Tunable multiple-scattering system
نویسندگان
چکیده
To study the propagation of multiply scattered waves, it is useful to have a medium in which the scattering properties can be easily controlled. Here, we describe such a system; it involves the propagation of ultrasonic surface waves in a medium with an aligned, disordered pattern of grooves. Waves propagating parallel to the grooves see a homogeneous medium; waves propagating perpendicular to the grooves are strongly scattered. By varying the source–receiver distance and orientation with respect to the grooves, we are able to map out the transition from ballistic to diffusive propagation. In addition, by using an optical detection system we are able to measure the wave motion inside the scattering medium. We measure the angle-dependent macroscopic properties of the medium, such as the group velocity as well as the mean-free path and the diffusion constant in the strong-scattering regime. © 2001 American Institute of Physics. @DOI: 10.1063/1.1402156#
منابع مشابه
Tunable Plasmonic Nanoparticles Based on Prolate Spheroids
Metallic nanoparticles can exhibit very large optical extinction in the visible spectrum due to localized surface plasmon resonance. Spherical plasmonic nanoparticles have been the subject of numerous studies in recent years due to the fact that the scattering response of spheres can be analytically evaluated using Mie theory. However a major disadvantage of metallic spherical nanoparticles is ...
متن کاملGeneration of coherent and tunable ultraviolet radiation by scattering processes
Tunable, coherent radiation in the ultraviolet region has been generated by stimulated Raman scattering, by anti-Stokes Raman lasers, and by frequency-mixing processes based on nonlinear polarizabilities of atomic and molecular systems. Present progress in the development of these laser-driven sources is reviewed, with examples of available systems and their characteristics. Applications in spe...
متن کاملPreparation and Characterization of Polystyrene-Silver NanocompositeUsing MicroemulsionMethod and its Antibacterial Activity
Polymer nanocomposites containing metals have been used in a wide range of applications due to their versatility, and tunable characteristics including physical, chemical, biological and mechanical properties. In this research work polystyrene-silver nanocomposite has been produced using polymerization of a w/o microemulsion system. Styrene monomer was used as the oil or continues phase of the ...
متن کاملDesign On-Line Tunable Gain Artificial Nonlinear Controller
One of the most important challenges in nonlinear, multi-input multi-output (MIMO) and time variant systems (e.g., robot manipulator) is designing a controller with acceptable performance. This paper focused on design a new artificial non linear controller with on line tunable gain applied in the robot manipulator. The sliding mode fuzzy controller (SMFC) was designed as 7 rules Mamdani’s infer...
متن کاملDesign On-Line Tunable Gain Artificial Nonlinear Controller
One of the most important challenges in nonlinear, multi-input multi-output (MIMO) and time variant systems (e.g., robot manipulator) is designing a controller with acceptable performance. This paper focused on design a new artificial non linear controller with on line tunable gain applied in the robot manipulator. The sliding mode fuzzy controller (SMFC) was designed as 7 rules Mamdani’s infer...
متن کاملCore-shell colloidal particles with dynamically tunable scattering properties.
We design polystyrene-poly(N'-isopropylacrylamide-co-acrylic acid) core-shell particles that exhibit dynamically tunable scattering. We show that under normal solvent conditions the shell is nearly index-matched to pure water, and the particle scattering is dominated by Rayleigh scattering from the core. As the temperature or salt concentration increases, both the scattering cross-section and t...
متن کامل