Positive focal shift of gallium nitride high contrast grating focusing reflectors

Shumin He, Zhenhai Wang, Qifa Liu

Результат исследований: Вклад в журналСтатьярецензирование

3 Цитирования (Scopus)


Wedesign a type of metasurfaces capable of serving as a visible-light focusing reflector based on gallium nitride (GaN) high contrast gratings (HCGs). The wavefront of the reflected light is precisely manipulated by spatial variation of the grating periods along the subwavelength ridge array to achieve light focusing. Different from conventional negative focal shift effect, a positive focal shift is observed in such focusing reflectors. Detailed investigations of the influence of device size on the focusing performance, especially the focal length, are preformed via a finite element method . The results show that all performance parameters are greatly affected by the reflector size. A more concentrated focal point, or a better focusing capability, can be achieved by larger size. With increasing reflector size, the achieved focal length decreases and gradually approaches to the design, thus the corresponding positive focal shift decreases. Our results are helpful for understanding the visible-light control of the planar HCG-based focusing reflectors.

Язык оригиналаАнглийский
Номер статьи095901
ЖурналMaterials Research Express
Номер выпуска9
СостояниеОпубликовано - сент. 2016
Опубликовано для внешнего пользованияДа


Подробные сведения о темах исследования «Positive focal shift of gallium nitride high contrast grating focusing reflectors». Вместе они формируют уникальный семантический отпечаток (fingerprint).