Laser source at 578 nm for an Yb optical lattice clock using second harmonic generation of a diode laser

A laser source at 578 nm with output power of more than 10 mW was obtained using a waveguide periodically-poled-lithium-niobate crystal as a nonlinear medium for second harmonic generation. To achieve this result, we made a high power 1156-nm external-cavity diode laser with maximum output power of more than 250 mW. This system is expected to be an excellent alternative to systems using sum-frequency generation with advantages of simplicity and cost-effectiveness, and will be used as a clock laser of an ytterbium optical lattice clock with robust and reliable operation.