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Prof. dr. K.S.E. Eikema

Director LaserLaB Amsterdam

Group leader of Ultrafast Laser Physics and Precision Metrology For Fundamental Tests

Part-time group leader (15%) of the EUV Generation and Imaging group at ARCNL


Vrije Universiteit
LaserLaB, Faculty of Sciences (FEW)
Atomic, Molecular, and Laser Physics Group
De Boelelaan 1081
1081 HV Amsterdam
The Netherlands

Room: T255
Tel. (31) 20-598 7957 (office) / 5987438 (lab)
Fax (31) 20-598 7992
e-mail: k.s.e.eikema@vu.nl

My group is part of the: Quantum Metrology and Laser Applications Group
(formerly known as "Atoms, Molecules and Lasers")


Research interests:

Precision tests of fundamental physics focusing on QED tests, and determination of fundamental constants and nuclear size effects (e.g. the Proton Radius Puzzle), using atoms like helium and helium+ ions and H2 molecules. Other interests: testing the stability of fundamental constants (such as alpha using e.g. quasar data), development of frequency comb lasers, high-power (TW-class) ultrafast lasers and ultrafast phenomena, coherent X-ray generation, ion-trapping, laser-produced plasmas, and lensless imaging with light ranging from infrared to soft-X-ray wavelengths.

Have a look at the home page of my group: Ultrafast Laser Physics and Precision Metrology For Fundamental Tests,
and at this link: EUV Generation and Imaging Group at ARCNL, where I work for 15% of my time.


Currently I teach Classical Mechanics in period 1 (September-October) of the first year of the combined UvA-VU Physics curriculum, and Ultrafast Laser Physics in period 4 (February-March) the AMEP track of the Physics Master. I also organize the 'Showcase' lectures for AMEP Master students advertising the research at the VU and the possibilities for doing Master projects.

Faculty activities

I am director of the LaserLaB Amsterdam, and as a result also part of a team preparing the move of the Physics department to the new SWT building (mid 2023 or later) and I help organize the annual LaserLaB Symposium (in December). I am also a member of a working group promoting the "Profielthema's" (focus areas) of our university. Apart from these activities I take part in committees for appointing and evaluating staff members.

A short CV

2018 - now: Director LaserLaB Amsterdam
2014 - now: Group leader (initially for 30%, now 15% fte) at ARCNL of the EUV Generation and Imaging Group (together with Dr. S. Witte).
2013 - now: Full professor at the VU University
2010 - 2015: Professor by special appointment (bijzonder hoogleraar) at the Rijksuniversiteit Groningen - KVI.
2008-2010: Associate professor ('Universitair hoofddocent') at the VU
2003-2008: Assistant professor ('Universitair docent') at the VU
2000/2001-2003: Project leader of a Vernieuwingsimpuls project (VIDI), grant for 5 years
1996-2000: Post-doctoral fellow at the Max-Planck-Institute fuer Quantenoptik, in the group of prof. T.W. Haensch
1991-1996: PhD (cum laude) at the Vrije Universiteit, group of prof. Wim Hogervorst,
Thesis title: QED and the ground state of helium, precision extreme ultraviolet spectroscopy.
1988-1991: Physics at the Vrije Universiteit, Amsterdam
1984-1988: Technical Physics at the 'HTS Rijswijk'


Fresnel Prize 2003 (for fundamental aspects) from the European Physical Society

Personal Grants

In March 2016, I received a European Research Council (ERC) Advanced Grant of 2.5 MEuro to investigate QED and the 'proton radius puzzle' by precision spectroscopy on the 1S-2S transition in trapped helium+ ions. You can find a short description at the group research page, and at the section about open PhD and Postdoc positions. ERC logo
Other personal grants:
2013 Projectruimte grant from FOM "Testing the boundaries of QED with He+"
2007 'Vici' grant from NWO
2001 FOM projectruimts FSTO grant
2001 'Vidi' grant from NWO

Other grants obtained in collaborations (incomplete list):

2016: FOM/NWO Program "The mysterious size of the Proton" of 1.8 MEuro
Program leader K.S.E. Eikema, in collaboration with W. Ubachs, J.C.J. Koelemeij and H.L. Bethlem
2013/2014 Member of the Science Team that wrote the winning proposal for the Advanced Research Center for Nanolithography (ARCNL), that started in 2014 in Amsterdam.
2010 FOM Programme (VU & KVI): "Broken Mirrors and Drifting Constants"
2008 NWO-Groot for an X-ray imaging facility
2006 FOM Metrology

Selected high-profile publications

Full list of publications

S. Patra, M. Germann, J.-Ph. Karr, M. Haidar, L. Hilico, V.I. Korobov, F.M.J. Cozijn, K.S.E. Eikema, W. Ubachs, J.C.J. Koelemeij
Proton-electron mass ratio from laser spectroscopy of HD+ at the part-per-trillion level
Science 10.1126/science.aba0453 (2020)

M. Beyer, N. Hoelsch, J. Hussels, C.-F. Cheng, E.J. Salumbides, K.S.E. Eikema, W. Ubachs, Ch. Jungen, and F. Merkt
Determination of the interval between the ground states of para- and ortho-H2
Phys. Rev. Lett.
123, 163002 (2019)
L.S. Dreissen, C. Roth, E.L. Gruendeman, J.J. Krauth, M. Favier and K.S.E. Eikema
High-precision Ramsey-Comb Spectroscopy Based on High-Harmonic Generation
Phys. Rev. Lett. 123, 143001 (2019)

N. Holsch, M. Beyer, E.J. Salumbides, K.S.E. Eikema, W. Ubachs, C. Jungen, F. Merkt

Benchmarking Theory with an Improved Measurement of the Ionization and Dissociation Energies of H2
Phys. Rev. Lett. 122, 103002 (2019)

R.J. Rengelink, Y. van der Werf, R.P.M.J.W. Notermans, R. Jannin, K.S.E. Eikema, M.D. Hoogerland, W. Vassen,
Precision spectroscopy of helium in a magnetic wavelength optical dipole trap
Nature Physics 14, 1132 (2018)

C-F Cheng, J. Hussels, M. Niu, H.L. Bethlem, K.S.E. Eikema, E.J. Salumbides, W. Ubachs, M. Beyer, N. Holsch, J.A. Agner, F. Merkt, T.G. Tao, S.M. Hu, C. Jungen,
Dissociation Energy of the Hydrogen Molecule at 10(-9) Accuracy
Phys. Rev. Lett. 121, 013001 (2018)

F.M.J. Cozijn, P. Dupre, E.J. Salumbides, K.S.E. Eikema, W. Ubachs,
Sub-Doppler Frequency Metrology in HD for Tests of Fundamental Physics
Phys. Rev. Lett. 120, 153002 (2018)

R.K. Altman, L.S. Dreissen, E.J. Salumbides, W. Ubachs and K.S.E. Eikema,
Deep-Ultraviolet Frequency Metrology of H2 for Tests of Molecular quantum Theory
Phys. Rev. Lett. 120, 043204 (2018)

R.K. Altmann, S. Galtier, L.S. Dreissen, and K.S.E. Eikema,
High-Precision Ramsey-Comb spectroscopy at Deep-Ultraviolet Wavelengths
Phys. Rev. Lett. 117, 173201 (2016)

J. Biesheuvel, J-P Karr, L. Hilico, K.S.E. Eikema, W. Ubachs, J.C.J. Koelemeij,
Probing QED and fundamental constants through laser spectroscopy of vibrational transitions in HD
Nat. Comm. 7, 10385 (2016)

K.S.E. Eikema,
News and Views: Twisted high-harmonic generation
Nat. Photon. 9, 710-712 (2015)

Front page of
                      Light:Science and applications
S.M. Witte, V.T. Tenner, D.W.E. Noom, K.S.E. Eikema
Lensless diffractive imaging with ultra-broadband table-top sources: from infrared to extreme ultraviolet wavelengths
Light: Science and Applications 3, 1-7 (2014)    (open access)

Nature Physics January
                      2014 cover
J. Morgenweg, I. Barmes and K.S.E. Eikema,
Ramsey-comb spectroscopy with intense ultrashort laser pulses
Nature Physics 10, 30-33 (2014)

Also see the News and Views by Scott A. Diddams on page 8-9 of the same issue:

I. Barmes, S. Witte, K.S.E. Eikema
High-precision spectroscopy with counterpropagating femtosecond pulses
Physical Review Letters 111, 023007 (2013)

I. Barmes, S. Witte, K.S.E. Eikema,
Spatial and spectral coherent control with frequency combs
Nature Photonics 7, 38-42 (2013)

Also see the News and Views article by A. M. Weiner on page 6-8 of the same issue:

G.D. Dickenson, M.L. Niu, E.J. Salumbides, J. Komasa, K.S.E. Eikema, K. Pachucki, W. Ubachs
Fundamental Vibration of Molecular Hydrogen
Phys. Rev. Lett. 110, 193601 (2013)

R. van Rooij, J.S. Borbely, J. Simonet, M.D. Hogerland, K.S.E. Eikema, R.A. Rozendaal, W. Vassen,
Frequency metrology in quantum degenerate helium: direct measurement of the 2 3S1 - 2 1S0 transition
Science 333, 196-198 (2011)

K.S.E. Eikema,
Frequency Combs liberated from material dispersion
Nature Photonics 5, 258-260 (2011)   (News and Views)

D.Z. Kandula, C. Gohle, T.J. Pinkert, W. Ubachs, K.S.E. Eikema,
Extreme Ultraviolet Frequency Comb Metrology,
Physical Review Letters 105, 063001 (2010),

Highlighted in the issue of Phys. Rev. Lett. itself,
and in Physics Synopsys: http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.105.063001,
and Research Highlights: Nature 466, 798 (2010).

A.L. Wolf, S.A. van den Berg, W. Ubachs, K.S.E. Eikema,
Direct Frequency Comb Spectroscopy of Trapped Ions
Physical Review Letters 102, 223901 (2009)

E.J. Salumbides, D. Bailly, A. Khramov, A.L. Wolf, K.S.E. Eikema, M. Vervloet, W. Ubachs,
Improved laboratory values of the H2 Lyman and Werner lines for constraining time variation of the proton-to-electron mass ratio
Physical Review Letters 101, 223001 (2008)

Deep ultraviolet quantum-interference metrology with ultrashort laser pulses
S. Witte, R.Th. Zinkstok, W. Ubachs, W. Hogervorst, K.S.E. Eikema
Science 307, 400-403 (2005)

Continuous coherent Lyman-alpha excitation of atomic hydrogen
K.S.E. Eikema, J. W. Walz, T.W. Haensch
Physical Review Letters 86, 5679-5682 (2001)

Continuous wave coherent Lyman-alpha radiation
K.S.E. Eikema, J. W. Walz, T.W. Haensch
Physical Review Letters 83, 3828-3831 (1999)

Precision measurements in helium at 58 nm: Ground state Lmb shift and the 1 S-1 2 P-1 transition isotope shift
K.S.E. Eikema, W. Ubachs, W. Vassen, W. Hogervorst
Physical Review Letters 76, 1216-1219 (1996)

1st laser excitation of the He-4 1(1)S-2(1)P resonance line at 58 nm
K.S.E. Eikema, W. Ubachs, W. Vassen, W. Hogervorst
Physical Review Letters 71, 1690-1692 (1993)