吸收性液滴的彩虹现象

提出了基于彩虹散射光吸收系数的液滴吸收率测量方法.采用基于Mie理论的改进算法进行数值模拟.研究表明,液滴的吸收性不改变彩虹光强波峰及对应频峰的位置,但改变彩虹光强强度,尤其对彩虹表面波结构及Airy结构影响较大,并因此降低了彩虹的可见度.计算发现液滴散射光吸收系数的最大值出现在彩虹区,并随液滴吸收率和粒径的增加稳定在彩虹最大波峰角位置,而且此处的吸收系数与吸收率之间有着线性关系.基于彩虹测量技术具有易检测、易标定的特点,因此有望发展为一种新的液滴吸收系数测量方法.

Rainbow phenomena of absorbing droplet

The rainbow phenomena of the absorbing droplet was studied and a method of droplet absorption measurement was proposed based on absorption coefficient of scattering light.The absorption effect of scattering light at the rainbow angle was simulated using a new algorithm based on Mie theory.Results show that the positions of the supernumerary bow peaks and corresponding frequency peaks of the primary rainbow are not shifted by droplet absorption,while the droplet absorption reduces the light intensity,which depresses the rainbow visibility.It is observed that the maximum of the absorption coefficient occurs in the rainbow region,and approaches the stable position at the maximum rainbow peak angle when the droplet absorption and diameter increase.Also the absorption coefficient at this position has a linear relation with the droplet absorption.The simplicity on detection and calibration implies a potential use of rainbow detection for measuring droplet absorption coefficient.