Generation of multiple photonic hooks in reflection mode

• Published in: Optical materials 2022-12, Vol.134, p.113127, Article 113127
• Main Authors: Yang, Yu-Jing, Hua, Ping-Rang, Zhang, De-Long
• Format: Article
• Language: English
• Subjects: Multi-dielectric structure; Photonic hooks; Reflection mode
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2022.113127

Generation of multiple photonic hooks (PHs) at THz region in reflection mode by a multi-dielectric structure that consists of periodical or aperiodical scatterer units on top surface of a reflection screen has been systematically studied. The study focuses on effects of geometric and optical parameters of the multi-dielectric structure on characteristics of the PHs generated, especially the bending angle. These geometric and optical parameters include spacing between adjacent scatterer units, length of reflection screen, as well as the size, refractive index and number of scatterer units. The results show that these geometric and optical parameters are key factors in tailoring the performance of the multiple PHs generated. The spacing determines bending direction of PHs and there exists a critical spacing value. Smaller than this critical value, the PHs generated bend outwards. Larger than this critical value, the PHs bend inwards. In addition, the spacing can be also used to effectively adjust the intensity and bending angle of the PHs. Screen length affects mainly PH's bending. The size and refractive index differences between scatterer units introduce additional optical inhomogeneity that leads to the generation of asymmetrical multiple PHs. Finally, the possibility of generation of an arrayed PHs in the reflection mode is demonstrated. •Generation of photonic hooks (PHs) array in reflection mode is studied.•PHs formation is ascribed to optical inhomogeneity of multi-dielectric structure.•PHs performance can be effectively tailored by geometric and optical parameters.•PHs generated at smaller or larger spacing bend in opposite directions.•Optical-axis asymmetric structure generates asymmetrical PHs array.