Digital micromirror device characterisation for ultrashort laser applications

In recent years, the wide variety of digital micromirror device (DMD) applications has extended significantly across various fields of optics, including ultrafast optics. Despite these advances, the interaction between DMDs and ultrashort pulses remains poorly understood. To address this gap, this study presents a comprehensive characterization of the behaviour of a DMD system when interacting with ultrashort laser pulses. In this work, the fluence threshold for multi-shot damage was first determined to be 0.12 J/cm-2. Regarding the temporal effects, the group delay dispersion (GDD) of intrinsic materials was experimentally measured for the zeroth order and was determined to be 190 fs2. The temporal dispersion introduced by the DMD was then theoretically quantified for higher diffraction orders, showing that it generates a broadening and a spatiotemporal shift that depend on the diffraction order. Concerning spatial effects, the lateral chromatic aberration for a broad wavelength range was analysed, revealing the spatial separation of different wavelength components due to the wavelength dependence of the order of diffraction. Finally, the capability of the DMD to analyse the intensity spatial distribution of the light beam was demonstrated using a single-pixel imaging technique. These findings contribute to the understanding of the effects resulting from the interaction of ultrashort pulses with the DMD, thereby facilitating applications.