Terahertz tunable filter of metal photonic crystal

Abstract

The invention discloses a Terahertz tunable filter device of a metal photonic crystal and a control method thereof. A photonic crystal metal column array is encapsulated in a high-density polyethylene box which is filled with liquid crystals. The pointed angles of the liquid crystal molecules filled around the metal column are changed by controlling voltage, so that the energy band and band clearance position of the metal photonic crystal is changed to control the movement of a filter passband position and realize the function of tunable filtering. As a metal material is adopted to manufacture the photonic crystal, the shortcomings that the passband width is narrowed and the transmission rate is reduced in the tuning process of a medium photonic crystal are conquered; and the turning range of the photonic crystal is greatly extended. As the metal column serves as a special structure of an electrode, so that the distance between the anode and cathode is reduced; the consistency of liquid crystal distribution is improved; the working voltage is reduced and the response time is enhanced. The Terahertz tunable filter of the metal photonic crystal disclosed by the invention has the advantages of wide transmission band width and tunable range, stable passband width and transmission rate in the tuning process, less power consumption and high extinction ratio and is convenient for minimization and integration.

Description

technical field [0001] The invention belongs to the field of terahertz application technology, and in particular relates to a terahertz wave tunable filter and a control method thereof. Background technique [0002] Terahertz (THz, 1THz=10 12 THz) waves refer to electromagnetic waves with a frequency in the range of 0.1-10 THz (corresponding to a wavelength of 3 mm to 30 μm). This band is between microwaves and light waves, and is the cross field of electronics and photonics. Due to its special position in the electromagnetic spectrum, terahertz waves have many superior characteristics such as perspective, safety, and high signal-to-noise ratio, and have very important academic and application values ​​in the fields of spectroscopy, imaging, and communication. Terahertz functional devices such as filters, switches, beam splitters, polarizers, phase retarders, etc. are important components in terahertz application systems, and terahertz filters are the key core components of...

AI Technical Summary

Problems solved by technology

Although this type of filter is flexible in design and easy to implement, most of them are band-stop filters, the filter spectrum is not ideal, the dispersion is large, and the extinction ratio is low.

(2) Terahertz filters based on one-dimensional dielectric photonic crystals, which have very narrow bandwidths and are not suitable for existing broadband terahertz systems

However, after the traditional dielectric photonic crystal is filled, the tuning range is very limited due to the reduction of the dielectric constant difference between the filling material and the base material constituting the photonic crystal, and the passband spectral bandwidth of the filter is reduced, and the transmittance Decline [H. Zhang, S. J. Chang et. al, J. Opt. Soc. AmB, 26(1): 101-106, 2009]

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