SQUEEZING-INDUCED TRANSPARENCY IN A 2-LEVEL ATOM

The effect of an off-resonance squeezed field on the weak probe-beam absorption spectrum of a two-level atom is discussed. A threshold effect for the squeezing is found, below which the spectrum consists of an absorptive and an emissive doublet of the same width and above which the spectra consists of two partly absorptive, partly dispersive features of different widths and both centered on the squeezing frequency. It is shown that below threshold a spectral hole may appear at the probe-beam frequency separated from the atomic transition frequency by twice the detuning of the squeezed field centre frequency from atom resonance. For a minimum uncertainty squeezed field of high intensity the probe absorption can be totally suppressed at this frequency and the system is transparent for the probe beam. These effects suggest new alternatives for the experimental study of the interaction of atoms with squeezed light. Described is a possible technique for testing these predictions, using a microscopic Fabry-Perot cavity.