Zhao Jing-Ru, Wu Zhen-Jie, Wang Gui-Qiang, Wang Chun-Nan, Deng Bo-Fu, Sun Shu-Qing
Appl Opt. 2022 Dec 1;61(34):10065-10071. doi: 10.1364/AO.465029.
A total internal reflection system based on the weak value amplification principle is set up for the precise measurement of the thickness of an ultra-thin film. In this system, the film thickness is derived from the change of the double-peak pointer caused by the effective refractive index of the film, which is correlated to its thickness. The sensitivity and resolution of this system reached 2727.21 nm/RIU and 7.2×10 , respectively, determined by using a sodium chloride solution with a refractive index of 1.331911. The growth process of TA/Fe(III) assembled films with thicknesses in the few nanometers range is monitored using the as-set-up system, and the experimental results are consistent with a theoretical calculation based on the Maxwell Garnett effective medium. Additionally, we theoretically calculated the detection limit for the thickness measurement of the film as 22 pm. We clearly provide a potential method for the precise measurement of the thickness of an ultra-thin film.
搭建了基于弱值放大原理的全内反射系统，用于精确测量超薄膜的厚度。在该系统中，薄膜厚度由薄膜有效折射率引起的双峰指针变化推导得出，而有效折射率与薄膜厚度相关。通过使用折射率为1.331911的氯化钠溶液确定，该系统的灵敏度和分辨率分别达到2727.21 nm/RIU和7.2×10 。利用所搭建的系统监测了厚度在几纳米范围内的TA/Fe(III)组装膜的生长过程，实验结果与基于麦克斯韦-加内特有效介质的理论计算结果一致。此外，我们从理论上计算出该薄膜厚度测量的检测限为22 pm。我们明确提供了一种精确测量超薄膜厚度的潜在方法。
