论文部分内容阅读
报道铕铌酸锂晶体双光束耦合在５５，７０和１１０℃附近出现的异常温度现象，该现象与晶体在这些点发生了结构相变有关，相变诱发出内电场，改变了空间电荷场的结构，影响了双光束耦合。采用唯象的办法给出相变电场随温度的变化公式，结合一能级单载流子带导模型给出了理论曲线，能很好地解释实验。推算出相变电场的数量级介于扩散电场和最大空间电荷场之间，为１０￣５Ｖ·ｍ￣（－１）。
It is reported that anomalous temperature phenomenon occurs at 55, 70 and 110 ℃ for the double-beam coupling of europium-lithium niobate crystals. This phenomenon is related to the structural phase transition of the crystal at these points. The phase transition induces an internal electric field and changes the space charge field The structure affects the two-beam coupling. Using the phenomenological method, the formula of the change of electric field with temperature is given. The theoretical curve is given according to the one-band single-carrier guided model, which can explain the experiment well. It is deduced that the magnitude of the phase change electric field is between 10 ~ 5V · m ~ (-1) between the diffusion electric field and the maximum space charge field.