One-way waveguide and one-way optical fiber

Abstract

The invention provides a production method of a one-way waveguide. The production method comprises the step of carrying out spiral spatial modulation on Weyl crystals. The Weyl crystals contain Weyl points in an energy band structure. The one-way waveguide produced by adopting the method provided by the invention can eliminate reflection of wave and replace an isolator, also eliminates various types of linear scattering and reduces loss and also inhibits non-linear scattering, so that waveguide signal strength threshold is improved; meanwhile, a transmission mode that any number of group and phase velocities are the same can be realized, so that synchronous transmission of signals is realized.

Description

technical field [0001] The present invention relates to a waveguide, in particular to a method for preparing a unidirectional waveguide, and more particularly to a unidirectional optical fiber and a method for preparing the unidirectional optical fiber. Background technique [0002] A waveguide is a structure that confines or guides waves. As an optical waveguide tool, an optical fiber is widely used in communication, sensing, biomedicine, and other optical wave technology fields. Ordinary optical fibers are mainly composed of a core and a cladding, as shown in Figure 1(a), which realizes light transmission by means of total reflection of light at the interface between the core and the cladding. Photonic Crystal Fibers (PCF), also known as Micro-Structured Fibers (MSF), see Figure 1(b), which has attracted widespread attention in recent years, and its cross-section has a more complex refractive index distribution , usually contain air holes in different arrangements. The si...

AI Technical Summary

Problems solved by technology

However, the performance of existing optical fibers is limited due to the existence of scattering and reflection, for example, Rayleigh scattering determines the lower limit of fiber loss, Mie scattering at irregular interfaces and microbends produces fiber loss, stimulated Bri Deep Scattering (SBS) will back-couple the forward signal to limit the signal strength in the fiber, Fresnel reflections at the joints and defects cause reflections in the fiber, therefore, the fiber in the prior art is not a unidirectional fiber

Although there have been some reports about unidirectional waveguides in the prior art, the existing unidirectional waveguides are all realized at the edge of the two-dimensional system, and there are at most four transmission modes in these known unidirectional waveguides, and these transmission modes The group and phase velocities of the modes are different, so the synchronous transmission of signals cannot be achieved

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