TUNABLE 397-NM LIGHT-SOURCE FOR LASER COOLING OF CA IONS BASED ON FREQUENCY-DOUBLING OF DIODE-LASER

We have fabricated an rf ion trap and laser-cooling light sources to o bserve shelving transition in a single calcium ion. All the radiation required for laser cooling and observation of the transition can be pr epared with diode lasers in this system. Continuous-wave radiation at 397 nm for laser cooling was generated by frequency doubling of a GaAl As laser iii an external enhancement cavity. As a preliminary experime nt for observing the shelving transition, laser cooling of one hundred calcium ions was demonstrated using this radiation and another diode laser.