A simple and effective method for shaping Gaussian beam into collimated flat-top beam

The flat-top beam is required in lots of practical applications. However, the semiconductor laser which is widely used as light source has a Gaussian or Gaussian-like energy distribution. In this work, a beam shaping system consisting of aspherical circular lens, Powell lens and cylindrical lens is proposed to transform the semiconductor laser beam into a collimated flat-top beam. The parameters of the Powell lens are designed based on the energy conservation between the incident and output beams, and the cylindrical lens is used for beam collimation. Simulation and experimental analysis are conducted to investigate the energy distribution of the shaped beam at various distances. The results demonstrate a strong agreement between the theoretical expectations and experimental observations, confirming the feasibility and scientific validity of the shaping system. This approach provides an effective method for shaping Gaussian beams into collimated flat-top beams.