Dr. Bahabad Alon

Affiliation:Faculty of Engineering
Electrical Engineering - Labs building
room 227
Tel:  (972)-3-6409423
Fax: (972)-3-6423508
Email: alonb@eng.tau.ac.il
Personal Website:

Postal Address:Faculty of Engineering
Tel Aviv University
Tel Aviv 69978

Research Interest

Nonlinear optics, extreme nonlinear optics, nanophotonics, quantum optics

We are interested in theoretical and experimental research in various areas of physical optics.
One of our major areas of research is the generation of coherent light sources at very high photon energies (soft X-rays). For this we employ the extreme nonlinear optical process of high-harmonic-generation (HHG). HHG is driven with an intense ultra-short light pulse which ionizes a gaseous medium. The liberated electron is then oscillating in the laser field, gaining kinetic energy. There is a small chance that the electron will encounter the ion from which it was liberated and would recombine with it. The excessive kinetic energy that was gained by the electron is released in the form of a high energy photon. During such a process hundreds of the photons of the laser field can be converted to a single high energy photon. We are interested in mediating this process by employing Plasmon-assisted field enhancement.  When the laser light interacts with a metallic nanostructure, electron oscillations on the metal surface can lead to a significant field enhancement. This can be utilized to assist with the process of HHG. In addition, the geometry of the metallic nanostructure can be used to control the beam shape and polarization state of the generated high harmonic radiation.  

Plasmon-assisted high-harmonic-generation. A femtosecond laser pulse interacts with a metallic nano-hole array. This interaction enhances significantly the field within the nano-holes allowing for the ionization of an atom (or a molecule) in a gas medium in the vicinity of the nano-hole array. The ionized electron oscillates in the enhanced femtosecond laser field, gaining kinetic energy. With some probability this electron can recombine with the parent ion, releasing excess energy in the form of a high-energy photon. The result is a coherent source of very short soft X-ray pulses. The geometry of the nano-hole array can be designed to modify the characteristic of the soft X-ray radiation.

Selected Publications

  • Alon Bahabad, Margaret M. Murnane and Henry C. Kapteyn, “Quasi Phase Matching of Momentum and Energy in Nonlinear Optical Processes”, Nature Photonics, 4, 570-575 (2010).
  • Tenio Popmintchev, Ming-Chang Chen, Alon Bahabad, Michael Gerrity, Pavel Sidorenko, Oren Cohen, Ivan P. Christov, Margaret M. Murnane and Henry C. Kapteyn, “Phase Matching of High Harmonic Generation Throughout the Soft and Hard X-Ray Regions of the Spectrum”, Proceedings of the National Academy of Science, 106, 10516-10521 (2009).
  • Alon Bahabad and Ady Arie, "Generation of Optical Vortex Beams by Nonlinear Wave Mixing", Optics Express, 15, 17619-17624 (2007).
  • Alon Bahabad, Noa Voloch, Ady Arie, Ariel Bruner and David Eger, "Unveiling Quasi-periodicity through Nonlinear Wave Mixing in Periodic Media", Physical Review Letters, 98, Issue 20, 205501 (2007).
  • Ron Lifshitz, Ady Arie and Alon Bahabad, “Photonic quasicrystals for general purposes nonlinear optical frequency conversion”, Physical Review Letters, 95, Issue 13, 133901 (2005).