UIM Electromagnetic Waves
Microwave Spatial Modulation
Chiral light-matter interaction
vdW materials & Valleytronics
The technologies to suppress light reflections from surface are important in the field of optical energy harvesting system and light emitting diodes to enhance the performance of these devices. To minimize light reflections, anti-reflection(AR) coating methods such as quarter wave matching AR, multilayered AR and graded refractive index matching section AR are introduced. Graded refractive index matching section shows superior anti-reflection spectral bandwidth over quarter wave AR and multilayered AR so many researchers investigate graded index AR to widen the bandwidth with optimized graded index profile. However, it is unclear what the exact admittance matching condition with graded index profile is to reduce reflection from surface so optimized graded profile is usually found with numerical optimization by lowering averaged spectral reflectance. To make a clear view for finding AR conditions, we investigate the exact electromagnetic solutions inside graded index profile and the admittance matching conditions . Furthermore, we find new methodology to control light reflection from surface of an object. We expect this work will open new design toolkits for optical filter, sensor and optoelectronic devices.
 Kim, KH & Park, QH Perfect anti-reflection from first principles. Sci. Rep. 3, 1062; DOI:10.1038/srep01062 (2013)