DEVELOPMENT OF NEAR INFRARED DIELECTRIC METAGRATINGS BASED ON VARIOUS PERIODICITY DESIGNS

Abstract

Metasurfaces are critical to miniaturizing future optical elements. Periodic metasurfaces, known as metagratings, have been extensively studied for various applications. In this thesis, three dielectric metagrating devices have been studied in the near infrared region based on different periodicity designs. The first design has the normal periodicity and is utilised as resonators. Then, double periodicities in one direction are introduced to propose the second design that can integrate multiple optical functions. The third metagrating design has a bi-layered structure with variable periodicity in the two orthogonal directions to enable period-tuning. Furthermore, the second and the third metagrating designs demonstrate the near field Moiré effect with dielectric substrates for the first time. Our designs can lead to miniaturized applications in the near infrared region and contribute to the advancement of flat optics.