Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Laser Biomedical Research Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Laser Biomedical Research Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
Methods. 2018 Mar 1;136:35-39. doi: 10.1016/j.ymeth.2017.10.006. Epub 2017 Oct 25.
Interferometric microscopy (IM) can provide complex field information of the biological samples with high spatial and temporal resolution with virtually no photodamage. Measuring wavelength-dependent information in particular has a wide range of applications from cell and tissue refractometry to the cellular biophysical measurements. IM measurements at multiple wavelengths are typically associated with a loss in temporal resolution, field of view, stability, sensitivity, and may involve using expensive equipment such as tunable filters or spatial light modulators. Here, we present a novel and simple design for an interferometric microscope that provides single-shot off-axis interferometric measurements at two wavelengths by encoding the two spectral images at two orthogonal spatial frequencies that allows clean separation of information in the Fourier space with no resolution loss. We demonstrated accurate simultaneous quantification of polystyrene bead refractive indices at two wavelengths.
干涉显微镜（IM）可以提供具有高空间和时间分辨率的生物样品的复杂场信息，几乎没有光损伤。特别是测量波长相关的信息，从细胞和组织折射率测量到细胞生物物理测量，有广泛的应用。在多个波长下进行 IM 测量通常会导致时间分辨率、视野、稳定性和灵敏度的降低，并且可能需要使用昂贵的设备，如可调谐滤波器或空间光调制器。在这里，我们提出了一种新颖而简单的干涉显微镜设计，该设计通过在两个正交空间频率上对两个光谱图像进行编码，提供了单次离轴干涉测量，在不损失分辨率的情况下，在傅立叶空间中可以干净地分离信息。我们证明了在两个波长下对聚苯乙烯珠折射率的准确同时定量。
