Digital Research Lithium Niobate Crystal Electro-optical Modulation Systems

Firstly, the background as well as the applications of electro-optical modulation is introduced, and the application on the polarization coding is emphasized. Secondly the principle of electro-optic modulation and an electro-optic modulation experiments based on the electro-optical modulation are elaborated. In existing electro-optical modulation experiment, the waveform can only be observed through oscilloscope, and the image data can not be extracted, nor their further processing. To solve this problem, a new electro-optical modulation experiment system is designed. The new system comprises a laser, polarizing prisms, electro-optical crystal, a quarter-wave plate, CCD image pickup device, the CCD can receive the image data at the other side of the electro-optical crystal, or other components, as the laser passing through it. Then on this basis, the MFC in the VFW video editing software is used to write electro-optic modulation image data acquisition software system, then the software system obtained images through CCD, with the software system designed to take advantage of the obtained image data, the half-wave voltage of crystals, and some basic characteristics of the crystal light cone interferogram can be achieved with further analysis and calculation. Experimental results show that the designed hardware and software systems can work normally, and the requirement and the expected goal are well met. This is followed by the analysis of experimental data on the interference pattern of crystal light cone, which can be used to do further research, and thus providing the system conditions for the crystal polarization coding study.