Broadband Achromatic Metalens in Mid‐Wavelength Infrared. Issue 9 (9th July 2021)

• Record Type: Journal Article
• Authors: Ou, Kai; Yu, Feilong; Li, Guanhai; Wang, Wenjuan; Chen, Jin; Miroshnichenko, Andrey E.; Huang, Lujun; Li, Tianxin; Li, Zhifeng; Chen, Xiaoshuang; Lu, Wei
• Is Part Of: Laser & photonics reviews. Volume 15:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-09
• Subjects: achromatic focusing -- focusing optical vortex -- imaging -- mid‐wavelength infrared; Lasers -- Periodicals; Photonics -- Periodicals; Lasers -- Périodiques; Photonique -- Périodiques; 621.36
• DOI: 10.1002/lpor.202100020
• Languages: English
• ISSNs: 1863-8880

Abstract

Abstract: Metasurface provides a powerful platform to correct the chromatic aberration of conventional lenses in a flexible, integratable, and ultra‐compact manner. Mid‐wavelength infrared has promised many exciting applications ranged from molecular fingerprint detection to low‐light‐level night vision. Developing broadband achromatic metalens in mid‐wavelength infrared becomes necessary to meet the increasingly urgent demands on high performance photonic devices. Here, we demonstrate the broadband achromatic metalenses from 3.5 to 5 µm with all‐silicon metasurfaces. Large phase dispersion control range is achieved to realize metalenses with both large numerical apertures and sample sizes while maintaining high focusing efficiency. The experimental results verify the diffraction‐limited achromatic focusing and imaging of the metalenses in mid‐wavelength infrared. Additionally, we also demonstrate the versatility by successfully implementing the generation of the broadband achromatic focusing optical vortex ( L = 2). This work represents a solid step toward practical implementation of metalens and may find applications in mid‐wavelength infrared imaging and detections. Abstract : Broadband achromatic metalenses with multiple functions based on an all‐silicon platform are demonstrated in mid‐wavelength infrared. This work endows polarization‐switchable varifocal metalens via dispersion‐engineered metasurfaces. With this general achromatism, high‐performance metadevices for focusing, imaging, and wavefront‐steering are achieved. It represents a significant step forward in the development of efficient and functional achromatic metalens to meet diverse applications in mid‐wavelength infrared.