小动物活体荧光成像系统是研究现代生物医学的有力手段之一，但是现有的荧光成像系统穿透深度低、信噪比不高，严重制约了荧光成像技术在生物医学中的应用。利用近红外Ⅱ区光（1000~1350 nm）在生物组织中的穿透深和成像信噪比高的特点，研制出了一套高性能的近红外小动物活体荧光成像系统。模拟实验表明：该系统具有信噪比高（57 dB）和穿透深度深（大于10 mm）的特点。通过利用该近红外小动物活体荧光成像系统对静脉注射有Ag2S量子点（荧光发射波长为1200 nm）的小鼠进行观察，获得了小鼠全身血管网络及深层组织器官的高分辨率图像。

Small animal fluorescence imaging system is an important tool in life sciences and medicine research because of its in vivo and noninvasive imaging ability. But the relative low penetration depth of the visible light of existing small animal imaging systems, as well as the relative low signal-to-noise, prevents this technology from deep tissue imaging. Fluorescence single in the second near-infrared window (NIR II, 1000~1350 nm) could be utilized to improve the imaging depth due to the relative low tissue scattering. The presented work describes the design and performance evaluation of a near-infrared small animal fluorescence imaging system working in this particular spectrum window. Simulation experiments indicate that this imaging system achieves a relative high signal-to-noise ratio (57 dB) and large penetration depth (deeper than 10 mm). Vascular networks and organ of the mouse are clearly visualized using this imaging system by injection of Ag2S quantum dots (QD) emitting at 1200 nm.