Light storage protocols in Tm:YAG

We present two quantum memory protocols for solids: A stopped light approach based on spectral hole burning and the storage in an atomic frequency comb. These procedures are well adapted to the rare-earth ion doped crystals. We carefully clarify the critical steps of both. On one side, we show that the slowing-down due to hole-burning is sufficient to produce a complete mapping of field into the atomic system. On the other side, we explain the storage and retrieval mechanism of the Atomic Frequency Comb protocol. This two important stages are implemented experimentally in Tm$^{3+}$- doped yttrium-aluminum-garnet crystal

Spectral phase encoding for data storage and addressing

We propose to use a broad-bandwidth laser source for storing and retrieving multiple holograms in a photorefractive material. Each storage address is defined by a specific spectral encoding of the reference beam. The validity of the spectral encoding method is tested in a preliminary experiment

Experimental investigation of deterministic and stochastic frequency noises of a rapidly frequency chirped laser

The different types of errors affecting the spectral purity of a rapidly chirped continuous wave laser are experimentally studied using an unbalanced interferometer. The response of the interferometer to the deterministic (periodic and aperiodic) and stochastic quantum and technical laser frequency noises is theoretically analysed and experimentally investigated with an external cavity diode laser operating at 793 nm and providing chirps in excess of 10 GHz on the ms timescale. The system is shown to be able to measure the laser frequency to better than 1 MHz during the chirp. It provides an error signal that can be used to servo-control the laser frequency in real time while it is chirped

Analyseur de spectre RF présentant une bande passante de 10 GHz ainsi qu'une résolution sub-MHz basé sur le creusement spectral dans des cristaux Tm3+^{3+}:YAG

Nos travaux s'inscrivent dans le cadre des expériences de traitement optique des signaux hyperfréquence utilisant des ions de terres rares en matrice cristalline excités par des sources lasers agiles en fréquence. Nous présentons la réalisation d'un analyseur de spectre avec une bande passante de 10 GHz et une résolution ultime en dessous du MHz

Coherent driving of Tm

We investigate the coherent driving of atomic systems by Complex Hyperbolic Secant (CHS) pulses in optical domain. First, with the help of a Rapid Adiabatic Passage approach we get physical insight into the process. We discuss the limiting factors on spectral selectivity and transfer efficiency, such as finite coherence lifetime and excitation finite duration. Then, with a highly-stabilized cw laser and fast electronic equipment, we experimentally explore the CHS process at $\mu$s-timescale in a Tm3+:YAG crystal. We demonstrate efficient adiabatic transfer over a few hundreds of kHz-wide spectral interval within the inhomogeneous linewidth. We calculate and detect the Free Induction Decay signal as the signature of the atomic coherences during the process

Direct observation of rare-earth-host interactions inEr:Y2SiO5

International audienceWe report the direct observation of Er-Y and Er-Si interactions in Er:Y2SiO5 by spin-echo measurements. Modulations in the spin-echo decay of Er3+ ions are due to magnetic interactions between the rare earth and the host nuclear spins. The closest yttrium ions were found to be out of resonance compared to the yttrium ions farther away from the rare earth. This strong “frozen core” effect around the Er3+ ions suggests that the influence of Y3+ ions on the decoherence processes of erbium is weaker than what can be deduced from the yttrium in the bulk

Hyperfine structure of Tm3+ in YAG for quantum storage applications

International audienceQuantum storage of photons in an atomic ensemble can be obtained by using three-level K systems. In these schemes, two levels are coupled by optical transitions to a third one. Ideally, the two transitions should have similar intensities and long coherence lifetimes. Rare earth ion doped crystals are attractive materials for quantum storage because their hyperfine levels can have coherence lifetimes longer than 100 ls and thus can be used to build K systems. Tm3+ ions are especially interesting since they can be excited by ultra-stable laser diodes. In this paper, the hyperfine structures of the 3H6(0) and 3H4(0) crystal field levels of Tm3+ in Y3Al5O12 are investigated by hole burning spectroscopy under a magnetic field. The results are compared to theoretical calculations and found to be in reasonable agreement. Moreover, it is shown that an appropriate magnetic field is able to relax the selection rule on the nuclear spin projection, an absolutely necessary condition to obtain an efficient three-level K system with Tm3+ in this host. Finally, a magnetic field orientation optimized with respect to the K system transition intensity ratio is predicted for a convenient experimental set-up