c向切割掺杂LiNbO3晶体中的光耦合

实验研究了三种c向切割的不同掺杂的LiNbO3：Fe晶体中入射光与反射光的耦合情况.发现沿-c轴方向入射时透射光与反射光强的准周期振荡行为是光生伏打机制占优势的瞬态能量转移和扩散机制引起的相反方向的能量转移所致，不是光生伏打场的表面击穿引起的.当入射光沿+c方向入射时，由于两种机制引起的能量转移方向相同，因而不会产生这种振荡. 关键词： 准周期振荡 反射光栅 瞬态能量转移 扩散机制

Light coupling in c-cut doped lithium niobate crystals

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.