Study On Test System Of Ultrafast Photoconductive Switch

With the development of micro-electronics and optic-electronics andthe improvement of micro-fabrication technology, ultrafast electronicdevices and ultra fast optic-electronic devices are playing the more and moreimportant role in information processing field. In present condition oftechnology, however, it is difficult to measure the performances andparameters of those devices conveniently and accurately. Therefore, thedemand to ultra fast optic-electronics measurement system with widebandwidth and high sensitivity is urgent. Under this background, the ultra fast optic-electronics measurementsystem based on photoconductive switch is studied, designed, andconstructed. Through the analysis of principle of ultra fast photoconductive,the optic path and electric circuit to implement ultra fast electro-opticsampling and data acquisition are designed, at the same time, the key partswhich will influence the whole measurement performances are discussedand analyzed. The main contents and achievements of this paper are as follows: 1. A large number of technical references are searched and analyzed; an overview of the current domestic and international situation and development in the field of ultra fast optic-electronics measurement is reached. 2. The principle, theoretical model, and fabrication of ultra fast photoconductive switch are analyzed; the new structure for photoconductive switch is designed. 3. The principle and implement of electro-optic sampling by use of the general principle of crystal optics are studied and analyzed; the optic structure of electro-optic sampling system is designed. 4. The circuits of optic-electronic conversion and micro current amplifying are designed; communication between different instruments is set; stepping motor and lock-in amplifier ofmeasurement system are programmed with LabView via GPIB-PCI interface; the convenient and effective auto-measurement system is constructed. 5. By AFM tip induced oxidation, the fabrication of photoconductive switch on Ti film is tried; relevant mechanism is analyzed. 6. The mechanism of optic-mechanical delay line is analyzed; by use of laser interferometer, the effect of subdivision and precision of movement of stepping motor is measured; the feasibility and reliability of structure of optic-mechanical delay line are validated. 7. The partial optic-path of measurement system is constructed; the factors which influence performance of whole measurement system are analyzed and the correlative experiment is developed.