Distortion-free laser beam shaping for material processing using a digital micromirror device

Thermal aberrations and structured light II: experimental simulation with DMDs

“…Structured light is a highly topical field and describes the ability to tailor light in all its degrees of freedom, opening up a myriad of applications [8,[43][44][45][46], and fuelling the development of structured light sources [44], particularly at high powers [47][48][49][50][51][52][53]. In parallel, DMDs have been used extensively to create [54][55][56][57][58][59][60][61][62][63][64] and to a lesser extent detect [65][66][67][68] structured light fields, and have gained in popularity of late [69]. However, they have yet to be used to simulate perturbing media, and in particular thermally induced optical effects.…”

Closed-loop corrective beam shaping for laser processing of curved surfaces

“…The corrected beam shape will take into account the local surface gradients, so that the projection on the surface will not appear stretched. Others have demonstrated a solution to a related problem, wherein a tilted beam output from the DMD results in a distorted image [14], and mask transformations are applied to recover the intended image on a surface orthogonal to the beam direction, which was intended for a fixed display purpose and hence did not involve closed-loop feedback for a changing surface orientation. Here, a beam optimised for output close to the normal of the DMD surface is used, and the surface at which the mask is imaged is tilted.…”