超透镜是一种近年来新兴的基于超材料的先进平面光学装置，可以高自由度设计入射光的振幅、相位和偏振度以满足应用要求。超透镜可以通过不同的结构设计实现多种功能，例如达到衍射极限的聚焦、像差消除等。本文总结了超透镜的发展过程、基本原理和应用；基于激发原理将超透镜归纳为等离激元型和介质型，基于功能性将其归纳为变焦距型、像差消除型，以及宽带无色散型；分类综述了超透镜的最新进展和研究趋势；总结了相关研究的参数数据、优缺点、商业化进程并展望了未来。本文的主要目的是让读者全面了解超透镜，并为设计高性能的超透镜提供潜在的灵感。

The fluorescence-based in vivo flow cytometry (IVFC) is an emerging tool to monitor circulating cells in vivo. As a noninvasive and real-time diagnostic technology, the fluorescence-based IVFC allows long-term monitoring of circulating cells without changing their native biological environment. It has been applied for various biological applications (e.g., monitoring circulating tumor cells). In this work, we will review our recent works on fluorescence-based IVFC. The operation principle and typical biological applications will be introduced. In addition, the recent advances in IVFC flow cytometry based on photoacoustic effects and other label-free detection methods such as imaging-based methods, diffuse-light methods, hybrid multimodality methods and multispectral methods are also summarized.

Recent studies in oncology have addressed the importance of detecting circulating tumor cell clusters because circulating tumor cell clusters might survive and metastasize more easily than single circulating tumor cells. Signals with larger peak widths detected by in vivo flow cytometer (IVFC) have been used to identify cell clusters in previous studies. However, the accuracy of this criterion might be greatly degraded by variance in blood flow and the rolling behaviors of circulating tumor cells. Here, we propose a criterion and algorithm to distinguish cell clusters from single cells. In this work, we first used area-based and volume-based models for single fluorescent cells. Simulating each model, we analyzed the corresponding morphology of IVFC signals from cell clusters. According to the Rayleigh criterion, the valley between two adjacent peak signals from two distinguishable cells should be lower than 73.5% of the peak values. A novel signal processing algorithm for IVFC was developed based on this criterion. The results showed that cell clusters can be reliably identified using our proposed algorithm. Intravital imaging was also performed to further support our algorithm. With enhanced accuracy, IVFC is a powerful tool to study circulating cell clusters.

肿瘤一直威胁着人类的健康, 大多数肿瘤患者死于转移性瘤而非原发性瘤。循环肿瘤细胞(CTC)是肿瘤转移的重要标志, CTC的检测可以用来监控肿瘤的转移情况及预后评估。在体光声流式细胞术(PAFC)利用CTC与血液背景的光吸收差异可以实现CTC的在体检测。相比于传统的CTC检测方法, PAFC可以无创、高灵敏地检测循环系统中的CTC数目。总结了PAFC无标记检测黑色素瘤CTC信号及纳米颗粒靶向标记乳腺癌CTC信号的方法, 以及这些方法在肿瘤转移、治疗效果评估中的应用。

基于多波长光束组合技术,利用光栅的衍射和外腔的反馈,将激光二极管阵列(LDA)发光单元锁定在不同的波长上,以近似平行光束沿光栅的-1级衍射方向组合输出,改善LDA输出光束质量。实验采用发光单元宽度为100 μm、周期为500 μm,由19个单元构成的1 cm普通商用LDA,在连续运行最大注入电流60.6 A时,自由运转输出功率49.8 W时,获得功率为20.1 W的组合光束稳定输出,其光谱宽度为15 nm,对应的远场发散角由约70 mrad变为1.66 mrad,改善后光束质量因子约为32,其值与单个发光单元的光束质量相当。