Comparative analysis of optical setups for excitation of dynamic gratings by ultrashort light pulses

Abstract

The application of ultrashort light pulses for the generation of laser-induced dynamic gratings requires special pump arrangements to overcome the limitations originating from the short pulse duration. In this paper a comparative analysis of three earlier proposed setups is given. They are comprised of a transmission grating, which is imaged onto the sample by different imaging optics. Lower limits of the applicable pump duration, the quality of the spatial overlap, the sensitivity of the setups to the errors of positioning and practical aspects of applicability are discussed. According to our calculations all three setups can be used for experimental techniques that use pulses as short as 20 fs with tolerable loss of time resolution, in case the setups are aligned perfectly. However, there are significant differences regarding the ease of implementation, the sensitivity to errors of positioning and the ability of the setups to create dynamic gratings having variable grating groove density.