Verrier N, Donnarumma D, Tessier G, Gross M
Appl Opt. 2015 Nov 10;54(32):9540-7. doi: 10.1364/AO.54.009540.
A holographic microscopy reconstruction method compatible with a high numerical aperture microscope objective (MO) up to NA=1.4 is proposed. After off-axis and reference field curvature corrections, and after selection of the +1 grating order holographic image, a phase mask that transforms the optical elements of the holographic setup into an afocal device is applied in the camera plane. The reconstruction is then made by the angular spectrum method. The field is first propagated in the image half-space from the camera to the afocal image of the MO optimal plane (the plane for which the MO has been designed) by using a quadratic kernel. The field is then propagated from the MO optimal plane to the object with the exact kernel. Calibration of the reconstruction is made by imaging a calibrated object such as a USAF resolution target for different positions along z. Once the calibration is done, the reconstruction can be made with an object located in any plane z. The reconstruction method has been validated experimentally with a USAF target imaged with a NA=1.4 microscope objective. Near-optimal resolution is obtained over an extended range (±50 μm) of z locations.
提出了一种与数值孔径高达NA = 1.4的高数值孔径显微镜物镜（MO）兼容的全息显微镜重建方法。在进行离轴和参考场曲率校正后，以及在选择 +1 光栅级全息图像后，在相机平面中应用一个相位掩模，该相位掩模将全息装置的光学元件转换为无焦装置。然后通过角谱法进行重建。首先使用二次核函数将场从相机在图像半空间中传播到MO最佳平面（MO所设计的平面）的无焦图像，然后用场精确核函数将场从MO最佳平面传播到物体。通过对校准物体（如美国空军分辨率靶标）在沿z轴的不同位置进行成像来进行重建校准。一旦完成校准，就可以对位于任何z平面的物体进行重建。该重建方法已通过使用NA = 1.4显微镜物镜对美国空军靶标进行成像实验验证。在z位置的扩展范围（±50μm）内获得了接近最佳的分辨率。
