摘要
研究了一种窄带脉冲激励下Gauss聚焦波的非线性声场特性.采用解析方法求解KZK方程,理论研究了基波和二次谐波的空间分布规律.结果表明,基波和二次谐波声场沿径向均近似服从Gauss函数规律,且二次谐波波束更窄,但仅在准单色波条件下波束宽度与2成近似反比关系,时域方法的数值计算结果验证了理论结论.
In order to study the nonlinear field of the focused Gaussian beam with a band-limited pulse excitation,the KZK equation was solved analytically to study the spatial distribution of the fundamental and second harmonic component.The result indicates that the distribution of the fundamental and second harmonic field along the radial direction follows a law of Gaussian function approximately and the second harmonic has narrower beam-width,but the beam-width is inversely-proportional to 2 only under a quasi-monochromatic condition.The numerical result with a time-domain method verifies the theoretical conclusion.
基金
国家自然科学基金(30800270)
中国科学技术大学青年科学基金(KA2100230001)资助
