Stabilization of the 397 nm and 866 nm external cavity diode lasers for cooling a single calcium ion

The linewidth of a 397 nm laser was narrowed below 1 MHz by locking it to a Fabry-Perot interferometer. In addition, the cavity length of the interferometer was referenced to the Optogalvanic signal of calcium ions. The long-term drift of the laser frequency was reduced below 10 MHz over 2 h. This frequency stabilization was also applied to an 866 nm laser. With such lasers, we can achieve better signals from a single calcium ion confined in a miniature Paul trap.