Miyazaki Jun, Tsurui Hiromichi, Kobayashi Takayoshi
Advanced Ultrafast Laser Research Center, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan ; JST, CREST, K' Gobancho, 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
Department of Pathology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Biomed Opt Express. 2015 Aug 4;6(9):3217-24. doi: 10.1364/BOE.6.003217. eCollection 2015 Sep 1.
A scheme for reducing image distortion in photothermal microscopy is presented. In photothermal microscopy, the signal shape exhibits twin peaks corresponding to the focusing or defocusing of the probe beam when a sample is scanned in the axial direction. This causes a distortion when imaging a structured sample in the axial plane. Here, we demonstrate that image distortion caused by the twin peaks is effectively suppressed by providing a small offset between two the focal planes of the pump and the probe beams. Experimental results demonstrate improvement in resolution, especially in the axial direction, over conventional optical microscopy-even with the focal offset. When a dry objective lens with a numerical aperture of 0.95 is used, the full width at half the maximum of the axial point spread function is 0.6 μm, which is 50% (62%) smaller than the focal spot sizes of the pump (probe) beam. Herein, we present high-resolution three-dimensional imaging of thick biological tissues based on the present scheme.
提出了一种减少光热显微镜中图像失真的方案。在光热显微镜中，当在轴向方向上扫描样品时，信号形状呈现出对应于探测光束聚焦或散焦的双峰。这在对轴向平面中的结构化样品进行成像时会导致失真。在此，我们证明通过在泵浦光束和探测光束的两个焦平面之间提供小的偏移，可以有效抑制由双峰引起的图像失真。实验结果表明，即使存在焦偏移，与传统光学显微镜相比，分辨率也有提高，特别是在轴向方向上。当使用数值孔径为0.95的干式物镜时，轴向点扩散函数半高宽为0.6μm，比泵浦（探测）光束的焦斑尺寸小50%（62%）。在此，我们基于本方案展示了厚生物组织的高分辨率三维成像。
