Compensation of distorted wave front using ultra-thin mirror with very large aperture

Because of low frequency distorted wave front impacting on beam quality, a thin mirror with a diameter of 300 mm and a ratio of radius to thickness of 20 is optimized in order to compensate the distorted wave front. Meanwhile, the far field beam quality before and after compensating distorted wave front is discussed in detail. The analysis results show that the amplitude of the phase decreases obviously, the phase gradient reduces during the whole spatial period, the peak of far field intensity increases, the power focusability of focal spot is improved greatly and the power focusability can increase by as much as 50% compared with the results before compensation whether the space scale parameter of the low frequency phase is altered or the amplitude of the phase varies.