Diode laser spectrometer at 493 nm for single trapped Ba+ ions

+ ions. Frequency doubling of a 100 mW diode laser at 986 nm results in up to 60 mW output power at 493 nm in a bandwidth of less than 60 kHz with respect to the cavity used for locking. Reference frequencies of 18 spectral lines of Te₂ near the 493 nm resonance of Ba⁺ have been measured using modulation transfer spectroscopy. The fluorescence excitation spectrum of a single Ba⁺ ion, measured with this laser, exhibits well-resolved dark resonances, which confirms the versatility of the system for quantum optical experiments. Received: 12 June 1998