Although various advanced super-resolution microscopies have been developed, conventional microscopes are still the most widely used. Therefore, it is still one of the goals of light microscopists to improve the imaging performance of conventional microscopes. Ernst Abbe had proven the resolution of a bright-field microscope can be improved by oblique illumination in 1873, but the approach has not been widely applied in practice due to the intrinsic drawback that the lateral resolution of the image is anisotropic. In this article, computational oblique illumination microscopy (COIM) is proposed to isotropically improve lateral resolution. Benefiting from outstanding performance of light emitting diodes (LEDs), the programmable symmetrical oblique illumination by LEDs can easily be implemented. COIM uses symmetrical oblique illuminations to enhance the absorption contrast and weaken the phase contrast in images; then an iterative algorithm is used to fuse an image with the isotropic high lateral resolution. Unlike synthetic aperture imaging, COIM does not require phase involvement, so there are no troublesome phase detection schemes. The experimental results indicate that COIM can resolve Element 6 in Group 11 (bar or space width 137 nm) of a USAF test target using a high numerical aperture (NA) objective lens (NA = 1.25) and oblique-illumination sources (center wavelength 520 nm). The proposed technique provides a new way to improve the resolution of bright-field microscope.

中文翻译：

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具有各向同性高分辨率的计算倾斜照明显微镜

尽管已经开发了各种先进的超分辨率显微镜，但常规显微镜仍然是应用最广泛的。因此，提高传统显微镜的成像性能仍然是光学显微镜工作者的目标之一。Ernst Abbe 在 1873 年证明了通过倾斜照明可以提高明场显微镜的分辨率，但由于图像的横向分辨率是各向异性的固有缺陷，该方法在实践中并未得到广泛应用。在本文中，提出了计算倾斜照明显微镜 (COIM) 以各向同性地提高横向分辨率。得益于发光二极管 (LED) 的出色性能，可以轻松实现 LED 的可编程对称倾斜照明。COIM使用对称斜向照明来增强图像中的吸收对比度并减弱相位对比度；然后使用迭代算法融合具有各向同性高横向分辨率的图像。与合成孔径成像不同，COIM 不需要相位介入，因此没有麻烦的相位检测方案。实验结果表明，COIM 可以使用高数值孔径 (NA) 物镜 (NA = 1.25) 和斜光源（中心波长 520纳米）。所提出的技术为提高明场显微镜的分辨率提供了一种新方法。与合成孔径成像不同，COIM 不需要相位介入，因此没有麻烦的相位检测方案。实验结果表明，COIM 可以使用高数值孔径 (NA) 物镜 (NA = 1.25) 和斜照明源（中心波长 520纳米）。所提出的技术为提高明场显微镜的分辨率提供了一种新方法。与合成孔径成像不同，COIM 不需要相位介入，因此没有麻烦的相位检测方案。实验结果表明，COIM 可以使用高数值孔径 (NA) 物镜 (NA = 1.25) 和斜光源（中心波长 520纳米）。所提出的技术为提高明场显微镜的分辨率提供了一种新方法。