Laser cooling of trapped Ca^+ and measurement of the 3 ^2D_5/2 state lifetime

We describe the laser cooling of Ca(+) ions in a rf ion trap and the measurement of its 3(2)D(5/2) state lifetime. The ions are cooled to below 1 K by radiation from a frequency-doubled Ti:sapphire laser and a laser diode. The radiative lifetime is measured by observing the change in fluorescence when the ions, which are optically pumped to the metastable state, return to the cooling cycle. The lifetime of the 3(2)D(5/2) state is measured to be 0.77 +/- 0.07 s.