Generation & application of circularly-polarized high-order harmonics and attosecond pulses
High harmonic generation (HHG) is an extreme nonlinear optical process where many visible or infrared photons are converted into a single high-energy photon in the extreme UV and x-ray spectral regions. Light sources based on HHG exhibit unique and very useful features, including pulses with attosecond to femtosecond duration, and broadly tunable bandwidths (femto and atto stand for 10-15 and 10 -18). Indeed, over the past several years scientists around the world learn to employ HHG for exploring new frontiers in optical, atomic, molecular and solids state physics.
Science’s cover highlighting our demonstration of bright circularly-polarized high-harmonics in its special issue for 2015 international year of light. When an atom is shined by a strong rosette-shape laser pulse (purple), which corresponds to superposition of red and blue circularly-polarized lasers with opposite helicity, an electron (green) is ripped from, and recollides with the parent ion from three directions. As a result, circularly-polarized high-order harmonics are emitted. This long-sought-for bright and chiral probe at the extreme UV allows unraveling the physics of ultrafast chirality.
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- O. Kfir, P. Grychtol, E. Turgut, R. Knut, D. Zusin, D. Popmintchev, T. Popmintchev, H. Nembach, J. M. Shaw, A. Fleischer, H. Kapteyn, M. Murnane, O. Cohen, Generation of bright phase-matched circularly-polarized extreme ultraviolet high harmonics, Nature Photonics 9, 99–105 (2015)
- A. Fleischer, P. Sidorenko, and O. Cohen, Generation of high-order harmonics with controllable elliptical polarization , Opt. Lett. 38, 223 (2013)
- A. Fleischer, O. Kfir, T. Diskin, P. Sidorenko, and O. Cohen, Bright high-order harmonics with controlled polarization, Optics and Photonics News, Special Issue: Optics in 2014
- C. A. Mancuso, D. D. Hickstein, P. Grychtol, R. Knut, O. Kfir, X.-M. Tong, F. Dollar, D. Zusin, M. Gopalakrishnan, C. Gentry, E. Turgut, J. L. Ellis, M.-C. Chen, A. Fleischer, O. Cohen, H. C. Kapteyn, and M. M. Murnane, Strong-field ionization with two-color circularly polarized laser fields, Phys. Rev. A 91, 031402(R) (2015)
- T. Fan, P. Grychtol, R. Knut, C. Hernández-García, D. D. Hickstein, D. Zusin, C. Gentry, F. J. Dollar, C. A. Mancuso, C. W. Hogle, O. Kfir, D. Legut, K. Carva, J. L. Ellis, K. M. Dorney, C. Chen, O. G. Shpyrko, E. E. Fullerton, O. Cohen, P. M. Oppeneer, D. B. Milošević, A. Becker, A. A. Jaroń-Becker, T. Popmintchev, M. M. Murnane, and H. C. Kapteyn, Bright circularly polarized soft x-ray high harmonics for x-ray magnetic circular dichroism, Proceedings of the National Academy of Sciences of the United States of America 112, 14206 (2015)
- C. Chen, Z. Tao, C. Hernandez-Garcia, P. Matyba, A. Carr, R. Knut, O. Kfir, D. Zusin, C. Gentry, P. Grychtol, O. Cohen, L. Plaja, A. Becker, A. Jaron-Becker, H. Kapteyn and M. Murnane, Tomographic reconstruction of circularly polarized high-harmonic fields: 3D attosecond metrology, Science Advances, 2, e1501333 (2016).
- O. Kfir, P. Grychtol, E. Turgut, R. Knut, D. Zusin, A. Fleischer, E. Bordo, T. Fan, D. Popmintchev, T. Popmintchev, H. Kapteyn, M. Murnane and O. Cohen, Helicity-selective phase-matching and quasi-phase matching of circularly polarized high-order harmonics: towards chiral attosecond pulses, J. Phys. B, 49, 123501 (2016). Invited article.
- O. Kfir, E. Bordo, G. Ilan Haham, O. Lahav, A. Fleischer and O. Cohen, In-line production of a bi-circular field for generation of helically polarized high-order harmonics, Appl. Phys. Lett., 108, 211106 (2016).
- A. Fleischer, O. Kfir, P. Sidorenko, and O. Cohen, High-order harmonics with frequency-varying polarization within each harmonic, J. Phys. B., 50, 034001 (2017)
- O. Neufeld, A. Fleischer and O. Cohen, High harmonic generation with fully tunable polarization by train of linearly-polarized pulses, New Journal of Physics, 19, 023051 (2017)
- G. Lerner, T. Diskin, O. Neufeld, O. Kfir and O. Cohen, Selective suppression of high-order harmonics within phase matched spectral regions, Opt. Lett. 42, 1349 (2017)
- O. Neufeld, E. Bordo, A. Fleischer and O. Cohen, High Harmonics with Controllable Polarization by a Burst of Linearly-Polarized Driver Pulses, Photonics, 4, 31 (2017)
- O. Kfir, S. Zayko, C. Nolte, M. Sivis , M. Möller , B. Hebler , SSPK. Arekapudi, D. Steil , S. Schäfer , M. Albrecht , O. Cohen, S. Mathias , and C. Ropers, Nanoscale Magnetic Imaging using Circularly Polarized High-Harmonic Radiation, Science Advances 3, eaao4641 (2017)
- D. Azoury, O. Kneller, M. Kruger, B. Bruner, O. Cohen, Y. Mairesse and N. Dudovich, Interferometric attosecond lock-in measurement of extreme ultraviolet circular dichroism, Nat. Photonics, 13, 198 (2019) Article was highlighted in Physics Today – Circular polarization made to order in the extreme UV
- E. Bordo, O. Neufeld, O. Kfir, A. Fleischer and O. Cohen, Spectroscopy of atomic orbital sizes using bi-elliptical high-order harmonic generation, Phys. Rev. A 100, 043419 (2019)
- Zayko, O. Kfir, E. Bordo, A. Fleischer, O. Cohen and C. Ropers, A Dynamical symmetry triad in high-harmonic generation revealed by attosecond recollision control, New J. of Phys., 22, 053017 (2020)
- E. Bordo, O. Kfir, S. Zayko, O. Neufeld, A. Fleischer, C. Ropers and O. Cohen, Interlocked attosecond pulse trains in slightly bi-elliptical high harmonic generation, Journal of Physics: Photonics, 2 034005 (2020)
- L. Hareli, G. Lerner, O. Cohen and A. Bahabad, Circularly polarized high harmonic generation through virtual circular birefringence, App. Phys. Lett. 118, 221106 (2021)