Monemhaghdoust Zahra, Montfort Frédéric, Emery Yves, Depeursinge Christian, Moser Christophe
Ecole Polytechnique Fédérale de Lausanne, Laboratory of Applied Photonics Devices, CH-1015 Lausanne, Switzerland.
Ecole Polytechnique Fédérale de Lausanne, Laboratory of Applied Photonics Devices, CH-1015 Lausanne, Switzerland ; Lyncée Tec SA, CH-1015 Lausanne, Switzerland.
Biomed Opt Express. 2014 May 1;5(6):1721-30. doi: 10.1364/BOE.5.001721. eCollection 2014 Jun 1.
We propose and experimentally demonstrate a digital holographic camera which can be attached to the camera port of a conventional microscope for obtaining digital holograms in a self-reference configuration, under short coherence illumination and in a single shot. A thick holographic grating filters the beam containing the sample information in two dimensions through diffraction. The filtered beam creates the reference arm of the interferometer. The spatial filtering method, based on the high angular selectivity of the thick grating, reduces the alignment sensitivity to angular displacements compared with pinhole based Fourier filtering. The addition of a thin holographic grating alters the coherence plane tilt introduced by the thick grating so as to create high-visibility interference over the entire field of view. The acquired full-field off-axis holograms are processed to retrieve the amplitude and phase information of the sample. The system produces phase images of cheek cells qualitatively similar to phase images extracted with a standard commercial DHM.
我们提出并通过实验证明了一种数字全息相机，它可以连接到传统显微镜的相机端口，用于在短相干照明下以自参考配置单次获取数字全息图。一个厚全息光栅通过衍射在二维上对包含样品信息的光束进行滤波。滤波后的光束形成干涉仪的参考臂。基于厚光栅的高角度选择性的空间滤波方法，与基于针孔的傅里叶滤波相比，降低了对角度位移的对准灵敏度。添加一个薄全息光栅会改变厚光栅引入的相干平面倾斜度，从而在整个视场中产生高可见度的干涉。对采集到的全场离轴全息图进行处理，以检索样品的幅度和相位信息。该系统产生的脸颊细胞相位图像在质量上与用标准商用数字全息显微镜提取的相位图像相似。
