GHz oscilloscope to monitor µs-fast phenomena with single-pulse THz spectroscopy

慢动作电影不仅观赏性强，还能让我们理解快速复杂现象的复杂细节。如果每一帧的图像都被太赫兹（THz）电磁波取代，这样的电影可以揭示大范围的低能量共振，帮助我们更好地理解结构、化学或生物过程的内在机制。太赫兹波段位于电磁波谱的深红外区域，已经越来越多地用于从低能振动模式中识别分子。所要求的GHz示波器是实现单脉冲太赫兹表征系统的关键仪器，该系统能够在难以访问的µs时间尺度上跟踪分子共振。实验概念是基于色散傅立叶变换技术，其中光脉冲分散在一公里长的光纤中，并由快速光电二极管检测，由要求的GHz示波器分析以提取其单个光谱强度。将该技术与编码太赫兹波形到啁啾近红外脉冲的光谱成分上的非线性效应相结合，形成了单脉冲太赫兹光谱仪。这样的系统可以监测独特的现象，具有快速和不可重现的动态，其灵敏度和分辨率最终受示波器性能的限制。最具体地说，所要求的GHz示波器将使m<e:1>博士成为第一个探索生物系统中一系列有趣的µs过程的人，例如酶催化循环的太赫兹动力学。这一领域的进展可能会带来革命性的应用，如精细化学品和药品的生物催化合成、代谢紊乱的治疗以及受污染的水和土壤的生物修复。最近，单脉冲太赫兹光谱仪已经在申请人的实验室中使用借来的GHz示波器进行了连续演示，使太赫兹光谱以前所未有的速度进行。一份总结这项工作的手稿正在审查中。及时获得GHz示波器对于继续进行该研究计划至关重要，同时继续获得动力并抓住新的机遇。租用一个类似的GHz示波器（55,000美元/年）既不经济也不可持续。单脉冲实验需要几个月的工作，并且需要全天候的设备，特别是完成影响最大的项目。因此，请求的GHz示波器对于申请人在渥太华大学的单脉冲太赫兹研究计划的延续至关重要；没有这个装置进行色散傅立叶变换光谱的能力，他的单脉冲太赫兹计划就不能继续进行。所要求的GHz示波器将用于每个单脉冲实验（每月80小时），并将在太赫兹光子学和材料物理的HQP培训中发挥核心作用。这个仪器将被所有学生常规使用。

Slow-motion movies are not only fascinating to watch, they also allow us to understand intricate details of fast and complex phenomena. If the images in each frame are replaced by terahertz (THz) electromagnetic waves, such movies can reveal a large range of low-energy resonances that help us to better understand inner mechanisms of structural, chemical or biological processes. The THz band, located in the deep infrared region of the electromagnetic spectrum, has been increasingly used to identify molecules from their low-energy vibrational modes. The requested GHz oscilloscope is a critical instrument to implement a single-pulse THz characterization system able to trace molecular resonances on the hard-to-access µs time scale. The experimental concept is based on a dispersive Fourier transform technique in which optical pulses, dispersed in a km-long fiber and detected with a fast photodiode, are analyzed by the requested GHz oscilloscope to extract their individual spectral intensity. A single-pulse THz spectrometer is formed when this technique is combined with a nonlinear effect encoding a THz waveform onto the spectral components of a chirped near-infrared pulse. Such a system can monitor unique phenomena featuring fast and non-reproducible dynamics with a sensitivity and resolution ultimately limited by the performance of the oscilloscope. Most specifically, the requested GHz oscilloscope will allow Dr. Ménard to be the first to explore a range of intriguing µs processes in biological systems, such as the THz dynamics of enzyme catalytic cycles. Advances in this field could lead to revolutionary applications such as biocatalytic syntheses of fine chemicals and pharmaceuticals, treatment of metabolic disorders, and bioremediation of contaminated water and soil. Recently, the single-pulse THz spectrometer has already been successively demonstrated in the applicant's lab with a loaned GHz oscilloscope, allowing THz spectroscopy to be performed at unprecedented rates. A manuscript summarizing this work is under review. Timely acquisition of the GHz oscilloscope is crucial to pursue this research program while continuing to gain momentum and seize new opportunities. The cost of renting a similar GHz oscilloscope ($55,000/year) is not economical nor sustainable. Single-pulse experiments require months of work, and the equipment is needed on a full-time basis, especially to complete projects with the highest impact. As such, the requested GHz oscilloscope is essential for the continuation of the applicant's single-pulse THz research program at uOttawa; Without the ability to perform dispersive Fourier transform spectroscopy with this unit, his single-pulse THz program cannot continue. The requested GHz oscilloscope will be used in every single-pulse experiments (>80 hours/month) and will play a central role in the training of HQP in THz photonics and material physics. This instrument will be routinely used by all students.