Study of the fine dividing technique for unity interference fringe by using OCV

Both of counting the interference fringes and fine dividing unity interference fringe are important essential technique in the field of the accurate measurement. The counting technique has been ripe, but the fine dividing technique (FDT) is just developing. There are several FDT such as: electronics method, optical frequency doubling method, CCD method and computer programing method, etc. A new FDT with opti- cally controlled varactor (OCV) is reported in this paper. A real-time data acquisition system consisted the OCV as photoelectric detector and a special interface circuit connected with microprocessor for coun- ting the interference fringes and fine dividing unity interference fringe has been developed which can print and process data. Advantages of this system are following: real-time operation, intellectuality, and it is simple, reliable and economical. The photoelectric device OCV is a kind of new type detector and is very sensitive to weak light and the spectrum response peak condition, the capacitance of the OCV has a direct relationship to light in- tensity. It is small size and fast response. This system for fine dividing of unity interference fringe with OCV device not only can be of great use for the interference fringe but also for the Moire fringe. The test results indicate: The fine dividing for unity interference fringe can be accurate to l%( /100).