摘要
研制了利用直线法设计的基于 Ga As衬底上的 Mach- Zehnder行波光调制器 .波导层使用了场诱折射率改变量较大的非对称多量子阱结构 ,采用脊型波导 ,并湿法刻蚀出台面以消除波导区以外的载流子引起的损耗 .调制器电极微波特性测试结果表明频率响应在 2 .5～ 2 0 GHz没有明显的起伏 ,但在低频段响应下降很快 ,另外微波损耗较大 ,讨论了其原因和改进方法 .
The Mach Zehnder traveling wave modulator designed by method of lines is fabricated on the substrate of semi insulator GaAs.The optical waveguide layer adopts the asymmetric multiple quantum wells with larger change of field induced reflective index.Ridge waveguide is used for the optical transmission,and a mesa is wet etching to reduce microwave loss for the unnecessary carriers.The properties of microwave frequency response are analyzed in the experimental results.The frequency response drops faster at lower frequency,and keeps no evident drop in the range of 2 5～20GHz.The bandwidth is more than 20GHz for the limitation of measurement.The microwave loss is relatively large.The reason is discussed and the way for improving is suggested.
基金
国家自然科学基金资助项目 (批准号 :60 2 770 3 4)~~
