Quantum Zeno effect in a probed down-conversion process - art. no. 013804

The distortion of a spontaneous down-conversion process caused by an auxili ary mode coupled to the idler wave is analyzed. In general, a strong coupli ng with the auxiliary mode tends to hinder the down-conversion in a nonline ar medium. On the other hand, provided that the evolution is disturbed by t he presence of a phase mismatch, the coupling may increase the speed of dow n-conversion. These effects are interpreted as being manifestations of quan tum Zeno and anti-Zeno effects, respectively, and they are understood by us ing the dressed mode picture of the device. The possibility of using the co upling as a nontrivial phase-matching technique is pointed out.