J. Eur. Opt. Society-Rapid Publ. 22, 46( 2026) 461
Figure
5.( a) Schematic representation of the experimental setup.( b) Images illustrating the dispersion of the light spectrum captured by the infrared camera:( i) full pulse after reflection by the DMD, pulse after passing through( ii) 780 nm,( iii) 800 nm, and( iv) 820 nm bandpass filters.
Figure
6.( a) Schematic diagram of the optical setup showing the optical path of the light beam reflected by the DMD and focused by a pair of lenses onto the photodiode.( b) Horizontal intensity profile of the light beam along the axis corresponding to the point of maximum intensity. The inset shows the two-dimensional( 2D) irradiance distribution reconstructed using the single-pixel imaging technique.
distribution, expressed in arbitrary units, has a FWHM of 0.84 mm as shown in Figure 6b.
5 Conclusion
This study provides substantial technical understanding of the DMD laser interaction to further improve its utilisation in diverse optical applications. In this work, the damage fluence of a DMD under ultrashort pulsed laser irradiation was first calculated, to ensure its safety operation in ultrafast laser systems. Experimental results showed that the damage threshold fluence of the DMD is 0.12 ± 0.02 J / cm 2. Moreover, the GDD introduced by the DMD was evaluated from the nominal characteristics of its components, and was measured to be 190 fs 2. This value was further verified through autocorrelation measurements.
The analysis also included the diffractive properties and dispersion effects that result from the interaction of ultrashort pulses with the DMD. Theoretical modelling detailed how the DMD affects the pulses through diffraction, showing a spatiotemporal shift and spatial broadening that depend on the diffraction order. Experimental verification was carried out by observing the dispersed pulse spectrum projected on a screen and by measuring the spectra before and after the interaction of the ultrashort pulses with the DMD, showing this significant spatial broadening of the different wavelengths.
Finally, the versatility of the DMD as an imaging device was demonstrated in which the spatial irradiance distribution of the pulse was reconstructed using single-pixel imaging techniques. Overall, the results demonstrate that the DMD is a promising platform for producing highly accurate and efficient images of ultrashort light pulses.