用于微波光子系统的铌酸锂集成电光调制器研究

设计和制作了一种高速铌酸锂电光调制器。波导采用双Y定向耦合器型结构以提高线性度,同时能够提高工艺容差;电极采用CPW行波电极结构。通过分析比较不同相速匹配程度及微波损耗程度对电极系统带宽的影响,选择合适的设计参数及工艺参数,制作的调制器样品插入损耗为3dB,开关消光比为34dB,偏置电极半波电压为7V,行波电极半波电压为5.5V,电反射小于-10dB,6dB调制带宽约18GHz,可实现0～18GHz模拟调制。

Research on LiNbO3 Integrated Electro-optical Modulator for Microwave Photonics System

High-speed LiNbO3 electro-optical modulators were designed and fabricated. Dual-Y directional coupler structure was used to improve the linearity of the modulator and the process tolerance. By applying CPW type traveling-wave electrode, the effects if different phase velocity mismatch and microwave loss on the system bandwidth were analyzed comparatively. By selecting optimal process parameters, the fabricated modulators obtain the insert loss of less than 3dB, the extinction ratio of 34dB, the halfwave voltage of the traveling-wave electrode pf 5.5V, the power reflection of less than -10dB, and the 6dB modulate bandwidth of about 18GHz.