2026-05-27T05:34:43Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/176102026-02-03T12:10:49Zcom_10630_2254col_10630_37959

Luque-González, José Manuel Herrero-Bermello, Alaine Ortega-Moñux, Alejandro Molina-Fernández, Íñigo Velasco, Aitor V. Cheben, Pavel Schmid, Jens H. Wang, Shurui Halir, Robert 2019-05-03T06:28:06Z 2019-05-03T06:28:06Z 2019-05-03 https://hdl.handle.net/10630/17610 Subwavelength gratings (SWG) are periodic structures which behave as controllable homogeneous metamaterials. SWGs are extremely interesting when they are used in platforms with a limited choice of material refractive indices, enabling the design of a myriad of high-performance devices. Here we present a novel technique to gain control over the intrinsic anisotropy of the synthesized metamaterial. We show that tilting the silicon segments in a SWG structure mainly affects the in-plane (TE) modes, with little impact on the out-of-plane (TM) modes. Moreover, we present a methodology to quickly but accurately calculate the modes of a tilted periodic structure modeling the structure as a rotated uniaxial crystal which can be solved with an anisotropic mode solver. Measurements on a set of fabricated tilted SWG waveguides validate our simulation results. By using the presented technique, we design a polarization beam splitter based on a 2x2 multimode interferometer. The design is based on the optimization of the tilting angle to tone the beat length of the TE modes to be a half of the beat length of the TM modes. eng open access Optica integrada Materiales ópticos Metamateriales Designing polarization management devices by tilting subwavelength grating structures conference output