Metal nanoparticle-insulator composite material grating coupler

Abstract

The invention discloses a metal nanoparticle-insulator composite material grating coupler and a preparation method and an application thereof. The grating coupler is composed of a metal nanoparticle-insulator composite material coupling grating and an insulator optical planar waveguide. The metal nanoparticle-insulator composite material coupling grating is a two-dimensional orthogonal rectangular diffraction grating which is prepared on the surface of the insulator optical planar waveguide implanted with metal ions by use of electron beam lithography and reactive ion beam etching technologies based on a formed metal nanoparticle-insulator composite material modified layer. Compared with an insulator grating coupler of the same structure, the grating coupler of the invention has higher coupling efficiency, and there is no loss caused by free carrier absorption. In addition, the grating coupler is insensitive to the polarization direction of light. In the realization process of light coupling, light can be filtered, split and deflected with the aid of the formation of guided wave and diffraction distortion. The metal nanoparticle-insulator composite material grating coupler can be used in the field of preparation of large-scale integrated optical circuits.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of nanophotonics, and relates to the preparation technology of grating couplers in visible and / or near-infrared bands, in particular to a metal nanoparticle-insulator composite grating coupler working in visible and / or near-infrared bands. device and its preparation method. [0003] Background technique: [0004] Grating couplers play an important role in the construction of integrated optical devices and large-scale integrated optical circuits. Using grating couplers, optical signals in the visible and / or near-infrared bands can be effectively introduced into or extracted from optical planar waveguides, thereby realizing optical signal directional transmission and subsequent processing. A grating coupler is an integration of a coupling grating and a planar waveguide. According to the material on which the coupling grating is based, the existing grating couplers can be divided into two categories, na...

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Problems solved by technology

It is worth noting that although the two-dimensional periodic plasmonic structure proposed by Stepanov et al. can be used as a diffraction grating, it cannot be compared with SiO 2 The planar waveguide constitutes a practical high-efficiency grating coupler. The main reason is that its grating constant is too large. According to the scanning electron microscope observation results given in the literature, the grating constants on the row and column are 49 and 49 respectively. 36μm, for applications in the visible and / or near-infrared bands, such a large grating constant makes the diffraction of small orders unable to meet the matching conditions at all, so it is impossible to form a strong guided wave in the planar waveguide

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