Light scattering and radiative processes (LSRP)

Overview

Light Scattering and Radiative Processes is a sub-area of the Centre for Atmospheric and Climate Physics (CACP). Researchers from this area have been engaged for nearly thirty years in the theory and application of laser light scattering to non-destructive measurement and characterisation of microparticles and living cells. Optical trapping and electrodynamic levitation techniques have also been developed and refined (e.g. through work on beam theory and theoretical optics) to support fundamental experimental investigations of particle scattering phenomena. A study taking advantage of particle trapping focuses on scattering properties of atmospheric ice crystals. We also describe a recent discovery of aerosol particle alignment in the atmosphere, together with its consequences for remote sensing and dust transport. Theoretical work encompasses both direct and inverse scattering problems (respectively, computation of scattering from the knowledge of particle properties, and extraction of particle parameters such as size, shape and refractive index from scattering data) for particles of various geometries. The direct problems research currently concentrates on scattering from objects such as crystals or particles with rough surfaces. The inverse problems research includes novel transform techniques based on Gegenbauer polynomials, the application of neural networks and the development of global stochastic optimization methods and sizing using speckle. Sponsors of the Group's work have included the EPSRC, NERC and industry. The research interacts closely with CACP's Particle Instruments and Diagnostics, who have implemented many of the LSRP developments as practical instrument systems, Atmospheric Processes, Air Quality and Climate sub-areas, and Centre for Astrophysics Research. We recommend you visit their pages too.

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e.hesse@herts.ac.uk