title: Experimental demonstration of in-plane negative-angle refraction with an array of silicon nanoposts.
abstract: Controlling an optical beam is fundamental in optics. Recently, unique manipulation of optical wavefronts has been successfully demonstrated by metasurfaces. However, these artificially engineered nanostructures have thus far been limited to operate on light beams propagating out-of-plane. The in-plane operation is critical for on-chip photonic applications. Here, we demonstrate an anomalous negative-angle refraction of a light beam propagating along the plane, by designing a thin dielectric array of silicon nanoposts. The circularly polarized dipoles induced by the high-permittivity nanoposts at the scattering resonance significantly shape the wavefront of the light beam and bend it anomalously. The unique capability of a thin line of the nanoposts for manipulating in-plane wavefronts makes the device extremely compact. The low loss all-dielectric structure is compatible with complementary metal-oxide semiconductor technologies, offering an effective solution for in-plane beam steering and routing for on-chip photonics.
authors: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050, China.
authors: Aimin
authors: A
authors: Wu
authors: Hao
authors: H
authors: Li
authors: Junjie
authors: J
authors: Du
authors: Xingjie
authors: X
authors: Ni
authors: Ziliang
authors: Z
authors: Ye
authors: Yuan
authors: Y
authors: Wang
authors: Zhen
authors: Z
authors: Sheng
authors: Shichang
authors: S
authors: Zou
authors: Fuwan
authors: F
authors: Gan
authors: Xiang
authors: X
authors: Zhang
authors: Xi
authors: X
authors: Wang
keywords: Negative-angle refraction; circularly polarized dipoles; nanophotonics; on-chip beam steering; resonant particle; silicon nanoposts