报告题目：Optical Multi-Dimensional Coherent Spectroscopy and Quantum Interference Control of Injected Photocurrents
报告人：Steven T. Cundiff
报告人单位：Departments of Physics and Electrical Engineering and Computer Science & the Quantum Research Institute, University of Michigan
主持人：蒋燕义 研究员
报告时间：2025年5月14日（周三）下午14:00
报告地点：光学大楼三楼报告厅
报告内容：
I will cover two topics in this talk, optical multidimensional coherent spectroscopy and injection of photocurrents using quantum interference.
The concept of multidimensional Fourier transform spectroscopy originated in NMR where it enabled the determination of molecular structure. The key concept is to correlate what happens during multiple time periods between pulses by taking a multidimensional Fourier transform. Migrating multidimensional Fourier transform spectroscopy to the optical regime is difficult because phases are critical. I will give an introduction to optical two-dimensional coherent spectroscopy, using an atomic vapor as simple test system, but also show unexpected results due to atomic interactions. I will then present our use of it to study optical resonances in semiconductor nanostructures, defects in diamond and two-dimensional materials.
Typically, the absorption of light in a semiconductor does not result in a current unless there is an applied bias electric field. However, the quantum interference between linear/nonlinear absorption processes with differing number of photons can result in an imbalanced momentum space distribution of electrons, which is a current. I will present our experimental work on this topic, initially motivated by using it to detect the carrier-envelope phase of ultrashort optical pulses, including more recent work on higher order processes that result in narrower angular distributions in momentum space.
报告人简介：
Steven T. Cundiff 是密歇根大学Harrison M. Randall物理学教授和电气工程与计算机科学教授。1992年，他获得了密歇根大学应用物理学博士学位。1999年-2015年，在JILA工作。2015年加入密歇根大学。2023年，他被任命为密歇根大学量子研究所的创始联合主任。Cundiff 教授是美国物理学会、美国光学学会、美国电气和电子工程师协会和美国科学促进会的会员。他获得了Optica/OSA颁发的Meggers奖和美国物理学会颁发的Schawlow激光科学奖。
Cundiff教授从事超快光学领域的研究。他的工作跨越了从超短光脉冲的产生、操纵到利用它们实现复杂光谱技术的领域。他的研究内容包括开发和应用多维相干光谱，用于从原子蒸气到半导体纳米结构的广泛材料系统。其他研究领域包括产生频率梳的新方法，例如直接从带间二极管激光器生产，使用频率梳实现量子干涉控制和实现多维光谱。他还研究了产生超短脉冲的锁模激光器的动力学等。