VECSEL systems for quantum information processing with trapped beryllium ions

We demonstrate two systems based on vertical-external-cavity surface-emitting lasers (VECSELs) for produc-ing ultraviolet laser light at wavelengths of 235 and 313 nm. The systems are suitable for quantum information processing with trapped beryllium ions. Each system consists of a compact, single-frequency, continuous-wave VECSEL producing high-power near-infrared light, tunable over tens of nanometers. One system generates 2.4 W at 940 nm, using a gain mirror based on GaInAs/GaAs quantum wells, which is converted to 54 mW of 235 nm light for photoionization of neutral beryllium atoms. The other system uses a gain mirror based on GaInNAs/GaAs quantum wells, enabling wavelength extension above 1200 nm with manageable strain in the GaAs lattice. This system generates 1.6 W at 1252 nm, which is converted to 41 mW of 313 nm light that is used to laser cool trapped 9Be+ ions and quantum state preparation and detection. The 313 nm system is also suitable for implementing high-fidelity quantum gates.(c) 2023 Optica Publishing Group