photonic crystals are 'optical semiconductors' whose properties make them uniquely suitable for the fabrication of photonic integrated circuits. Their characteristic property is a 'photonic band gap' - a forbidden frequency range within which the structure acts as an optical insulator. 'Doping' with structural defects introduces localized electromagnetic modes which may be engineered to create the components of integrated optical devices, such as waveguides and microcavities. The high level of optical isolation that may be achieved within a photonic crystal means that photonic crystal-based integrated optical circuits promise to approach the density of integration of electronic devices, a development which will revolutionize the handling of telecommunications signals. In a collaboration between the Physics and Chemistry Departments at Oxford University we have developed a completely new way to make photonic crystals. We use a three-dimensional holographic laser interference pattern to create the necessary sub-wavelength microstructure in a thick film of photoresist. We then use a purpose-built confocal microscope to modify the structure to create waveguide etc. structures within it. This technique is inherently cheap and quick / it gives uniquely flexible access to a wide range of 3D photonic crystal phenomena and could be readily scaled up to commercial manufacture. In this proposal we aim to create 3D photonic crystals which are suitable for use in the range of wavelengths used in optical fibre telecommunications. We also aim to create engineered structural defects within 3D photonic crystals and to investigate the relationship between the structure of the defects and the optical properties of the 'doped' crystal as an important step towards three-dimensional integration of micrometer-scale optical devices.
Description EP/D051193/1 is a grant for equipment purchase only, made in response to an urgent application for funds to replace a laser . This purchase was necessary to enable continuation of an EPSRC-funded project, GR/T18752 'Photonic Crystals: Holographic Fabrication and 3D Lithography'

This equipment grant was successful in allowing us to complete our research programme under GR/T18752: for further discussion please see outcomes of GR/T18752.
Exploitation Route Photonic crystal structures are the subject of active research internationally which could lead to developments in both active and passive optical devices that would be of great importance (as a disruptive technology) to the optoelectronics industry. A rate-limiting step in this development process is the fabrication of photonic microstructures with precisely determined sub-wavelength structure. The primary goal of this programme was to create a fabrication technology using low-cost materials that should be readily adaptable to volume production. It is in the interests of the industry that these developments be hastened by investment in research in fabrication technology: it is certainly in the interests of U.K industry that significant developments In this area are made in the U.K allowing rapid transfer of expertise. Efficiency and cost gains in the manufacture of telecommunications hardware will benefit all sectors of British industry as well as domestic consumers through lower prices and improved reliability.

The physics of microstructured photonic materials and micro-cavities, as well as the electromagnetic processes that occur within them are the subject of research, ranging from device technology to quantum computation, in many U.K. and international institutions. Our results have contributed to the development of research into the physical properties and engineering applications of photonic crystal devices in academic and industrial laboratories around the world - as reported in the 'Narrative Impact' section.
Sectors Digital/Communication/Information Technologies (including Software),Manufacturing, including Industrial Biotechology

Description Our technique of holographic lithography has been taken up by groups at, e.g., Bell Laboratories, MIT, the Korea Advanced Institute for Science and Technology, the Royal Institute for Technology, Sweden, and Karlsruhe, Pennsylvania State, Illinois, Toronto, Osaka, California (UCSB), Sun Yat Sen, Hong Kong, Zhongshan and Shandong Universities. This research grant was the basis for a collaborative research project with QinetiQ to create photonic crystal lens structures and a new collaboration with Georgia Tech on photonic crystal infiltration.
First Year Of Impact 2006
Sector Other
Impact Types Economic

Description GaTech 
Organisation Georgia Institute of Technology
Country United States 
Sector Academic/University 
PI Contribution Provision of 3D photonic crystal templates created by holographic lithography
Collaborator Contribution Infiltration and inversion of photonic crystal templates by atomic layer deposition to create high-index replicas
Impact Replicated photonic crystals by atomic layer deposition within holographically defined polymer templates E. Graugnard, O. M. Roche, S. N. Dunham, J. S. King, D. N. Sharp, R. G. Denning, A. J. Turberfield and C. J. Summers Appl. Phys. Lett. 94, 263109 (2009) Infiltration and inversion of holographically defined polymer photonic crystal templates by atomic layer deposition J. S. King, E. Graugnard, O. M. Roche, D. N. Sharp, J. Scrimgeour, R. G. Denning, A. J. Turberfield and C. J. Summers Adv. Mater. 18, 1561-1565 (2006)
Description QinetiQ 
Organisation Qinetiq
Department QinetiQ (Malvern)
Country United Kingdom 
Sector Private 
PI Contribution Research into photonic crystal lenses
Collaborator Contribution Computational modelling of photonic crystal lenses
Impact N/A
Start Year 2007