Overcoming losses in superlenses with synthetic waves of complex frequency

• 成果类型: Article
• 署名作者: Guan, Fuxin; Guo, Xiangdong; Zeng, Kebo; Zhang, Shu; Nie, Zhaoyu; Ma, Shaojie; Dai, Qing; Pendry, John; Zhang, Xiang; Zhang, Shuang
• 署名单位: University of Hong Kong; Chinese Academy of Sciences; National Center for Nanoscience & Technology, CAS; University of California System; University of California Berkeley; Imperial College London; University of Hong Kong; University of Hong Kong; University of Hong Kong
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11056
• DOI: 10.1126/science.adi1267
• 发表日期: 2023-08-18
• 页码: 766-771
• 关键词: time-reversal; phase-conjugation

摘要

Superlenses made of plasmonic materials and metamaterials can image features at the subdiffraction scale. However, intrinsic losses impose a serious restriction on imaging resolution, a problem that has hindered widespread applications of superlenses. Optical waves of complex frequency that exhibit a temporally attenuating behavior have been proposed to offset the intrinsic losses in superlenses through the introduction of virtual gain, but experimental realization has been lacking because of the difficulty of imaging measurements with temporal decay. In this work, we present a multifrequency approach to constructing synthetic excitation waves of complex frequency based on measurements at real frequencies. This approach allows us to implement virtual gain experimentally and observe deep-subwavelength images. Our work offers a practical solution to overcome the intrinsic losses of plasmonic systems for imaging and sensing applications.