Introducing nonlinear fluorophore excitation into structured illumination microscopy (SIM) can further extend its spatial resolution without theoretical limitation. However, it is a great challenge to recover the weak higher-order harmonic signal and reconstruct high-fidelity super-resolution (SR) images. Here, we proposed a joint optimization strategy in both the frequency and spatial domains to reconstruct high-quality nonlinear SIM (NL-SIM) images. We demonstrate that our method can reconstruct SR images with fewer artifacts and higher fidelity on the BioSR dataset with patterned-activation NL-SIM. This method could robustly overcome one of the long-lived obstacles on NL-SIM imaging, thereby promoting its wide application in biology.

中文翻译：

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用于改善非线性结构照明显微镜超分辨率图像的频空域联合优化

将非线性荧光团激发引入结构化照明显微镜 (SIM) 可以进一步扩展其空间分辨率，而不受理论限制。然而，恢复微弱的高次谐波信号和重建高保真超分辨率（SR）图像是一个巨大的挑战。在这里，我们提出了一种在频域和空间域中的联合优化策略来重建高质量的非线性 SIM (NL-SIM) 图像。我们证明了我们的方法可以在具有模式激活 NL-SIM 的 BioSR 数据集上以更少的伪影和更高的保真度重建 SR 图像。该方法可以有力地克服 NL-SIM 成像的长期障碍之一，从而促进其在生物学中的广泛应用。