Frequency doubled 1534 nm laser system for potassium laser cooling.

We demonstrate a compact laser source suitable for trapping and cooling potassium. By frequency doubling a fiber laser diode at 1534 nm in a waveguide, we produce 767 nm laser light. A current modulation of the diode allows us to generate the two required frequencies for cooling in a simple and robust apparatus. We successfully used this laser source to trap K39.