Liu Shuoqing, Zheng Dandan, Yang Qiang, Chen Shizhen, Wen Shuangchun, Luo Hailu
Key Laboratory of Micro-/Nano-Optoelectronic Devices of Ministry of Education and Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China.
Nanophotonics. 2024 Jan 24;13(3):327-338. doi: 10.1515/nanoph-2023-0688. eCollection 2024 Feb.
Detection of transparent phase specimens especially biological cells with desired contrasts is of great importance in visual display and medical diagnosis. Due to the pure-phase nature, conventional detection approaches may damage samples or require complex operations. Computing liquid crystal (LC) is a thin and flat optical element with excellent capability in optical field modulation, which gives a feasible way to this issue from the perspective of analog optical computing. We here propose and experimentally implement an electrically switched two-dimensional (2D) differential microscopy based on computing LC platforms. The Pancharatnam-Berry phase LC polarization grating induces light's spin separation to promote the 2D differential operation. Using the electrically tunable LC plate as the system phase retardance provider, the detecting mode can be flexibly switched from bright-field images to edge-enhanced images with desired contrasts. Remarkably, owing to the wavelength-independent feature closely related to the geometric phases, our proposed scheme is demonstrated to be applicable to the multi-wavelength microscopy imaging. These results open avenues to form real-time all-optical image processing and may facilitate multifunctional differential microscopy.
检测具有所需对比度的透明相标本，尤其是生物细胞，在视觉显示和医学诊断中具有重要意义。由于其纯相性质，传统的检测方法可能会损坏样本或需要复杂的操作。计算液晶（LC）是一种薄而扁平的光学元件，具有出色的光场调制能力，从模拟光学计算的角度为解决这个问题提供了一种可行的方法。我们在此提出并通过实验实现了一种基于计算液晶平台的电开关二维（2D）微分显微镜。潘查拉特纳姆 - 贝里相液晶偏振光栅诱导光的自旋分离以促进二维微分操作。使用电可调液晶板作为系统相位延迟器，检测模式可以灵活地从明场图像切换到具有所需对比度的边缘增强图像。值得注意的是，由于与几何相位密切相关的波长无关特性，我们提出的方案被证明适用于多波长显微镜成像。这些结果为形成实时全光图像处理开辟了道路，并可能促进多功能微分显微镜的发展。
