Second-order polarizability holograms in few-mode fibers: phase conjugation and angular selectivity

Second-order polarizability holograms in optical fibers were recorded by picosecond radiation of a neodymium laser together with its second harmonic. High angular selectivity of holograms was observed for various input angles of the reading IR beam. We observed phase conjugation of the green signal by using an oppositely directly IR beam to read the holograms. Coherent erasure of a hologram was demonstrated by means of a second exposure by an interference pattern of opposite sign.