Laser precision metrology for probing variation of fundamental constants

Ubachs, W.M.G. [Promotor]Eikema, K.S.E. [Copromotor

Accurate level energies in the EF1S+g, GK1S+g, H1S+g, B1S+u, C1Pu, B'1S+u, D1Pu, I1Pg, J1Dg states of H2

International audienceBy combining results from a Doppler-free two-photon laser excitation study on several lines in the EF1g+ - X1g+ (0,0) band of H2 with results from a Fourier-transform spectroscopic study on a low-pressure discharge in hydrogen, absolute level energies, with respect to the X1g+, v=0, N=0 ground level, could be determined for 547 rovibronically excited states in H2. While for some of the levels in the EF1g+ and B1u+ states the uncertainties are as low as 0.0001 cm-1, the accuracy of other levels is less accurate. The general improvement on the accuracy for the comprehensive data set of level energies is by an order of magnitude with respect to previous measurements. An updated listing of transition wavelengths of the spectral lines in the Lyman and Werner bands is presented, based on combination differences between the presently obtained B1u+ and C1u level energies and those in the X1g+ ground state

Constraints on extra dimensions from precision molecular spectroscopy

9 págs.; 2 figs.; 2 tabs.; Open Access funded by Creative Commons Atribution Licence 3.0Accurate investigations of quantum-level energies in molecular systems are shown to provide a testing ground to constrain the size of compactified extra dimensions. This is made possible by recent progress in precision metrology with ultrastable lasers on energy levels in neutral molecular hydrogen (H2, HD, and D2) and molecular hydrogen ions (H2+, HD+, and D2+). Comparisons between experiment and quantum electrodynamics calculations for these molecular systems can be interpreted in terms of probing large extra dimensions, under which conditions gravity will become much stronger. Molecules are a probe of spacetime geometry at typical distances where chemical bonds are effective (i.e., at length scales of an Å). Constraints on compactification radii for extra dimensions are derived within the Arkani-Hamed-Dimopoulos-Dvali framework, while constraints for curvature or brane separation are derived within the Randall-Sundrum framework. Based on the molecular spectroscopy of D2 molecules and HD+ ions, the compactification size for seven extra dimensions (in connection to M-theory defined in 11 dimensions) of equal size is shown to be limited to R7 < 0.6 mμ . While limits on compactification sizes of extra dimensions based on other branches of physics are compared, the prospect of further tightening constraints from the molecular method is discussed. © 2015 IOP Publishing Ltd and Deutsche Physikalische GesellschaftThis work was supported by the Netherlands Foundation for Fundamental Research of Matter (FOM) through the program ‘Broken Mirrors & Drifting Constants’. B Gato-Rivera and A N Schellekens have been partially supported by funding from the Spanish Ministerio de Economia y Competitividad, Research Project FIS2012- 38816, and by the Project CONSOLIDER-INGENIO 2010, Programme CPAN (CSD2007-00042).Peer Reviewe

Frequency comb generation by CW laser injection into a quantum-dot mode-locked laser

100 GHz) RF generation and telecommunication applications. (C) 2012 Optical Society of Americ

Bounds on the number and size of extra dimensions from molecular spectroscopy

Presentación de 30 diapositivas; 70th International Symposium on Molecular Spectroscopy (ISMS), University of Illinois at Urbana−Champaign, June 22 to 26, 2015Peer Reviewe

High precision frequency measurement of the 423 nm Ca I line

We have performed an accurate frequency calibration of the 4s2 1

Improved Laboratory Values of the H-2 Lyman and Werner Lines for Constraining Time Variation of the Proton-to-Electron Mass Ratio

Two distinct high-accuracy laboratory spectroscopic investigations of the H-2 molecule are reported. Anchor lines in the EF1 Sigma(+)(g)-X-1 Sigma(+)(g) system are calibrated by two-photon deep-UV Doppler-free spectroscopy, while independent Fourier-transform spectroscopic measurements are performed that yield accurate spacings in the B-1 Sigma(+)(u)-EF1 Sigma(+)(g) and I-1 Pi(g)-C-1 Pi(u) systems. From combination differences accurate transition wavelengths for the B-X Lyman and the C-X Werner lines can be determined with accuracies better than similar to 5x10(-9), representing a major improvement over existing values. This metrology provides a practically exact database to extract a possible variation of the proton-to-electron mass ratio based on H-2 lines in high-redshift objects. Moreover, it forms a rationale for equipping a future class of telescopes, carrying 30-40 m dishes, with novel spectrometers of higher resolving powers