Femtosecond measurements of electric fields: from classical amplitudes to quantum fluctuations. (9th January 2017)

• Record Type: Journal Article
• Authors: Riek, Claudius; Seletskiy, Denis V; Leitenstorfer, Alfred
• Is Part Of: European journal of physics. Volume 38:Number 2(2017:Mar.)
• Publication Date: 2017-01-09
• Subjects: time-domain spectroscopy -- electromagnetic fields -- quantum optics; Physics -- Periodicals; Physics -- Study and teaching (Higher) -- Europe -- Periodicals; 530
• DOI: 10.1088/1361-6404/aa53a2
• Languages: English
• ISSNs: 0143-0807

Abstract

Abstract: Ultrabroadband electro-optic sampling is presented as an extremely sensitive technique to detect electric field amplitudes in free space. The temporal resolution provided by few-femtosecond laser pulses results in a bandwidth exceeding 100 THz, potentially covering the entire infrared spectral range. A pedagogic introduction to the operational principle of the method is given along the lines of a classical coherent input field and a zincblende-type electro-optic sensor. We then show that even the bare vacuum fluctuations of the electric field in the quantum ground state may be detected. This time-domain approach to quantum physics operates directly on sub-cycle scales where no local energy conservation holds. Therefore, signals may be obtained from purely virtual photons without amplification to finite intensity.