Characterization of Frequency-Doubled 1.5- m Lasers for High-Performance Rb Clocks.

We report on the characterization of two fiber-coupled 1.5-μm diode lasers, frequency-doubled and stabilized to Rubidium (Rb) atomic resonances at 780 nm. Such laser systems are of interest in view of their implementation in Rb vapor-cell atomic clocks, as an alternative to lasers emitting directly at 780 nm. The spectral properties and the instabilities of the frequency-doubled lasers are evaluat...