Development of an all-optical, broadband electron paramagnetic resonance spectrometer with picosecond time-resolution

在主要研究仪器(MRI)和化学研究仪器和设施(CRIF)计划的支持下，芝加哥伊利诺伊大学的W.Andreas Schroeder、Charles E.Brown和James W.Longworth以及芝加哥大学的James R.Norris将开发一种时间分辨率为皮秒的全光学、宽带电子顺磁共振(EPR)光谱仪。这台超快EPR光谱仪将允许研究人员对化学体系和生化酶中三重态、自由基和自由基离子对的形成和衰变进行皮秒时间分辨吸收和回声光谱。该光谱仪将具有10皮秒的时间分辨率，比传统的EPR光谱仪快三个数量级。该仪器将需要建造一个高功率皮秒激光系统，通过光学参数产生产生光学频率，通过光学整流产生超短微波脉冲，其光传播，通过电光采样进行检测，并通过先进的信号处理对检测到的微波信号进行分析。其中每一项都体现了当前最先进的技术，因此对研究生和本科生来说都是一个教育机会。由于光化学和光生物学在研究和工业上的重要意义，这项技术将被广泛采用。

With support from the Major Research Instrumentation (MRI) and the Chemistry Research Instrumentation and Facilities (CRIF) Programs, W. Andreas Schroeder, Charles E. Brown and James W. Longworth of the University of Illinois in Chicago, and James R. Norris of the University of Chicago will develop an all-optical, broadband electron paramagnetic resonance (EPR) spectrometer with picosecond time resolution. This ultrafast EPR spectrometer will allow the investigators to perform picosecond time-resolved absorption and echo spectroscopy on the formation and decay of triplet states, radicals, and radical ion pairs in both chemical systems and biochemical enzymes. The spectrometer will have 10 picosecond temporal resolution, which is three orders of magnitude faster than conventional EPR spectrometers. This instrument will require the construction of a high-power picosecond laser system, the generation of optical frequencies by optical parametric generation, the generation of ultrashort microwave pulses by optical rectification, its optical propagation, detection by electro-optic sampling and analysis of the detected microwave signals by advanced signal processing. Each of these exemplifies the current state-of-the-art and thus represents an education opportunity for both graduate and undergraduate students. This technology will become widely adopted, due to the significance of photochemistry and photobiology in both research and industry.