基于光、電調(diào)控的太赫茲人工電磁材料特性研究
發(fā)布時間：2018-08-30 12:48
【摘要】：人工電磁微結(jié)構(gòu)的興起為太赫茲技術(shù)走向成熟應(yīng)用提供了新的發(fā)展機遇,特別是功能與特性能夠被動態(tài)操控的超材料設(shè)計已成為太赫茲領(lǐng)域新的研究熱點。本文圍繞光、電可調(diào)控的太赫茲功能器件開展了如下的工作,具體的內(nèi)容包括:1,通過對太赫茲技術(shù)研究范疇與應(yīng)用價值的介紹總結(jié)出當(dāng)前發(fā)展所面臨的瓶頸和問題,闡述了主動可調(diào)控的功能器件是突破太赫茲技術(shù)限制的有效途徑,針對本課題中三個主動功能器件的實現(xiàn),介紹相關(guān)用于擬合和解釋微結(jié)構(gòu)電磁響應(yīng)的理論模型、樣品制備和具體加工工藝流程和基于波面傾斜技術(shù)的光泵太赫茲探測實驗系統(tǒng)的設(shè)計。2,光控寬帶的太赫茲等離子誘導(dǎo)透明超材料的設(shè)計與性能測試。該超材料的單元結(jié)構(gòu)是由一根中央的金屬棒和環(huán)繞其周圍的四個U形金屬環(huán)組成,多個暗模與明模增強的耦合作用導(dǎo)致了寬帶的PIT效應(yīng),整個結(jié)構(gòu)被制作在光敏感的SOS襯底上,通過對硅的巧妙設(shè)計實現(xiàn)了帶寬為0.54~0.82THz透明窗口的光開關(guān)效應(yīng)。在對樣品軟件模擬、樣品加工、實驗測量的基礎(chǔ)上,從耦合的洛倫茲諧振子模型出發(fā)得出該器件主動調(diào)制的機制歸結(jié)于光照抑制了充當(dāng)暗模的四個U形金屬環(huán)的諧振激發(fā)。3,電磁人工微結(jié)構(gòu)近場諧振模式的動態(tài)耦合效應(yīng)研究。通過使用電磁仿真軟件CST模擬了由三個不等邊長的同心金屬方環(huán)結(jié)構(gòu)的電磁響應(yīng),相鄰方環(huán)之間的電容耦合導(dǎo)致很強的透射峰和相反的表面電流,整個結(jié)構(gòu)制作在SOS襯底上,光敏的硅嵌入到相鄰的方環(huán)之間,模擬上通過改變硅的電導(dǎo)率和實驗上通過改變光照的能量都實現(xiàn)了耦合諧振峰的動態(tài)調(diào)制,增強光照能量能夠?qū)崿F(xiàn)由電容耦合向電導(dǎo)耦合的轉(zhuǎn)變,理論上從耦合的洛倫茲諧振模型出發(fā)解釋了主動調(diào)控的機制緣于自身諧振和鄰近模式耦合激發(fā)的共同受阻。4,基于超表面相位不連續(xù)的電控太赫茲分束器研究。該器件的結(jié)構(gòu)周期由8個振幅相等、相位依次相差π/4的開口環(huán)形金屬孔構(gòu)成,能夠?qū)崿F(xiàn)帶寬為0.48~0.93THz正交偏振的異常透射,不同的頻率將沿著不同的角度出射,以n型摻雜的砷化鎵層作為基底,與金屬結(jié)構(gòu)層之間形成肖特基接觸,通過施加反向偏置電壓來動態(tài)調(diào)控異常透射的振幅,調(diào)制的深度和速率分別可達46%和3k Hz�；谏榛壔纂妼�(dǎo)率變化的CST模擬很好的再現(xiàn)了實驗的結(jié)果。
[Abstract]:The rise of artificial electromagnetic microstructures provides a new development opportunity for the mature application of terahertz technology, especially the design of metamaterials whose functions and characteristics can be dynamically manipulated has become a new research hotspot in the field of terahertz. In this paper, the following work has been done around the optical and electrically adjustable terahertz functional devices. The specific contents include: 1. Through the introduction of the research category and application value of terahertz technology, the bottlenecks and problems faced by the current development are summarized. This paper expounds that active and adjustable functional devices are an effective way to break through the limitation of terahertz technology. Aiming at the realization of three active functional devices in this paper, the relevant theoretical models used to fit and interpret the electromagnetic response of microstructures are introduced. The sample preparation and processing process and the design of optical pump terahertz detection experimental system based on wave surface tilt technology. The design and performance test of optically controlled wideband terahertz plasma-induced transparent supermaterial. The unit structure of the metamaterial is composed of a central metal rod and four U-shaped metal rings around it. The coupling of several dark modes and the open-mode enhancement results in the broadband PIT effect, and the whole structure is fabricated on a light-sensitive SOS substrate. The optical switch effect with bandwidth of 0.54~0.82THz transparent window is realized by the ingenious design of silicon. On the basis of sample software simulation, sample processing and experimental measurement, Based on the coupled Lorentz harmonic oscillator model, it is concluded that the active modulation mechanism of the device is attributed to the suppression of resonance excitation of four U-shaped metal rings acting as dark modes by illumination, and the study of dynamic coupling effect of near-field resonant modes in electromagnetic artificial microstructures. By using electromagnetic simulation software CST, the electromagnetic response of three concentric metal square rings with different length is simulated. The capacitive coupling between adjacent square rings leads to strong transmission peak and opposite surface current. The whole structure is fabricated on SOS substrate. Guang Min's silicon is embedded between adjacent square rings, and the dynamic modulation of the coupling resonance peak is realized by changing the conductivity of silicon and experimentally changing the energy of illumination. The enhancement of illumination energy can realize the transition from capacitive coupling to conductance coupling. Based on the coupled Lorentz resonance model, the mechanism of active regulation is explained by the mutual hindrance of self-resonance and adjacent mode coupling excitation. The study of electronic terahertz beam splitter based on the discontinuity of supersurface phase is presented. The structure period of the device is composed of eight open annular metal holes with equal amplitude and phase difference 蟺 / 4, which can realize the abnormal transmission of the bandwidth of 0.48~0.93THz orthogonal polarization, and the different frequencies will be emitted at different angles. Schottky contact was formed between n-doped GaAs layer and metal structure layer. The amplitude of abnormal transmission was dynamically adjusted by applying reverse bias voltage. The modulation depth and rate were up to 46% and 3 k Hz., respectively. The CST simulation based on the variation of the conductivity of gallium arsenide substrate reproduces the experimental results well.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：O441.4
本文編號：2213112
[Abstract]:The rise of artificial electromagnetic microstructures provides a new development opportunity for the mature application of terahertz technology, especially the design of metamaterials whose functions and characteristics can be dynamically manipulated has become a new research hotspot in the field of terahertz. In this paper, the following work has been done around the optical and electrically adjustable terahertz functional devices. The specific contents include: 1. Through the introduction of the research category and application value of terahertz technology, the bottlenecks and problems faced by the current development are summarized. This paper expounds that active and adjustable functional devices are an effective way to break through the limitation of terahertz technology. Aiming at the realization of three active functional devices in this paper, the relevant theoretical models used to fit and interpret the electromagnetic response of microstructures are introduced. The sample preparation and processing process and the design of optical pump terahertz detection experimental system based on wave surface tilt technology. The design and performance test of optically controlled wideband terahertz plasma-induced transparent supermaterial. The unit structure of the metamaterial is composed of a central metal rod and four U-shaped metal rings around it. The coupling of several dark modes and the open-mode enhancement results in the broadband PIT effect, and the whole structure is fabricated on a light-sensitive SOS substrate. The optical switch effect with bandwidth of 0.54~0.82THz transparent window is realized by the ingenious design of silicon. On the basis of sample software simulation, sample processing and experimental measurement, Based on the coupled Lorentz harmonic oscillator model, it is concluded that the active modulation mechanism of the device is attributed to the suppression of resonance excitation of four U-shaped metal rings acting as dark modes by illumination, and the study of dynamic coupling effect of near-field resonant modes in electromagnetic artificial microstructures. By using electromagnetic simulation software CST, the electromagnetic response of three concentric metal square rings with different length is simulated. The capacitive coupling between adjacent square rings leads to strong transmission peak and opposite surface current. The whole structure is fabricated on SOS substrate. Guang Min's silicon is embedded between adjacent square rings, and the dynamic modulation of the coupling resonance peak is realized by changing the conductivity of silicon and experimentally changing the energy of illumination. The enhancement of illumination energy can realize the transition from capacitive coupling to conductance coupling. Based on the coupled Lorentz resonance model, the mechanism of active regulation is explained by the mutual hindrance of self-resonance and adjacent mode coupling excitation. The study of electronic terahertz beam splitter based on the discontinuity of supersurface phase is presented. The structure period of the device is composed of eight open annular metal holes with equal amplitude and phase difference 蟺 / 4, which can realize the abnormal transmission of the bandwidth of 0.48~0.93THz orthogonal polarization, and the different frequencies will be emitted at different angles. Schottky contact was formed between n-doped GaAs layer and metal structure layer. The amplitude of abnormal transmission was dynamically adjusted by applying reverse bias voltage. The modulation depth and rate were up to 46% and 3 k Hz., respectively. The CST simulation based on the variation of the conductivity of gallium arsenide substrate reproduces the experimental results well.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：O441.4
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2 寶日瑪;趙昆;田璐;周慶莉;施宇蕾;趙冬梅;張存林;趙卉;朱守明;苗青;藍興英;;汽油的太赫茲時域光譜特性研究[J];中國科學(xué):物理學(xué) 力學(xué) 天文學(xué);2010年08期
，本文編號：2213112
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