Analogous Optical Activity in Free Space Using a Single Pancharatnam–Berry Phase Element. Issue 1 (13th November 2021)

• Record Type: Journal Article
• Authors: Liu, Sheng; Qi, Shuxia; Li, Peng; Wei, Bingyan; Chen, Peng; Hu, Wei; Zhang, Yi; Gan, Xuetao; Zhang, Peng; Lu, Yanqing; Chen, Zhigang; Zhao, Jianlin
• Is Part Of: Laser & photonics reviews. Volume 16:Issue 1(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-13
• Subjects: Bessel beams -- liquid crystal -- Pancharatnam–Berry phase -- polarization rotation; Lasers -- Periodicals; Photonics -- Periodicals; Lasers -- Périodiques; Photonique -- Périodiques; 621.36
• DOI: 10.1002/lpor.202100291
• Languages: English
• ISSNs: 1863-8880

Abstract

Abstract: It is commonly believed that optical activity (OA) is manifested mainly in chiral media, but rare in non‐chiral structures. Here, an analog of OA in free space is experimentally demonstrated by using a single liquid‐crystal Pancharatnam–Berry phase element (PBPE), for which the mechanism is highly consistent with that of the traditional OA. The specifically designed PBPE supports the direction‐dependent polarization rotation of a Bessel beam with controllable "rotatory power." Such a polarization rotation can be revoked by another PBPE with the same structure. Unlike in a chiral medium, this scheme shows simultaneous realization of equivalent leverotation and dextorotation merely by switching the optical element orientation, promising for applications non‐magnetic optical devices such as optical isolators. Abstract : An analog of optical activity is demonstrated in free space by using liquid‐crystal Pancharatnam–Berry‐phase plates, which supports the direction‐dependent polarization rotation (leverotation and dextorotation) of a Bessel beam with controllable "rotatory power." Such a polarization rotation can be revoked by another plate with the same structure, promising for applications non‐magnetic optical devices such as optical isolators.