Watt-class injection-locked diode laser system at 399 nm for atomic physics

We demonstrate an injection-locked 399 nm laser system with up to 1 W output power and a locked power fraction of 0.57. The system consists of a high-power, multimode diode laser that is seeded by 5 mW from a single-mode external-cavity diode laser. The locked high-power laser inherits the frequency agility and linewidth of the seed laser with 3.9kHz broadening. With active stabilization, the injection lock can be maintained for more than a day. We verify the utility of this system for atomic physics by performing spectroscopy of a ytterbium atomic beam.