The Design And Implementation Of Semiconductor Laser Characteristic Detection System

With the development of society and economy and advancement of science, fiber communication technology has been greatly developed and widely applied. Not only transmission speed is highly expected, but also its transmission quality. As one of the most important components of fiber communication system, the quality of characteristic parameter of semiconductor laser can directly affect the transmission quality of system. Therefore, the research on characteristic parameter detection system of semiconductor laser is of vital importance.The characteristic parameter detection system of semiconductor laser this paper designs mainly contains semiconductor laser,MCU hardware detection platform and upper-machine PC controlling platform. Firstly, this paper introduces the development of semiconductor laser tester in foreign countries and makes comparison and analysis of tester in domestic and overseas markets. Specially, it introduces research of domestic semiconductor laser tester system and analyse their strength and weakness comprehensively. And then, it explains inner structure and operational principle of semiconductor laser, and combined with testing objects of semiconductor laser testing system, some main characteristic curves and hold values of semiconductor laser has been analysed with great emphasis.In the design of MCU hardware testing platform, outside testing circuit module has been divided to be MCU outside controlling circuit,parameter testing circuit and power amplification circuit according to practical performance requirement and which then have been analysed and introduced; As for analysis of MCU controlling system software design modules, programming of pulse width modulation module,A/D conversion module and UART module and configuration of main registers of MCU have been explained based on programming flow diagram. As for design of upper-machine PC controlling platform, the author creatively introduces current virtual instrument technology, which is based on LabVIEW from American NI company as its development environment and which can make full use of PC's strong power in data processing so as to improve operating speed. Finally, in order to decrease the influence of error on result, combined with practice, curve fitting optimization algorithm has been introduced and precision of testing result and credibility has been great enhanced.According to test, this system can successfully describe V-I characteristic curve,P-I characteristic curve and Im-I characteristic curve of tested semiconductor laser and can calculate its characteristic parameters.