PHASE PROPERTIES OF CHI(2) GRATINGS IN GLASS

A new method for the measurement of the phase shift between second-har monic light generated by a bulk glass and the injected second-harmonic seed is presented. A linearly polarized pump and a second-harmonic se ed with noncollinear polarizations were used for preparation of cerium -doped lead-silica glass. Independence of the phase shift from the ang le between the polarizations of the recording waves is demonstrated, a nd a phase shift value close to 90-degrees is observed, i.e., the chi( 2) grating was in phase with the real [E(EE)].