Research On Design Of Laser Arrays In Coherent Combination

Since the laser was invented in1960, it has a rapid development in high power and high quality. However those could not meet people’s needs in some special occasions. Then the technique of coherent combination comes into being. Coherent combination, which bases on the fact that laser is highly monochromatic, with a long coherence length, is a kind of technology, to get higher power density and increase the effective propagation distance.The author’s work in this paper mainly includes:Making an investigation of the development of coherent combination technology in domestic and foreign institutions, and summarizing the various experiment methods to achieve coherent combination.Calculating the propagation of the fundamental mode Gaussian beams and super Gaussian beams in vacuum or in the Fraunhofer system, in theory. The super Gaussian beams or the flat-topped beams is proposed to be described by the coherent combination of multi-Gaussian beams. Establishing models for the systems with lens and without lens, and finding out the methods to evaluate the coherent combination efficiency in different systems.Carrying out numerical computer simulations of coherent combination systems with and without lens. Calculating and analyze the impact on the combination efficiency by changing the array arrangement, the array size, filling factor and the propagation distance. Using phase addition to focus the beams instead of the lens, and analyze its advantages and disadvantages.Carrying out numerical computer simulations of coherent combination systems with the array formed circular super Gaussian beams or square super Gaussian beams. Calculating and analyze the impact on the combination efficiency by changing the array arrangement, the array size, filling factor and the propagation distance. And comparing the results with the fundamental mode Gaussian beam arrays.Conclusion in the fitting curve of the combination efficiency. And designing the beam array arrangement for different coherent combination conditions.