Zhang Yuanlong, Kong Lingjie, Xie Hao, Han Xiaofei, Dai Qionghai
Opt Express. 2018 Aug 20;26(17):21518-21526. doi: 10.1364/OE.26.021518.
Compared with two-photon point-scanning microscopy, line-scanning temporal focusing microscopy breaks the limitation on imaging rate and maintains the axial resolution, which makes it promising for various biomedical studies. However, for deep tissue imaging, it suffers from reduced axial resolution and increased background noise due to sample induced wavefront distortion. Here, we propose a spatio-spectral focal modulation technique to enhance axial resolution and background rejection by simply subtracting an aberrated image, which is induced by a spatial light modulator, from an unaberrated image. The proposed technique could improve the axial resolution by a factor of 1.3 in our implementation, verified by both simulations and experiments. Besides, we show that compared with spatial modulation alone, spatio-spectral modulation induces less peak intensity loss caused by image subtraction. We further demonstrate the performance of our technique on the enhanced axial resolution and background rejection by deep imaging of cleared mouse brains and in vivo imaging of living mouse brains.
与双光子点扫描显微镜相比，线扫描时间聚焦显微镜打破了成像速率的限制并保持了轴向分辨率，这使其在各种生物医学研究中具有广阔前景。然而，对于深层组织成像，由于样品引起的波前畸变，它会出现轴向分辨率降低和背景噪声增加的问题。在此，我们提出一种时空光谱聚焦调制技术，通过简单地从无像差图像中减去由空间光调制器诱导的像差图像来提高轴向分辨率和背景抑制能力。在我们的实验中，所提出的技术可将轴向分辨率提高1.3倍，这一结果通过模拟和实验均得到了验证。此外，我们表明，与单独的空间调制相比，时空光谱调制在图像相减时引起的峰值强度损失更小。我们进一步通过对透明小鼠大脑的深度成像和活体小鼠大脑的体内成像，展示了我们技术在增强轴向分辨率和背景抑制方面的性能。
