Adaptive self-reconstruction and autocorrelation of nondiffracting wavepackets

摘要

The characterization of laser pulses with pulse durations in few-cycle range is highly challenging because the transfer of spatial and temporal information is sensitive against even slight amplitude and phase distortions. It can be improved by exploiting the propagation features of distortion-tolerant nondiffracting beams. The availability of novel types of MEMS components enables to realize smart and robust autocorrelators which combine low-dispersion and adaptive functionality of MEMS mirrors with the self-reconstructing properties of non-diffracting beams shaped by axicons. Two basic concepts of adaptive non-collinear, nonlinear autocorrelation are presented here: (a) autocorrelation with adaptive self-reconstruction, and (b) discrete phase shifting methods. By tuning the superposition angle in non-collinear autocorrelation it is possible to bypass the corruption of temporal information by distortions. This is demonstrated by performing autocorrelation experiments with a MEMS-type Fresnel mirror with hysteresis compensation. It is show that a spatially located distortion can be sampled in temporal domain. Phase-shifting approaches promise improvements with respect to the time resolution.