Quantum optics at Terahertz frequencies

太赫兹频率的量子光学

• 批准号: 1944833
• 金额: --
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1944833
• 关键词: Quantum; optics; Terahertz; frequencies

Research questions: Measuring THz radiation is essential for many engineering challenges, such as the detection of concealed weapons, the quality control in the pharmaceutical industry and for the identification of hazards such as explosives. Currently, one of the main approaches to detect THz radiation relies on measuring the signal that originates from the nonlinear interaction between the unknown THz radiation and a short laser pulse into specific crystals. With this project, we aim to investigate a way to overcome the current limitation of this detection scheme relying on the properties of quantum states of light. Specifically, squeezed radiation can increase the detect insensitivity by providing a lower noise probe pulse for THz detection.Approach: For this project, we have three main activities.1) Novel THz antennas2) Generation and detection of squeezed states3) Quantification of the signal-to-noise and sensitivity enhancement due to the use of nonclassical statesFor part 1), the student will design a new THz emitter that is optimised on the characteristic of the available laser. This activity includes numerical simulation and the study of previous literature. As a backup plan, the student will have access to an already functioning, but not optimised THz generation antenna.Part 2 will see the student developing both the source of squeezed radiation and the relevant detection tools. The source will be a standard parametric down-conversion in type II nonlinear crystal. The detection, instead, will require to design a specific electronic amplifier to drive two, high-quantum efficiency, InGaAs photodiodes. The design of the amplifier should be such that it will enable detection of sub-shot-noise signals at ~100kHz.Part 3 will require understanding how the signal to noise ratio and dynamic range are in a standard THz time-resolved detection and will include the characterisation of the setup developed by the student. Hence, these parameters will be recorded using a two-mode squeezed probe pulse and compared to the classical case.Novel engineering and physical sciences contentThe novelty of this research program is in the use of quantum technologies, such as squeezed state metrology, to improve the capabilities of a well-established and broad impact technique, that is, time-domain THz spectroscopy. New technical tools will need to be developed, such as a non-classical scheme for time-domain spectroscopy, along with the required components, such as THz antenna arrays and low-noise current amplifiers.

研究问题：测量THz辐射对于许多工程挑战至关重要，例如隐藏武器的检测，制药行业的质量控制以及爆炸物等危险的识别。目前，检测THz辐射的主要方法之一依赖于测量来自未知THz辐射与进入特定晶体的短激光脉冲之间的非线性相互作用的信号。通过这个项目，我们的目标是研究一种方法来克服这种依赖于光的量子态特性的检测方案的当前限制。具体而言，压缩辐射可以通过为THz探测提供更低噪声的探测脉冲来增加探测不灵敏度。本项目主要有三个方面的工作：1）新型太赫兹天线的研究2）压缩态的产生和探测3）非经典态的引入对信噪比和灵敏度的提高进行了量化1），学生将设计一种新的太赫兹发射器，该发射器根据现有激光器的特性进行优化。这项活动包括数值模拟和以前的文献研究。作为备用计划，学生将有机会获得一个已经运行，但没有优化的太赫兹产生天线。第2部分将看到学生开发压缩辐射源和相关的检测工具。源将是一个标准的参数下转换在II型非线性晶体。相反，检测需要设计一个特定的电子放大器来驱动两个高量子效率的InGaAs光电二极管。放大器的设计应使其能够检测~ 100 kHz的亚散粒噪声信号。第3部分要求理解标准THz时间分辨检测中的信噪比和动态范围，并包括学生开发的设置的特性。因此，这些参数将被记录使用一个双模压缩探测脉冲，并与经典的cases.Novel工程和物理科学contentThe新颖的这项研究计划是在使用量子技术，如压缩态计量学，以提高一个完善的和广泛的影响技术，即时域太赫兹光谱的能力。需要开发新的技术工具，如时域光谱学的非经典方案，沿着所需的组件，如太赫兹天线阵列和低噪声电流放大器。