We propose a method to observe phase-dependent spectra in resonance
fluorescence, employing a two-level atom driven by a strong coherent field and
a weak, amplitude-fluctuating field. The spectra are similar to those which
occur in a squeezed vacuum, but avoid the problem of achieving squeezing over a
4π solid angle. The system shows other interesting features, such as
pronounced gain without population inversion.Comment: 4 pages and 4 figures. Submitted to Phys. Rev. Let