Shape the unstable laser beam using diffractive optical element Array

The structure combining the microlens and DOE is not sensitive to the incident beam and can control the overall shape profile flexibly. So that the structure called DOE array is designed in this paper in order to shape the unstable laser beam to the four polar uniformity distribution. The paper gives the principle of the DOE array and the design process. The array element determines the profile of the output beam. It is designed using the G-S algorithm and the Adaptive Addition algorithm (A-A). The number of the DOEs is optimized and analyzed. The simulative diffraction efficiencies are 89% and non-uniformities are less than 3% when the incident beams are Gaussian, supper-Gaussian, paraboloid and random distributions. In experiment, diffraction efficiency of 77% and maximum non-uniformity of 5.6% are got on the condition of the different input laser beam. So the effect on the instability of the incident beam could be decreased.