Spectral domain optical coherence tomography with sub-micrometer sensitivity for measurement of central corneal thickness

We demonstrated a method for measurement of central corneal thickness(CCT) with a sub-micrometer sensitivity using a spectral domain optical coherence tomography system without needing a super broad bandwidth light source. By combining the frequency and phase components of Fourier transform, the method is capable of measurement of a large dynamic range with a high sensitivity. Absolute phases are retrieved by comparing the correlations between the detected and simulated interference fringes. The phase unwrapping ability of the present method was quantitatively tested by measuring the displacement of a piezo linear stage. The human CCTs of six volunteers were measured to verify its clinical application. It provides a potential tool for clinical diagnosis and research applications in ophthalmology.     

谱域相位显微成像的相位解包裹

提出了一种应用于谱域相位显微成像的相位解包裹方法。利用傅里叶变换及合成波长相位计算方法分别得到具有较小噪声的包裹相位和具有较大噪声的解包裹相位,利用解包裹相位与包裹相位之差计算包裹相位的包裹次数,以此对具有较小噪声的包裹相位进行解包裹。该方法消除了现有方法引入的边界分段错误。建立了一种基于合成波长的谱域相位显微成像系统,使用压电位移台定量验证了该系统可以用于大梯度边界的相位解包裹,并进行了红细胞和倾斜镜面的相位成像。该系统在空气中的位移灵敏度为0.043 nm。     

超小间距纳米柱阵列中的谐振调制

本文首先研究了具有通常柱间距（大于100 nm）的纳米柱阵列在近红外波段的光学特性并实现了通过改变阵列参数（如周期）来调制局域表面等离子体谐振. 随后,通过使用电子束直写和离子束刻蚀的方法制备出具有超小柱间距（小于50 nm）和超高密度（ultrahigh density）的纳米柱阵列并通过对表面等离子体谐振的调制实现了在可见光波段滤出不同颜色的单色光. 本文中所展示的纳米柱功能阵列可以与现有的数字光处理（digital light processing,DLP）技术相兼容进而构造具有超小像素的显示屏,可以在显示、成像等领域取得广泛的应用. 关键词： 纳米柱 超小间距 超高密度 显示