TY - JOUR
T1 - High-Performance NIR Laser-Beam Shaping and Materials Processing at 350 W with a Spatial Light Modulator
AU - Zuo, Shuchen
AU - Wang, Shuai
AU - Pulham, Cameron
AU - Tang, Yin
AU - Perrie, Walter
AU - Allegre, Olivier J.
AU - Tang, Yue
AU - Sharp, Martin
AU - Leach, Jim
AU - Whitehead, David J.
AU - Bilton, Matthew
AU - Mirihanage, Wajira
AU - Mativenga, Paul
AU - Edwardson, Stuart P.
AU - Dearden, Geoff
PY - 2025/5/28
Y1 - 2025/5/28
N2 - Shaping or splitting of a Gaussian beam is often desired to optimise laser–material interactions, improving throughput and quality. This can be achieved holographically using liquid crystal-on-silicon spatial light modulators (LC-SLMs). Until recently, maximum exposure has been limited to circa 120 W average power with a Gaussian profile, restricting potential applications due to the non-linear (NL) phase response of the liquid crystal above this threshold. In this study, we present experimental tests of a new SLM device, demonstrating high first-order diffraction efficiency of η = 0.98 ± 0.01 at 300 W average power and a phase range Δφ > 2π at P = 383 W, an exceptional performance. The numerically calculated device temperature response with power closely matches that measured, supporting the higher power-handling capability. Surface modification of mild steel and molybdenum up to P = 350 W exposure is demonstrated when employing a single-mode (SM) fibre laser source. Exposure on mild steel with a vortex beam (m = +6) displays numerous ringed regions with varying micro-structures and clear elemental separation created by the radial heat flow. On molybdenum, with multi-spot Gaussian exposure, both MoO3 films and recrystallisation rings were observed, exposure-dependent. The step change in device capability will accelerate new applications for this LC-SLM in both subtractive and additive manufacturing.
AB - Shaping or splitting of a Gaussian beam is often desired to optimise laser–material interactions, improving throughput and quality. This can be achieved holographically using liquid crystal-on-silicon spatial light modulators (LC-SLMs). Until recently, maximum exposure has been limited to circa 120 W average power with a Gaussian profile, restricting potential applications due to the non-linear (NL) phase response of the liquid crystal above this threshold. In this study, we present experimental tests of a new SLM device, demonstrating high first-order diffraction efficiency of η = 0.98 ± 0.01 at 300 W average power and a phase range Δφ > 2π at P = 383 W, an exceptional performance. The numerically calculated device temperature response with power closely matches that measured, supporting the higher power-handling capability. Surface modification of mild steel and molybdenum up to P = 350 W exposure is demonstrated when employing a single-mode (SM) fibre laser source. Exposure on mild steel with a vortex beam (m = +6) displays numerous ringed regions with varying micro-structures and clear elemental separation created by the radial heat flow. On molybdenum, with multi-spot Gaussian exposure, both MoO3 films and recrystallisation rings were observed, exposure-dependent. The step change in device capability will accelerate new applications for this LC-SLM in both subtractive and additive manufacturing.
U2 - 10.3390/photonics12060544
DO - 10.3390/photonics12060544
M3 - Article
SN - 2304-6732
VL - 12
JO - Photonics
JF - Photonics
M1 - 544
ER -
