A sideband-injection locked extended cavity diode laser for interrogating cold trapped Strontium ions

A simple optical sideband injection locking technique is demonstrated to frequency offset-lock a 674 nm slave extendedcavity diode laser to a single frequency source. By injecting light from a master laser into either sideband of the frequency modulated extended cavity slave laser, it is shown that the carrier of the slave is frequency locked to the master laser with a relative linewidth much less than 10 Hz. The locking bandwidth is investigated to determine the largest capture range. An observation of the 674 nm S-2(1/2)-D-2(5/2) transition in a single ion of Sr-88(+) was performed using this laser system, yielding approximate to 1 kHz linewidth Zeeman structure, limited by the master laser linewidth. (C) 1998 National Physical Laboratory. Published by Elsevier Science B.V. All rights reserved.