相位补偿型电光A/D转换器的优化设计

提出了一种可以提高泰勒型电光A/D转换器有效位的方案,其原理是用相位补偿的直接转向波导或分支波导代替传统的S-弯曲波导.采用有限差分束传输法设计出由质子交换工艺制作的高折射率微棱镜进行相位补偿的4位电光A/D转换器的波导结构,利用保角变换方法对调制电极参数进行优化.最后得到优化结构参数为设计4-6位的高速电光A/D转换器提供了理论依据,同时也得到了一些对实际设计有一定指导意义的结论.

Optimal Design of Electrooptic Analog-to-Digital Converter with Proton-exchanged Microprism

A scheme that can greatly enhance the significant bit of the Taylor-type electrooptic analog-to-digital (A/D) converter is presented. The operation principle is that conventional S-bend branching-waveguide of the A/D converter is replaced by phase compensation low-loss bent waveguide or Y-branching waveguide. The optical waveguide structure of 4-bit electrooptic A/D converter with proton-exchanged microprism for phase compensation was designed using finite-difference beam propagation method (FD-BPM). The electrode parameters of the converter are optimized using conformal mapping method. The resultant optimal parameters provide theoretic basis for the designs of 4-6 bit high-speed electrooptic A/D converter, and at the same time, some conclusions are drawn, which can be used as guidance for practical designs.