电光强度调制器的小信号测试法

Small-Signal Measurement of Optical Intensity Modulator Frequency Response

对电光强度调制器频率响应特性的小信号测试方法进行了理论推导,分析了调制微波的低频方波失真对测试精度的影响,给出了在调制信号较强时,测量可能出现的最大误差。发现当驱动电压低于半波电压的一半时,测试的精度在92%以上。证明,小信号测试方法完全可以应用到调制器的大信号测试。最后提出点频测试法,并给出了系统的校准方法。

The formulas explaining the principle of small-signal swept-fre- queney technique for measuring the frequency response of optical intensity modu- lators are derived.The effect of square wave distortion on the accuracy of measurement in case of large-signal modulation is discussed in detail.It is shown that if the drive voltage is smaller than 1/2 V,the maximum relative error will be lower than 8%.Therefore,this technique can be used to measure thef requency response of large-signal modulation.Finally,a simple measuring setup is proposed and the calibration of the system is given as well.