基于空间频谱,对光谱色散匀滑(SSD)技术与衍射光学器件(DOE)联用的焦面光强分布进行了严格的理论分析。与光谱色散匀滑技术联用前后,衍射光学器件焦面光强分布均可转化为一系列不同频率、不同复振幅的正余弦函数的叠加。光谱色散匀滑技术对衍射光学器件焦面光强分布空间频谱进行调制,该调制不仅与光谱色散匀滑参数,还与衍射光学器件相位分布有关。该技术使得衍射光学器件焦面光强分布变得更平缓,但要获得良好的联用性能,需根据光谱色散匀滑参数进行衍射光学器件的优化设计。在某一给定的光谱色散匀滑参数条件下,进行了衍射光学器件的优化设计。结果表明,与光谱色散匀滑技术联用后,衍射光学器件对入射波前畸变的宽容度有较大提高。

The focal plane intensity distribution, realized by the diffractive optical element (DOE) and the smoothing by spectral dispersion (SSD) technique, is theoretically analyzed based on the spatial frequency spectra. The focal plane intensity distributions of the DOE can be expressed as the sum of a series of sine and cosine functions with different harmonic spatial-frequencies and complex amplitudes, no matter whether the SSD technique is adopted or not. Theoretical analysis shows that the spatial frequency spectra are modulated by the SSD technique, and the modulation is determined not only by parameters of the SSD technique, but also by phase distribution of the DOE. The SSD technique smoothes the focal plane intensity distribution of the DOE. But to obtain good beam smoothing performance, the DOE should be optimized considering the parameters of the SSD technique. Finally the DOE is optimized at a certain choice of SSD parameters. The simulated results show that the tolerance of the DOE to incident wave-front distortion is improved with the use of the SSD technique.