Application of cooled spatial light modulator for high power nanosecond laser micromachining

Abstract

The application of a commercially available spatial light modulator (SLM) to control the spatial intensity distribution of a nanosecond pulsed laser for micromachining is described for the first time. Heat sinking is introduced to increase the average power handling capabilities of the SLM beyond recommended limits by the manufacturer. Complex intensity patterns are generated, using the Inverse Fourier Transform Algorithm, and example laser machining is demonstrated. The SLM enables both complex beam shaping and also beam steering.

Laser microsculpting for the generation of robust diffractive security markings on the surface of metals

“…The design of the security markings (reflective phase CGHs) has been performed using the Iterative Fourier Transform Algorithm (IFTA) described in details by Wyrowski and Bryngdahl, 1988). The algorithm, which was successfully implemented in our previous work for laser marking of metals using a spatial light modulator (see Beck et al, 2010 andWlodarczyk et al, 2014), was optimised for designing the holograms containing square-shaped individual elements (pixels). The IFTA enabled the design of both two-level and multi-level CGHs for the generation of diffractive images in the far field.…”

Pulsed fibre laser with spatial and temporal control

“…In this paper, we present a novel approach that enables full spatio-temporal control in a pulsed fibre laser with fast, electronically controllable switching of the output beam. Current approaches in pulsed MOPA Fibre Lasers typically rely on mechanical mode coupling [2] that is inherently slow or by using spatial-light modulators [3][4] that are power limited and require feedback loop control. Here, a redENERGY G4 pulsed fibre laser from SPI Lasers Ltd [5] is modified to accommodate two semiconductor seed diodes operating at different wavelengths, while a piece of resonant fibre is incorporated in the beam delivery fibre of the MOPA.…”

Wavefront Shaping by a Small-Aperture Deformable Mirror in the Front Stage for High-Power Laser Systems

“…High-power laser is of great interest for inertial confinement fusion [1][2][3], industrial processing [4,5], optoelectronic countermeasures [6], strong-field physics [7,8], and scientific research [9][10][11][12]. As an important factor related to the beam quality, a uniform wavefront is conducive to maintaining the high quality spatial distribution in propagation.…”