Large area optical mapping of surface contact angle.

Top-down contact angle measurements have been validated and confirmed to be as good if not more reliable than side-based measurements. A range of samples, including industrially relevant materials for roofing and printing, has been compared. Using the top-down approach, mapping in both 1-D and 2-D has been demonstrated.

The acoustic field in biomedical tissue with midscale inhomogeneities.

Biomedical ultrasound is often used for investigations within and close to tissue inhomogeneities, such as lesions and plaques, that are midsized compared with the ultrasound wavelength. The scaled wavenumber is typically in the range 1 to 100. Even with small (less than 10%) sound speed variations, such objects are associated with very complicated diffractive field magnitude modulations.

Light acceptance properties of multimode microstructured optical fibers: Impact of multiple layers.

We present a study of the large numerical aperture and high capture efficiency in a class of microstructured optical fibers, also called ???air-clad??? fibers. We employ a recently developed method where the leaky modes supported by a waveguide are used to determine the far-field angular intensity distributions. These distributions are subsequently used to calculate the capture efficiency and numerical aperture.