  We propose an enantio-detection method of chiral molecules in a cavity with
external drive. The chiral molecules are coupled with a quantized cavity field
and two classical light fields to form the cyclic three-level systems. The
chirality-dependent cavity-assisted three-photon process in the three-level
systems leads to the generation of intracavity photons. Simultaneously, the
drive field also results in the chirality-independent process of the generation
of intracavity photons. Based on the interference between the intracavity
photons generated from these two processes, one can detect the enantiomeric
excess of chiral mixture via monitoring the transmission rate of the drive
field.
