Department of Physics and Astronomy, the University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK
Dr. Paul Walker
Paul works in the Low Dimensional Structures and Devices Group at the University of Sheffield. His main focus is on the optical properties of semiconductor micro- and nano-structures in which photons couple strongly to quantum-wells excitons to form exciton-polaritons. He has a previous and continuing interest in the properties of quantum fluids formed by polariton condensation in both planar microcavities and micro and nano structured monolithic and tunable open cavities.
Currently he is studying nonlinear optics in exciton-polariton waveguides where the light-matter coupling leads to massive dispersion and nonlinearity. This allows nonlinear phenomena such as optical solitons to become apparent on short length scales suitable for integrated optical circuit fabrication.
Other interests include numerical modelling of the linear and nonlinear optical and acoustical properties of semiconductor micro- and nano-structures using both frequency (e.g. matrix methods and rigourous coupled wave analysis) and time domain (e.g. FDTD and split step fourier) methods.
During his PhD at the University of Nottingham he also gained experience in ultrafast (100GHz – 1THz) acoustics, where high frequency sound waves are used to modulate the optical, or other, properties of semiconductor devices.