共查询到18条相似文献,搜索用时 78 毫秒
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太赫兹量子级联激光器 总被引:1,自引:0,他引:1
太赫兹技术近年来发展迅速,应用越来越广泛,是当前的热门研究领域。太赫兹量子级联激光器是产生太赫兹辐射的重要器件,对太赫兹量子级联激光器的发展,以及有源区和波导层的设计等进行了详细讨论。 相似文献
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随着无线通信速率需求的增加和材料生长、器件工艺制作水平的提高,太赫兹(THz)通信已成为未来高速无线通信系统发展的一个重要方向。介绍了太赫兹通信的特点以及国际上太赫兹通信系统的发展现状,并报导了一种利用太赫兹量子级联激光器(THz QCL)作为发射源,太赫兹量子阱探测器(THz QWP)作为接收器的太赫兹数字通信演示系统。该系统采用On-Off-Key(OOK)调制和直接强度检测方式,通信频点为3.9 THz,通信距离为2.2 m,传输速率可达1 Mbps 以上。最后探讨了该系统的带宽限制因素及其在通信速率方面的潜力。 相似文献
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太赫兹量子阱探测器具有皮秒级的响应时间和1 GHz以上的高速调制性能,是太赫兹快速成像和高速无线通信应用领域非常有前景的探测器.文章综述了太赫兹量子阱探测器的探测原理和设计方法、器件主要性能指标和基于该探测器的应用技术研究进展.研究表明,基于太赫兹量子阱探测器的快速成像系统可以获得物体的细节信息,有望用于安全检查和无损... 相似文献
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太赫兹量子级联激光器和太赫兹量子阱探测器都是基于子带间电子跃迁的半导体器件,具有体积小、频率可调、响应速度快等优点。其工作波长位于微波波长和红外波长之间,其光谱涵盖了众多气体分子、化合物以及凝聚态物质的频谱特征,在天文观测、公共安全、生物医药等领域中有重大应用前景。近年来,太赫兹量子级联激光器和太赫兹量子阱探测器的性能有了显著提高,其应用也受到关注。回顾了太赫兹量子级联激光器和量子阱探测器的发展历程,简述了其工作原理和器件结构,介绍了器件性能在工作温度、光谱范围等方面的最新进展及其在高分辨光谱、太赫兹成像、无线宽带通信等方面的应用,并在此基础上分析了目前存在的问题和研究热点,对其未来发展进行了展望。 相似文献
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由于太赫兹辐射的独特性质和潜在的应用价值, 国内外关于太赫兹波的产生和探测的研究正呈现日益繁荣的景象, 目前太赫兹相干辐射源的研究已成为太赫兹技术领域最重要的前沿课题之一。介绍了产生太赫兹相干辐射的三种主要途径:一是光学技术, 它从高频向低频发展, 其代表为太赫兹激光器, 如气体激光器、半导体激光器和量子级联激光器等; 二是电子学技术, 它由低频向高频发展, 如微波管、固体微波源等; 三是光电子技术, 其频率由1 THz向两侧展宽, 采用超快激光脉冲触发产生太赫兹脉冲。设计了基于光学技术的太赫兹相干辐射系统, 该装置根据气体振转能级跃迁原理, 采用高压直流激励方式产生受激辐射, 波导管谐振腔体, 工作气体为N2, CD4和D2, 经过优化设计, 预计可以产生1.54 THz和1.58 THz的波连续输出。 相似文献
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太赫兹量子级联激光器(QCL)有源区设计主要包括啁啾超晶格、束缚-连续态跃迁和共振声子等模式。本文利用密度矩阵方法模拟太赫兹QCL光增益谱的基本特征,特别是通过分析太赫兹QCL光增益特性与子带寿命的依赖关系,理解太赫兹QCL对超晶格子带间非辐射跃迁寿命的要求。进而根据这些要求给出一种基于束缚-连续态跃迁和共振声子混合模式的太赫兹QCL有源区设计方案,利用纵光学声子共振帮助缩短束缚-连续态跃迁模式中下辐射态寿命。 相似文献
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半导体太赫兹量子级联激光器(THz QCL)是一种相干性好线宽窄的太赫兹辐射源,有潜力获得高的输出功率.采用基于非平衡格林函数(NEGF)方法的计算工具设计、生长、制备了基于砷化镓系材料的THz QCL.在10 K温度下,峰值功率达到270 mW,平均功率为2. 4 mW,单位面积的输出功率与已报道的最高值相当.采用NEGF方法对器件的温度变化特性做了详细的分析. 相似文献
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基于光学方法的太赫兹辐射源 总被引:19,自引:0,他引:19
太赫兹波技术在物理、化学、生命科学等基础研究学科,以及医学成像、安全检查、产品检测、空间通信、武器制导等应用学科都具有重要的研究价值和应用前景,而太赫兹辐射源正是太赫兹技术发展的关键部分。概述了基于光学方法产生太赫兹辐射的几种常用方法,着重叙述了利用非线性光学差频技术和基于横向晶格振动光学模受激电磁耦子散射过程的太赫兹参量振荡技术工作原理,以及目前的研究状况,并对这两种方法产生太赫兹波辐射源未来的发展方向进行了展望。 相似文献
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Seung‐Heon Lee Bong Joo Kang Ba‐Wool Yoo Seung‐Chul Lee Seung‐Jun Lee Mojca Jazbinsek Hoseop Yun Fabian Rotermund O‐Pil Kwon 《Advanced functional materials》2017,27(14)
For terahertz (THz) wave generators based on organic electrooptic crystals, their intrinsic phonon modes are playing an essential role in THz generation characteristics. Here, this study proposes an effective design strategy for THz phonon mode engineering of organic electrooptic salt crystals for efficient optical‐to‐THz frequency conversion. To reduce phonon‐mode intensity, strongly electronegative trifluoromethyl group acting as strong hydrogen‐bond acceptor is incorporated into molecular anions. New 2‐(4‐hydroxy‐3‐methoxystyryl)‐1‐methylquinolinium 4‐(trifluoromethyl)benzenesulfonate (HMQ‐4TFS) crystals exhibit a relatively small absorption coefficient in the THz spectral range between 0.5 and 4 THz, which is attributed to suppressed molecular vibrations due to strong hydrogen bonds involving the 4TFS anion. In addition, HMQ‐4TFS crystals possess a very large macroscopic optical nonlinearity, comparable (or even higher) to benchmark stilbazolium crystals. Based on the low‐intensity THz phonon modes and the large optical nonlinearity, a 0.37 mm thick HMQ‐4TFS crystal pumped with 150 fs infrared laser pulses facilitates very efficient THz wave generation by optical rectification, delivering 23 times higher peak‐to‐peak THz electric field than the widely used standard inorganic ZnTe crystal (1.0 mm thick) and a broader spectral bandwidth. Therefore, strongly electronegative groups introduced into molecular salt electrooptic crystals provide a very promising design strategy of THz phonon mode engineering for developing intense broadband THz sources. 相似文献
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太赫兹技术的发展现状及应用前景分析 总被引:1,自引:0,他引:1
简要介绍了太赫兹辐射源和太赫兹探测器,特别是THz量子级联激光器(QCL)和THz量子阱红外光子探测器(QWIP)的原理、特点及研究现状.分析了太赫兹技术工程应用前景及限制因素.指出作用距离是决定太赫兹技术应用的关键因素之一.如果太赫兹辐射在大气对流层内传输时的衰减问题不能得到有效解决,那么太赫兹技术在地面或海上的应用可能受到严重制约.基于机载或星载平台的太赫兹雷达或通信,则具有诱人的应用前景. 相似文献
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测量液体或气体样品的太赫兹光学参数时,常采用石英玻璃作为容器,因此在计算样品的折射率和吸收率时需要考虑石英玻璃太赫兹光学参数的影响。文中利用太赫兹时域谱技术测量了石英玻璃的太赫兹时域光谱,根据测量模型计算了太赫兹波段的折射率和吸收率,并利用误差传播理论分析了这些光学参数的误差。结果发现折射率误差在0.2~2.0 THz范围内基本保持不变,而吸收率误差则随频率增大而呈指数增大。这对于提高测量石英玻璃容器中的气体及液体样品太赫兹光学参数的准确性具有重要价值。 相似文献
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Chan‐Uk Jeong Bong Joo Kang Seung‐Heon Lee Seung‐Chul Lee Won Tae Kim Mojca Jazbinsek Woojin Yoon Hoseop Yun Dongwook Kim Fabian Rotermund O‐Pil Kwon 《Advanced functional materials》2018,28(30)
This study presents newly developed yellow‐colored organic electro‐optic crystals to provide high terahertz (THz) wave generation efficiency. Compared with currently existing red‐ or orange‐colored electro‐optic crystals, which are used for most benchmark organic THz sources, yellow‐colored crystals have additional superior advantages for THz wave generation, e.g., higher transparency in the visible wavelength range with accompanying different phase‐matching possibilities. The new yellow‐colored crystals consist of a highly nonlinear optical 4‐(4‐hydroxystyryl)‐1‐methylpyridinium (OHP) cation, with a relatively short wavelength of maximal absorption at 390 nm in solution, and various halogen‐substituted benzenesulfonate anions, with strong secondary‐bonding ability. OHP 4‐chlorobenzenesulfonate (OHP‐CBS) crystals exhibit large off‐resonant macroscopic optical nonlinearity and high transparency, with a cut‐off wavelength for solid‐state absorption near 490 nm. OHP‐CBS crystals provide excellent THz wave generation characteristics based on optical rectification. A 0.53 mm thick OHP‐CBS crystal delivers ≈27 times higher optical‐to‐THz conversion efficiency and a much broader spectrum bandwidth compared with the standard 1.0 mm thick ZnTe at 1300 nm pumping. Particularly, compared with a benchmark organic quinolinium crystal with a similar thickness of 0.55 mm, OHP‐CBS crystals exhibit 1.7 times higher optical‐to‐THz conversion efficiency, and show a significantly different THz spectral shape. 相似文献
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太赫兹的大气传输特性对太赫兹的空间应用非常重要.对太赫兹波在Kolmogorov湍流大气中的水平传输特性展开了研究.分析了太赫兹平面波在湍流大气中传输时其闪烁指数、饱和距离等参数随频率、空间传输距离和湍流强弱程度等因素的变化.以高斯波束为例,研究了太赫兹波束在湍流大气中传输时闪烁指数、束宽等参数随传输距离等物理量的演化规律.研究结果表明,在太赫兹波段,频率越高,闪烁指数越大,饱和距离就越小.总体上看,太赫兹波在大气中传输时受大气湍流的影响程度介于光波和微波之间;对于太赫兹大气通信和成像等短程应用,太赫兹波在湍流大气中传输时一般都处于弱起伏状态;但对于太赫兹雷达和遥感等应用,由于传输距离较远,可能会出现强起伏. 相似文献
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New Class of Efficient Terahertz Generators: Effective Terahertz Spectral Filling by Complementary Tandem Configuration of Nonlinear Organic Crystals 下载免费PDF全文
Bong Joo Kang Seung‐Heon Lee Won Tae Kim Seung‐Chul Lee Kanghee Lee Giordano Benacchio Germano Montemezzani Mojca Jazbinsek O‐Pil Kwon Fabian Rotermund 《Advanced functional materials》2018,28(15)
Intense table‐top terahertz (THz) sources, which have progressed tremendously in the last decade, are becoming more important for advanced THz science to study light–matter interactions and subsequent applications. Nonlinear optical organic crystals exhibit great potential for intense broadband THz wave generation due to their large nonlinearities and advantageous phase‐matching characteristics. However, the phonon‐induced absorption of most organic crystals in the THz region leads to undesired modulation of the spectrum and limits the THz output efficiency. To overcome such drawbacks, phonon‐mode engineering by modification of molecular structures is suggested, but intrinsic limitations still remain. Here, an efficient alternative approach has been recently proposed for generating intense broadband THz waves based on a tandem configuration that combines two complementary nonlinear organic crystals. Such configuration compensates for the spectral gap of the generated THz waves mainly caused by phonon absorption and additionally enhances the optical‐to‐THz conversion efficiency. The proposed organic tandem generator indicates a substantial enhancement of the peak‐to‐peak THz electric field due to effective spectral filling at phonon absorption gaps. As a result, such tandem configuration provides a versatile platform to generate gapless broadband THz spectra with suppressed phonon absorption and contributes to advancing the development of intense broadband coherent THz sources. 相似文献
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Eui Su Lee Namje Kim Sang‐Pil Han Donghun Lee Won‐Hui Lee Kiwon Moon Il‐Min Lee Jun‐Hwan Shin Kyung Hyun Park 《ETRI Journal》2016,38(4):665-674
We designed and fabricated a semiconductor optical amplifier‐integrated dual‐mode laser (SOA‐DML) as a compact and widely tunable continuous‐wave terahertz (CW THz) beat source, and a pin‐photodiode (pin‐PD) integrated with a log‐periodic planar antenna as a CW THz emitter. The SOA‐DML chip consists of two distributed feedback lasers, a phase section for a tunable beat source, an amplifier, and a tapered spot‐size converter for high output power and fiber‐coupling efficiency. The SOA‐DML module exhibits an output power of more than 15 dBm and clear four‐wave mixing throughout the entire tuning range. Using integrated micro‐heaters, we were able to tune the optical beat frequency from 380 GHz to 1,120 GHz. In addition, the effect of benzocyclobutene polymer in the antenna design of a pin‐PD was considered. Furthermore, a dual active photodiode (PD) for high output power was designed, resulting in a 1.7‐fold increase in efficiency compared with a single active PD at 220 GHz. Finally, herein we successfully show the feasibility of the CW THz system by demonstrating THz frequency‐domain spectroscopy of an α‐lactose pellet using the modularized SOA‐DML and a PD emitter. 相似文献