光学测量如何解释S21信号

您可能需要查看一个HP / 8702D光波组件网络分析仪的手册。
我相信它基本上是一个带有一些额外光学位的8753。
VNA用于测量S参数。
S参数根据电压比而非功率来定义。
S21具有幅度和相位。
戴夫。



     以下为原文

  You might want to look at the manual of a for one HP /8702D Lightwave Component Network analyzer. I believe it is basically an 8753 with some extra optical bits.

VNAs are used to measure S parameters. The S-parameters are defined in terms of ratios of voltages,  not powers.  S21 has both a magnitude and a phase.  

Dave.

嗨戴夫，谢谢你的想法。
1）我应该补充一些细节。
我在测量光学响应的​​同时测量DUT的S11参数（电反射） - 因此首先使用VNA。
DUT发射400-450nm的光，这使事情复杂化。
我研究了Lightwave组件分析仪;
它们会很棒，因为集成光学探测器在幅度和相位方面都经过校准，但它们似乎都专用于红外电信波长。
因此，我相信我唯一的选择是使用插在VNA第二个端口上的“标准”光电探测器进行仅振幅S21测量。
我现在正在做这个并且正在接收信号，但是没有任何校准步骤（我只校准了S11），频率响应具有寄生效应。
我想知道一些（振幅）校准步骤是否有意义。
或者，是否有人知道可见光范围内的光电探测器带有校准数据（在HF寄生效应的意义上）？
2）是的，S-params =电压测量，没有问题，谢谢！



     以下为原文

  Hi Dave, thanks for the thoughts. 

1) I should have added a few more details. I am measuring the DUT's S11 parameter (electrical reflection) at the same time as its optical response - hence the use of a VNA in the first place. The DUT emits light at 400-450nm which complicates things. I looked into Lightwave component analyzers; they would be great, as the integrated optical detectors are calibrated in both amplitude and phase, but they appear to all be dedicated for infrared telecom wavelengths.

So, I believe my only option is to use a "standard" photodetector plugged on the VNA's second port for an amplitude-only S21 measurement. I am doing this now and am getting a signal, but without any calibration step (I only calibrated S11) the frequency response has parasitics. I'm wondering if some (amplitude) calibration step makes sense. Alternately, does anyone know of a photodetector in the visible range with calibration data (in the sense of HF parasitics)?

2) Yes, S-params = voltage measurements, no problem there, thanks!