Albane Douillet

Frequency doubling of CO 2 laser radiation at 10.6 μm in the highly nonlinear chalcopyrite LiGaTe 2

Type-I phase matching for second-harmonic generation at 10.6 microm in LiGaTe(2) is demonstrated by using a tunable single-frequency continuous-wave CO(2) laser, and the nonlinear coefficient of LiGaTe(2) is determined from comparison with AgGaSe(2). The effective nonlinearity of LiGaTe(2) for this process amounts to 34.5 pm/V.

Two-photon spectroscopy of trapped HD+ ions in the Lamb-Dicke regime

We study the feasibility of nearly-degenerate two-photon rovibrational spectroscopy in ensembles of trapped, sympathetically cooled hydrogen molecular ions using a resonance-enhanced multiphoton dissociation (REMPD) scheme. Taking advantage of quasi-coincidences in the rovibrational spectrum, the excitation lasers are tuned close to an intermediate level to resonantly enhance two-photon absorption. Realistic simulations of the REMPD signal are obtained using a four-level model that takes into account saturation effects, ion trajectories, laser frequency noise and redistribution of population by blackbody radiation. We show that the use of counterpropagating laser beams enables optical excitation in an effective Lamb-Dicke regime. Sub-Doppler lines having widths in the 100 Hz range can be observed with good signal-to-noise ratio for an optimal choice of laser detunings. Our results indicate the feasibility of molecular spectroscopy at the

Preparing single ultra-cold antihydrogen atoms for free-fall in GBAR

10^{-14}

Hydrogen molecular ions: new schemes for metrology and fundamental physics tests

accuracy level for improved tests of molecular QED, a new determination of the proton-to-electron mass ratio, and studies of the time (in)dependence of the latter.

Note: A high transmission Faraday optical isolator in the 9.2 μm range

We discuss an experimental approach allowing to prepare antihydrogen atoms for the GBAR experiment. We study the feasibility of all necessary experimental steps: The capture of incoming

\(\bar{\text{H}}^{+}\) Sympathetic Cooling Simulations with a Variable Time Step

\bar{\rm H}^+

Towards a test of the weak equivalence principle of gravity using anti-hydrogen at CERN

ions at keV energies in a deep linear RF trap, sympathetic cooling by laser cooled Be

SHG of CO 2 laser radiation at 10.6 μm in the highly nonlinear chalcopyrite LiGaTe 2

^+

A phase-locked frequency divide-by-three optical parametric oscillator based on periodically poled lithium niobate

ions, transfer to a miniaturized trap and Raman sideband cooling of an ion pair to the motional ground state, and further reducing the momentum of the wavepacket by adiabatic opening of the trap. For each step, we point out the experimental challenges and discuss the efficiency and characteristic times, showing that capture and cooling are possible within a few seconds.

The GBAR antimatter gravity experiment

High-accuracy spectroscopy of hydrogen molecular ions has important applications for the metrology of fundamental constants and tests of fundamental theories. Up to now, the experimental resolution has not surpassed the part-per-billion range. We discuss two methods by which it could be improved by a huge factor. Firstly, the feasibility of Doppler-free quasidegenerate two-photon spectroscopy of trapped and sympathetically cooled ensembles of HD+ ions is discussed, and it is shown that rovibrational transitions may be detected with a good signal-to-noise ratio. Secondly, the performance of a molecular quantum-logic ion clock based on a single Be+-H2 + ion pair is analyzed in detail. Such a clock could allow testing the constancy of the proton-to-electron mass ratio at the 10-17/yr level.