Design Of Laser Z-scan Automatic Detection System

Sheik Bahac introduced a high sensitive single-beam Z-scan technique in 1989.It requires relatively simple experimental apparatus and simple analysis. Z-scan technique has been widely employed since it is reported. Now, it has become an important method used in studying the nonlinear optical characteristics.We describe simply the single-beam Z-scan technique and method. Because there are some abuses when we studied and detected nonlinear optical properties of materials previously, we design a laser Z-scan automatic detection system on the base of the single-beam Z-scan method. The hardware and the software are included in the Z-scan detection system. The hardware has a optical part and a circuit part. Our mission is the design of a circuit part mainly. There are two control units,a personal computer and a single-chip microcomputer, including stepping motor,drive circuit,single-chip microcomputer control circuit,serial communication circuit,data acquisition card,personal computer, in the circuit system. In circuit design, we use the design software of Protel 99.Moreover, we use mainly the develop tools of Keil C51 and Visual C++ 6.0 in the design of the personal computer and single-chip microcomputer system software. It is used to realize the functions such as the state control of stepping motor,serial communication,instructions coding and transfers,data acquisition, data processing, data accessing and graphics display.Based on achieving the design of hardware and software, we test and validate the whole function of the detect system. At the same time, we describe the method of building the system,the way of testing and the last result. Finally, we analyses the result of testing and draw a conclusion: we have completed the design mission and meet the target. The system has realized the function basically and finished the normal testing of nonlinear optical materials. Moreover, we have validated the single-beam Z-scan technique and method.