Perovskite QDs-based Terahertz Modulator

Terahertz wave is in the transition region between the microwave band and the optical band,which has both microwave and light wave characteristics.Terahertz wave play a very critical role in the next generation of communication systems,and have very important application value in the fields of biomedicine,safety monitoring,biosensing,and material detection.As a very important part of terahertz technology application in these fields,terahertz modulator is one of the international academic research directions most concerned by scientists.It is lagging behind terahertz emitters and detectors,so the development of high-rate terahertz wave modulators has important scientific significance and practical application value.This article briefly introduces the development status of terahertz wave modulators at home and abroad,combing the characteristics of perovskite quantum dot materials to develop terahertz wave modulators based on perovskite quantum dots.The main research contents of this paper are as follows:1.A double-opening metal ring perovskite quantum dots terahertz modulator was designed.Through numerical calculation and simulation,the optimal size parameter of the structure was obtained.The equivalent circuit model is used to analyze the working principle of the device.The calculation results are consistent with the electromagnetic simulation results.The modulator has a modulation depth of 99%and a response time of 0.3μs,which means that the maximum modulation rate can reach 3.3MHz.2.A dual-C metamaterial-perovskite quantum dots terahertz modulator is proposed,and the device size parameters are obtained through modeling and simulation.The working principle is also analyzed through the equivalent circuit model.Finally,the device processing and testing are completed.The modulation depth of the modulator is 88.3%and the modulation speed is 5MHz by using the terahertz system.3.A kind ofΩ-shaped metamaterial-perovskite quantum dots terahertz modulator was studied.The post-device parameters were obtained through electromagnetic simulation.The performance and mechanism of the device were further analyzed through the equivalent circuit model,followed by sample processing and experiments.Test results show that the modulation depth of the modulator is 84%,and the modulation rate is 8MHz.4.A silicon waveguide-perovskite quantum dots terahertz modulator is proposed.The surface of the local waveguide tapered structure is attached with perovskite quantum dots material,and the performance of the perovskite quantum dots material is controlled by external laser to achieve the on-off.Calculation and analysis show that the structure can realize terahertz wave modulation,the modulation depth reaches82%,the modulation rate reaches 6.7MHz,and polarization-insensitive characteristics are obtained.5.Using the terahertz modulator developed by ourselves,a terahertz communication verification system is built to realize the real-time transmission of video signals,and the bit error rate is less than 10^-6,which provides an idea for the future terahertz communication system.