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EE Devices Seminar - Mohammed Hassan, University of Arizona

Friday, October 14, 2022
3:00pm to 4:00pm
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Chen 100
Imaging and controlling the quantum electron motion in action
Mohammed Hassan, Assistant Professor of Physics and Optical Sciences, Physics Department and James C. Wyant College of Optical Sciences, Bio5 Institute/University of Arizona,
*Refreshments at 2:45pm*

I will present our demonstration of establishing a petahertz optical oscilloscope for light field sampling of ultrafast laser pulses spanning two optical octaves, from near-infrared (NIR) to deep-ultraviolet (DUV), with attosecond resolution (1, 2). Moreover, I will show our developed light field synthesizer device, which we used for the on-demand tailoring of light field waveforms (2). We utilized complex synthesized waveforms to demonstrate the quantum electron motion control in dielectric systems (1). This fine control allowed for switching the optical signal (ON/OFF) with sub-femtosecond time resolution (3). Furthermore, we demonstrated the encoding of binary data on ultrashort light waveforms. This technology can be implemented on a chip to establish optical switches and light-based electronics with petahertz speeds, several orders of magnitude faster than the current semiconductor-based electronics, opening a new realm in information technology, optical communications, and photonic processors technologies.

Moreover, we were able to attain the native electron motion (attosecond) temporal resolution in the transmission electron microscope—orders of magnitude faster than the highest reported imaging resolution—by generating a single-isolated attosecond electron pulse inside the microscope and establishing what we so-called "Attomicroscopy" (4-6). We utilized the Attomicroscopy to obtain a movie of the electron motion in solid-state. The attosecond electron imaging provides more insights into the electron dynamics in real time and space with attosecond and picometer resolutions. Attomimcroscopy opens a window for humankind to see the quantum world in real systems and promises to find long anticipated real-life attosecond science applications in quantum physics, chemistry, and biology.


  1. D. Hui et al., Attosecond electron motion control in dielectric. Nat. Photonics, (2021).
  2. H. Alqattan, D. Hui, V. Pervak, M. T. Hassan, Attosecond light field synthesis. APL Photonics 7, 041301 (2022).
  3. H. Dandan, A. Husain, H. Mohammed, Attosecond Optical Switch. Nature Portfolio In Review, (2021).
  4. M. T. Hassan, J. S. Baskin, LiaoB, A. H. Zewail, High-temporal-resolution electron microscopy for imaging ultrafast electron dynamics. Nat. Photonics 11, 425-430 (2017).
  5. M. T. Hassan, Attomicroscopy: from femtosecond to attosecond electron microscopy. J Phys. B At. Mol. Opt. Phys. 51, 032005 (2018).
  6. D. Hui, H. Alqattan, M. Sennary, N. Golubev, M.T. Hassan, Attomicroscopy imaging of quantum electron motion in real time and space. (in preparation), (2022).

EE Devices is a new seminar series sponsored by the Caltech Dept. of Electrical Engineering. Please use this form to suggest speakers for the EE Devices Seminars in the Fall 2023:

For more information, please contact Caroline Murphy by phone at 626-395-2084 or by email at [email protected].