Research On Measurements Of High Speed Optoelectronics

The increasing demand for communication is direct driving force behind modern fiber communication systems, which are always based on high-speed optoelectronics. High-speed optical photodetectors and modulators are the core devices of fiber communication systems, and they are used to transform optical signals into electrical signals and to modulate optical signals respectively.Optical photodetectors and modulators are critical components of optical fiber communication system. Improvement of their performance as well as accurate measurement of them is becoming a research hotspot. In this thesis, theoretical and experimental research is carried out on almost all important parameters of them and the following achievements are acquired:1. The 40GHz high-speed frequency response measurement platform for wide-bandwidth optical intensity modulator is set up using a vector network analyzer and a referenced standard photodetector. The effect of microwave amplifier is distracted through transformation between S parameters and T parameters. From 120MHz to 35GHz, the measured data agrees very well with that supplied by the manufacturer.2. The measurement method of frequency response using lightwave component analyzer is deeply studied. New measurement system is laid out, and it expands the range of frequency which we can measure from 20 GHz to 40GHz.3. Parameters of photodetector, such as I-V characteristic, dark current, quantum efficiency and frequency response are studied experimentally and theoretically. The influences of different physical structure on the properties of photodetector are acquired through the experimental results. 4. With the research on the principle of pulse response techniques, the pulse response measurement system is established. It showed us the different effects on measurement results with pulse width using different laser sources. After analyzing the results, some suggestion of improving this method are brought up.5. The automatic spectrum response measurement system for photodetector is developed using C# programming language and VISA application programming interfaces. It is easy to use and have advantages in real-time data acquisition as well as measurement result analysis. As a result, it improves the accuracy and efficiency of our experiment greatly.