Narrow-linewidth laser system for precise spectroscopy of the indium ion clock transition

Summary form only given. A single laser-cooled indium ion, stored in a radio-frequency trap, is expected to be one of the most promising candidates for the creation of a new generation of optical frequency standards with an anticipated accuracy of up to 10/sup -18/. On the way to achieving such a high level of accuracy, one of the main limitations is the short-term frequency instability of the laser system, used to excite the narrow /sup 1/S/sub 0/-/sup 3/P/sub 0/ In/sup +/ clock transition. Since the signal from the single ion is small, the laser system should posses extremely high frequency stability (on the level of /spl Delta/v/v=10/sup -14//spl divide/10/sup -15/) for averaging times of about one second in order to reduce statistical uncertainties and to minimize the time of experiment. In this paper, we report our recent results on the improvement of the short-term frequency stability of the laser system.