Simulational and experimental investigation on the wavefront sensing method based on near-field profile acquisition in high power lasers

Abstract

This paper presents a novel wavefront sensing method based on near-field profile acquisition (NIA) to acquire the wavefront information. This method uses a cross mark at the focal plane of the spatial filter to directly obtain wavefront slope from the power spectral density (PSD) distribution of the output near-field profile. Principles of this method are introduced and the numerical simulation model is built. The influence of primary parameters on the measurement precision are analyzed and discussed. Based on the designed cross mark structure, an experiment is carried out in a multi-pass amplification high power laser and the wavefront of the pre-amplifier is reconstructed. Experimental results show that the difference between the reconstructed wavefronts by using the traditional Shack–Hartmann (SH) and the NIA wavefront sensing method is as small as 0.09μm (peak-to-valley value).