The application of ptychography in the field of high power laser

The commonly used interferometer and Hartmann-Shack sensor are not ideally qualified for the phase or wavefront measurement in the field of high power laser because the optical elements always have large aperture, the steep phase gradient and very irregular surface profile. The ptychography, which is a newly developed coherent diffraction method for the imaging with short wavelength, can be a perfect alternative to traditional technologies due to its outstanding advantages. The complex transmittance of the optical element can be obtained by measuring its transmitted and incident fields with ptychography and calculating their phase difference. Since ptychography can realize measurement with a resolution comparable to that of interferometry, it can find lots of applications in the field of high power laser such as the measurement of the complex transmittance of large optical element, the thermal distortion of the gas-cooled Nd:glass amplifier, and the focal length of the lens array etc.