Opt Lett. 2019 Aug 1;44(15):3897-3900. doi: 10.1364/OL.44.003897.
We present photoacoustic shadow-casting microscopy (PASM), a technique that allows high-resolution imaging of weakly absorbing biological samples with unprecedented sensitivity. In PASM, a uniform optical absorbing layer is placed in contact with the samples and is excited by the light transmitted through the sample, producing photoacoustic (PA) waves with an increased signal-to-noise ratio compared with that generated by the sample itself. Therefore, given a desired image quality, the required excitation fluence is much reduced, alleviating the photothermal damage to the specimen. The system provides a lateral resolution of 5 μm when using a 0.30 NA microscope objective lens. To demonstrate PASM, we present images of bovine red blood cells and microbeads.
我们提出了光声阴影投射显微镜（PASM），这是一种能够以空前的灵敏度对弱吸收生物样本进行高分辨率成像的技术。在 PASM 中，将均匀的光学吸收层与样品接触，并通过穿过样品的光来激发，与样品本身产生的光声（PA）波相比，产生的信号噪声比增加。因此，在给定所需的图像质量的情况下，所需的激发光通量大大减少，减轻了对样品的光热损伤。该系统使用 0.30 NA 显微镜物镜时提供 5 μm 的横向分辨率。为了展示 PASM，我们呈现了牛红细胞和微珠的图像。
