矩形光束合成的建模与实验验证

Modeling and experimental validating on array combination of rectangle laser beams

光束合成是高功率固体激光器进一步发展的必由途径。板条的激光介质产生的矩形光束通过阵列合成能实现较高的近场光斑填充因子,有利于提高远场光束的能量集中度,从而获得更好的光束质量。根据激光器远场光束的测量方式,利用光束传输变换规律,建立矩形光斑双束合成的理论模型。通过数值模拟,在相干、非相干条件等典型情况下得到的子束合成不同远场的光斑图形,与相同条件下诺.格公司给出的实验结果一致,从而验证了理论模型的正确性。为进一步分析子束间距、整体相位差、偏振态、随机像差对矩形光束合成的影响奠定了基础。

Beams combination is the only way for development of high power solid state lasers.Since the beam combination of rectangle beamlets from slab lasing mediums have larger fill factor of near-field spot,it can improve central energy of far-field spot and has better beam quality.According to measurement method of far-field spot of laser and propagation equation of Gaussian beam,the mathematical model of array combination for two rectangle beams was established.Applying this model,the intensity distributions in coherent and incoherent conditions were analyzed,and its simulated far-field spots were in good agreement with the experimental results of Northrop Grumman Corporation.It proves that our combination model is right.It lays the basis that intensity distribution of combined far-field spots changes with some factors,such as interval,integer phase difference,polarization and random aberration of array beams.