摘要
本文计算了不同折射率膜层下，非对称法布里珀罗腔模式波长随膜层厚度的变化．分析了在膜层折射率较低时，模式波长随层厚的增加反而减小的机理，并在实验中研究这种现象．利用湿法腐蚀的方法移动模式波长，补偿由生长误差引入的模式波长偏差，从而做到模式波长可控，获得高消光比的器件．同时利用湿法腐蚀方法将模式波长调整到不同位置。
Abstract The control of ASFP mode position with the thickness of different index coating layers is calculated. The mechanism for blue shift of ASFP mode with the increasing of thickness of low index coating layer is analyzed and the phenomenon is observed in experiment. With wet etching method, ASFP model can be tuned and thus the deviation of growth can be compensated .This method is used to improve the contrast ratio of modulator. With ASFP model located at different position relative to the e hh peak, different modulation characteristics are demonstrated.
