Terahertz liquid crystal phase shifter based on magnetic nanoparticle and preparation method thereof

Abstract

The invention discloses a terahertz liquid crystal phase shifter based on magnetic nanoparticles and a preparation method thereof. The phase shifter disperses the magnetic fluid of Fe<3>O<4> magneticnanoparticle dispersion liquid into liquid crystal 5CB solvent at a normal temperature to form ferromagnetic liquid crystal, wherein the concentration ratio of the magnetic fluid of Fe<3>O<4> magneticnanoparticle dispersion liquid and the liquid crystal 5CB solvent is 0.05 wt%, and encapsulates the ferromagnetic liquid crystal into a non-oriented liquid crystal box with an interval of 1 mm by UVglue. The phase shifter utilizes the magnetic interaction between the magnetic chain formed by the Fe<3>O<4> magnetic nanoparticles under the action of an external magnetic field and the liquid crystal so as to achieve the initial anchoring orientation of the randomly arranged liquid crystal molecules in a thick liquid crystal box, so that the optical axis of the liquid crystal molecules can be deflected by 90 degrees only by changing the size of a magnetic field. Compared with the traditional liquid crystal phase shifting device based on magnetic control, the terahertz liquid crystal phase shifter based on magnetic nanoparticles does not need to change the direction of a magnetic field and require the pre-orientation of liquid crystal molecules, so that the practicability and the stability of the phase shifter are greatly improved. Thus, the phase shifter can be used in terahertz phase and polarization control devices and the like.

Description

technical field [0001] The invention belongs to the technical field of terahertz applications, and in particular relates to a terahertz magnetic nano liquid crystal phase shifter and a preparation method thereof. Background technique [0002] Terahertz (THz, 1THz=10 12 THz) waves refer to electromagnetic waves with an oscillation frequency in the range of 0.1-10 THz, and their corresponding wavelength ranges from 3 mm to 30 μm. This band is between microwaves and light waves, and is an intersecting field between electronics and photonics. Due to its special position in the electromagnetic spectrum, THz waves have the advantages of low photon energy, high penetration, fingerprint spectrum and high signal-to-noise ratio, and have broad application prospects in the fields of safety detection, nondestructive testing, and material spectroscopy. With the rapid development of terahertz sources and detectors, there is an increasing demand for high-performance functional devices, su...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a terahertz magnetic nano-liquid crystal phase shifter and its preparation method, so as to solve the...

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