title: Polarization-independent and omnidirectional nearly perfect absorber with ultra-thin 2D subwavelength metal grating in the visible region.
abstract: A polarization-independent and omnidirectional nearly perfect absorber in the visible region has been proposed. The absorber is two-layer structure consisting of a subwavelength metal grating layer embedded in the high refractive index and lossless dielectric layer on the metal substrate. Extraordinary optical absorption with absorption peaks of over 99% can be achieved over the whole visible region for both TM and TE polarization. This absorption is attributed to cavity mode (CM) resonance caused by the coupled surface plasmon polaritons (SPP). Through adjusting the grating thickness, the absorption peak can be tuned linearly, which is highly advantageous to design various absorbers. Furthermore, the absorbance retains ultra-high over a wide angular range of incidence for both TM and TE polarization. This nearly perfect absorber offers great potential in the refractive index (RI) sensors, integrated photodetectors, solar cells and so on.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Zhou
authors.forename: Kaiwei
authors.initials: K
authors.lastname: Li
authors.forename: Chao
authors.initials: C
authors.lastname: Song
authors.forename: Peng
authors.initials: P
authors.lastname: Hao
authors.forename: Mingbo
authors.initials: M
authors.lastname: Chi
authors.forename: Muxin
authors.initials: M
authors.lastname: Yu
authors.forename: Yihui
authors.initials: Y
authors.lastname: Wu