Study On Coupling Technique Of High-power Semiconductor Lasers

The development fields of high-power semiconductor lasers are wider and wider, such as the light sources and pumping sources of optical fiber amplifies in optical fiber communication systems, laser surgery operation in medicine, laser welding and heat processing in materials mechanical process and so on. The distance z light transfers, displacement offset and angle offset are crucial factors. So we design a kind of simulation software to simulate the couple between LD and lensed fiber.The simulation software contains the main interface and three lened fiber coupling system--spherical lensed fiber coupling system, taper lensed fiber coupling system, wedge lensed fiber coupling system. By setting the parameters of high-power semiconductor laser and lens, the soft can simulate their mode fields, the coupling efficiency change with mode field, focal length, displacement offset and angle offset.Firstly, we analyze mode distributions and matches to set models of the coupling systems. We can get the relation between the coupling efficiency and z. With the optimal z we can analyze how the displacement offsets, angle offsets of x, y direction influence the coupling efficiency.The simulation software is designed implying the mixed programming VB and MATLAB.VB has unique advantages in user interface design and rapid development, but has disadvantage in dealing with complex data information. MATLAB is a powerful, operation simple language, which is of the ability in numerical calculation, symbolic computation and graphical visualization. We simulate the models with MATLAB and design the user interface with VB. ActiveX automation (OLE automation) method realize automation connection between VB and MATLAB.The simulation software interface contains the main interface and three kinds of lened fiber coupling system --spherical lensed fiber coupling system, taper lensed fiber coupling system, wedge lensed fiber coupling system. By setting the parameters of high-power semiconductor laser and lened fiber, we can simulate the modes and the coupling efficiencyWe test the simulation software to find the differences and errors by comparing the simulation data with experimental data. Due to limited experimental condition, we compare the simulation data with experimental data to analyze the differences between simulation results and experimental results of different reasons, such as the loss caused by the researchers'improper operation in the experimental process.In addition, this paper discuss another issue--combiner. At present, the research level on combiner abroad is higher than that of domestic research. In a word, the research achievements are few, of a strong confidentiality, and of important practicality, so research combiner is of important significance.The main experiment equipments are combined beams are taper broaching machine, welding machine etc. In the experimental process, we need to constantly try to set the speed and the flame temperature of pull cone machine, which determine the fusion degree of a number of fibers. After many experiments, we make the 3 x 3 coupler whose output optical efficiency is 95%. We analyze the problems of experiment, and puts forward some suggestion for improvement.