Actively Switchable Beam‐Steering via Hydrophilic/Hydrophobic‐Selective Design of Water‐Immersed Metasurface. Issue 17 (4th June 2021)

• Record Type: Journal Article
• Authors: Li, Zhe; Wan, Chengwei; Dai, Chenjie; Zhang, Jian; Zheng, Guoxing; Li, Zhongyang
• Is Part Of: Advanced optical materials. Volume 9:Issue 17(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-04
• Subjects: actively switchable -- beam steering -- hydrophilic/hydrophobic selective -- immersion metasurfaces -- liquid wetting; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202100297
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Liquid immersion on metasurface was earlier demonstrated to realize spectral control. However, it remains a great challenge to achieve tunable phase modulation and versatile beam‐steering performance, which are critical for practical optoelectronic devices. Here, a new liquid‐immersive mechanism with metasurfaces for active beam‐steering is proposed and experimentally realized. Based on the dielectric‐on‐metal nanostructure with selective hydrophilic/hydrophobic properties, the switchable beam‐steering is initiated and successfully presented in the broadband visible regime with a large reflection angle of ≈±30°. Specifically, the beam diffraction direction is tuned between two opposite‐directional channels by water immersion or drying in a repeatable and controllable manner. The proposed straightforward tuning strategy enjoys great convenience in structural patterning and large‐area implementation, instead of requiring any complicated contact patterning or external modulation. This study provides an alternative optical platform for switchable beam‐steering functionality, which is promising for potential applications in tunable display, directional emission, sensing technologies, etc. Abstract : An active tuning approach based on liquid‐wetting selectivity of immersion metasurfaces is proposed to enable switchable beam‐steering. Through engineering nanostructured arrays of hydrophilic/hydrophobic properties, the active beam‐switching with a large angular tuning span of 60° is theoretically and experimentally presented for the broadband visible light. The proposed tunable strategy exhibits great simplicity and a significant potential for large‐area tunable devices.