An optical modulation device, modulation method and device for terahertz waves

Abstract

The invention discloses a terahertz wave optical modulation device which is used for modulating terahertz waves. The terahertz wave optical modulation device comprises a composite layer which is composed of a metal layer and an intrinsic semiconductor layer attached to the surface of one side of the metal layer. The maximum plasma frequency under the modulation of intensity of light irradiating the surface of the intrinsic semiconductor layer is smaller than the frequency of terahertz waves within the modulation range. The composite layer is provided with a sub-wavelength hole array structure. The invention further discloses a terahertz wave optical modulation method, wherein terahertz waves are emitted from one side of the intrinsic semiconductor layer of the optical modulation device to the other side. By changing the intensity of light irradiating the surface of the intrinsic semiconductor layer of the optimal modulation device, intensity of terahertz waves penetrating through the optical modulation device is changed, and therefore terahertz waves are modulated. Intensity of terahertz waves can be modulated under the normal temperature, the modulation frequency range and modulation amplitude range are wide, the modulation speed is high, and cost is low.

Description

technical field [0001] The invention relates to electromagnetic wave modulation technology, in particular to an optical modulation device, modulation method and device for terahertz waves. Background technique [0002] Terahertz (THz) waves usually refer to electromagnetic waves with frequencies ranging from 0.1 to 10 THz and wavelengths ranging from 30 μm to 3 mm. But for a long time in the past, due to the lack of effective generation and detection methods, people's understanding of the nature of electromagnetic radiation in this frequency band is very limited, so that this frequency band is called the last undeveloped frontier of the electromagnetic spectrum, the so-called " Terahertz Blank". Although the current terahertz wave science and technology are far from mature, its important theoretical research value and broad application prospects have attracted widespread attention and great interest in the academic community. The terahertz frequency band is the only frequen...

AI Technical Summary

Problems solved by technology

In this method, blades placed in parallel are used to realize the mutual conversion between terahertz waves and terahertz surface plasmon waves. The conversion efficiency of this method is too low, and the construction of the optical path is also difficult.

In addition, the semiconductor used in this method needs to meet the plasma frequency at room temperature in the terahertz band, and only a few semiconductors such as indium antimonide meet this condition, so this method can only be used for some frequency bands close to the semiconductor plasma frequency The terahertz wave can be modulated, it can be seen that the modulation frequency range of this modulation method is limited

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