Chapter 4
Light-Dressed Spectroscopy of Molecules
Tamás Szidarovszky, Gábor J. Halász, Attila G. Császár, and Ágnes Vibók
Abstract We present a theoretical approach for simulating rovibronic spectra of
molecules dressed by medium-intensity laser fields. Numerical results, obtained
through the formalism described, are presented for the homonuclear diatomic
molecule Na 2 , a system suitable for demonstrating and understanding various aspects
of light-dressed spectroscopy. We discuss the physical origin of the peaks in the lightdressed spectrum of Na 2 and investigate the light-dressed spectrum in terms of its
dependence on the dressing field’s intensity and wavelength, temperature, and the
turn-on time of the dressing field. The possibility of using light-dressed spectroscopy
to derive field-free spectroscopic quantities is also addressed.
4.1 Introduction
Despite the long history of spectroscopy, spanning two centuries, new approaches
and methods are being developed in it to this day [1]. This is principally due to the
great success of atomic and molecular spectroscopy, both in fundamental research
T. Szidarovszky (B) · A. G. Császár
Institute of Chemistry, Eötvös Loránd University and MTA-ELTE Complex Chemical Systems
Research Group, Pázmány Péter sétány 1/A, Budapest 1117, Hungary
e-mail: tamas821@caesar.elte.hu
A. G. Császár
e-mail: csaszarag@caesar.elte.hu
G. J. Halász
Department of Information Technology, University of Debrecen, PO Box 400,
Debrecen 4002, Hungary
e-mail: halasz.gabor@inf.unideb.hu
Á. Vibók
Department of Theoretical Physics, University of Debrecen, PO Box 400,
Debrecen 4002, Hungary
e-mail: vibok@phys.unideb.hu
ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3, Szeged
H-6728, Hungary
© Springer Nature Switzerland AG 2020
K. Yamanouchi and D. Charalambidis (eds.), Progress in Ultrafast
Intense Laser Science XV, Topics in Applied Physics 136,
https://doi.org/10.1007/978-3-030-47098-2_4
77
Light-Dressed Spectroscopy of Molecules
Tamás Szidarovszky, Gábor J. Halász, Attila G. Császár, and Ágnes Vibók
Abstract We present a theoretical approach for simulating rovibronic spectra of
molecules dressed by medium-intensity laser fields. Numerical results, obtained
through the formalism described, are presented for the homonuclear diatomic
molecule Na 2 , a system suitable for demonstrating and understanding various aspects
of light-dressed spectroscopy. We discuss the physical origin of the peaks in the lightdressed spectrum of Na 2 and investigate the light-dressed spectrum in terms of its
dependence on the dressing field’s intensity and wavelength, temperature, and the
turn-on time of the dressing field. The possibility of using light-dressed spectroscopy
to derive field-free spectroscopic quantities is also addressed.
4.1 Introduction
Despite the long history of spectroscopy, spanning two centuries, new approaches
and methods are being developed in it to this day [1]. This is principally due to the
great success of atomic and molecular spectroscopy, both in fundamental research
T. Szidarovszky (B) · A. G. Császár
Institute of Chemistry, Eötvös Loránd University and MTA-ELTE Complex Chemical Systems
Research Group, Pázmány Péter sétány 1/A, Budapest 1117, Hungary
e-mail: tamas821@caesar.elte.hu
A. G. Császár
e-mail: csaszarag@caesar.elte.hu
G. J. Halász
Department of Information Technology, University of Debrecen, PO Box 400,
Debrecen 4002, Hungary
e-mail: halasz.gabor@inf.unideb.hu
Á. Vibók
Department of Theoretical Physics, University of Debrecen, PO Box 400,
Debrecen 4002, Hungary
e-mail: vibok@phys.unideb.hu
ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3, Szeged
H-6728, Hungary
© Springer Nature Switzerland AG 2020
K. Yamanouchi and D. Charalambidis (eds.), Progress in Ultrafast
Intense Laser Science XV, Topics in Applied Physics 136,
https://doi.org/10.1007/978-3-030-47098-2_4
77