Probing the Vacuum Induced Coherence in a $\Lambda$-system

Abstract

We propose a simple test to demonstrate and detect the presence of vacuum inducde coherence in a $\Lambda$-system. We show that the probe field absorption is modulated due to the presence of such a coherence which is unobservable in fluorescence. We present analytical and numerical results for the modulated absorption, the cosine and sine components of which display different types of behavior.

9 pages, 4 postscript files. Submitted for the special issue of "Laser Physics" on "Lasing without inversion and Interference phenomena in Atomic systems", Vol 9, #3, 1999