Rare‐Earth‐Doped Y2SiO5Crystal Directly Bonded on Glass for Efficient Optical Quantum Technologies Platform

For high‐efficiency optical quantum technology platforms, bonding rare‐earth doped crystals on glass are of great interest, enabling the enhancement of the optical guided mode interaction with the active rare‐earth ions. Optical coherence lifetimes and stable operation are operated at very low temperature (3–4 K). Bonding should be preferably performed without adding any intermediate sticking layer in order not to hamper the optical mode distribution and propagation. Directly bonded Y2SiO5crystal on a borosilicate glass is shown and the bonding mechanisms are discussed. For high‐efficiency optical quantum technology platform, bonding rare‐earth doped crystals on glass is of great interest, enabling the enhancement of the optical guided mode interaction with the active rare‐earth ions. Directly bonded Y2SiO5crystal on a borosilicate glass is demonstrated and the bonding mechanisms, including the dissociation of Na2O, is discussed.