title: Influence of second-order Doppler effect on optical Ramsey fringe profiles.
abstract: Resolution sufficient to resolve second-order Doppler broadening (3.9 kHz) has been obtained for the Ca (1)S(0)-(3)P(1) transition (657 nm) by using an atomic beam and optical Ramsey fringe techniques. Laser-beam separations up to 21 cm yield Ca linewidths (HWHM) as narrow as 1 kHz. As resolution is increased to approach, then exceed the second-order linewidth, large asymmetries, shifts, and shape changes occur in the Ramsey fringe profile.
authors.forename: R L
authors.initials: RL
authors.lastname: Barger