Dual-Comb Ranging

Absolute distance measurement is a fundamental technique in mobile and large-scale dimensional metrology.Dual-comb ranging is emerging as a powerful tool that exploits phase resolution and frequency accuracy for high-precision and fast-rate distance measurement.Using two coherent frequency combs,dual-comb ranging allows time and phase response to be measured rapidly.It breaks through the limitations related to the responsive bandwidth,ambiguity range,and dynamic measurement characteristics of conventional ranging tools.This review introduces dual-comb ranging and summarizes the key techniques for realizing this ranging tool.As optical frequency comb technology progresses,dualcomb ranging shows promise for various professional applications.

Frequency-Self-Adaptive Radio Frequency Power Harvester Enabled by Shape-Reconfigurable Liquid Metal

Radio frequency(RF)energy harvester as an efficient tool for capturing and converting the flourishing ambient RF energy provides a promising solution for long-term powering the wireless sensor networks and the Internet of things(IoTs).However,the actual distribution of the environmental RF signals is dynamically frequency-dependent due to the diverse wireless terminals only interacting with specified frequencies.To take full advantage of the RF energy carrying this characteristic,an intelligent RF energy harvester is in demand to automatically sense the frequency information of an incident signal and conduct the corresponding RF-to-direct current transformation process.Here,to the best of my knowledge,a frequency-self-adaptive RF harvester is first presented with the help of the shape-reconfigurable liquid metal,which can precisely identify and efficiently convert an arbitrary signal from the frequency span of 1.8 to 2.6 GHz.Companied with a microcontroller unit and a tensile system,the dynamic functionality of the entire system is comprehensively demonstrated,showing promising potential to significantly advance various fields,including sustainable IoT applications,green wearable technologies,and self-powered devices.

Plasmonic evolution maps for planar metamaterials

Understanding the mode’s origin in planar metamaterials is fundamental for related applications in nanophotonics and plasmonics.For complex planar metamaterials,conventional analysis that directly obtains the final charge/current distribution of a mode is usually difficult in helping to understand the mode’s origin.In this paper,we propose a mode evolution method(MEM)with a core analysis tool,i.e.,plasmonic evolution maps(PEMs),to describe the mode evolution in several complementary planar metamaterials with designed plasmonic atoms/molecules.The PEMs could not only clearly explain a mode’s origin,but also reveal the role of a structure’s symmetry in the mode formation process.The MEM with PEMs can work as a simple,efficient,and universal approach for the mode analysis in different kinds of planar metamaterials.