Widely tuneable coherent light source necessary for attosecond condensed matter experiments

阿秒凝聚态物质实验所需的宽可调相干光源

• 批准号: RTI-2019-01001
• 负责人: Hammond, Thomas
• 金额: $ 10.93万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=652963
• 关键词: Widely; tuneable; coherent; light; source

Attosecond science (1 as = 10-18s), or attoscience, studies electron dynamics. In the gas phase, valence electron motion in an atom or molecule is well understood. By transferring these measurement techniques – initiating and following dynamics on an attosecond timescale – to condensed matter (CM), we open up a large frontier in light-matter interaction, namely quantum and nonlinear optics, electro-optics, CM physics, and materials science. Furthermore, the techniques created for attoscience have led to unprecedented field sensitivity that can be used not only for next-generation electronics, electrical engineering, and photonics, but also for molecular detection, standoff detection, and biosensing.***However, to transfer the techniques of attoscience from the gas phase – where absorption is mainly in the vacuum ultraviolet – to CM – where absorption occurs in the visible and short wavelength infrared (SWIR) – requires a widely tuneable infrared laser. To access these energies, highly qualified personnel (HQP) will perform research using an optical parametric amplifier (OPA) to drive the experiments. This research will be performed in the attosecond condensed matter experiments (ACME) laboratory at the University of Windsor. ACME HQP will leverage attosecond techniques in CM to discover ultrafast processes, control electronic motion in engineered material, and develop new photonics technologies. An OPA is essential to transfer these technologies to CM and access this frontier in light-matter interaction.***An OPA has several unique properties. First, it can efficiently convert high-intensity visible ultrafast laser pulses to the SWIR and mid-IR. Second, the tuneability of the OPA will allow for HQP to study radiation from SWIR to the mid-IR, spanning spectroscopic absorption bands of water and organic molecules that are relevant to security and medical applications. Furthermore, the strong fields generated by an OPA and energy tuneability will access different multiphoton effects near the bandgap of semiconductor materials. Additionally, attosecond resolution requires careful absolute phase control of the laser pulse, which naturally occurs in an OPA but requires cumbersome additional feedback electronics in a laser.***The applications of this OPA will include high harmonic generation (HHG) in semiconductors to study attosecond dynamics in CM and to create an efficient XUV source for spectroscopy. Because HHG in semiconductors is sensitive to external fields, we will use modulations to the HHG signal to temporally reconstruct optical waveforms in the IR, measuring the amplitude and phase of water and biologically relevant absorption signatures. Moreover, the increased sensitivity to perturbing fields can be leveraged with other established techniques such as atomic force microscopy (AFM) for attosecond time resolution at the nanoscale – an unprecedented combination of two disparate areas of research.**

阿秒科学（1 as = 10-18s）或阿托科学研究气相中的电子动力学，通过转移这些测量技术（在阿秒时间尺度上启动和跟踪动力学），可以很好地理解原子或分子中的价电子运动。到凝聚态物质（CM），我们在光与物质相互作用方面开辟了一个广阔的前沿，即量子和非线性光学、电光、凝聚态物理和材料科学。 attoscience 带来了前所未有的场灵敏度，不仅可用于下一代电子、电气工程和光子学，还可用于分子检测、远距离检测和生物传感。***然而，将 attoscience 的技术从气相 – 吸收主要发生在真空高紫外线中 – 到 CM – 吸收发生在可见光和短波长红外 (SWIR) 中 – 需要广泛可调的红外激光 要获取这些能量，需要合格人员 (HQP) 来执行。使用光学参量放大器 (OPA) 驱动实验的研究 这项研究将在温莎大学的阿秒凝聚态实验 (ACME) 实验室中进行，ACME HQP 将利用 CM 中的阿秒技术来发现超快过程、控制电子。 OPA 对于将这些技术转移到 CM 并进入光与物质相互作用的前沿至关重要。*** OPA 具有几个独特的特性。其次，OPA 的可调谐性将使 HQP 能够研究从短波红外到中红外的辐射，跨越水和有机分子的光谱吸收带。此外，OPA 和能量可调性产生的强光将在半导体材料的带隙附近产生不同的多光子效应。此外，阿秒分辨率需要对激光脉冲进行仔细的绝对相位控制，这是自然发生的。在 OPA 中，但需要在激光器中使用繁琐的额外反馈电子器件。***该 OPA 的应用将包括半导体中的高次谐波发生 (HHG)，以研究 CM 中的阿秒动力学，并为光谱学创建高效的 XUV 光源。由于半导体对外部场敏感，我们将使用对 HHG 信号的调制来临时重建红外光波形，测量水的振幅和相位以及生物相关的吸收特征，此外，还会提高对外部场的敏感度。扰动场可以与其他成熟技术结合使用，例如原子力显微镜（AFM），以实现纳米级阿秒时间分辨率——这是两个不同研究领域的前所未有的结合。**