ABSTRACT
We report the generation of shock waves in a disperse medium with absorbing particles of black pigment in the water using continuous laser radiation. As a result of the experimental investigation it was found that the illuminating beam diameter growth at the constant laser power results in the decrease of the signals' modulation frequencies, improving their stability and increasing their amplitudes. In turn, the decrease of the signal's modulation frequency is caused by the growth of time, which is needed for heating the medium to the critical temperature of cavitation. Improving the stability and the increase of optical and acoustic signal amplitudes take place, due to the growth of the medium volume and hence the number of pigment particles that participate in cavitation.
ABSTRACT
The feasibilities for optical correlation diagnostics of rough surfaces with large surface inhomogeneities by determining the transformations of the longitudinal coherence function of the scattered field are substantiated and implemented.
Subject(s)
Fractals , Interferometry/methods , Models, Theoretical , Optics and Photonics , Computer Simulation , Scattering, Radiation , Surface PropertiesABSTRACT
The feasibilities of using interferometric and chromascopic techniques in the diagnostics of phase singularities and in the study of a phase structure of the field in their vicinity are demonstrated. The peculiar evolution of singularities into caustics produced by phase elements of singularity-generating objects of spherical and cylindrical shape is studied.
Subject(s)
Algorithms , Color , Colorimetry/methods , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Information Storage and Retrieval/methods , Interferometry/methods , Models, Theoretical , Refractometry/methods , Computer Simulation , Feasibility StudiesABSTRACT
We introduce the singular-optics approach for classification of rough surfaces with large-scale inhomogeneities into random and fractal surfaces. The maps of amplitude zeros of a field versusthe parameters of the rough surfaces and the position of the observation zone are obtained and analyzed. It is shown that the local density of amplitude zeros in the scattered field serves as an appropriate parameter with which to classify the surface of interest into a surface with a height distribution that can be described as a random or a fractal process.
Subject(s)
Fractals , Models, Theoretical , Optics and Photonics , Scattering, Radiation , Surface PropertiesABSTRACT
The topology of a partially developed speckle field was studied by use of interference techniques through computer simulation. Amplitude and phase structures in the vicinity of caustics for a coherent radiation field scattered at a surface with large inhomogeneities were investigated. It was confirmed that the caustics are indispensible components of the procedure for the formation of networks of amplitude zeros for a coherent field scattered by a rough surface with large inhomogeneities. It is shown that the formation of interference forklets in the field gives evidence of changes in the field's topology, as these forklets are a diagnostic sign of transition from a caustic to a three-dimensional pattern of a diffraction catastrophe.