An integrated laser system for manipulating trapped ions qubits

In experiments with atomic qubits encoded in the hyperfine levels of cold atoms or ions, the generation and control of multiple laser frequencies are often required for laser cooling and qubit manipulation. In this work, we demonstrate a laser system that integrates laser cooling, qubit initialization and detection, and Raman operations into a single setup, utilizing fiber laser technology and nonlinear optics. Specifically, a 369 nm laser for preparing and detecting ${}^{171}{\mathrm{Yb}}^{+}$ ions, and a 554 nm laser for qubit Raman manipulation, are generated by modulating a seed laser at 1108 nm through a fiber electro-optic modulator (EOM), amplified by a Yb-doped fiber amplifier, and then converted to 369 nm and 554 nm using two sequentially placed periodically-poled nonlinear crystals. This method offers significant flexibility and scalability, as different laser frequencies can be generated by adding specific radio-frequency signals to the electronic system, without altering the optical setup. The switching time between laser frequency channels is measured at 6.5 ns. With a modulation bandwidth of 20 GHz, this approach can accommodate the hyperfine splittings of various ion species. Overall, This scheme optimizes the optical configuration for atom and ion operations, minimizes insertion losses, and provides an efficient multi-channel laser frequency generation solution, making it highly beneficial for atomic and ionic quantum information experiments.