Abstract

For coherent coupling of the emission of two separated parametric down converters generally two different strategies can be applied. In the first coherence can be realized by induced emission. In this case the strong idler field of the first crystal is used to stimulate the emission of the second crystal. The phase of the amplified idler field will be the same phase as of the incident locking field. If, in this way, the two idler fields from the two crystals are locked the two signal fields will be phase locked also, since the sum of the signal and idler phase is determined by the pump phase in both crystals in the same way. Thus the two signal fields will show first order coherence, with in principle 100% visibility, obtainable at the final beam splitter BS₂ in Fig. 1. Without the induced emission, the two signals will be incoherent, and no interference will occur.

© 2013 IEEE