Light coupling in c-cut doped lithium niobate crystals

Abstract

We investigated experimentally the coupling behaviours of the transmitting and reflected light in three c-cut doped lithium niobate crystals.We find that when the direction of the incident light is along the -c axis,the quasi-period oscillation behaviour of the reflectivity and transmissivity is caused by the energy transfer with diffusion and the photovoltaic-effect related transient energy transfer,the directions of these energy transfers are opposite to each other,but not caused by quasi-breakdown of the photovoltaic field.When the direction of the incident light is along +c axis,the directions of energy transfers caused by both mechanisms are the same,so oscillations will not appear.