Molecular-level in-situ observation of water-ice crystal (melt-crystal) interfaces by developing ultrahigh sensitivity phase contrast microscopy

为了在分子水平上对熔体-晶体界面进行原位观察，我们尝试显著提高相衬光学显微镜的对比度（放置在物镜的后焦平面）和薄1/4倍的环形狭缝（我们新准备了一个物镜和一个环形狭缝），以降低透射光的强度，并增加衍射光的强度。然后，我们成功地提高了He La细胞（生物学中的标准样品）和水-冰（熔体-晶体）界面的相衬水平，分别高出约2.1和1.5倍。这些结果表明，通过使透射光和衍射光的强度完全匹配，添加可以任意降低透射光强度的装置可以进一步提高相位对比度水平。

We tried to improve the contrast level of phase-contrast optical microscopy significantly, aiming at molecular-level in-situ observation of melt-crystal interfaces.We made widths of an orbicular filter (placed at a back focal plane of an objective) and a ring slit 1/4 times thinner (we newly prepared an objective and a ring slit), to decrease the intensity of transmitted light and also to increase the intensity of diffracted light. Then we succeeded in improving the phase-contrast levels of He La cells (standard samples in biology) and water-ice (melt-crystal) interfaces about 2.1 and 1.5 times higher, respectively. These results suggest that the addition of a device that can arbitrarily decrease the intensity of transmitted light can further improve phase contrast level, by perfectly matching the intensities of transmitted and diffracted light.