In this chapter, coherent effects that accompany the propagation of laser radiation in tissues and the interaction of laser radiation with cell flows are considered. These effects include diffraction, formation of speckle structures, interference of speckle fields, scattering from moving particles, etc. Principles of quasi-elastic light scattering (QELS) spectroscopy, diffusion wave spectroscop...

In practice, SAR images are very often disturbed by a correlated speckle noise. Correlation influence on wavelet coefficients is a difficult problem degrading detection and filtering performances dramatically. We establish a simple analytic relation between high order wavelet coefficient moments/cumulants and speckle second order statistics. The proposed solution is shown to improve detection a...

The reeectivity due to stimulated Brillouin backscattering (SBS) from an ensemble of independent laser speckles is investigated for diierent speckle statistics. Calculations are based on numerical simulations with a multidi-mensional code and a compact model describing the main features of speckle self-focusing. In particular, the simulations and the model are applied to speckle ensembles due t...

Holographic speckle is a major impediment for the emerging applications of multiphoton holographic projection in biomedical imaging, photo-stimulation and micromachining. Time averaging of multiple shifted versions of a single hologram ("shift-averaging") is a computationally-efficient method that was recently shown to deterministically eliminate holographic speckle in single-photon application...

ultrasound images suffer of multiplicative noise named speckle. different de-speckling algorithms run either in spatial domain or in transformed domain. in this paper, an adaptive filter in spatial domain according to assume the nakagami distribution as the statistic of log-compressed ultrasound images is used. for de-speckling in transformed domain, the non-sub sampled shearlet transform is us...

Imaging observations are generally affected by a fluctuating background of speckles, a particular problem when detecting faint stellar companions at small angular separations. These speckles can be created by both short-lived atmopsheric aberrations and slowly changing distortions in the optical system. Over the course of a long-exposure image, the combination of many independent realizations o...

This article is a short overview of some recent research activity in the Laboratory of Inorganic Synthesis and Catalysis (LSCI) at EPFL-ISIC. It summarizes the work on Ni-catalyzed cross-coupling reactions of non-activated alkyl halides. It then describes and discusses the work on the bio-mimetic chemistry of [Fe]-hydrogenase.

Laser Speckle Contrast Imaging (LSCI) is a minimally invasive full field optical technique used to generate blood flow maps with high spatial and temporal resolution. The lack of quantitative accuracy and the inability to predict flows in the presence of static scatterers such as an intact or thinned skull have been the primary limitation of LSCI. We present a new Multi-Exposure Speckle Imaging...

Laser speckle imaging (LSI) is an interferometric technique that provides information about the relative speed of moving scatterers in a sample. Photothermal LSI overcomes limitations in depth resolution faced by conventional LSI by incorporating an excitation pulse to target absorption by hemoglobin within the vascular network. Here we present results from experiments designed to determine the...

In the field of biomedical imaging, the ultrasound imaging is a vital tool for diagnosis of various disease or abnormalities. Unfortunately, the presence of speckle noise in these images affects edges and fine details which limit the contrast resolution and make diagnostic more difficult. Hence speckle noise reduction is an important task for developing a effective diagnosis system. In this pap...