We demonstrate three-dimensional quenched narrow-line laser cooling and trapping of <sup>40</sup>Ca. With 5 ms of cooling time we can transfer 28% of the atoms from a magneto-optic trap based on the strong 423-nm cooling line to a trap based on the narrow 657-nm clock transition (which is quenched by an intercombination line at 552 nm), thereby reducing the atoms’ temperature from 2 mK to 10 μK. This reduction in temperature should help to reduce the overall systematic frequency uncertainty for our Ca optical frequency standard to <1 Hz. Additional pulsed, quenched, narrow-line third-stage cooling in one dimension yields subrecoil temperatures as low as 300 nK and makes possible the observation of high-contrast two-pulse Ramsey spectroscopic line shapes.
© 2003 Optical Society of America
(020.7010) Atomic and molecular physics : Laser trapping
(140.3320) Lasers and laser optics : Laser cooling
(300.6320) Spectroscopy : Spectroscopy, high-resolution
(300.6360) Spectroscopy : Spectroscopy, laser
E. Anne Curtis, Christopher W. Oates, and Leo Hollberg, "Quenched narrow-line second- and third-stage laser cooling of 40 Ca," J. Opt. Soc. Am. B 20, 977-984 (2003)