通过实验和理论分析研究1064 nm激光不同输出功率对小鼠皮肤的热损伤规律。利用皮肤镜与光学相干断层成像（OCT）评估小鼠皮肤组织热损伤程度；参考Arrhenius热损伤方程进行理论分析，并与实验结果对比。结果显示，当激光连续辐照时间为400 ms时，激光输出功率密度小于958 W/cm²时，激光辐照处泛红；激光输出功率密度为958～1160 W/cm²时，损伤呈白色水疱状；激光输出功率密度为1160～1370 W/cm²时，损伤呈浅坑状焦黄斑，损伤斑周围伴一圈鼓起的白色皮肤水疱；激光的功率密度在1370～2190 W/cm²，损伤呈红色坑状斑，损伤斑周围伴黑黄色焦痂。

通过实验和理论分析的方法研究1064 nm激光不同辐照时间对小鼠皮肤的热损伤规律。利用皮肤镜图像和光学相干断层图像评估小鼠皮肤组织热损伤程度，利用Arrhenius热损伤方程计算热损伤参数，建立激光诱导皮肤组织热损伤模型，并与实验结果进行对比。结果表明，在靶功率密度为30 W/mm²的1064 nm激光辐照下，0～100 ms辐照时间内，小鼠皮肤组织损伤可恢复；150～280 ms辐照时间内，小鼠皮肤组织出现水肿现象和热凝固损伤；280～550 ms辐照时间内，小鼠皮肤表皮层出现汽化现象，损伤斑周围出现焦痂，真皮层发生变性；660 ms辐照时间以上，小鼠皮肤表皮层和真皮层出现汽化现象，伤口渗出组织液，皮下组织发生变性。理论分析与实验结果一致，建立的热损伤模型能够验证小鼠皮肤热损伤程度。

We demonstrate high-resolution and high-quality terahertz (THz) in-line digital holography based on the synthetic aperture method. The setup is built on a self-developed THz quantum cascade laser, and a lateral resolution better than 70 μm (～λ) is achieved at 4.3 THz. To correct intensity differences between sub-holograms before aperture stitching, a practical algorithm with global optimization is proposed. To address the twin-image problem for in-line holography, a sparsity-based phase retrieval algorithm is applied to perform the high-quality reconstruction. Furthermore, a new autofocusing criterion termed “reconstruction objective function” is introduced to obtain the best in-focus reconstruction distance, so the autofocusing procedure and the reconstruction are unified within the same framework. Both simulation and experiment prove its accuracy and robustness. Note that all the methods proposed here can be applied to other wavebands as well. We demonstrate the success of this THz synthetic aperture in-line holography on biological and semiconductor samples, showing its potential applications in bioimaging and materials analysis.