High-Performance NIR Laser-Beam Shaping and Materials Processing at 350 W with a Spatial Light Modulator

Zuo, S, Wang, S, Pulham, C, Tang, Y, Perrie, W, Allegre, OJ, Tang, Y, Sharp, M, Leach, J, Whitehead, DJ, Bilton, M, Mirihanage, W, Mativenga, P, Edwardson, SP and Dearden, G (2025) High-Performance NIR Laser-Beam Shaping and Materials Processing at 350 W with a Spatial Light Modulator. Photonics, 12 (6).

Preview

Text photonics-12-00544.pdf - Published Version Available under License Creative Commons Attribution. Download (7MB) | Preview

Abstract

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.

Item Type:	Article
Uncontrolled Keywords:	5102 Atomic, Molecular and Optical Physics; 51 Physical Sciences; 5102 Atomic, molecular and optical physics
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Divisions:	Engineering
Publisher:	MDPI
Date of acceptance:	26 May 2025
Date of first compliant Open Access:	5 June 2025
Date Deposited:	05 Jun 2025 11:13
Last Modified:	05 Jun 2025 11:15
DOI or ID number:	10.3390/photonics12060544
URI:	https://researchonline.ljmu.ac.uk/id/eprint/26524

View Item