Linear and non-linear spectroscopy of Ho³⁺-doped YVO₄and LuVO₄

Abstract

Rare-earth-doped crystals can be attractive materials for quantum information processing, because of the long coherence times that can be expected, in particular, from non-Kramers ions. In this paper, Ho3+-doped yttrium and lutetium vanadate single crystals have been investigated using linear and coherent optical spectroscopy. For Ho3+:YVO4, the crystal-field levels of the 5I8, 5F5, 5F4 and 5S2 multiplets have been determined and compared with crystal-field level calculations. This allowed us to unambiguously assign most of the observed transitions, although some results suggest that the site symmetry of the Ho3+ ion could deviate from D2d. Similar conclusions were reached for Ho3+:LuVO4. Hole burning measurements indicate that the coherence time of the 5I8–5F5 optical transitions is rather short in both compounds (around 40 ns). Assuming that the coherence is limited by spin interactions, this is accounted for by the high nuclear moment of the nearby vanadium ions, since the large crystal-field level splittings of the 5I8 and 5F5 multiplets do not favour a large enhanced nuclear Zeeman effect.

Rare Earth Doped Crystals for Quantum Information: Quantum Computing and Quantum Storage

“…According to the literature, it is YVO 4 in this case, although some discrepancies are found in the CF level energies. To solve these disagreements, we performed a detailed spectroscopic and CF analysis of 1 at.% Ho 3+ :YVO 4 and Ho 3+ :LuVO 4 samples [21]. We were able to conclude that in both crystals, the separations between the two lowest CF levels of the 5 I 8 and 5 F 5 multiplets are higher than 12 cm -1 .…”

“…The coherence lifetime of the 5 I 8 (0) -5 F 5 (0) transition has been measured by holeburning spectroscopy [21]. In Ho 3+ :YVO 4 , the homogeneous linewidth is found to be Γ h =6.5 MHz, corresponding to T 2 =1/πΓ h =49 ns.…”

Photoluminescence of Ho3+:YVO4 crystals

“…A special attention was paid in the case of Ho 3+ :YVO 4 crystals to the very long lifetime fluorescence of the 2017 nm emission, which is around 3 ms [5], so that this material can be used as a very efficient and high-energy laser device like in the case of Ho 3+ :YAG crystals [6]. A very interesting application of Ho 3+ :YVO 4 could be in the field of quantum information processing due to the relatively long coherence time of some optical transitions [7].Although a considerable amount of study has been made for Ho 3+ :YVO 4 crystals, several aspects of the optical spectroscopy are still to be investigated, especially concerning the near-infrared emission, and the properties of the defects present in the crystals grown using high temperature techniques. For these reasons, we found it interesting to expand the previous spectroscopic investigations of this important luminescent crystal.…”