The BIPM laser standards at 633 nm and 532 nm simultaneously linked to the SI second using a femtosecond laser in an optical clock configuration

The study of an optical clock based on an iodine-stabilized Nd:YAG laser has been performed using a femtosecond laser. The optical frequency of the iodine-stabilized He-Ne laser at 633 nm and the Nd:YAG laser at 532 nm have been measured simultaneously with a relative uncertainty below 1/spl times/10/sup -12/.