基于相位差法的波前检测技术

基于相位差法的波前检测技术,主要是利用在焦面和离焦位置上同时采集的一对图像,对光瞳上的波前相位分布进行恢复,同时也可以对目标进行恢复。与哈特曼波前传感器和剪切干涉仪等波前检测技术相比,相位差法具有光路简单、易于实现的特点,同时可以采用扩展目标作为参考源,主要适用于对实时性要求不高的领域。在计算机模拟大气湍流和成像系统的基础上,我们使用有限内存拟牛顿法对波前相位和目标进行了恢复。模拟研究结果表明,相位差法可以较准确的恢复出波前相位,并且最优化的离焦波面差为一个波长。

Wavefront sensing using phase diversity method

As a wavefront sensing technique, phase diversity can estimate the pupil phase and object from pairs of simultaneously recorded focused and defocused images. Compared with Hartman wavefront sensor and Shear interferometer, the optical beam train of phase diversity is simpler. In addition, phase diversity can be used with extended sources and is suited to slower application. The aberration induced by atmospheric turbulence and the image-forming system have been simulated by computer, and the unknown wavefront and object have been estimated by using limited memory Broyden-Fletcher-Goldfarb-Shanno (BFGS) method. Simulation results show phase-diversity method can accurately retrieve the wavefront and defocusing of one wavelength is optimal.