Enhancement of Luminous Intensity Emission from Incoherent LED Light Sources within the Detection Angle of 10° Using Metalenses

Abstract

In this work, we present metalenses (MLs) designed to enhance the luminous intensity of incoherent light-emitting diodes (LEDs) within the detection angles of 0° and 10°. The detection angle of 0° refers to the center of the LED. Because the light emitted from LEDs is incoherent and expressed as a surface light source, they are numerically described as a set of point sources and calculated using incoherent summation. The titanium dioxide (TiO2) and amorphous silicon (a-Si) nanohole meta-atoms are designed; however, the full 2π phase coverage is not reached. Nevertheless, because the phase modulation at the edge of the ML is important, an ML is successfully designed. The typical phase profile of the ML enhances the luminous intensity at the center, and the phase profile is modified to increase the luminous intensity in the target detection angle region. Far field simulations are conducted to calculate the luminous intensity after 25 m of propagation. We demonstrate an enhancement of the luminous intensity at the center by 8551% and 2115% using TiO2 and a-Si MLs, respectively. Meanwhile, the TiO2 and a-Si MLs with the modified phase profiles enhance the luminous intensity within the detection angle of 10° by 263% and 30%, respectively.

Recent advancements of metalenses for functional imaging

“…Of course, there are limitations such as operating bandwidth, focusing efficiency, large-scale metalens design and manufacturing method, and high price, but studies using metalens are actively being conducted to overcome these limitations. Thus far, studies have actively investigated the functionalities of metalenses, and now, they are actively investigating applications of metalenses [57,[159][160][161][162][163][164][165][166][167][168][169][170][171][172]. We expect that metalenses with ultrahigh performance and compact sizes will replace existing optics in the future.…”

Metalens in Improving Imaging Quality: Advancements, Challenges, and Prospects for Future Display

“…The application of grating, curved surface, diaphragm, and metalens can realize the extension FOV. [139][140][141][142][143][144][145] The following is mainly to describe the classification and research status of metalens in FOV's expansion. In imaging applications, metalens with extended FOV can be classified according to the number of layers, which can be roughly divided into the following two types.…”