Study for Instrumentation of Electrooptic Constant and of Photorefractive Sensitivity

研究了高精度电光常数和光折变灵敏度的测量方法，并测量了光波导材料的电光常数和光折变灵敏度。计算了在Z切LiNb03晶体上制作的单模质子交换平板光波导层的电光常数，并考虑了传输TM0模的场分布。还研究了退火对未掺杂、钛扩散和镁掺杂三种类型的锂离子交换光波导中电光常数R33的影响。精确的估算表明，电光常数的劣化可以通过退火来恢复，其中未掺杂的效果最好，掺钛次之，掺镁的效果最差。利用PITI工艺可以制作出简单、易控制的偏振无关开关。尽管使用PITI工艺的波导损耗最小，但人们担心el…更多的电光效应将被退化，使得较小的E-O系数R22无法使用。为此，我们进行了一系列的实验，以验证在电场作用下，Peti光波导的行为与普通的钛光波导结构相同。定量测量了质子交换的LN和LT光波导和Rb离子交换的KTP光波导的光折变灵敏度，并估计了它们对光波导应用的影响。测量了液相外延生长的LiNb03薄膜光波导的光折变灵敏度。在所有被测量的样品中，形成在钽酸锂晶体上的退火质子交换光波导被证明是最抵抗光折变效应的，是一种有吸引力的短波应用材料。研究了在钽酸锂晶体上形成的质子交换光波导的光折变效应与温度的关系。当样品在高达80ﾟC的温度下加热时，对光折变效应的抵抗能力被证明是显著提高的。

Instrumentation of the electrooptic constant and photorefractive sensitivity with high precision is investigated and the electrooptic constants and photorefractive sensitivity of optical waveguide materials are measured. Electro-optic constants of single-mode proton-exchanged slab waveguiding layrs fabricated on z-cut LiNb03 crystal are estimated, taking into account the field distribution of the propagating TM0 mode. The effect of annealing on the electrooptic constant r33 in the proton-exchanged optical waveguides on three types of lithium niobate crystals : undoped, titanium-indiffused and MgO-doped, are also investigated. The exact estimation shows that the deterioration of electrooptic constant is recovered by annealing ; the best in undoped, then titanium-indiffused and the worst, MgO-doped. The simple easily controllable polarization independent switches can be fabricated by the PETi process. Although waveguide loss is minimal using the PETi process there is the fear that the el … More ectro-optic effects will be degraded, making the smaller E-O coefficient r22 unusable. Therefore a series of experiments were undertaken to verify that PETi waveguides act in the same was as normal Ti waveguide structures under the influence of the electric field. The photorefractive sensitivity of proton-exchanged LN and LT waveguides and Rb ion exchanged KTP waveguides is quantitatively mesured and their influence on the waveguide applications is estimated. The photorefractive sensitivity of the thin-film LiNb03 waveguides grown by the liquid-phase epitaxy is also measured. The annealed proton-exchanged waveguides formed on the lithium tantalate crystal are proven to be the most resistant to the photorefractive effect in all the measured samples and are attractive materials for short-wavelength applications. Temperature dependence of the photorefractive effect in proton-exchanged waveguides formed on lithium tantalate crystal is investigated. Resistance to the photorefractive effect is proven to be greatly improved when the samples are heated at temperatures as high as 80ﾟC. Less