Zheng Cheng, Jin Di, He Yanping, Lin Hongtao, Hu Juejun, Yaqoob Zahid, So Peter T C, Zhou Renjie
The Chinese University of Hong Kong, Department of Biomedical Engineering, Hong Kong, China.
Massachusetts Institute of Technology, Department of Mechanical Engineering, Cambridge, Massachusetts, United States.
Adv Photonics. 2020 Nov;2(6). doi: 10.1117/1.ap.2.6.065002. Epub 2020 Nov 26.
A new optical microscopy technique, termed high spatial and temporal resolution synthetic aperture phase microscopy (HISTR-SAPM), is proposed to improve the lateral resolution of wide-field coherent imaging. Under plane wave illumination, the resolution is increased by twofold to around 260 nm, while achieving millisecond-level temporal resolution. In HISTR-SAPM, digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability. An off-axis interferometer is used to measure the sample scattered complex fields, which are then processed to reconstruct high-resolution phase images. Using HISTR-SAPM, we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap (i.e., a full pitch of 330 nm). As the reconstruction averages out laser speckle noise while maintaining high temporal resolution, HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells, such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells. We envision that HISTR-SAPM will broadly benefit research in material science and biology.
一种名为高空间和时间分辨率合成孔径相显微镜（HISTR-SAPM）的新型光学显微镜技术被提出来，以提高宽场相干成像的横向分辨率。在平面波照明下，分辨率提高了两倍，达到约260纳米，同时实现了毫秒级的时间分辨率。在HISTR-SAPM中，数字微镜器件被用于以高稳定性高速主动改变样品照明光束角度。一个离轴干涉仪被用于测量样品散射的复场，然后对其进行处理以重建高分辨率的相位图像。使用HISTR-SAPM，我们能够绘制亚波长光子结构的高度轮廓，并分辨出线宽为198纳米、间隙为132纳米（即全间距为330纳米）的周期结构。由于重建在保持高时间分辨率的同时平均掉了激光散斑噪声，HISTR-SAPM还能够对活细胞的纳米级动力学进行成像和定量分析，如红细胞膜波动和成核细胞内亚细胞结构动力学。我们设想HISTR-SAPM将广泛有益于材料科学和生物学研究。
