A Limiting Structure of One-dimensional Photonic Crystal Based on Topological Interface State and Optical Kerr Effect

Abstract

The invention proposes a photonic crystal limiting structure based on topological interface state and optical Kerr effect, and the limiting structure is composed of four kinds of media arranged periodically in a certain order to form photonic crystals. Assuming that the four media are A, B, C and D, the photonic crystal structure containing N periods is (A 0.5 BA 0.5 ) N (C 0.5 DC 0.5 ) N , where media A and B are nonlinear optical materials, which constitute the left part of the photonic crystal ( PC_L ), media C and D are linear optical materials, which constitute the right part of the photonic crystal ( PC_R ), the subscript 0.5 represents half of the basic unit of the medium. The topological properties of the left part of the photonic crystal and the left part of the photonic right crystal are different. The present invention can realize high transmittance for weak light and high attenuation rate for strong light for 1064.15nm laser. By selecting appropriate materials and adjusting thickness parameters, the structure can also be applied to laser limiting of other wavelengths.

Description

technical field [0001] The invention relates to the fields of topological states, photonic crystals and nonlinear optics, in particular to a one-dimensional photonic crystal limiting structure based on topological interface states and the optical Kerr effect, which can be applied to require high transmittance of weak light and high intensity of strong light. Decay rate for nonlinear laser limiting applications. Background technique [0002] Due to the excellent performance of lasers in terms of brightness, monochromaticity, directionality and monochromaticity, lasers are widely used in industrial, medical, military and other fields. However, high-intensity lasers will cause irreversible damage to the human eye and various optical detectors. For example, Q-switched lasers can easily reach MW / cm 2 The high power density of the order of magnitude, so it is necessary to limit the strong laser. And the laser with relatively weak power can be used as a signal detection light wit...

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Problems solved by technology

Its function is similar to a diode, which cannot achieve high transmittance under weak light and high attenuation rate under strong light

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