Terahertz Photonic Devices

当前的通信技术利用在电磁频谱的低频区域中操作的电子器件或在光谱中的光子技术。在这些区域之间，太赫兹（THz）频带从100 GHz延伸到100 THz。在几百GHz以上，没有可用的信号处理技术，尽管在过去十年中已经开发了许多基于半导体的THz发射器和探测器。PI建议开发光子半导体异质结构器件，允许操作THz信号以及超快THz脉冲的逻辑处理。本计画的目标是推导出太赫兹子带间元件的基本特性，并证明在太赫兹频率下光子信号处理的概念。所提出的工作的战略方法是制造半导体异质结器件，并证明其在太赫兹频率的操作。该器件将由调制n掺杂GaAs/AlGaAs异质结构组成，在太赫兹频率下具有子带间共振。这些器件将通过THz技术来表征，THz技术直接显示了器件在时域中的性能。在第一步中，PI将研究THz器件的线性特性，并将从调制频率、效率和工作温度方面对其进行表征。基本的逻辑运算将在自由空间几何中演示。在第二步中，我们将重点关注非线性区域。吸收饱和和负微分行为将被证明。最后，将研究器件集成。所需的器件尺寸的结果将深入了解未来的集成density.Terahertz光子学与半导体异质结构是一个新的概念，超快信号处理，并可能允许开关速率超过1太赫兹。预期的结果可能会影响光纤通信和芯片之间的高速互连。除了预期的速度，两个技术参数使太赫兹光子学具有吸引力：太赫兹光子学与标准半导体器件制造技术的兼容性以及由于低开关能量而减少的散热。研究生和本科生将参与拟议的研究。所有学生将获得多学科的教育，其中包括半导体器件技术，太赫兹技术和光子学。

0245461KerstingCurrent communications technologies make use of either electronics operating in the low frequency region of the electro-magnetic spectrum or of photonic techniques in the optical spectrum. Between these regions, the terahertz (THz) frequency band extends from 100 GHz to 100 THz. Above few hundred GHz, no technology for signal processing is available, although many semiconductor-based THz emitters and detectors have been developed during the past decade. The PI proposes to develop photonic semiconductor heterostructure devices that will allow the manipulation of THz signals as well as logical processing of ultrafast THz pulses. The goals of this project are to deduce fundamental properties of THz intersubband devices and to demonstrate a proof of concept for photonic signal processing at THz frequencies. The strategic approach of the proposed work is to fabricate semiconductor heterostructure devices and to demonstrate their operation at THz frequencies. The devices will consist of modulation n-doped GaAs/AlGaAs heterostructures, which have intersubband resonances at THz frequencies. The devices will be characterized by THz techniques, which directly show the device performance in time-domain. In the first step the PI will investigate the linear properties of THz devices and will characterize them with respect to modulation frequency, efficiency, and operation temperature. Fundamental logical operations will be demonstrated in free-space geometry. In the second step we will focus on the nonlinear regime. Absorption saturation and negative differential behavior will be demonstrated. Finally, device integration will be investigated. Results on the required device dimensions will give insight into future integration densities.Terahertz photonics with semiconductor heterostructures is a novel concept for ultrafast signal processing and may allow switching rates beyond 1 THz. The expected results may impact optical fiber communications and high speed interconnects between chips. Besides the expected speed, two technological arguments make THz photonics attractive: The compatibility of THz photonics with standard semiconductor device fabrication technologies and the reduced heat dissipation due to low switching energies.Graduate and undergraduate students will participate in the proposed research. All students will gain a multidisciplinary education, which covers semiconductor device technology, THz technology, and photonics.