A Broadband Tunable Terahertz Waveplate

Abstract

The invention discloses a broadband-adjustable terahertz wave plate component which comprises two quartz substrates, metal wire gratings are arranged inside the quartz substrates, the metal wire gratings on two sides are parallel to each other, and the two quartz substrates form a liquid crystal box through frame glue. The liquid crystal box comprises an optical control orientation layer and a liquid crystal material. Liquid crystal is an electric control large birefringence liquid material. The optical control orientation layer and the liquid crystal material of the liquid crystal box achieve parallel orientation of the liquid crystal through an optical control orientation method, the orientation direction of the optical control orientation layer and the direction of the metal wire gratings form a 45-degree angle, and the liquid crystal box can achieve an adjustable one quarter or a half wave plate in a terahertz frequency range. The broadband-adjustable terahertz wave plate has the advantages of being wide in frequency range, self-polarization, high in transmittance, large in modulation quantity, fast in response and the like. In addition, the manufacture cost is low, efficiency is high, the broadband-adjustable terahertz wave plate can be produced in massive mode, and the application prospects are wide.

Description

technical field [0001] The invention relates to the technical field of terahertz optoelectronics, in particular to the design and preparation of a broadband tunable terahertz waveplate based on subwavelength metal wire grids and liquid crystal materials. Background technique [0002] Liquid crystal materials have both the fluidity of liquids and the orderliness of crystals. Due to their excellent tuning characteristics of external fields (electric field, light field, sound field, temperature field, etc.), they play an important role in information display and adjustable photonic devices. . Nematic liquid crystal is the most commonly used phase state, and in all nematic liquid crystal applications, orientation is the first step. The traditional orientation method, rubbing orientation, is the most widely used method, which has defects such as mechanical damage to the surface, electrostatic charge residue and particle contamination, and difficulty in realizing multi-domain str...

AI Technical Summary

Problems solved by technology

However, when applied to the terahertz frequency band, on the one hand, the commonly used transparent conductive film indium tin oxide will no longer be applicable, and a simple metal layer cannot meet the requirements, so it is necessary to seek new electrode designs such as sub-wavelength metal wire grids instead traditional film

On the other hand, the birefringence of most liquid crystal materials will be relatively small in the terahertz frequency band, so the adjustable amount is also small, and it is difficult to meet practical requirements in general design

And some special means to increase the amount of modulation, such as stacked structures, will significantly increase the manufacturing difficulty and cost of the device.

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