High-speed terahertz modulator and production method thereof

Abstract

The invention discloses a high-speed terahertz modulator and a production method thereof. The terahertz high-speed modulator comprises a substrate layer, a buffer layer growing on the substrate layer, a strained quantum well structure growing on the buffer layer and a metal meta-material structure, wherein the metal meta-material structure is prepared on the upper surface of the strained quantum well structure and consists of a periodical array of metal resonant units. Besides, the buffer layer and the substrate layer are made of the same materials, the band gap of a potential well layer is smaller than that of a potential barrier layer, and the difference between the lattice constants of the potential barrier layer and the substrate layer is controlled within 0.5%. A strong piezoelectric field generated from strain is formed in strained quantum well structure, and accordingly recombination lifetime of photon-generated carriers is prolonged and concentration thereof is increased evidently, and requirements for power of a modulated laser are lowered greatly. By changing the In component and quantum well width in the InGaAs / GaAs strained quantum well structure, the strength of the piezoelectric field inside and charge spatial isolation degree can be regulated flexibly, and accordingly the modulation rate of the high-speed terahertz modulator can be regulated conveniently.

Description

[0001] technical field [0002] The invention belongs to the field of terahertz wave communication, and in particular relates to a terahertz wave modulator and a manufacturing method thereof. Background technique [0003] The contradiction between the limited spectrum resources of wireless communication and the rapidly growing high-speed business demands forces people to develop new spectrum bands. Terahertz waves refer to electromagnetic waves with frequencies ranging from 0.1 THz to 10 THz (1 THz = 10 12 Hz), the wavelength is 0.03 mm to 3 mm, and has a large bandwidth, so the development of THz wireless communication technology has important practical application value. Among them, the terahertz wave modulator is one of the essential devices in the terahertz communication system, but the performance of the terahertz modulator is mainly limited by the selection and preparation of materials. The organic combination of new semiconductor substrate materials and electromagn...

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Problems solved by technology

However, due to the short lifetime of carriers in GaAs, the response time can reach the order of 130 ps, ​​so although the modulation rate of the THz wave can reach the order of GHz in theory, in order to obtain a higher concentration of photogenerated carriers and a higher Large modulation depth, the luminous flux of the 810 nm modulated laser needs to reach an extremely high level of 0.8 μJ / cm2, and the corresponding continuous wave output laser power needs to reach 105 W above, which makes it extremely limited in practical applications

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