扫频法精确测量高速光调制器频率响应

Accurate measurement of frequency response of high-speed optical intensity modulator using frequency sweeping method

同微波网络一样,可以用S参数来精确描述光电子器件的性能。根据微波网络的S参数,详细推导了光电子器件的S参数。搭建了40GHz高速测试系统,利用矢量网络分析仪(带宽40GHz)和作为参考的标准高速光探测器(带宽45GHz),测量了宽带光强度调制器(实测带宽35GHz)的频率响应。理论上,通过S参数和T参数的互相转换,扣除了微波放大器对测试结果的影响。在120MHz～35GHz范围内,测得的结果与出厂数据取得了很好的一致性。文中通过合理的简化,得到了光调制器频率响应的简明表达式,从而降低了数据处理的复杂度。

The S parameters can be used to precisely describe characteristics of optoelectronic components in the same way of microwave networks. In this paper, S parameters of optoelectronic components were derived from those of microwave networks. A 40 GHz high-speed measurement system was set up, the frequency response of a wide-bandwidth （e.g. 35 GHz） optical intensity modulator was accurately measured using a vector network analyzer with bandwidth up to 40 GHz and a referential standard high-speed photodetector with bandwidth up to 45 GHz. The effect of microwave amplifier was detracted through transform between S and T parameters. From 120 MHz to 35 GHz, the measured data agreed very well with those given by the manufacturer. A concise expression of frequency response of optical modulator was obtained through reasonable simplification. It reduces complexity of data processing.