Holography by nondegenerate chi(2) interactions

We consider noncollinear interaction among three amplitude-modulated plane waves in a uniaxial crystal under type I phase-matching conditions. If one among the interacting fields can be taken as undepleted during the interaction, the remaining two fields are holographic replicas of each other: the undepleted field acts as the reference field in holography. We develop a general method to calculate the holographic wave front generated by a nonplane object wave front and a plane reference wave front. We present experiments in which a holographic image of an object consisting of a pointlike light source is obtained by choosing the object- and reference-field frequencies among \omega1, \omega2, and \omega_3 ( with \omega_3 = \omega1 + \omega2) in any of the possible combinations.