The Elliptical Cylindrical Liquid Lens

摘要

The problem of the focusing of pressure wave by a thick elliptical cylinder liquid lens has been treated in a rigorous manner. The size of the lens is of the order of or slightly greater than the wavelength of the incoming acoustic signal. Detailed computation has been carried out for a representative case in which a liquid lens with index of refraction of 1.8 and density of 1900 kg/cubic meter is assumed to be immersed in seawater. It is shown that a slight deformation of the boundary surface of a circular liquid lens results in significant changes in the location of the focalregion and that elliptical lens may provide stronger focusing than an equivalent circular lens. This research also points out the necessity pursuing an investigation on thin lenses where the focal regions are located outside the lenses. (Author)