A broadband reflective-type half-wave plate employing optical feedbacks

作者：Zhou, Gaochao^*; Zhu, Bo; Zhao, Junming; Zhu, Guanghao; Jin, Biaobing^*; Feng, Yijun; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

来源：Scientific Reports, 2017, 7(1): 9103.

DOI：10.1038/s41598-017-09561-y

• POLARIZATION CONVERSION
• METASURFACES
• WAVELENGTHS
• REFRACTION
• WAVEPLATE
• ARRAY

We propose and demonstrate a type of a broadband half-wave plate that operates in the reflective mode. It consists of a metal grating embedded in a dielectric slab and placed on top of a grounded metal surface. We theoretically show that owing to the optical feedback effect which originates from the wave reflections at the air-dielectric interface, the proposed half-wave plate exhibits a broadened and flattened response when comparing to the case where the feedback effect is absent. Such a prediction is validated using both numerical and experimental works carried out on a half-wave plate designed at 10 GHz. Moreover, our theoretical analysis also reveals that the half-wave plate has an interesting feature of broad angular response. Taking advantage of these features, we experimentally demonstrate that the proposed device can function as a freely tunable linear polarization converter with polarization conversion residues less than - 20 dB in a wide frequency band, under the condition that the incident angle is as large as 45 degrees.

• 出版日期2017-8-22
• 单位南京大学