硅基全光控太赫兹波幅度调制器的研究
发布时间：2018-07-28 16:19
【摘要】：在太赫兹(THz)技术成为国际研究热点的同时,太赫兹高速通信器件及系统的研究热潮在国内外科研机构及高校蔓延开来。太赫兹吸收、滤波、开关、调制等功能器件在太赫兹应用系统中的地位相当于眼睛、耳朵在人体的地位,是不可或缺的部件。在太赫兹波调控技术方面,有电、光、热等多种方式的调控手段,但都存在一定的弊端。例如,半导体异质结的二维电子气对THz波的调制深度较小,热致相变特性的二氧化钒材料对温度的依赖特性使得器件的调制速率较慢。光控半导体硅(Si)调制器虽然具有较大的调制幅度和宽带特性,并且与现有半导体工艺相兼容,是实现太赫兹调控器件重要方式之一。然而,受制于本征Si对光的弛豫过程,使得光掺杂的Si对THz波的调制速率最高只能达到kHz量级。本文提出一种基于掺金硅的全光学太赫兹波调制器,通过深能级掺杂改善光作用本征Si(或高阻Si)的弛豫现象,实现对THz波的高速调控。在研究不同掺杂温度和时间对Si材料的太赫兹波调制特性的影响后,得到最佳处理工艺为900℃下热扩散60 min。少数载流子寿命测试的结果表明,掺杂的金(Au)原子为Si中的非平衡电子—空穴对提供有效复合中心,使其少数载流子寿命降低了2个数量级。为了进一步提高器件对THz波束的幅度利用率,采用金的微米圆点阵列进行高温扩散掺杂,在不损失THz波透射幅度的同时提高了调制器的调制速率。该器件在0.34 THz载波的动态调制测试中达到了4.3 MHz的调制速率,其最大调制深度约21%。此外,该器件没有频率选择特性,可工作在整个太赫兹频段内,且具有极化不敏感等特性。其次,将掺金Si与超材料相结合,实现具有频率选择特性的调制器件,在设计的工作频点或带宽内,通过光控实现对THz波束的调制。最后,将掺金Si器件与实验室现有的激光集成,构建光控太赫兹高速调制器,并同过100 kHz的调制速率成功将温度信息在0.34 THz的信道内调制、传输、解调与显示。该工作验证了全光控调制器的可靠性,并展示了一种THz无线通信系统的雏形。本论文提出的基于光控掺金硅的太赫兹调制技术,成本低、易实现,与半导体工艺相兼容。既适用于动态光与THz波耦合的场合,也是构建其他高速Si基太赫兹功能器件的重要基础,在太赫兹通信、探测和成像等方面均具有巨大的应用潜力和价值。
[Abstract]:While terahertz (THz) technology has become an international research hotspot, the research boom of terahertz high speed communication devices and systems has spread in domestic and foreign scientific research institutions and universities. Terahertz absorption, filtering, switching, modulation and other functional devices in the terahertz application system as the position of the eye, ear in the human body, is an indispensable component. In the aspect of terahertz wave control technology, there are many control methods, such as electricity, light, heat and so on, but they all have some disadvantages. For example, the modulation depth of THz wave in two-dimensional electron gas of semiconductor heterojunction is small, and the temperature dependence of thermo-induced phase transition vanadium oxide material makes the modulation rate of the device slower. The optically controlled semiconductor silicon (Si) modulator is one of the most important ways to realize terahertz control devices, although it has large modulation amplitude and wide band characteristics and is compatible with the existing semiconductor technology. However, due to the relaxation process of intrinsic Si to light, the modulation rate of photo-doped Si to THz wave can only reach kHz order of magnitude. An all-optical terahertz wave modulator based on au doped silicon is proposed in this paper. Deep level doping can improve the relaxation of intrinsic Si (or high resistivity Si) and realize the high speed regulation of THz wave. After studying the effect of doping temperature and time on the terahertz wave modulation characteristics of Si materials, the optimum treatment process is obtained at 900 鈩，
本文编号：2150860
[Abstract]:While terahertz (THz) technology has become an international research hotspot, the research boom of terahertz high speed communication devices and systems has spread in domestic and foreign scientific research institutions and universities. Terahertz absorption, filtering, switching, modulation and other functional devices in the terahertz application system as the position of the eye, ear in the human body, is an indispensable component. In the aspect of terahertz wave control technology, there are many control methods, such as electricity, light, heat and so on, but they all have some disadvantages. For example, the modulation depth of THz wave in two-dimensional electron gas of semiconductor heterojunction is small, and the temperature dependence of thermo-induced phase transition vanadium oxide material makes the modulation rate of the device slower. The optically controlled semiconductor silicon (Si) modulator is one of the most important ways to realize terahertz control devices, although it has large modulation amplitude and wide band characteristics and is compatible with the existing semiconductor technology. However, due to the relaxation process of intrinsic Si to light, the modulation rate of photo-doped Si to THz wave can only reach kHz order of magnitude. An all-optical terahertz wave modulator based on au doped silicon is proposed in this paper. Deep level doping can improve the relaxation of intrinsic Si (or high resistivity Si) and realize the high speed regulation of THz wave. After studying the effect of doping temperature and time on the terahertz wave modulation characteristics of Si materials, the optimum treatment process is obtained at 900 鈩，
本文编号：2150860
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