离轴积分腔输出光谱技术具有实验装置简单、灵敏度高、响应时间快等特点，常被应用于一些超高灵敏度的气体探测领域。高反射率镜片作为系统的重要组成部分，其反射率是影响整个光谱系统测量准确性的重要因素之一。结合射频噪声源搭建了一套离轴积分腔输出光谱测量系统，首先以CH₄气体在6046.96 cm^-1处的吸收谱线作为研究目标，对不同压力下有无噪声源时的腔镜反射率进行了标定研究，结果表明在有无噪声源两种不同条件下标定的镜片反射率具有一致性，而且反射率随着压力的增加有降低的趋势，计算得到的镜片最高反射率约为0.99992。进而对有无噪声源时0.4 μmol/mol浓度下的CH₄测量信号进行了研究，发现引入噪声源后，虽然降低了信号的峰值高度，但信噪比提高了约1.3倍，最小可检测浓度为0.0045 μmol/mol，表明该系统可有效用于大气环境以及工业应用过程中的CH₄高灵敏度测量。

Simultaneous wireless information and power transfer (SWIPT) architecture is commonly applied in wireless sensors or Internet of Things (IoT) devices, providing both wireless power sources and communication channels. However, the traditional SWIPT transmitter usually suffers from cross-talk distortion caused by the high peak-to-average power ratio of the input signal and the reduction of power amplifier efficiency. This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface (ASTCM). High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface. We demonstrate the feasibility of the proposed method through theoretical derivations and experimental verification, which is therefore believed to have great potential in wireless communications and the IoT devices.

1016001Wireless Power Transfer (WPT) and energy harvesting technologies are expected to provide revolutionary technological changes in important fields such as 5G communications and the Internet of Things. The short-range coupling WPT has gradually been commercialized, but there are still many technical bottlenecks in the practical process of microwave power transmission that can realize long-distance applications, such as the contradiction between the limited aperture of transceiver antennas and the WPT efficiency. The developments of electromagnetic metamaterials and metasurfaces have brought new breakthroughs for solving the above-mentioned problems. In this paper, we will focus on the combination of the two important technologies, and systematically review the applications of metamaterials in microwave wireless power transfer and wireless energy harvesting. The results show that the near-field focusing metasurface can significantly improve the transfer efficiency. We will also introduce the research progress of optically transparent metasurfaces and reconfigurable metasurfaces for improving WPT performance and practicability. Based on the periodically close arrangements of subwavelength metamaterial units, a wireless energy harvester with wide-angle incidence and polarization-insensitive characteristics is designed, which can replace conventional receiving antennas with higher harvesting efficiency. Furthermore, coplanar integration with the rectifying diodes makes a new concept of the rectifying metasurface, which can simplify the overall structure, reduce the size, and improve the efficiency. Finally, we will discuss the future progress of WPT, and point out the vital role that programmable and intelligent metamaterial technologies will play very important roles in future simultaneous wireless information and power transfer systems.